Rob T's 818R Build Thread

[Bob_n_Cincy]

Ambient temp 70-80F. Water temp was 190-195. Oil temp hit 240 as I drove harder, but stayed there. AWIC - 100 - 105. I drove the car as hard as I have ever driven it.

You Awic Temperature. Was that the air temperature going through the throttle body?

[Rob T]

Bob: Great question. I did a little more digging. I saved two datalogs from the Cobb unit.

In session 3, the average intake temp (according to Cobb) was 102.7F The max I saw was 109. This was over 16,454 points logged during the session. I did a quick scan of MAP and saw boost numbers as high as 18.4psi for brief periods. There was absolutely no issues with knock or knock adjustments in the datalog. I am running Speed Density tune.

If anyone is interested, let me know, and I will send the Cobb Datalog. I would appreciate any insight.

[Rob T]

Here are some "teaser" stats from my GPS/accelerometer based Tracqmate data logger. These are all Maximums for session 3
Max speed: 110.7
Max braking (g) 0.92
Max acceleration (g) 0.77
Max Right Turn (g) 1.37 - remember new Hoosiers
Max Left Turn (g) 1.61
HP 235
TQ 398 ft-lb - this is a calculated value. The previous session was 324 - no idea on accuracy, but fun to report anyway.

[Bob_n_Cincy]

Hey Rob, I love numbers, keep them coming.
The reason I ask about IAT (intake air Temp) is because I' think about moving my sensor. Right now I'm in the stock location(right after air filter). I want to move it to after the intercooler. Attached are my numbers on one lap around NCM. (Mitch's Track)
128920

[Rob T]

Here are a couple of Laps from Carolina Motorsports Park on Friday 5/22. I still have a lot to learn, but that doesn't mean I didn't have fun.

https://youtu.be/bhLvFV-YEJc

[Hobby Racer]

Rob,

I know you switched to 6 speed, do you know what ratios are in the unit Wayne instlled?

[Rob T]

Rob T's 818R Speed v Gear v RPM Calcs

Tire: Hoosier 245:40:17
Tire Circumference 24.3
Revs per mile 855
Final Drive Ratio 3.9
2,000 3,000 4,000 5,000 6,000 6,500 7,000
Ratio MPH
First 3.636 10 15 20 25 30 32 35
Second 2.375 15 23 30 38 45 49 53
Third 1.761 20 31 41 51 61 66 72
Fourth 1.346 27 40 53 67 80 87 94
Fifth 1.036 35 52 69 87 104 113 122
Sixth 0.842 43 64 85 107 128 139 150

Formatting is not pretty, but you get the idea.....

Rob

[Brd.Prey]

Can I get more details on the level on the transmission itself? I only have manipulated it on the lift with someone trying to shift the transmission. I noticed it has a pin hole lineup in the relaxed or closed but it seeems to have to go about 20degs. past the second hole alignment. Are u saying it needs to be moved twice while trying to get into reverse? Or will one motion of the lever allow reverse to be selected?

Thanks Ed

[Rob T]

I went to the track on 6/5. It was a good day, but by the end of the second session, I was suffering low oil pressure after the car was warm. My oil pressure was 50psi or so when running 4 - 5k rpm. 20psi at idle. I added a quart of oil for the third session and all was good in the pit. 85psi at start up. After two laps the oil temp went from 120F to 260F and pressure was low. I pulled off and went home. After thinking about this, and talking with Mitch, Gator and Phil at Element Tuning, and doing a little investigation, I believe my problem was a collapsing suction hose from the dry sump tank to the OEM pump. I was able to flatten this -12 braided line with my thumb and forefinger at room temperature. I think this line was heating up and getting softer. At speed, the OEM pump is drawing about 10gpm through this line. A "cold" line would be more stiff. A warm/hot line at 4,000-5,000 rpm is a different story.

I also went back and looked carefully at my videos from many previous track days. This issue was happening, to a lesser extent, any time the oil got above 220F. Not that this is a high oil temp, but I think the hose has been getting progressively worse. The car always had 90+ psi on cold starts and was always good everywhere but at the track.

Fearing the worst, I drained the oil yesterday and cut open the filter. Luckily, no evidence of any metal or bearing wear. I was pretty watchful of the pressure, always, and always came off the track when I noticed something amiss.

I have ordered a new, vacuum rated hosed, and will be installing that soon. Fingers crossed that this solves the issue. I won't know for certain until I get to the track again, but this makes sense. Phil at Element confirmed that they have had experience with collapsing feed hoses that exhibit this kind of issue.

Also, I tried some new Federal 100 tread wear tires that I got from Phil's tire service. Early impressions are really good. Purchased, installed and balanced for under $800.

[Scargo]

I believe my problem was a collapsing suction hose from the dry sump tank to the OEM pump. I was able to flatten this -12 braided line with my thumb and forefinger at room temperature. I think this line was heating up and getting softer. At speed, the OEM pump is drawing about 10gpm through this line. A "cold" line would be more stiff. A warm/hot line at 4,000-5,000 rpm is a different story....
I have ordered a new, vacuum rated hosed, and will be installing that soon. Fingers crossed that this solves the issue. I won't know for certain until I get to the track again, but this makes sense. Phil at Element confirmed that they have had experience with collapsing feed hoses that exhibit this kind of issue. ...

There is this (https://www.pegasusautoracing.com/productselection.asp?Product=3228-600)Stainless Steel Inner Hose Support Coil (https://www.pegasusautoracing.com/productselection.asp?Product=3228-600)
Obviously it adds a restriction.

[Bob_n_Cincy]

There is this (https://www.pegasusautoracing.com/productselection.asp?Product=3228-600)Stainless Steel Inner Hose Support Coil (https://www.pegasusautoracing.com/productselection.asp?Product=3228-600)
Obviously it adds a restriction.


Rob, You need to read this, Chad was chasing this problem for months. All three oil line connecting to the dry sump plate are under vacuum and subject to collapsing under heat.

https://thefactoryfiveforum.com/showthread.php?11129-Plavan-s-818R-Build-Thread&p=209432&viewfull=1#post209432

I use metal tubing for my scavenge lines and internal spring support in the hose from the oil tank.
Bob

[Rob T]

Thanks, Bob. I remembered about the springs in the return lines. Not in the suction line to the OEM pump. Phil at Element told me they have had instances of the coils "laying down" and also collapsing. That is why he recommend the Aeroquip AQP hose that is rated for 28 inches of vacuum.

Thanks for the advice. I'll take another look at the suction lines for the return.

[taco20]

Also, I tried some new Federal 100 tread wear tires that I got from Phil's tire service. Early impressions are really good. Purchased, installed and balanced for under $800.[/QUOTE]


Hey Rob

What Federal tires did you run? I have been running their 595RS-R tires for years now and they have been great tires. I have found now that I am pushing the car harder they seem to give up at the limit and plan to try a set of TOYO R888R’s once I get the car back together. I would be very curious about how you felt about the tires with a 100 tread wear and that price they might be another option for me to try.

[Rob T]

Federal FZ-201M 100 treadwear. Phil's Tire Service. I put 255 17's on the back and 235 17's on the front. Almost exactly matched the Hoosiers I was running ( 245's back, 225's front). I think the tires felt great. I was a second faster than the last time I was there on new Hoosiers, but I suspect that is me getting more comfortable with the car and the track, not so much the tires. I felt they communicated well, also. Nothing unexpected.

[Rob T]

Update on the Oil System:

Yesterday I built the new suction hose using Aeroquip AQP hose and installed it. Put oil in and fired up the car. 85psi at cold start. Ran the car until it was warm (in the garage). Got the water temp to 200F and the oil to about 180 (enough for the oil cooler fans to come on). When hot the idle pressure stayed at 50psi. At 3000 rpm, the oil pressure was 85 - 90 psi or better. I have never seen these kind of good pressures before. I suspect the collapsing hose was a factor for a while. I don't remember if I changed the hose when I redid the system in 2017. Here are some pictures of the old hose and the new hose. You can see the additional braid in the new hose.

129994129995

[jforand]

No comparison in those two lines. Glad you solved it!

A big thanks again for having me over to chat and look at the car. I very much look forward to meeting some of the others as well.

[Mulry]

Glad that's doing it for you. For others who experience this problem, XRP ProPLUS Xtreme race hose is another alternative I ran into at PRI a couple years ago. It's smooth bore on the interior and PTFE (so it will clean out when you fill it with glitter) but has a stainless wire woven into the external convolutions to prevent collapse under vacuum. It's what we are running from the dry sump plate to the suction stages and from the oil tank back to the suction stage of the pressure side of the dry sump pump. I bought mine from ANPlumbing.com (not a paid spokesman -- I wish I were!) and their customer service on it was just outstanding. They take online orders but are better if you work with them on the phone. Cheers.

[Rob T]

A big "thank you" to Mitch Wright for the support he gave me while I was visiting NCM Wednesday, Thursday and Friday. He helped/showed me how to do the alignment. We adjusted ride height and put the car on the scales. We then did some excellent exercises to help my braking, heel/to and cornering. A couple of lead follow sessions followed by....rain on Friday. All in, it was a great experience from a great teacher with deep experience.

[Rob T]

Pushing hard on the track, I can confidently say the oil pressure issues are solved. Had 85psi at speed under all conditions. Even with 90F ambient temps, the highest I saw on the coolant temp was 200F. 240 on the oil at the end of a session. Temp after the intercooler was 106 when I glanced at it and the supply to the intercooler averaged 101 with a max of 107 near the very end of the session. I wasn't logging the intake temp on the Cobb unit, but that is where I read the 106, pretty consistently.

I have new corner weight numbers now that the 6 speed is in. With me in the car and 17.5 gallons of fuel.. LF 463, RF 467, LR 743, RR 702, total 2375.

Ride height was changed also. LF 3 7/8, RF 3 13/16, LF 4 1/8, RR 4 1/8. Thanks again Mitch!

NCM is an awesome track, with great facilities and an excellent staff. By far the most technical track I have been on.

[Sgt.Gator]

I'll update the Post your Weights thread with your numbers. Did you check your tranny temps?

And I think you mean LR here: LF 4 1/8

[Rob T]

Gator: Correct - left rear. With everything going on, I did not get a chance to check my temps. I am confident that they were mid 200's again. I did check them after cool down and getting a tank of gas....they were about 175 after about 30 minutes. I am going ahead with the cooler for now. I have all the parts and will be working on it before my next track day in September.

[Bob_n_Cincy]

Gator: Correct - left rear. With everything going on, I did not get a chance to check my temps. I am confident that they were mid 200's again. I did check them after cool down and getting a tank of gas....they were about 175 after about 30 minutes. I am going ahead with the cooler for now. I have all the parts and will be working on it before my next track day in September.
Are you going back to NCM. These pictures are in the sink hole turn. 132142 132143

For Reference, Here is our temp and pressure data log running 2.5L forester stock tune at NCM.
132144
This was on the full coarse. I think is was me drive, my son 10 seconds faster. This is the second hot lap of a session. oil up to 200f and coolant 190f. top speed about 125. peak boost around 12.5.

FYI: this data recorded using my BTSSM phone app.

[Rob T]

134372
134373

Pictures are not great, but here is my water version of a 6MT trans cooler. Right now, the ball valve is fully open. This allows some water to the cooler, but most will bypass. If temps stay in line, I can slowly close ball valve and put more liquid through the trans cooler, but the system can never be totally blocked. The coolest water goes to the intercooler first. I have Temp sensor in the AWIC line just before the intercooler, one in the transmission fluid going to the cooler, and another sensor measuring air temp after the intercooler.

[Hobby Racer]

I am interested to see how it works and if your intercooler temps are effected. When is your next track day?

[Rob T]

Next track day is September 11 at the newly resurfaced Carolina Motorsports Park. This will be my first trip to my “home” track since I was at NCM with Mitch who helped me do a full alignment, ride height adjustment and corner balance. Also, at his suggestion, I have taken my wing to zero degrees. I still will get downforce, but this should help some with acceleration (less drag)

[Mitch Wright]

Rob with the 1/2 inch wicker you have on your wing it will be doing it's job and a good place to start.

Looking forward to hearing what you think about the new pavement at CMP.

[Frank818]

Hey Rob, those hoses black with yellow circle stripes, where did you get them?

[Rob T]

Frank: I am not sure. That was flexible ducting that Chad had in the car. It supplies air from the side scoops to the oil cooler, which is mounted in the rear of the car and visible in the pictures. It is like flexible dryer duct. Try Summit Racing Brake Duct Hose. It looks close to what I have.

[Frank818]

Tnx Rob! That's what I was looking for, plenty of choices I didn't think about Summit. :)

[Rob T]

They have become one of my favorite "candy stores" lately. Super fast shipping, lots of stuff. Sometimes a bit hard to find things if you don't know exactly what you are looking for or what it is called.

[Rob T]

I "chickened out" on a track day today at Carolina Motorsports Park based on a rainy weather forecast. I have an open trailer with an open car and none of it is any fun in the rain. There is another day scheduled on 9/18, so I am hoping for better weather. The car was loaded and ready to go. New trans cooler is ready....

On another note, has anyone ever lost the "gauges" on their Cobb Accessport? I went to run the car a few days ago and all of the gauges were blank. I checked the datalogging function and all of the right stuff was still "checked". I wonder if I did something accidentally that blanked all the gauges that normally display. I was able to recreate what I needed, but this was the first time this ever happened.

[Frank818]

Noooooooooooooooo. :( That sucks!

[Mitch Wright]

Its beautiful here in BG, come on up we have a track day Monday.

[Hobby Racer]

Its beautiful here in BG, come on up we have a track day Monday.

Boy Mitch, if I lived closer I'd have a real problem with my spouse as I'd be there all the time!

[Rob T]

Opted out of the track day today. Hurricane Sally came through and we had rain past midnight last night (2-5" depending where you were). At 7:00 this morning, pavement is still wet. I would have trashed my car towing it at 5:00 this morning on the open trailer.

There are a few upcoming track days. Fingers crossed for good weather. When it is right, it will work out. It's disappointing, but this is a hobby, not my job.....

[Rob T]

Open Throttle Trackdays is running a track day at CMP tomorrow. Guess what? Rain is forecast today and tonight (100% chance) with thunderstorms tomorrow (90% chance). Three track days in September possible, and rain/threat of rain for all.

Fingers crossed for October 9th.

[Frank818]

Man that is unlucky! We are now a week before and the forecast in Woodruff is dry. But rain on Saturday! So hopefully the forecast won't change!

[AZPete]

Ha. Here in the AZ desert the last rain was 103 days ago and that was 0.2 inch! Send some, please.

[Rob T]

I remember it well, with 2 years in NM. Same idea. On the plus side, everything is green here and I am surrounded by trees. Forecast is looking good for Friday, but I'm waiting another day or so to "pull the trigger". I am ready to go....

[Rob T]

Got to the track yesterday. A lot of other people had the same idea. New surface is spectacular. I have to analyze my data still but here are a few highlights. Air temps were mid 60's to mid 70's overcast.

1) I freaked myself out with some "rusty" driving and the car was upsetting on my aggressive upshifts. It felt like something loose in the rear end as the car would "shimmy" a bit. I cut my second session short out of caution and spent lunch checking all the suspension bolts. No issues found.
2) The trans cooler seemed to work well. I need to dig the data out of the system, but the transmission was cooler. The highest IAT I saw was 106F on the AWIC system in the fourth session driving hard.
3) Session 3 was cut short by a crash.
4) I stopped after 4 laps on session 4 because my oil temp was 250F and pressure was down to 50psi or so. Temps were 200 in the first session, 220 in the 3rd session and 250 in the fourth.
5) I skipped the fifth session, which was 40 minutes after session 4 to not risk high oil temps and pressures.

I do have an oil cooler in the back of car above the transmission. It does have fans and has 3" ducts just sitting in each of the side scoops. I am finding that as the car warms and I get more comfortable during the day, I cannot remove the heat from the oil. Water temps are right around 200F, so they are fine. One suggestion was to mount the cooler directly in one of the scoops, which would be easy to do. I am open to other ideas as well. I am running Red Line Race oil (15w-50).

[Frank818]

At least you made it! And back in one piece. I'm glad that time finally happened! When's the next? :)


106F is very acceptable in IAT, starts to get warm but not too hot. I quickly reach that temp when idling and not moving! Haven't driven hard enough yet to compare but when driving normal in town, at 65F I get 70-72F IAT. Street driving of course.
What AWIC setup you got? Cooler volume, water tank or not, pump power, etc... as long as it was stable across sessions it means it can handle it and not overheat, which is the 1st goal to reach!

At what RPM you got 50psi oil? If it's at idle, that's quite a lot! If it's at 8000, then iiisch....
Are you able to check if your oil flows within specs? Not too quickly and not too slowly?
Were you starting each session at about the same oil temp (apart from session 1 of course)?
How big is your cooler? Maybe it's just too small and keep the same location but use a bigger one. If you redirect air from the scoops through ducts in your cooler, I'm not that sure it would be more efficient by simply relocating it in one of the scoops, in terms of air flow solely.
Maybe you have very hot air around the cooler or that the fans are not pulling the air out efficiently?
Too close to the exhaust?

[Rob T]

A few follow ups

1) My video camera is "dead" and I didn't get any video. I suspect it got killed in the deluge when I was at NCM in July. I never thought to check it because it was always reliable. It's a bummer because I can't link the oil pressure to the rpm like I can when I had video.
2) The oil pressure was around 50psi or so while I was on the track, so at speed. 25 or so at idle, even when the oil was 250.
3) The AWIC has a separate radiator in front of the main radiator and a circulating pump. The line size for the water is 3/4" ID heater hose. I would suspect I get several gallons per minute of circulation. It looks like the water coming back to the AWIC was 85F at it's hottest, so about 15 above ambient, and the IAT was 15-20 above that. This is consistent with what I have seen in the past, but slightly hotter coming back from the radiator due to the load on the system from the transmission cooler.
4) Everything warms up more quickly on subsequent sessions, and I get more confident and push harder. There is a lot of time with WOT or close to it on this track. Also, several sections where I am close to red line.

Some data that I gleaned from my data-logger.

Best lap: 1:52.462, but pretty consistent when there was not any traffic. I got a bit "faster" each session.
Top Speed for the day: 112.66
Braking g's: 0.90
Accelerating g's: 0.71
Left turn g's: 1.59 max
Right turn g's 1.39 max

More to come on the oil cooler as I dig into it a bit. The current location, over the transmission at the very back of the car is tricky. It's hard to duct a lot of air there. I could do much better with the cooler in one of the scoops - more area, and no flow losses. Also close to the oil tank and other piping. As I already have another cooler left, I may just add one more ( I know, extra weight) and see if that solves the problem, before I rip the other one out. That would be relatively easy to do. More to come....

[Frank818]

Rob, I am very happy for you!
Your car is driveable, it WOTs, it redlines, it doesn't leak... when it does those 4 things it means everything else is minor issues. :) I'm sure you'll fix them in a jiffy.


- I do like your idea of a 2nd oil cooler, that will definately answer your question on that 1st cooler's capabilities/efficient flow. I would do the same for testing purposes. Can't wait to see pix of your setup.


- As for the oil psi, 25 at idle is plenty to me! 50 at speed seems low though, depending what rpm it was at. Basically, you probably know already, psi should increase/decrease with an almost 1.0 correlation with rpm. Maybe 0.9, say. Do you have access to a log that will display RPM vs oil psi? And do you know the std specs for the H4?



As a reference, although I know nothing about the H4, my VR6 runs at 8-8.5psi at 800rpm (freaking low but causes no issues at all) and 75psi at 4000rpm, which is very fine. This is reproducible all the time, give or take 10%. Of course oil temps make psi vary, those numbers I gave are at around 200-210F.

[Mechie3]

WRX engines are known to idle around 12 and run around 80psi at anything over 3000 rpms. Cruising is usually about 30psi,IIRC.

[Rob T]

As I mentioned earlier, I have been suffering from some of the dry sump issues others have talked about. One issue for sure is high oil temp when I am pushing the car hard. This week, I took one of my spare coolers and some -12 line and added a cooler in the driver's side scoop. I also built a a frame and box to mount it and force all of the air through the cooler and into the engine bay. I do not have a sheet metal sheer or a brake, so I made do with some scrap steel, a vice and a hammer. The material was 0.025 aluminum. I re-routed the oil from the discharge of the dry sump pump to the bottom of the new cooler and from the top of the new cooler to the existing cooler in the back. Everything is removeable in case I want to switch it back. I had my first experience with the much revered "CAD" program - Cardboard Aided Design. With decent success. Here are some pics.
The frame on my layout bench
136865

"CAD"
136866

136867
136868

Plan is to test this on 11/6 at Carolina Motorsports Park if the weather cooperates. I am unable to mimic the condition on the street. More to follow...

[Hobby Racer]

136867


I am eager to see your results. I have always wondered if coolers like yours placed at 90 degrees to the incoming air get much airflow.

[Rob T]

I am "hoping" that the scoop will be a higher pressure than the engine bay based on it's direct placement in the slip stream around the car. My old boss said that "hope" was not a strategy. I remember being told this was a high pressure point on the car. That said, that concern is precisely why I sealed around the cooler, so that the only path was through the fins. A lot more work, but should provide better results. I also have aluminum wheel wells....I should know more next Friday.

[Bicyclops]

It wouldn't be that hard to rig some piccolo tubes on the inlet and outlet sides of the oil cooler and run some tubing to an electronic manometer to measure the pressure differential. Taking readings while driving could be a challenge.

Ed Holyoke

[Bob_n_Cincy]

Rob,
Did you read this? Gator finally found the solution to our oil temp and pressure problems.

https://thefactoryfiveforum.com/showthread.php?26054-Gator-s-818R&p=430878&viewfull=1#post430878

[Rob T]

Bob: Yes, Gator and I have spoken. I am trying the cooler first, because it was easy and I had all the stuff I needed making it cheap. I suspect I have oil cooling problems with the cooler in the back.

[Rob T]

Had my track day better. First day with the new cooler in the driver's side scoop. The first three sessions were great, with oil in the 185 range and no pressure issues (85-95psi on track, 35+ in the paddock). The fourth session, I did not upshift in the carousel, a 270 degree tight, high speed that starts with a hard left followed by a continuous right turn onto a high speed straight. When I ran it in 5th, no issues. In 4th, with the RPM's up around 6,000, I started to see some slight pressure drop (55-65psi) and the temp of the oil went to 235. This was better than before, but still remnants of the same problem. I will be working with Gator's help to add the third scavenge line. This only happens under big loads at sustained high RPM's. Driving at 80% or less does not cause this issue. While I don't drive my car on the street, it is safe to say, that it would be unsafe to drive on the street in such a way as to cause this problem.

I did four sessions at CMP. It was crowded because NASA has a race weekend, so many were there. We had up to 50 cars in the run group. A few of the sessions I was fortunate to run near the front and got a couple of clean laps before catching the back of the line. In simple terms, I could easily hang with all the monster camaros and mustangs. I was much better braking and in the turns, but they could pull harder out of the turns. I could keep up on the straights. There were a few GT3RS's there. Could not hang with them. I suspect the car is close to capable enough. The driver is not. Yet.

Here are some quick stats for the day.

Max speed 115.9mph - new high for me on this track.
Max braking: 1.15g
Max Accel: 0.88g
Right Turn: 1.43 g
Left Turn: 1.39G
HP: around 265 Max except last session at 218 - oil in the sump, suspected.
Torque: 300ft-lb

It was a beautiful day with 60-73F temps and a little gusting wind. I'll try to get a video together.

[Sgt.Gator]

Great to see your progress. A 50 car run group, yikes. What tires Brand/Model and Sizes are you running?

[Rob T]

Here are some pics of my dry sump scavenge pump. Reference for all, and a comparison for Sgt.Gator137319
137320
137321
137322
137323

[Rob T]

To answer the question about what tires and sizes I am running...

Federal FZ-201, 100 treadwear. Front: 235:40 zr17 Rear: 255:40 zr17. I was targeting 35psi hot, but am interested if anyone else has experience with these tires. At the 35 hot, the "roll" marks on the tire are right at the little imbedded triangle markers....

[Mitch Wright]

Check with Phil at Phil's tire service, I am sure they can give you a operating range. For reference the BFG R1's I ran at 32-34 hot depending on the ambient and track temp. Next time out try a few PSI higher and drop the pressure a few pounds each time out to see what seat of the pants feel and lap times do.

[Rob T]

Quick update on the dry sump.....

1) Thanks to Gator for some extensive conversations and lots of "R&D" work. He's been a big help.
2) Also thanks to John at Aviaid and Phil at Element tuning. I also spoke to Scott at Flatirons. All have been very helpful and interested in this issue as it impacts the "community". John and his team did a great job turning around the order for parts.

So what am I going to do....All agree that there is a scavenge problem at some point, when running hard on the track. There is a lot of discussion of the "whys". I have decided to take a stepwise approach to see if it gets me there. Like Gator, I am adding a third "half section" scavenge pump to the Aviaid pump already in the car. It will tuck in under the manifold, and John had a trick ORB to -8 90 that will fit in there while allowing me to clear the -12 lines already installed. I will begin by plumbing this line to the third scavenge port on the bottom of the pan because it is easy to do. Gator modified his valve covers and I can go there, but will do so, only if needed. I have a track day on 12/5 (weather permitting) that should allow me to test this all out. More to come....

[Rob T]

I started the third scavenge stage install yesterday.
1) Drained all the oil and pulled the filter screen fittings on the pan.
2) Removed the Aviaid pump. The tensioner was a little tricky, so I ended up pulling the mounting bolts and dropping the whole thing so I could work on it on the bench. There are two jam nuts on the shaft, so I think the tensioner is being used as a "pusher" as opposed to a "puller". It works.
3) Rebuilt the dry sump pump and added the third stage. The hardest part was getting the seal out of the end. It had been lock-tighted in. These pumps are truly a precision piece of equipment. Very impressive. It's now all back together with the pulley mounted and spinning freely....ready for re-install and addition of the third scavenge line.

[Sgt.Gator]

For a visual reference here's the one we are installing on the STI this week. It's identical to the one on my 818R. Rob I think yours looks a lot like this, except we used a special hose with builtin ORB fitting to minimize the space requirement.

https://by3302files.storage.live.com/y4m5iLwa5xKEhyMYtQzASEOxXMrE9KDcIi213F1U_clvXESYIX QxDDH5mY-Cfv9FtLyYXwGlVgvlUa8IjVPCWXeMolGAFO9rLW1rlIUn40-AxJ-onBI2b90-POhjsqhdwFGJrzUlpV_Zvpkh0xzEULZqI5T7Na0ghGSeAQoInw X9vy-uBViYYLApVTzEngxGQ9h?width=1024&height=768&cropmode=none

[Rob T]

Gator: Close to the same except you have a different first stage than I do. Mine enters on the top and exits on the bottom. I did use a special ORB swivel fitting with standard -8 male on the end. Here are some pics. The unit is installed and seems to be working well. The new -8 line heated up more quickly than the -12's, so I know there is oil moving. Looks like rain for the coming Saturday track day, so I need to wait for the forecast to solidify before I sign up.

Original pump configuration with suction lines on the top and discharge line on the bottom of stage one.

138518

Oil Pan before installing the new line. You can see the port tucked under the OEM oil feed line. I ran a -8 line from there to the section side of the third pump section

138519

Modified pump installed. Internally, all of the discharges are "connected" to a single discharge port in stage 1

138520

[Sgt.Gator]

Looks good. Yes I originally had the bottom exit on stage one. I made the change to the side exit a couple of years ago when we rebuilt the pump, it makes it a lot easier to connect up the AN line that runs to the tank.
I need to move somewhere it's not snowing already! But then again the ski slopes are opening so I'll get my Need for Speed.
I'm looking forward to your first track oil data report.

[Rob T]

I did a destructive oil filter test when I was doing all of the dry sump work and had the system drained. Filter was spotless clean. Nothing found.

[Rob T]

Track Day Saturday! 36F to start and 56F for a high. Bright sun forecast after rain tonight. I am looking forward to testing the third stage on the dry sump. More to come. I know the turbo will be making crazy power tomorrow.

[Mitch Wright]

I was just at Road Atlanta yesterday with the same temps and it was a beautiful sunny day. By 10am I just had a sweat shirt on and the track had some grip.
Have fun.

[Hobby Racer]

Track Day Saturday! 36F to start and 56F for a high. Bright sun forecast after rain tonight. I am looking forward to testing the third stage on the dry sump. More to come. I know the turbo will be making crazy power tomorrow.

Remember, we need video or it didn't happen ;)

[Rob T]

AAAAARRRRGGGHGGHHH. I am not going to say that Hobby Racer jinxed me, but the track day did not happen. That doesn't mean that I didn't spend a lot of time in my truck driving to and from the track after getting up at 4:00.

Here's the story. In the end, it boils down to operator (me) error. About 15 minutes from the track, I prepared to stop at a stop sign and it felt like I got hit or my truck mis-shifted. Remember, it's still pitch black outside. I go to the next stop sign about two minutes later. Same thing. This time I get out and take a look at my car. Both straps have fallen off the front wheels. One to the inside and one to the outside. These are on E-track. The over wheel type, which have been absolutely awesome. What kept the car from rolling off the back of the trailer was the little clip and the strap that fell to the inside. But it sure was moving. I got everything hooked back up and went to the track, registered and prepared to unload my car. It started right up....then I thought to my self...maybe I should step on the brake pedal to see if anything bad happened. Yep...right to the floor and fluid all over the trailer where the strap went to the inside. Luckily, they offered my a refund for my registration (CMP is awesome). So I cinched everything down and added an extra strap to the front of the car (the old ones I used to use) and drove home. After unloading, I took a look at the front brakes. On the right side, the -3 fitting to the 18" flex line was sheared off at the caliper. Brake reservoir was empty.

What went wrong....I think I must not have had the straps tight enough or for some reason, the car shifted sideways a bit and loosened one of the straps. Like I said, I've used this arrangement several times with zero issues. Tighter next time.

To add insult to injury, it is 55 with bright sun and light winds today AND I have not validated Gator's dry sump solution yet. It will have to wait until the next track day, which looks like sometime in February, unless they have one in January (a possibility).

Everything happens for a reason...today wasn't my day.

[Sgt.Gator]

Dang! Glad it wasn't worse.

[Frank818]

Really sorry for the bad luck! It happened a few times already, that's enough, bad luck will never happen again starting nnnnnnnnnnnnnow!

[Rob T]

I am not a "life-long" track guy so I am having the "benefit" of cramming a lifetime of lessons and experiences into a few short years. Let's just say the rate of learning is very high. That makes it fun. Most of the time.....

[Rob T]

Check out the General Section of the 818 Forum for some exciting news about a track day at VIR on June 28/29. Hobby Racer and I have been working with Mitch Wright to make this happen. We'd love to see a good turnout. We will be "tagging along" with Mitch's NCM sponsored event. Check out the post....

[Rob T]

I posted a "for sale" item. I have a set of gears from a 5MT for sale(minus the pinion gear). I also have a full 5MT for sale. PM me if interested in either.

[Rob T]

Quick Update. Couldn't get in the track day this weekend because I waited too long on a weather forecast - the groups were full. There is another day the second week in March, which I signed up for. While I had the time, I fixed the broken brake line and purged the whole system - back to normal.

I had originally planned to change one thing on the dry sump system at a time, but with the extra "down time" I went ahead and changed the two -12 suction lines from the oil pan to the oil scavenge pump. These are the lines that work under vacuum, along with the oil supply line to the OEM pump. I went with AQP stainless braided hose, which is rated for vacuum. As I suspected (and thought I remembered) Chad has placed flexible stainless steel helixes in these lines to keep them from collapsing. While I believe they did keep the lines from collapsing, they certainly had a negative impact on flow. They don't take up a lot of space, but they make the inside of the tube a much more difficult flow path.

Interestingly, when I run the car in the garage, the -8 suction line heats up the fastest of the three when checked at the inlet to the pump. The -8 is at the front of the engine, is the smallest, and has the "newest" pump. All three lines are moving oil. There could be several reasons why...

1) -8 line is smaller and is a better "straw" for sucking out oil...
2) -8 line is smaller and has less mass, so heats up more quickly
3) -8 line is connected to the newest "half stage" gear pump, so it is more efficient
4) some combination of the above, or something else

The -8 line is not the shortest, so length is not the issue. In the end, I am not sure it makes any difference. The objective of getting more oil flow has been achieved. Now if I could only get my car to the track to verify. Fingers crossed.....

[DSR-3]

5) -8 port is at the front and the engine is tipped forward giving it better supply?
With 3 scavenge ports/pumps, there should be no shortage of capacity. Getting the oil them may be the challenge once you get moving (admit I have 0 boxer experience, but plenty of dry-sump battles!).
Good luck on the project!

[Rob T]

FINALLY - A Great Track Day.

1) Weather was perfect - 55-80F, slightly overcast, a few gusty breezes.
2) THE DRY SUMP ISSUE IS SOLVED - No issues with oiling. This is my first outing with the added "half stage" -8 scavenge line in addition to the two (2) -12 lines originally installed. I also replaced the -12 lines with Aeroquip AQP vacuum rated and removed the springs. Oil pressures were great at all times and oil temps got to 190 in the fourth session. I feel really good about this. I do have two coolers - one is the side pod and one in the back. I am going to leave these for now, as it is only going to get hotter. The engine temp stayed right at 190, on the last session, pushing hard with 80F ambient temp.
3) Car ran all day with massive power. I still have so much to learn, but now feel better about focusing on driving.
4) Trans temps hit 199 - this is with my restricted flow marine cooler tapped into the AWIC line after the AWIC unit. This is actual fluid temp. I have a sensor in the pumped line on the way to the marine cooler.
5) AWIC water, post front radiator was 80-95 F with IAT's in the 99-108 range.
6) I drove 4 sessions.

More to this week when I have time to look at the video and analyze the data.

[Rob T]

Got a chance to pull some data yesterday, but not process all of the video.

Best lap times

Session 1) 1:54.712
Session 2b) 1:53.124 - had to see starter after going off track.
Session 3) 1:54.700
Session 4) 1:55.446

Overall top speed: 110.76
Right turn G's: 1.42 - very consistent in the sessions.
Left turn G's: 1.32 - 1.53
Braking G's: 0.89-0.97
Accelerating G's: 0.65-0.92
Apparent HP Max: 249 - 270 across the sessions.
Apparent TQ Max: 286 - 316

More to come when I have time to do the video.

[Rob T]

Here is a video from one of my best laps (time only defines best). Lots for me to work on, but it was nice not working about oil pressure. More seat time is needed.

Thanks to Mitch Wright, who provided some excellent video coaching (after this day) and gave me some stuff to work on....

https://youtu.be/vZh0PdjC3UM

[Sgt.Gator]

What tires and age/condition?
The best way to learn is to share the car for a day with a better driver. After each session compare data. That how I've upped my game quite a bit by sharing my STI with Retro Racing in enduros. Retro's 3 driver team are multi year class champions in our Conference. I hope to do that again this year with both my 818R and my STI. If Canada and the US will allow them across the border.......
This only works if you have a good data system. I have both AIM and Video Vbox - (Racelogic) in the cars. AIM is great for engine-trans data and ok for driver data. But Video Vbox is still the best for driver development.
I also got a Garmin Catalyst this year but haven't had it on track. I'm not sure it will work in an 818R because the screen will probably wash out in bright sunlight. We'll see. Should be very cool in an enclosed car though.

[Rob T]

Thanks, Gator.

Federal 100 treadwear. Went on the car new on 6/5/20. A total of 19 sessions on 6 different days, but none of the sessions over 20 minutes, because of oiling issues that were a problem until the last session.

I am running a traqmate, which provides pretty good data for the track with GPS and G-sensors, and allows integration with video, as well as 3 analog inputs. Full suite of analytics, segment analysis and comparison, etc.

[Rob T]

Had a track day yesterday. Worked on a few things. Stopped after three sessions. Here's why...

On the way to the track on the third session, I notices a little screeching sound from the left rear, along with a little drag. It was intermittent and timed with the rotation of the wheel. It was very faint. I went out and ran the session and there was no noise when I came back in. An hour later, I was driving to the grid for the fourth session and had the same thing, only a little louder. I did not go do the session, but drove around the paddock a bit, and it seemed to go away. Thoughts range from a sticking piston in a caliper along with a slightly (very slight) out of round disk to something more serious like a failing bearing. It will be a few days before I can get the car on the lift. Any suggestions?

A few other notes: IR temp readings on the hub nut/shaft were identical left and right after session 3. The driver's side rotor measured after session 3 was actually 60 cooler on the left versus the right (I know, not super scientific). No handling issues or noises I could hear on the track. I am wondering if I just got the brakes really good and hot and this was just a bit of pad drag....but wanted to be safe.

Any help would be appreciated. What should I look at and how should I test?

[Hobby Racer]

If you can, take each rear wheel off one at a time and measure the run-out of the disc at the outer edge on the side that faces the pad. You must put the lug nuts on and torque them WITHOUT the wheel on. I usually do this by using regular nuts and washers instead of the conical lug nuts as to not damage the bolt holes on the discs.

You should have similar run out numbers on each side, usually less than 0.005" is good.

[jforand]

I find that there is always a bit of extra resistance when rolling a wheel on everything, It is never perfect and as Hobby said 5 thousands is really no issue, but you will certainly feel that with the wheel in the air and rotating by hand. So if certain conditions exist you could expect to hear it as you did as well.

Not sure of the brakes you are using and where you get them in their operational window, but they can be a tad different (surface wise) rolling back out of the paddock. If you come off hot and park it things can change a bit with the pads/rotor. Without rotation the pads and the covered portion of the rotor cool slower than the exposed portions of the rotor. This can lead to superficial surface variations and some induced warpage issues. Once you get into them again you scrub the surface layer and get them back into the temp window, as well as, even out any temp inconsistencies that might still exist. This effect can be greater as the pads get thinner, they heat quicker and such.

Best way to operate is to keep the rotor in good condition (replace if worn or cracking becomes significant), keep the pad material at least 1/3 of OEM or more, take a cool down spin (minimum to no brakes the last 1/2 lap or so), make sure those wheel lugs are clicked off to the right torque so things can't shift around if the rotor is differentially cooling in the paddock.

It does not sound like a bearing as your temps were tracking other locations, you reported no handling issues, and the sound went away. I assume you had the wheel jacked up and you were tugging on the wheel in several directions to check for a tight bearing.

[Rob T]

Thanks for the feedback. Got the car up in the air. Bearings good. Run out was decent with a total deviation around the outer caliper of 10 thousandths. Interestingly, there was no issue as I took the car off the trailer and moved it to the garage. I suspect Jforand was on to something with the temp and how things cooled. There was no pulsing on the steering wheel at any point during the day or after. Pads are at 95%, so no issue there. Rotors look good. I was braking harder than my "old normal". All suspension components looked good. Ready to hit the track again on 5/21....

[J R Jones]

Rob, A long shot is some type of interference at the axle, CV or even the tire.
If it is coming from the brake, you might try stopping, go to Reverse and stab the brakes. This causes the pads to thrust in the opposite direction and perhaps adjust in the caliper.
Have you inspected the pads for lifting of the friction material? Anti-rattle springs OK?

My race cars always got pushed several times after a session to dissipate caliper heat evenly. The objective was avoid rotor warp from caliper heat soak. 1/3 to 1/2 revolution each push.
BTW if a rear rotor is warped you will feel it in the seat of your pants. Front rotor warp makes the steering wheel shake.
jim

[Rob T]

TRACK DAY - NOT! Need some help.

Today was supposed to be a track day. Got up at 4:00, left at 4:45 and arrived at the track at 6:45, checked in, fired up the car and unloaded it. It was running at idle until I took it to tech about 20 minutes after starting it. Shut it off at tech. Restarted it at tech and drove it back to my paddock spot. About 90 minutes later, and 10 minutes before my first session, I went to start the car. I always turn off the run switch and the main power disconnect. I turned everything on and went to start the car. I don't remember hearing the fuel pump run, which it always does. Tried to start the car....nothing. It turned over briskly and would not start. All gauges were working and I could hear the throttle vane moving, but no fuel pump. Interestingly, the AFR gauge was reading "lean". Missed the first session and went into troubleshooting mode. Looked at all the fuses - all were OK. A couple of guys came over and we tried some stuff with several full power downs and re-starts. Everything came up, but no fuel pump sound. Engine would not fire. So....loaded the car on the trailer with the winch and came home....

Just for grins, I tried starting the car in my driveway after I got home. When I turned on the power switch, the fuel pump cycled and the car started right up. I did it 6 times, with no issues.

I am looking for ideas of what might have caused this. There is nothing worse than a failure like this with a yet unexplained cause. I need to run this down before I head to VIR in a few weeks. It's never happened before...

1) Flakey Fuel pump relay?
2) .....

The car battery is brand new and I have never seen this before.

The rest of the story....I haven't used my winch on my car trailer for the last 8-10 outings. Yesterday, as I was loading the car, I had a premonition to try the winch. It didn't work. The dedicated battery was toast. I ran to Sam's and got a new battery last night, at the last minute. It's odd. Premonition to test the winch, need for the winch today. Maybe God didn't want me on the track today....

BTW - The folks at Carolina Motorsports Park (CMP) are the best. They gave me a credit for the session for next time. They didn't have to, but they did.

[jforand]

Oh man, it seems a few of us registered for VIR are having a stressful last 5 weeks!

I would certainly be looking into the fuel pump relay, the fuel pump power circuit, and the grounds as the starting place. Intermittent failure seems to point to something that changes with movement/vibration like a bad ground or a wire that is shorting to ground if the conditions are correct.

On my first start after dieting and putting in the harness I had no joy on the fuel pump. There is a fuse in the smaller F/B fuse box and it was good. In the end I found that I had cut a conductor that brought power to the relay coil.

Do you have all the wiring diagrams that describe the fuel system wiring? I can shoot you over the ones for the '04 stuff. I have the section Engine Electrical System, Wiring System on the desk right now going after my no start issue. it starts with Page# WI-106. WI-106-108 are very informative for the fuel system.

[J R Jones]

Intermittent, the worst. My guess is a poor connection to the fuel pump or the fuel relay. Consider ignition on, pump disconnected, a test light on the fuel pump power lead, then wiggle the wires/harness and watch for a blink.

[aquillen]

10 years back my '90 Corvette stranded me after putting gas in the tank. An hour later it started like always, at the time I had no clue what was up. Eventually I found out the fuel pump was going bad - one brush in the motor was hanging just enough to not make contact with the motor armature correctly. It would run on one start, then sometimes not on the next try. Pretty sure I remember giving the top of the tank a thump after not hearing the pump prime at ignition on, and then it ran, changed it out then. Tore the motor apart after I changed the pump and I could see the brush was binding in the guide.

[Frank818]

Oh Rob I'm so disappointed!! :( Again... :(

I second the others and would check all electrical power to the pump first.
Or even try another one, if you have a spare pump.

Let us know.

[Rob T]

So....I have been going out daily and cycling the main power and the ignition switch to cycle the fuel pump. For two weeks and dozens of tries there were no issues. The other day, I tried and the fuel pump did not cycle. I used that opportunity to swap the Fuel Pump Relay. The pump did not cycle, so it's not the relay. On a whim, I unscrewed the 4 pin Milspec connector that is on the top of the fuel cell that powers the pump and re-tightened it. It was not loose, but the very next attempt, the pump cycled, and has continued to do so at least another 10 times.

Question: Is there any way to make sure the connections in this plug are "secure". The pins are potted in the receptacle on the dry sump. The female bits are in the plug, that also includes the threaded locking ring. The plug is slotted so there is only one way to plug it in. Tolerances for alignment are very tight.

I spoke to Fuelsafe about my issue. According to the person I spoke to, they have never seen an in-tank wiring failure, or issues with pumps other than the filter clogging with degrading tank foam causing fuel starvation. My issue is either the pump cycles or it doesn't. Then at some point, it all works again....

[Sgt.Gator]

Make sure the connections are clean. If for some reason someone used dielectric grease in the connection be sure to clean that stuff out.

[J R Jones]

Rob, In my past with pin/socket connectors, repeated seating (coupling) caused the female socket to get loose. Bending the wrap a bit makes the contact/fit better.
Sometimes the male pin will have a sprung tab on the side that also makes the M/F fit better. I have bent those out to improve contact.
The last pin/socket kit I bought on Amazon was cheap crap, the female socket material was thin and had little tensile strength to maintain contact. Hard to access on line.
jim

[Rob T]

Cleaned the sockets and the pins and re-installed. Car has been 100% reliable since doing that. I have run the car up to temperature(2x) and cycled the fuel pump daily for a few weeks. Fingers crossed for VIR.

[Frank818]

Same VIR event as Hobby?

[Rob T]

Yes...June 28th and 29th.

[Rob T]

It did not go so well for me at VIR. I was able to do three parade laps and 1.5 hot laps before my left rear spindle cracked and the left tire tilted and stopped spinning at 95mph. Luckily, the wheel stayed on the car, trapped by the end of the spindle and the brake caliper. The spindle nut was missing. All we can conclude, was at some point the bearings got a little loose, allowed the spindle to crack, then fail, which then unscrewed the nut, allowing the wheel to come off. Before coming to VIR I had been troubleshooting a slight brake dragging problem on the left rear after being on track. It would go away when the car was cool. I had checked bearing play and run-out before coming here. I never tightened the axle nut, but the dent keeper/indicator was in the right place. Here are some pictures of the damage. The car had to be hoisted off the track because it would not roll. The spindle, and caliper bracket are done, as are the bearings. The inside of the caliper is scored, there is aluminum deposited on the rotor and the inside of the wheel is scored. I am thankful the wheel stayed with the car and there was no apparent body damage or suspension damage.150033150034150035150036

[Rob T]

Here is a video of the failure. If you listen carefully, you can hear a big metallic pop at the top of the hill (Oak tree) followed a little while later by a squealing break sound. At speed, I thought the metallic pop was from a rock hitting the fender well. The car did not exhibit any real handling issues until the end....

https://youtu.be/QtJTvcx1oiE

[J R Jones]

Rob, I have been wondering how your event progressed, thanks for the update. The failure was catastrophic but fortunately limited in damage. It would be interesting to see the cracked spindle. You must be questioning the history of that part.
You state the spindle nut came off, I assume you mean the axle nut. That is hard to understand as the axle is splined to the hub, no relative motion.

We had a similar failure running a Mitsubishi EVO in SCCA T2 Nationals. The LR wheel, hub, disc and caliper left the car in Elkhart Lake's Canada Corner at 60(?) MPH.
We determined that the hub retention nut and bearing pre-load were not correct. The axle nut torque was 166 lbft and the bearing play was .002 in. Technician advice was to set the axle torque with the assembly off the ground and spinning the wheel while holding torque on the nut. Theory is the hub bearing balls seat while spin-torquing to make the end play measurement accurate.
Mitsubishi also used a hub/bearing bench test with special fixturing tools to simulate the axle to test bearing breakaway torque (0.74 lb ft) and the spec end play of .002 in.
jim
Rob, to clarify, our axle nut did not come off, the axle broke.
I watched the video a couple times more. Based upon sound and instability, I feel perhaps the nut came off first and the semi-unassembled state cracked the spindle.
Check the spline fit, hub to axle. If the splines are loose they might have worked on the nut to loosen it.

[Rob T]

Lots of theories, but here is what I think happened without doing any more analysis.

1) Last track day at CMP I noticed some brake noise as the left rear tire rolled through the paddock. I aborted the last two sessions and took the car home. I checked run out on the disk while the car was in the air and also tried to "wiggle" the bearings with the wheel on. I went as far as to lower the car almost to the ground and use a long 2X4 to try to get something to move. Nothing did. I remember looking at the axle nut to make sure that the indent was still at the slot. I figured I was good to go. In hindsight, I think the hub was already cracked or the bearings were loose enough to cause issues. However, the brake noise only occurred when the rotors/etc. were hot. Never cold. My assumption at this point was that the caliper piston was a bit "draggy".

2) Monday I did three parade laps at VIR. When I came off the track, there was a slight cyclical rubbing noise on the back left, just like the month before at CMP, but not as severe. By the time I was back to the garage the noise had stopped and it always stopped under braking. I rolled the car in the garage and heard nothing.

3) An hour later I was out for my first session. The loud bang happened after a warm up lap and 1/2 a more spirited lap. At the time, I reconciled the noise I heard to rock bouncing off the aluminum fender well. I never heard the grinding noise from the brake that is evident in the video. I wear ear plugs inside my helmet and my head is right next to the air intake. What I think happened was that the hub was already cracked at CMP a month ago. I think it failed catastrophically at the top of the hill with the sharp right hand turn. Now things that don't normally spin could and I think that unscrewed the nut. I've had 8 track days (multiple sessions per day) since I put those nuts on. A few of the folks at the track suggested that those nuts need to be re-torqued on a regular basis as the bearings wear.

The reason the tire stayed with the car is that the disk was jammed in the caliper and the end of the axle could not pull out of the spindle. The tire got far enough out that it jammed and stopped rotating.

That's what I know for now....more to come after I tear things apart

[Bob_n_Cincy]

This is my spindle that snaped.
150054
My spindle had been abused in 100s of autocross launches.
It broke during a normal stop at a red light. The nut and spline stayed together and shot out of the side of the car about 6 feet.
My failure was definitely because of rotational fatigue.

I wonder if the heat cycling (expansion/contraction) of the hub and rotor eventually longitudinally fatigued your spindle.
Bob

I'm glad it was just parts, could have been much worse at speed.

[J R Jones]

Rob, Look at everything for leads, like the bearings which may be loose or damaged, they do not wear. You mention "spindle" and "hub" as cracked, I assume that is the upright bearing carrier. If it is a progressive crack, you can inspect crack age by cutting it apart and look at the crack. A dirty section indicates an earlier failure.
Is the outer CV joint OK?
Visualize the things that happen suddenly and things that happen over time.
The bearings can deteriorate over time, and usually get loose and noisy as clearance opens-up.
It is hard to visualize the nut leaving suddenly, unless the threads were pulled-out. That would leave thread debris on the axle threads.
It would take time for the nut to lose clamp load and turn off. I assume there were 10-20 threads engaged. Again, if the splines are OK there is not much rotational movement to loosen the nut.
jim

[J R Jones]

Bob's photo shows the progression of a fracture. It is shiny and dark on the outside circumference and clean in the middle. The break started earlier in the splines. The twisted fragments indicate it was ultimately a (torsional) load failure.

[Frank818]

OMG Rob, you got so lucky not to crash out of control at that speed! How did you manage not to lose control?
That is a serious breakage. :(

[Rob T]

If you go back to the fourth picture above, you can see where the break happened and the resulting displacement of metal. The axle threads are not damaged and the axle splines appear to be intact. As for the bearing wear/looseness, I think that is possible. However, after my last track session I pushed, prodded, rolled, levered the wheel to see if I could figure out if there was any issues that would cause the brake dragging. While I am not an expert on bearings, there was no apparent looseness, that I could detect nor any sounds....I am not saying that everything was right. I just didn't see or hear anything wrong. More to come...

[C.Plavan]

If you go back to the fourth picture above, you can see where the break happened and the resulting displacement of metal. The axle threads are not damaged and the axle splines appear to be intact. As for the bearing wear/looseness, I think that is possible. However, after my last track session I pushed, prodded, rolled, levered the wheel to see if I could figure out if there was any issues that would cause the brake dragging. While I am not an expert on bearings, there was no apparent looseness, that I could detect nor any sounds....I am not saying that everything was right. I just didn't see or hear anything wrong. More to come...

Ohhh boy. Sorry to hear that Rob. The curse continues dang it. It sounds like a bearing/hub failure if I'm reading everything correctly. Are you sure the axel nut didn't come off first? Technically, you are not supposed to reuse axel nuts on a race car. If you do, make sure to use Red Loctite for piece of mind. I would put bearings on the list to replace every so often to be safe.

Sure you don't want an NP01 ;) ? I'm still just putting oil and gas in it and running it like I stole it for 5+ years. :)

[J R Jones]

Rob,
Sorry, I did not (do not?) understand the fourth photo.
The fracture shown is the outer portion of the steel hub/bearing carrier, still in the fange?
The attached photo is what it should look like?

If that is the case, the dark portion of the fracture is historic. The 30% clean/bright area is what you ran on this week until the incident.
I would say the fracture started at the 3:30 clock location from fatigue.
How many miles are on this part?
Something was wiggling the inside or the outside of the hub. What was it?
jim

150080

[Sgt.Gator]

Sure you don't want an NP01 ;) ? I'm still just putting oil and gas in it and running it like I stole it for 5+ years. :)

Hi Chad! I've been following your posts on the NP01 FB page. I take it you like the "Gen 2" upgrades?

It's taken a long time but I think we've about figured out how to race these 818Rs reliably, despite all of the ones at VIR failing after 2 days!
But yes, I keep up closely with what is happening with the NP01. Unfortunately to have anyone to race against I'd have to do some long travels, there is no NASA in the NW. Anytime you'd like to experience ORP you're welcome to come up here as my guest. I'd love to see your car on track here. We've had 3 members buy Radicals this year, and not the SR3, the SR8 and the one with the Ecoboost twin turbo V6. Crazy fast but they are just as unreliable as any other race car.

[jforand]

Rob, J R makes a great point about the progression. I noticed the color shift, but was not conscious enough to internalize the meaning at the time. The part work hardened over time from the outside in and once hard enough the surface started to crack. That circumferential crack deepened over time and dirt migrated into the fracture (as well as moisture and oxidation) causing the darkening. The non concentric bright metal ring was the last remaining attached material and that is the part that completely failed at VIR this week.

J R, that is not the correct part. That is a more modern design, which Subaru ultimately switched to, but Rob a d I both have the older press through the bearing hub. What Rob has is not a sealed bearing design. He has the two independent roller (or ball) bearings with the outer races pressed into the knuckle and the hubs collar/shaft section (the the wheel flange portion) pressers through those inner races holding the assembly together. The axle nut is torqued to preload the bearings. If the nuts loosen the bearings lose their preload and do not support the load properly causing damage to the bearings themselves. Of course, while the bearings are not properly doing their job holding the hub, it is allowed ‘freedom’ to wiggle about and do bad things, which I firmly believe with result in metal flex, work hardening, and ultimate fracture.

[J R Jones]

Justin, The update design looks good. The older design sounds similar to our Mitsu-EVO. In that case the rolling torque procedure is critical. Look to the bearings, they could have contributed.

[Rob T]

150117150118150119150120

Here are some pictures as I disassemble the car.

[Rob T]

The first is a picture of back of the hub. You can see that the fracture happened right on the line with the hub. The second picture is what the axle looked like after I took the tire and broken hub piece off. The third picture is the axle shaft. I "looks" OK to me. The fourth picture is the broken piece of the hub that I pressed out of the knuckle. the piece on the top is the outer bearing seal.

[Rob T]

I'd like your opinions, please. As I already have the "patient on the table". What are your thoughts about replacing the bearings and spindle on the right rear as well? Having the failure at speed was not an experience I'd like to repeat. Looking back, I think I had "warning" with the brakes rubbing slightly after sessions on the Left Rear. I do not have any of that on the right. However, based on the forensic evidence, the crack seems to have been around for a while....I don't know how long it took to manifest itself in either rubbing or a total failure.

[Hobby Racer]

I would definitely replace the bearings on both sides. The other spindle is kind of a shot in the dark. It could be fine if the the one that failed was due to metal fatigue because of being loose. There is not an easy way to tell if the good side is really good. I guess if the spindle is inexpensive, just replace it since you will have it apart to replace the bearings.

[J R Jones]

Rob, Good advice from John. I would also find a way to check the run-out on the axle shaft. Not easy with the CV joint. Maybe in a lathe with the end in a tailstock center. Perhaps a driveshaft shop can help.
jim

[C.Plavan]

I'd like your opinions, please. As I already have the "patient on the table". What are your thoughts about replacing the bearings and spindle on the right rear as well? Having the failure at speed was not an experience I'd like to repeat. Looking back, I think I had "warning" with the brakes rubbing slightly after sessions on the Left Rear. I do not have any of that on the right. However, based on the forensic evidence, the crack seems to have been around for a while....I don't know how long it took to manifest itself in either rubbing or a total failure.

Replace everything. Safety first. Watch and replace bearings every couple of years. Those bearings were new in 2013 when I built car. I bet the bearing was wearing everything (the noise you heard) and led to complete failure. Also repack the bearings yearly. Just my .02 cents.

[C.Plavan]

Hi Chad! I've been following your posts on the NP01 FB page. I take it you like the "Gen 2" upgrades?

It's taken a long time but I think we've about figured out how to race these 818Rs reliably, despite all of the ones at VIR failing after 2 days!
But yes, I keep up closely with what is happening with the NP01. Unfortunately to have anyone to race against I'd have to do some long travels, there is no NASA in the NW. Anytime you'd like to experience ORP you're welcome to come up here as my guest. I'd love to see your car on track here. We've had 3 members buy Radicals this year, and not the SR3, the SR8 and the one with the Ecoboost twin turbo V6. Crazy fast but they are just as unreliable as any other race car.

Not to hijack- but yes I updated to Gen 2. $5000 for new complete motor with 25 more HP and 400 RPM limit (new cams and ecu flash). I have my orginal motor that a may turbo charge for fun (glutton for punishment :P ) Also all the new aero and tunnel diffuser. Such a great race car and cheaper to run than a Miata. I get tired thinking of everything you guys have to do to the 818R. Don't worry about racing other NP01's, race it in a class it falls into where you are at. They are doing great in the WRL endurance races.

[Rob T]

The hub shaft broke at the end of the bearing. I got everything else apart yesterday. Now on to finding parts to replace.

150191150192

1) Hub (both wheels)
2) Seals (both wheels)
3) Bearings (both wheels)
4) Rotor (at least one wheel) and Bolts
5) Brake Mounting Plate (Subaru part)
6) Brake Plate to Caliper mounting plate (bent)

The odd thing to me is that was absolutely no bearing play evident after the last track day. I checked with the car in the air. The only clue was the dragging brake after a track session, that went away after the car cooled down.....

[Bob_n_Cincy]

Rob,
Did you find your axle nut? I'm curious if it spun off or did it get its threads ripped out of it?
Bob

[J R Jones]

Rob, There was an anomaly stressing the broken bearing carrier. Not all the parts can move with a rhythm that creates fatigue that causes the outer part to break-off.
Logic suggests the upright is stable and does not move with a rhythm.
That leaves the rotating parts.
bearings
axle/CV
wheel lug hub
the wheel
brake rotor
I suggest checking the run-out of all the rotating parts.
jim

[Rob T]

Bob: The track was "hot" the rest of the time I was there, so no opportunity to go look for it. That, and not knowing where exactly it came off, leaves over 3 miles of "haystack" to find a "needle" in. That said, I didn't notice any residual material in the threads of the axle. My money is on it spinning off completely after the break when the wheel could move differently than the axle when the hub was broken. Direction of travel would unscrew the nut.

[J R Jones]

Rob, In an effort to be as objective as possible here, I have a problem with your concept.
Before the break the splined portion of the hub was intact held together by the nut on the axle shaft. Because of the splines, the hub and axle turned together. No torsional load on the nut. (assuming the splines were OK)

After the outer portion of the splined hub broke free, the splines kept the hub segment turning with the axle. (unless I am missing something)

If we look at the timeline, there does not seem to be enough time after the the car became unstable, to your stop (10 seconds?) for the nut to turn off.
The ET of the last session when the hub broke was ~4.00 minutes. Was that enough time for the nut to turn off?
Have you summarized the total time the wheels were turning at the event?

It seems to me a tolerance opened up somewhere and/or something was running "out" causing the hub to fatigue and seperate.
jim

[Sgt.Gator]

I just checked the axle nuts on my STI. Two of them are starting to loosen:

Driver Side Rear:

https://bl6pap004files.storage.live.com/y4mJnj6KoyEvC1SlcfsMYg-NOaB7-GGatsH4g3R4v1ONYdKtYew5X3ucxtLMbk-5-vHXAGO8QXjhbbuXXtmNDMWwh7_nz6XU2D8wNTrfBap5vaI2Irw HlpwGEojtfybfQQt54JyymiZBGY5-5TDxaQGoWMfa730JC9ATsE_z-l3iz7mgbIrpaOpzxhosJb7SR33?width=768&height=598&cropmode=none

Passenger Side Front:

https://bl6pap004files.storage.live.com/y4m5QeN1GZGVJKJpfa3IHg_bePq_5ScRKK_Lej3AsytxrTfv-4OdQiSekO2ydG8FhDNF7tUA77azfoYyuxPgRCqeIaUJeTBkem4 o1f7xwWBCajdIDnZxviEHfRQdjMtu4_PKhzUkrnqTswGIu52Ci h3-NFnKQ1siNEq4SxVbf5vYrNw-EOiYGtqh44ep2n5wQSQ?width=768&height=794&cropmode=none

[Rob T]

Maybe we are on to something here....If my failure helps others from not having the issue or something really bad happening, then it wasn't just a bad day at the track....

Can anybody confirm what the nut torque is supposed to be? I have several documents with different numbers and have heard different numbers as well.

Factory Five mentioned to me that they always checked the torque before their track sessions. I am trying to reconcile that with the dimple on the nut that is supposed to "lock" the nut in place.

[Hobby Racer]

I use 140 ft lbs. of torque as stated in the 2006 Subaru WRX Factory Service Manual.

I also have one side that is starting to loosen, looks like Gator's pics. Not sure how to best lock these if the dimple does not do the job.

[Sgt.Gator]

Yeah the FSMs jump around a bit.
Hobby, I think you may be looking at the rear axle spec, not the front axle spec.

2003 Imprezza FSM, 2005 Imprezza FSM:
Front Axle: 162 Ft-Lb.
Rear Axle: 140 Ft-Lb.

2009 Legacy GT FSM:
Front Axle: 162 Ft-Lbs
Rear Axle: 177 Ft-Lbs

2019 WRX/STI:
Front Axle: 162.3 Ft-Lbs
Rear Axle: 162.3 Ft-Lbs.

Since we have Front Axles now at the back of the 818 that means 162 Ft-Lbs.

I put the yellow paint across them once they are tightened and staked down just to make it pretty obvious they are loosening if I remember to even glance at them when changing wheels and adjusting air pressures. That's my way of checking the torque. I can't imagine actually putting a TQ wrench on them at the track, or anytime if they haven't moved.

I've been at the track 3 times when wheels have come off from axle nuts....luckily never my own.

[Hobby Racer]

Yeah the FSMs jump around a bit.
Hobby, I think you may be looking at the rear axle spec, not the front axle spec.

2003 Imprezza FSM, 2005 Imprezza FSM:
Front Axle: 162 Ft-Lb.
Rear Axle: 140 Ft-Lb.


That is correct. The 818 uses the front inner CV joint in the rear at the trans input but uses the rear hub at the wheel and therefor you need to use the rear hub torque spec for the the axle nut.

140 Ft-lbs is the correct spec

Rob - how well do the splines on the axle shaft mate up with the new hub? Any apparent damage?

[J R Jones]

A torque specification is relevant to the nut and the shaft threads. The other bits being clamped-up are non-deformable and don't care what the clamp load is.
The Subaru design intentions' here are violated, front/rear, steer/non steer, side loads.
Despite the threads and matching torque, if there is a choice, given the non-production loads involved, I would go with the higher torque.
BTW the clamp load of a 20mm thread @ 140 lb ft is ~15,000 lbs. The clamp load @ 162 lb ft is ~18,000 lbs.
I'm with the Sgt on this.

John is appropriately concerned. It is unlikely that (lateral) thrust loads are loosening the nut, it is more likely twisting movement at the splines.
jim

[Sgt.Gator]

I looked up the specs in the 2005 Legacy GT FSM. It also uses the 5 x 100 hubs and R-160 rear diff.
Front: 162 Ft-Lbs
Rear: 177 Ft-lbs.
I personally will use the 162 ft-lbs on the 818.

[Ajzride]

Drill a hole and use a castle nut ;)

[Hobby Racer]

It's not a matter of using more torque. The tapered roller bearing cartridges in the hubs are designed for a certain amount of clamp force provided by the axles nut being torqued down. Each of the examples quoted above use different tapered roller bearing cartridges in their hubs and therefor need different axle nut torque settings. The hub bearings for the different vehicles/models are not interchangeable and neither are their torque settings.

Will the bearings fail if torqued to a higher value, no, but they will certainly wear quicker.



Drill a hole and use a castle nut ;)

I wish it were that easy. The splined sections on the axles are induction hardened. I don't think they can be drilled without very expensive tooling.

[Sgt.Gator]

Learn something new everyday!

I talked with another Subaru racer. He says the rear bearings being the press in replaceable type aren't effected by the axle nut TQ. The shoulder of the CV and the nut pinch the inner race and don't load the bearing.
YMMV!

[Hobby Racer]

I talked with another Subaru racer. He says the rear bearings being the press in replaceable type aren't effected by the axle nut TQ. The shoulder of the CV and the nut pinch the inner race and don't load the bearing.
YMMV!

That is exactly what the nut does. It pinches the inner races together and puts a thrust load on the bearings. Look at this cutaway of a Subaru style rear bearing cartridge and it becomes clear.

150905

[jforand]

Hobby has this one nailed. The nuts and axles shafts are not going to care what torque is used. They will be able to handle either easily. What matters is the bearing preload exactly as Hobby described. You need to determine what bearings are in your rear knuckle and go with that OEM torque value or whatever an after market bearing recommends should you be using something special.

My fronts are peened. There is no rotational torque up front on the 818 so I don’t think they will loosen. As long as the peen stays put I think it is safe to call them good. My back nuts (from the driveshaft shop, came with axles) do not peen. There is no locking mechanism. There are a couple options…..torque them very frequent as part of a checklist or locktite them torque and paint. If they ever move you might need to get creative with the retorque depending on the locktite you used (red for instance). Blue you could just retorque.

I will provide one note of caution with the red locktite. I could not keep the axle nuts tight on the Mustang. I ended up grabbing the red locktite. It worked very well. When I did have to take the nut off later I used a dewalt electric impact gun and it actually tore up the threads on the axle!!! The secret would be heat and working the nut back and forth until if fully loosens. If you power it off in a single brute force session it gets worse and worse. I got to drive all over town trying to find the correct die to re-chase the outer couple threads. Of course this was the day before a track event:D

[Frank818]

The hub shaft broke at the end of the bearing. I got everything else apart yesterday. Now on to finding parts to replace.

150191150192

1) Hub (both wheels)
2) Seals (both wheels)
3) Bearings (both wheels)
4) Rotor (at least one wheel) and Bolts
5) Brake Mounting Plate (Subaru part)
6) Brake Plate to Caliper mounting plate (bent)

The odd thing to me is that was absolutely no bearing play evident after the last track day. I checked with the car in the air. The only clue was the dragging brake after a track session, that went away after the car cooled down.....


Rob, were your drive shaft rods Subaru standard size and steel strength, or you were running slightly larger rods (I think it's possible but can't recall if mines are larger) but most of all with greater steel strength (chromoly or something like that)?

[Frank818]

Maybe we are on to something here....If my failure helps others from not having the issue or something really bad happening, then it wasn't just a bad day at the track....

Can anybody confirm what the nut torque is supposed to be? I have several documents with different numbers and have heard different numbers as well.

Factory Five mentioned to me that they always checked the torque before their track sessions. I am trying to reconcile that with the dimple on the nut that is supposed to "lock" the nut in place.

Oh absolutely! I will do like Gator and mark mines too, keeping an eye couple of times a year.

I use 140lbs in the back, like Hobby, even though I have more weight. Never was able to determine if I should go higher with 200-250lbs more weight in the back.

[Rob T]

Update: Waiting on parts....have everything I need but the backing plate for the left rear. First problem was I ordered the wrong one. I guess there were two brake packages for 2006 WRX's. The caliper bolt positions are different. I needed the one that fit the 2004 WRX. Second problem was the right part arrived damaged. Now I am waiting on a replacement. I am ready to put it all back together when the parts get here....Next track day is August 20th at CMP.

[Rob T]

Quick update:

1) Put the left, rear side back together yesterday. Had to machine the new backing plate for the Wilwood bracket clearance.
2) Started on the right rear. Disassembled, pressed out old bearing parts, cleaned everything, put in new bearing, pressed studs into hub and assembled everything. Today I mount the brake caliper, check the alignment with the rotor and re-install.
3) Neither of the rear axles had any part of the two inner seals. This may have contributed to the bearing/spindle failure on the left side. The right side (unbroken one) was pretty dirty.
4) I have not had a chance to pull the outer bearing and race off the right hub yet. I want to see if there is any evidence of cracking....

[Rob T]

I pulled the race off the right side hub yesterday. No evidence of cracking or anything abnormal. Got everything back together. Today I bleed the brakes and get the car down from the lift. The new bearings seem good. Just a little more friction than before with all three seals brand new and making good connection.

[J R Jones]

Rob, did you identify any damage to the rollers or races on the left side? I sure would feel better if you could find an anomaly.
Did you research hub failures as the initiating problem? Warranty failure data is never made public.
jim

[Frank818]

Rob,

It took me way too much time to log back in and tell you this, but if you ever want to make the axle/hub/CV assembly stronger, you could follow what I did.

All my parts came from DSS (DriveShaftShop. Now try to say that super quickly without screwing it up). Back in 2015 I didn't trust the subie axles would handle my torque in a 2WD and the guy at DSS told me they have seen way too many of these setups to fail. Rare are those that reliably handle more than 450hp (or 450tq).

What DSS proposed was to bore/broach the hubs to 1 inch using bigger splines and fitting a 1in rod (chromoly I think). CVs are also beefier. That upgraded setup should handle 700-800, he said.


Here are my hubs and iterations (it took a few CVs to find the right ones fitting properly, the ones grey could not push in enough and I had to get the black ones. Also the blue boots got trashed cuz the clamp had a too thick buckle and was hitting on the spindle right above the loooooooooooooong lateral link bolt. My inner CV boot also got changed for a Hypervelocity boot due to my constant high angle, but on the pic it's the kind of boot you'd get for the subie. All in all the thickness of the CVs, splines, etc., are correct):


151490151488151489151492151491

On the above 1st pic, the right CV is the OEM subie and left is DSS.

[Rob T]

Frank: Thanks for the update. I am running DSS axles. Splines go almost all the way through. The axle survived this whole mess with no issues. I agree that the axles are awesome.

The new hubs look to be a different pitch. Do they fit with everything else? I have the standard (modified) backing plate with the Wilwood brakes. Also, a new pitch would obsolete two very nice sets of wheels. If my failure was indeed caused by a loose axle nut (my car is only about 300hp/300ft-lb), my new marking and checking procedure for the nuts should help. The right rear was fine. Thankfully, I did get a warning when the hub was cracked, I just was not able to diagnose it. Now I know.

[Frank818]

The hubs fit everything else, they just need a specific CV for the added diameter and apparently stronger splines. I think I couldn't install the inner-inner seal so I have 2 instead of 3 seals, but wheels, bolts, offset, Wilwood, that all fits normal.

It's true if your loose nut was the culprit than you're probably fine with OEM specs, I forgot about that!

[J R Jones]

Rob, I do not understand the specific differences in the alternative parts you and Frank have discussed. There is a basic relationship between splined parts that is relevant to axle nut loosening.
As we have discussed the axle nut clamp load is huge, way more than dynamic side loading. It does not allow the axle to thrust in and out of the hub, causing loosening.
Accelerations and decelerations try to rotate the axle in the hub. The class of fit is important to minimize clearance and rotation. Even a micro-rotation counterclockwise tries to turn the nut off.
With clean splines, male and female, test the spline fit. Slide the axle into the hub without the nut and bend the joint to evaluate fit. Then rotate the axle in the hub, again looking for spline clearance.
Obviously no clearance is preferred, maybe a little interference is better. I do not know if a clearance specification exists. New parts would be the benchmark.
You mentioned "Splines go almost all the way through", that is not ideal. More spline engagement is better than less spline engagement.
jim
Does your hub fracture align with the "Splines go almost all the way through" end of the splines????

[Rob T]

A successful track day at Carolina Motorsports Park Yesterday.

1) No Issues with the new bearings, hubs, left rear rotor or backing plate!
2) No Fuel pump issues now that I went to a direct wired (circuit breaker, separate switch) fuel pump.
3) Only 6 cars in my run group.
4) Ran 4 sessions.
5) In the last session, I saw the DAM number with a low of 0.835 and end at 0.935. The fine knock was at 0.33. They have always been 1 and 0 before. I did see an IAT at 124F when I was pushing hard. Previous sessions had been no higher than about 118. It was 88F outside and probably hotter over the track.
6) Water temp hit 200. Oil temp was 200, even when running hard, so I feel very good about the third stage on the dry sump. Oil pressure was 80psi when at speed on the track. 40+ in the paddock.

Video and analysis to follow....

[Frank818]

Oh yes that is really good news!!! You must be so relieved now, I'm happy to hear that!

[Rob T]

As this is the first time I have seen knock/timing adjustments while on the track, do I need to be concerned about this? I am not a Cobb expert.

5) In the last session, I saw the DAM number with a low of 0.835 and end at 0.935. The fine knock was at 0.33. Both are displayed real time on the Cobb Unit. I was not logging at the time.
They have always been 1 and 0 before. I did see an IAT at 124F when I was pushing hard. Previous sessions had been no higher than about 118 IAT. It was 88F outside and probably hotter over the track.

[blomb11]

Given the high IAT temperatures you must have seen some knocking which resulted in the DAM going down as you mention. As long as you do not see anymore knocking the DAM should correct itself and go back to 1. Per Cobb as long as you are between 0.6-1.0 you are okay and it should resolve itself if the knock has stopped and gone back to 0. The DAM can also be triggered by bad fuel sometimes. I have had high knock around -2 and saw my DAM come down around 0.8XX as well, but it corrected itself later completing the next driving cycle not under high load.

Something to watch, but it does not sound like you need to be concerned unless it continues. You will see knocking at high IATs...

[Sgt.Gator]

I'm emailing you the Cobb Tuning Datalogging Subaru How To Guide. But in short:

Monitor: DAM
What it does: DAM, or Dynamic Advance Multiplier, is a learned correction that adjusts overall timing.
What the numbers mean: For the 02-05 WRX, this number ranges from 0 to 16. For all other turbo model Subarus, this number ranges from 0 to 1 in tenths of a decimal (ex: 0.8). The number advances upwards when no knock is detected and decreases for extreme knock situations. You always want this number to be at it’s maximum value.
Why you monitor it: If you ever see this number decreasing, you have a potential severe knock situation.
What to look for: The starting value will depend on the vehicle and tune, but it should always learn up to the maximum value. This value will reset to it’s starting point after a map Reflash, an ECU reset, or a battery disconnect. If you see this value begin to drop under any other circumstance, you most likely have a severe knock situation. You should immediately analyze the tune and mechanical condition of your vehicle.

Monitor: Fine Knock Learning
What is does: Fine Knock Learning is a learned correction that makes small corrections to timing once the DAM has settled.
What the numbers mean: The values are degrees of timing being added or subtracted. An initial correction is typically -1.4, but is learned away in increments of 0.35.
Why you monitor it: When Fine Knock Learning hits extreme values, the ECU may start to adjust the DAM.
What to look for: Occasionally under low loads you might see an initial knock value followed by several values of that number decreasing in the incremental value (ex: -1.4, -1.05, -0.7, etc). This would mean that the ECU is already learning the correction away, and would be nothing to worry about. These values would also immediately go away after an ECU reset. If the ECU is making consistent and multiple knock corrections under load (such as full throttle and full boost) all in a row, you could have a potential knock situation.

Hope this helps!

[Rob T]

Thanks for the help Gator. I appreciate it.

[Rob T]

8/20 Track Day Summary at CMP

1) I drove 4 sessions, about 33 laps total, 75 miles, and used 11.25 gallons of fuel or about 6.7 mpg.
2) Highest transmission temp I saw was 210 using and IR gauge
3) AWIC supply (to the cooler) went from 90 - 100 - 104 - 110 as the day heated up. It was over 90 for the last session. IAT went from 102 to 115 to 118 to 124. I did see some DAM adjustment and Fine Knock Learning in the last session at the 124 IAT.
4) Oil temps were 200 in the last session. No issues with pressure, ever.
5) Water temp was 200 in the last session, but 190 for the others.
6) My best lap was 1:55.304
7) Best acceleration was 0.72G
8) Best braking was 0.92G and there is more there, I am sure.
9) Right Turn G's max 1.53
10) Left turn G's max 1.45 (100 treadwear Federal tires)
11) Max speed 108.29
12) Max calculated HP - 244
13) Max calculated TQ - 335
14) No issues with fuel delivery.

I am still working on driving skills and consistency. It's great to have the car running well, and be able to focus on driving.
Next track day scheduled for 9/10. I am hoping for a little cooler weather. 90+, high humidity and a heat soaked car, seem about the limit for what I have.

[Frank818]

Really happy everything got finally sorted! :D You deserved it very well, it's time to clock in lots o' miles and smiles!

[Rob T]

Track Day Scheduled for 9/10. Weather looks good so far with highs about 85F. Carolina Motorsports Park

[Rob T]

Track Day was a Success! Weather was perfect...65F at start, 81 at finish, low humidity, some wind. Ran 4 sessions at CMP of 7-8 laps. All temperatures were good. No fuel system issues. No timing issues (must have been heat last time with Cobb pulling timing). Only issue was my run group was a bit crowded and I had a hard time getting clean laps. I had fun! More to follow.

[Rob T]

Here are some numbers from my track day. Video to follow when I have a chance to process it.

Best Lap: 1:54.070
Coolant: <190F
Oil: 195F Max
IAT: 111F Max on last session - No timing issues
Trans Temp: 195F Max on circulating fluid, 215F with IR on back top of trans
AWIC supply water Temp: 100F on last session.
Max Speed: 113mph
Max left G: 1.44
Max right G: 1.38
Max acceleration: 0.82g
Max braking: 0.96g
Calculated Torque: 345ft-lb
Calculated HP: 254
I used 11 gallons of 93 octane gas on 32 laps or 73 track miles - 6.6mpg

[Hobby Racer]

I used 11 gallons of 93 octane gas on 32 laps or 73 track miles - 6.6mpg

Wow, I only get about 3.5mpg at Watkins Glen. That's about 1 gallon per lap!

[Bob_n_Cincy]

Wow, I only get about 3.5mpg at Watkins Glen. That's about 1 gallon per lap!

Quit slowing down for the corners and your MPG will go up.

[Rob T]

Hobby: Those two extra cylinders don't move for free, you know....

[aquillen]

One thing I'm not going to complain about is getting 28 - 30 MPG this year in my 3.0 818, highway and often 70+ MPH for a big chunk of many fill-ups. I've done 4900 miles this year, don't tell Haggerty... :)

[jforand]

Great to hear you are up and running again Rob.


Wow, I only get about 3.5mpg at Watkins Glen. That's about 1 gallon per lap!

That is way lower than I would have expected.

My '16 Mustang GT with a big old 5.0L V8 weighs about 3850lbs with 435 stock NA HP. My record low track MPG is 5.6MPG. I would have thought at a car with half the weight and something close to the same or less horsepower would have done much better on fuel.

[Rob T]

Canceled my scheduled track day today. It's been raining for three days in my part of SC. Open top trailer, open top car and rain are not a recipe for big fun. Nothing scheduled at the moment. I hope CMP adds some days in December, January or February. It's disappointing, but all things happen for a reason. With my "extra" time, I can do an oil change on my daughter's car.

[Rob T]

BACK TO THE TRACK! I made it to the track (CMP) yesterday for my first session of the year. I spent Thursday doing and oil/filter and trans oil change as well as checking everything out. Interestingly, I did find that the left side axle nut had loosened about 15 degrees during my last track day, so I re-torqued that and made the "dimple" a little more robust. All three other nuts were fine.

I did three morning sessions before I packed it up and left - two reasons - my left front tire was going flat (not sure why yet) and a big storm was headed our way. At the end of the day, my Federal tires have 34 heat cycles on them and they are still doing great. I managed to log my second fastest lap time ever at CMP. It was between 45 and 50F which made the turbo happy, and everything stayed cool....Only about 10 cars in my run group, so lots of space on the track.

My second session was my best, with the fastest lap. Here are the stats from that lap....

Time: 1:53.332
Braking g (max) 1.06
Accel g (max) 0.75
Left G (max) 1.38
Right G (max) 1.28
Average spd 72.74mph
Max spd 116 mph
Calc TQ max 308 ft-lb
Calc HP max 256

I still have a lot to learn, and seat time is helping. I feel good about how the car is running, especially the dry sump with the additional 1/2 stage. I am working on braking later and better lines through the corners.

Since I started tracking the car in 2016, I have logged 20 track days and a total of 71 sessions of between 5-10 laps.

[Hobby Racer]

So jealous! It snowed today and we got 8 inches :mad:

[Rob T]

Time to Upgrade my safety equipment: One of the things the new owners at CMP implemented was checking dates on safety equipment. My 6-pt harness and Hans device were expired. I replaced my harness with a rated Racequip 6-pt belt that I got from Naroescape Motorsports. I got my Hans recertified (new tether and sticker) at Discovery Parts in Dawson GA. You can just ship it to them and they turn it right around. Both vendors had exceptional customer service.

You'd think putting a new harness in would be "easy". Took about 3 hours by the time I removed some of the seat bolts and adjusted everything the way it needed to be.

[Rob T]

I was able to make it to CMP again yesterday. Weather was great, if a little windy. 50F for the first session, about 65 for the third. I drove 3 of 5 sessions. There was a 2 hour gap after the 3rd and before the 4th and I had a two hour drive to get home. A few more cars this time (about 20 in the run group), so multiple clean laps were harder to come by. Analysis to follow.

[Rob T]

Here are "stats" from round 2, my best round.

1:54.692 - a bit slower than last time, but track more crowded, so I didn't get as many clean laps. Also, 37 heat cycles on the tires, which are still holding up well and are good for practice.
9.8 gallons of fuel for 27 laps at 2.279 miles per lap or 61.53 track miles. 6.27mpg....
Braking g max: 1.06
Accel g max: 0.875
Left g max: 1.32
Right g max: 1.41
Calculated HP: 265
Calculated max TQ: 296
Max spd: 112mph

No issues with oil temp, coolant temp, AWIC temps. Trans temp got to 196F. Overall, a great day.

[J R Jones]

Rob, Rear axle nut torque?
jim

[Dave 53]

I noticed my right rear axle nut loosened up at the track several weeks ago (Big Willow Springs). A professional race mechanic friend that does Subaru rally cars said it's a common Subaru issue and the axle nut torque is "4 feet of wrench leverage and tight until it won't move". Tightened it up and hit the track the weekend before last (Thunderhill West). After Saturday, I noticed the nut loosened up just a bit, but I couldn't find the right socket in the pits. Just the right rear. After Sunday's sessions, I noticed it loosened up about 1/8 of a turn. Got home and it didn't loosen 1/8 of a turn. It loosened 1 1/8 turns! 6,000 road miles without a problem - this is a track car issue. Hammering the nut into the axle keyway isn't enough.

My friend suggested drilling and pinning the nut. I've done it on go karts and not sure I'm gonna do it on the 818. But of course, I will be bringing the socket to future track days and snugging up the nut with every tire pressure check.

If you track or autocross, I'd suggest taking the nice Factory Five axle nut covers off the wheel for regular axle nut inspections.

[J R Jones]

Dave,
My theory based on exhaustive discussion on the earlier failure is that the rotating tolerance in the drive splines allows micro-rotation of the shaft causing the nut to incrementally loosen.
The peen is not enough, perhaps safety wire would help. Since the right side is not loosening, MAYBE if the loosening side had left hand threads, the micro rotation would not be problematic.
jim

[Rob T]

From the previous session on 3/11, I noticed the left rear nut (the one that came off at VIR and caused all the excitement) had loosened just a bit against the peen mark. I snugged it back up before the track day on 3/25 and made the peen a bit more severe. I had torqued the nut to 160 ft-lb.and bent in the tab. No issues on the left front. All of the nuts are marked and I check them regularly.


I'll let Mitch Wright weigh in, but I believe he told me he used to put blue loctite on the nuts. This is a problem we need a solution for.

What does anybody think about tapping the nut at the collar and running a set screw into the keyway on the axle shaft?

[Hobby Racer]

What does anybody think about tapping the nut at the collar and running a set screw into the keyway on the axle shaft?

Ooh, that sounds like a good idea! I was going to go the locktite route but I like the set screw idea much better. The hardness of the shaft means the set screw should not damage the shaft at all.

The trick is you'll have the install the nut first. Mark where the set screw needs to go then remove and drill / tap it and reinstall. A bit tedious, but good piece of mind.

[J R Jones]

From the previous session on 3/11, I noticed the left rear nut (the one that came off at VIR and caused all the excitement) had loosened just a bit against the peen mark. I snugged it back up before the track day on 3/25 and made the peen a bit more severe. I had torqued the nut to 160 ft-lb.and bent in the tab. No issues on the left front. All of the nuts are marked and I check them regularly.


I'll let Mitch Wright weigh in, but I believe he told me he used to put blue loctite on the nuts. This is a problem we need a solution for.

What does anybody think about tapping the nut at the collar and running a set screw into the keyway on the axle shaft?

Rob, "No issues on the left front." Good to observe that but the dynamics are not the same. Yes the brakes arrest the wheel from turning but the spindle shaft does not decelerate or accelerate. It is (rotationally) unloaded.

The rear hubs are similarly arrested by the brakes but the hub and axle is coupled to the engine and transmission.
Whenever the drive is engaged to the engine, and you are not feathering the throttle, there is load into the drive wheel hubs.
The load reverses:

* Under acceleration the axle to hub is trying to spin the tires. Hard upshift = big load spike to the splines.
* Under deceleration, the hub to axle spline is spinning the engine. Hard downshift = big load spike to the splines.

When the splines wear, the rotational clearance increases and the torque spikes increase.
Expecting the nut to constrain the drive torque under racing loads is a leap of faith.
Tight splines are more resistant to this problem, I do not know if Loctite on the splines would survive. It certainly would complicate service.
jim

[Dave 53]

Ooh, that sounds like a good idea! I was going to go the locktite route but I like the set screw idea much better. The hardness of the shaft means the set screw should not damage the shaft at all.

The trick is you'll have the install the nut first. Mark where the set screw needs to go then remove and drill / tap it and reinstall. A bit tedious, but good piece of mind.

The nut is recessed into the hub, so there doesn't seem to be access to a set screw tapped into the nut. Doesn't look like there is enough meat on the collar for a set screw.

The method of peening the collar into the keyway might make a difference. So that it isn't just a smooth dimple, but the collar actually gets cut in a way that wedges against the key way like a fish hook.

Maybe other than peening technique, I'm not seeing a solution that doesn't require pulling the axle off the car to drill a proper hole. Doesn't seem to be a street driving issue - only a track issue. At the track, I'm going to inspect after each session and give it a snugging up if there is any movement. Easy solution - just gotta bring the socket and know to do it.

Interesting that on my car, it's the right rear loosening and on Rob T's car it's the left rear.

[J R Jones]

Rob, I have always had a keen interest in fasteners, and it is a broad subject.
I referenced my FFR Assembly Manual and it does not specify torque beyond installing the axle nut finger tight during assembly WT? The WRX blog states 162 lb ft.

I have used jamb nuts but I never realized the science of using them. This technical paper/video describes the optimum way jamb nuts are applied:
https://www.boltscience.com/pages/twonuts.htm

Near the end they are described as perhaps the best method of retaining nuts.
The thin nut nut is installed first and torqued to 30-50% of total torque or 80 lb ft.
Then the wide nut is installed to total torque.

You should visualize that when the thin nut is installed and torqued, the force is loading the nut outward from the hub.
When the wide nut is (full) torqued against the thin nut, the thrust against each other pushing out on their respective threads..
The retention advantage is that total torque is achieved between the nuts and across 150% of one nut threads. It seems to me that even if the shaft to hub is rotating, the nut retention is between the nuts, not the hub surface. If the shaft rotates cyclically the nuts turn with it, but not loosen.

This all assumes there is enough axle shaft for two nuts. You may have to make thin nuts from thick nuts.

What does Sgt Gator do to retain axle nuts in endurance races?
jim

[carnutdave]

I was on a Formula SAE team in college and we used locking spanner nuts to retain our front hubs in the hub carrier. They used a Nylon locking element and didn't need to be peened. We also used smaller Nylock nuts on the axles. Never had any issues with them loosening to my knowledge. I did a little digging and it seems the WRX axle nut thread is M22-1.5 (check out Dorman PN 615-160). McMaster Carr carries Nylock spanner nuts in that size, PN 3552N29 and may be worth a try. May have to make a tool that adapts the spanner flats to a torque wrench though.

[J R Jones]

Rob, Sometimes no reply is a reply.
We can agree track sessions is the most expensive way to test your prospective solutions. High risk too. Here is another suggestion.
Shop test your axle nut retention configurations and pick a winner Use "breakaway torque".
Assemble the axle nut to torque and remove it with the torque wrench. What is the breakaway torque?
Reinstall the nut and peen the interference tab. What is the breakaway torque?
Loctite the threads, I suggest red. What is the breakaway torque?
Install Nylock nut. What is the breakaway torque?
Install jamb nuts. What is the breakaway torque? This is more difficult as an effective test is breakaway torque applied to the innermost nut.
jim

[Rob T]

I like the idea. I have been tied up a bit lately and did not reply quickly. I have also been thinking about the idea. In my heart, I really like the positive stop idea, like the "fish hook" that was described above. I'm thinking: torque the nut. Mark it, remove it, then at the mark, use my dremel cutoff wheel to cut the outside peen edge of the nut parallel to the axle, reinstall the nut, then really bend the one end at the cut down into the keyway on the axle. This would provide a positive stop and not just a peened edge to be "rolled over". It would be relative simple to bend it back up when then nut needed to be removed.

[J R Jones]

Rob, cutting the lock flange would IMO weaken the material cross section.
Brainstorming: You could drill and tap the hub next to the torqued nut flat and install a socket head cap screw or a roll pin. It would likely be the perfect location once. Might work in subsequent installations, might need a second hole.
Kind of an act of desperation.
jim

[jforand]

I would be VERY CAREFUL with Red Locktite on the axle nuts. I have this issue on my Mustang and finally got annoyed enough to red locktite them. The next time I had to pull the nut off I tore up the driveshaft threads. This was of course the day before a track event and I spent all day running all over Atlanta trying to get the dye, a socket to fit it, and a new nut. Of course they formed the perfect triangle around the entire city.

Red locktite really is considered permanent unless you heat it and I think it is somewhere near 500 deg F when it liquifies. Not a huge fan of pouring all that heat to them. I use a lot of blue locktite, mark the alignment and keep and eye on them.

[J R Jones]

Rob, Red Loctite has been good to me, or perhaps I am lucky. I have even used green retaining compound in desperate times.

Safety wire is a traditional solution easier than some of our other discussion. It would be interesting to accumulate race time on a safety wired set-up, then, assuming it is intact, remove the safety wire and measure the breakaway torque. That would tell you if the stack-up under the nut is diminished, causing the nut to loose clamp load, (and loosen).
jim

[Rob T]

Lots of really good input here and a lot to consider. I always have the 32mm socket with me so checking it after every session is easy. The last three sessions, especially after I made the divot bigger, there has been no movement past the keyway.

[Dave 53]

Seems a castle nut is the answer.

On my go kart, I've drilled lots of nuts and bolts. We wired or pined any bolt that got hot and used Nylock nuts on bolts that stayed cool. Never used loctite. Castle nuts are preferred in locations that the nut has to routinely come on and off. On a go kart, the front axles because we would routinely make track width adjustments. A castle nut would also solve our 818 on a track issue.

To drill a proper hole in the axle, I'd put the axle in a drill press because the hole has to be pretty precise. The hole has to be at, for example, 12:00 and 6:00. If the hole is misaligned, if it's at 12:00 and 6:30, the pin wont got through. I've never had much luck freehand drilling a bolt with enough precision to use a castle nut.

I'm not gonna pull my axle just to drill a castle nut hole, but next time it's off for some other reason... Until then, routine checks between track sessions.

[Sgt.Gator]

Up to now we haven't done anything outside the Subaru FSM to secure our axle nuts on both the 818 and the STI. The simplest additional would be to use Loctite. I no longer use Red now that they have Orange. At PRI 2019 the Permatex engineer said the Orange is as strong as Red but can be broken free with normal hand tools, no heat required.
For it to work the axle obviously can't get too hot. I'll put our IR thermometer on them at our next track day to see how hot the nuts are getting. I'm guessing that if the wheel bearing is failing that will heat things up. Maybe a good indicator? Just guessing here.

[Rob T]

Thanks Gator. That will be good to know. I know how hot my rotors are after about 3 minutes. Just shy of 300F with an IR. No real science, but a data point. No way the axle or bearings would be that hot strictly from braking, and for me, I am only driving up to 25 minute sessions.

[Sgt.Gator]

It may be worth noting that the axle nuts are one time use nuts. You're supposed to throw the used ones away and use a new one anytime you remove and install them. I keep a couple of old ones around for the Cam gear weld on nut trick.

https://youtu.be/WjZ0XtLYtzc

[J R Jones]

Sgt Gator, That is a terrific fix but also an excellent repair video. That guy knows his craft and how to demonstrate in less that 180 seconds. Great communicator.
BTW I pulled the oil pump (in-car) on a Wisconsin H6 with 180K miles. I had to weld-extract eight (of 64) M6 cam cover bolts.
jim

[jforand]

Great video on the cam sprocket bolts. I have personally had to do it three times. Worst designed bolt ever! The allen head is simply not capable of dealing with the breaking torque generated by that large flange. I would love a Hex or Torx alternative.

[Sgt.Gator]

Great video on the cam sprocket bolts. I have personally had to do it three times. Worst designed bolt ever! The allen head is simply not capable of dealing with the breaking torque generated by that large flange. I would love a Hex or Torx alternative.

Here you go, TIC FU Cam Bolts. They are sold by many of the tuners, Outfront, FastWRX, IAG, Flatirons...but may not be in stock. Call before you order them.

https://www.outfrontmotorsports.com/cam-bolts/tic-fu-cam-bolt-kit-single-avcs

https://www.flatironstuning.com/tic-fu-cam-bolt-kits

[jforand]

Ah, super awesome. So I think I remember torquing to a specific value and then it was another 45 degrees. This is the classic instruction on a torque to yield bolt. 52 bucks a pop gets steep, but then again I think the Subi ones are 8-10 each as well. Maybe they aren’t torque to yield and then a one time purchase ends the saga. I’ll have to research

Thanks.

[Rob T]

Track day today at CMP. 5 cars in my run group. Perfect weather. It doesn’t get any better. Did three sessions of about 7 laps each. Car ran great. No issues with oil temp or loose axle nuts. More to follow.

[Rob T]

It took a me a while to get my data analyzed from the 4/22 track day. Life has been busy and I will not likely have another track day until August at the earliest. Overall, a good day with three sessions and a total of 25 laps. I used 10.2 gallons of gas. After today, I have 40 heat cycles on my Federal Tires. Tread still looks pretty good and my times have not dropped too dramatically.

Best Lap: 1:54.198
Best Theoretical Lap: 1:53.087
Braking g's max: 1.11
Accelerating g's max: 0.84
Right turn g's max: 1.38
Left turn g's max: 1.37
Horsepower max: 259
Torque max: 304
Max speed: 111.61
Highest average lap speed: 71.99

Oil time, Water temp, pressures all good.

[Sgt.Gator]

Those are impressive Lat G's for old heat cycled Federals! You're doing great. Maybe time to get some A7s and head for Road Atlanta!

[Rob T]

Keep in mind that those are "max" numbers per session. When I look at the friction circle and the "cloud" of data points, there are a lot of values in the 1.25g range, which is still really awesome. The filtered data has me at a solid 1g+ on the longish sweepers. And that's me driving at 7/10.

The cool thing about these tires is that they have been extremely consistent for me and, of course, a great value.

[Rob T]

Happy Father's Day. Got this from one of my girls.
168332

[Rob T]

Track Day! I made it to the Carolina Motorsports Park for a track day yesterday. Weather was perfect with 70-80F temps and pretty light winds. About 10 cars in my run group. I ran three sessions and had a blast. More to come after I get a chance to analyze the data. Car ran very well. Water temp was about 85F, Coolant was 185, AWIC supply got to 95F with the Air Temp to the engine at 109, but I had no issues with timing being pulled.

[Rob T]

Here is an update from the track day. I drove a total of 27 laps, 21 of them "hot". At the end of the third session, it marked 43 heat cycles (sessions) on my tires. Still some tread left and still very consistent.

Best Lap: 1:53.349 - within a second of my best lap of all time.
Braking g - 1.02
Accel g - 0.78
Left g - 1.35
Right g - 1.42
HP (calculated) 252 in the third session.
TQ (calculated) 345 in the third session.
Max Speed - 113

Trans fluid got to 205 at the end of the third session.
12.45 gallons of gas burned - or 4.95 mpg (this includes some warm up time, moving the car to tech, etc...)
No issues with oil temp or pressure fluctuation with the third scavenge pump running. For this car....oil problems are solved.
Next Possible opportunities for me are 10/7 or 12/10.

[Rob T]

Here is a video of my best lap from session 2.

https://youtu.be/SW08BtCMO6c

I'm still learning to drive better....

[Rob T]

Track Day tomorrow at CMP. Weather looks perfect. 11 people in my run group. I've gotten a few pointers from Mitch Wright after my last sessions, so I have some new things to try. More to follow.

[Hobby Racer]

Man I'm jealous. It's going to be a long winter getting my car back to racing condition.

[Rob T]

Initial Report: Car ran great. Temps were between 55-75F. I pushed the car harder than I have, using Mitch's suggestions and ran the best lap ever at CMP. 1:51.8 Last time there was a 1:53.2 I also played "tag" with a Caterham driven by one of the instructors. I couldn't pass him, but he couldn't get away. He estimated we were running low 1:50's based on the fact that he works at the track. He said he was running hard....unfortunately, my Traqmate datalogging computer was not working that session, so I have no video or data. More to come when I process everything. When pushing hard that last session, my water temp was 195, Oil temp was 200 and the temp after the AWIC was 115, but there was no timing adjustment. It was a fun day.

[Sgt.Gator]

It's great you have the car sorted and can concentrate on driving it closer to the max. Now get your SCCA or NASA Competition License and do some Time Trials!

[Rob T]

Here are some stats from the track day:

Ambient Temp: 60-70
Highest AWIC water Feed: 95.8, corresponding to an air temp to the engine of about 115
Trans Temp - measured in the fluid line. 207
46 heat cycles on the tires at the end of session 3.

Best Lap: 1:51.830 - Best ever for me at CMP
Braking G max: 1.27
Accel G max: 0.73
Right G max: 1.28
Left G max: 1.49
HP max: 264
TQ max: 311
High Speed: 114.77
Avg Spd: 73.56
Theoretical Best Lap from all Session 2 Laps: 150.775

Probably My tightest grouping of decent time for the seven full laps:

1) 1:53.797
2) 1:53.418
3) 1:51.839
4) 1:53.274
5) 1:52.279
6) 1:52.301
7) 1:51.830

The last track day, my BEST times for three sessions were 1:55.388, 1:53.349 and 1:55.325. Thanks for the pointers Mitch!

I think session 3 was just as good as session two, but my data logging was frozen. Seems to be working OK now. Next possible track day for me is 12/10. Video to follow when I get it processed.

[Rob T]

Had the car on the lift yesterday for pre-season maintenance. Oil/filter, transmission fluid, brake fluid, general safety inspection. Found and repaired the drive pulley for the dry sump pump moving away from the pump on the shaft about 1/4". Hope to make a track day on Friday 2/24....

[Hobby Racer]

Good catch on the pulley, that could have been catastrophic. Here in the north east we won't be heading out to the track until April / May :(

[Rob T]

Had a good track day on the 24th. It was 75 and sunny. All of us there recognize how fortunate we are to be on track this early in the year. First session was a little tough. It had rained the night before and the track was still wet. Coming out of the carousel on the first "green" lap I decided I wasn't done "spinning" and got caught by - driver error (me), surging turbo boost (cool morning), cold tires that sat all winter, and a wet track. Result: Snap oversteer to full backward and off the track. I spent the rest of the session about 50 feet off the track because there was no safe way to get back on. No damage to the car. Expected damage to ego....Funny thing was I was really taking it easy. Clearly not easy enough. By the time the next sessions came around for me, the track was dry and things returned to "normal". That day for me was a clear indication of how "good" the "nannies" are - anti-lock brakes, traction control, yaw control, throttle blipping, etc. My car, by design, has none of those, because I wanted to really "drive". I got a really good lesson that day, for a good price.... I did talk to several HPDE instructors that day who told me that the "nannies" can do some amazing things but that they wished everybody had to learn in a bare bones Miata. More analysis and video to come. My education, AND fun continue.

[Rob T]

Headed to CMP tomorrow for a track day. Weather forecast is perfect.

[Rob T]

I had a good track day yesterday. I am feeling like the car is sorted out now and I can focus on driving. No issues with oil pressure, oil temperature, or coolant temps. There were about 10 cars in my run group at CMP. Temps were 60-75. I did three sessions in the morning with about 40 minutes in between. If you remember back a bit, my variable speed fuel pump regulator started to flake out. I bypassed it with a single relay and a switch on my dash. It works great for my purposes. I like that I can leave the fuel pump off and crank the car until the oil pressure comes up.

Some non-car data: I wear a Fitbit. During the track sessions my heart rate averages 122bpm and the Fitbit thinks I am "outdoor biking". My resting heart rate is 58....hard treadmill workouts are in the high 160's.

More track data to follow. The instructor at the driver's meeting made a great comment yesterday. He said "What are you here to learn today? This is HDPE. If you are not trying to learn anything, you are just wasting tires and gas. Pick a corner and try to learn something."

[J R Jones]

Googled it: High Density Poly Ethylene
I guess you had to be there.

[RPGs818SNA]

Maybe NASA's HPDE? https://drivenasa.com/hpde/

[Rob T]

Sorry for the confusion. I am a chemical engineer. I typed "HDPE" - High Density PolyEthylene" I meant to type "HPDE" - High Performance Driver Education. At CMP there are three run groups on TurnOne track days. A novice group, with instructors and classroom, a solo group and an advanced group. ALL passing is done by point by. In the novice group, passing is allowed on the long straights. In the solo group, anywhere the wheels are "straight" and in the advanced group, anywhere on the track. I run in the solo group.

[driveslikejehu]

Did you improve your time over last year? I see your best last October was a 1:51.8. Which I think is pretty good.
I've only been to CMP once, last May, with my Cayman. My best time was 1:54.3. Probably could do a bit better with more time on that track.
I'm always interested in what times folks are getting with the 818 compared to the Cayman.
Hoping for a first outing with the 818 next month at Blackhawk Farms here in Illinois.

[Rob T]

Track Day tomorrow at Carolina Motorsports Park. Hope to get three morning sessions in before 11:30. It supposed to be 95 tomorrow by the afternoon, but should be in the 70's when I start.

[Hobby Racer]

Track Day tomorrow at Carolina Motorsports Park. Hope to get three morning sessions in before 11:30. It supposed to be 95 tomorrow by the afternoon, but should be in the 70's when I start.

Good luck & Have fun!

[Rob T]

Sorry for the slow reply. I left for vacation the following day. Had three great sessions. The track was experimenting with a Monday track day. It was good for me. Only four cars in my run group, so basically an open track. Got to "play cat and mouse with a Corvette". He was a bit quicker on the straights, but I got it all back in the braking zones and the turns. He told me later that it was the fastest he'd run there. I was a bit slower than my best, but still OK and really fun. The weather was the hottest I had run this year. The last session was 90F. Highest water temp was 206, Highest oil was 204. The water to the AWIC after the front radiator and pump was 106 and the AIT was 124. No issues with timing being pulled, etc. as I monitor that on my COBB real-time. The trans fluid got to 206. Like Gator, my temp issues seem to be solved, although I am running 20 minute sessions, not hour long events. For calibration, this data was from my third session and there was about an hour between sessions. At there end of the day, there were 55 approximately 20 minute sessions on my tires....A great day overall.

[Rob T]

Headed to the track (Carolina Motorsports Park) tomorrow. Weather forecast is perfect. Start around 60 with high around 80. More information when I am done...

[Rob T]

Had a great track day yesterday. Weather was perfect. No issues with the car. Temps started about 60 and got to about 70. I did three sessions of about 20 minutes each. High temp for coolant was 190. Same for the oil. IAT high was 111. The supply of water to the AWIC hit a high of 91. High temp for the trans was 211 at the end of the third session. The three sessions were all in the morning with the first one starting 8:50 and the third one ending at 11:00, so the car never really cooled down during "breaks". I'll post some more performance data when I get it. BTW, running Redline Race 50wt (really 15W50) I am seeing no less than 85psi on the track and around 35-40 psi at idle after the session.

[Rob T]

191148191149

Some Pictures from my last track day.

[Dave 53]

Nice pictures. Any video you could share?

[Rob T]

Here is a link to my best lap on session 2. 57 heat cycles (20 minute sessions) on these Federal Tires.

https://youtu.be/B1U_dYLRvM0

[Rob T]

Track Day tomorrow. Carolina Motorsports Park. Cloudy skies, high 72. Data to follow afterward.

[Hobby Racer]

Man, high of 34 here tomorrow. Very jealous! Have fun.

[Rob T]

Good Day! Three sessions (my normal) and then packed up and headed home. Got sprinkled on most of the way home, so glad I didn't stay at the track. Conditions were very good. Started about 65 and got to 77F with some very gusty winds that moved the car a bit. Today I experimented with lower "hot" air pressure than I have been running. Lap times were a bit better, but what was most noticeable was how the car approached the limit. The tires felt much more linear as they started to slip sideways. More to come on that experiment. I'll post some data a video later.

[Dave 53]

Thunderhill West for me tomorrow. I'm used to 5 20 minute session with several run groups. Tomorrow is 2 run groups and 9 20 minute sessions! I'm gonna do my best to do all 9.

25 hours of Thunderhill starting tomorrow on the East track.

[BigDanSubaru]

Man, I bet the sound in the driver's seat is wicked with the intake right next to your ear. Love the Martini vinyl design.

[Rob T]

I have Chad Plavan to thank for the Martini design. I get a lot of complements. As for the sound, helmet plus earplugs are a necessity. Yes the sound is pretty awesome. If you go back a bit in my thread, you can hear it in the video. The camera/microphone is right behind my head, dead center.

[Rob T]

Here is a link to the video of my best lap at CMP on 11/10/2023.

https://youtu.be/kwI3drvcLT0

3 session Maxes:
Left g's: 1.29
Right g's 1.23
Braking g's: 1.14
Accel g's: 0.73
Max Speed: 112.1
Highest trans temp - fluid: 200F
Highest AWIC water feed: 100 with a 115 AIT.
Ambient Temp 65-75F
Oil Temp Max: 200F
Water Temp Max 195F

[Rob T]

Track days are fast approaching with my first potential day on 3/8/24 at CMP. To get ready I had the car on the lift this week. 1) Oil/filter change - fresh Redline 50wt race. 2) New transmission fluid in the 6 speed. 3) Rebuilt the rear Wilwood brake calipers. A few of the pistons were sticking. I swapped out a few new pistons and installed new o-rings all around. The first caliper took two hours. The second, under and hour. Very smooth operation now. 4) Replaced all of the hose from the remote brake fluid reservoir to the master cylinder. After 9 years the hose just cracked and I found it leaking after the winter. This lead to some tight space work and some creative reconstruction, but now good as new. 5) Got some new Federal FZ 201's. I got 61 20 minute track sessions on the old tires, so it was time for some new ones. Phil's Tire Service had a sale and got all four tires, heat cycled, shipped and mounted/balanced at a local shop for $750. 6) Cut the old oil filter for inspection. Not a single speck of metal found. 7) Did a thorough once over on the entire car - suspension bolts, bearings, brake pads, hose clamps, etc. Everything is ready to go. When I get the boots for the front calipers, I have the O-rings to rebuild those as well. I'm looking forward to getting back on the track.

[jforand]

Sounds productive! Be safe out there. That is some serious mileage out of those tires!!

Mine is getting close. It is rapidly coming up on 3 years since it grenaded at VIR with you and the others. Last trip home I got it to a tuner and dyno’d. Still more to tidy up and then shake down. Hope we can all get out there again sometime in the future.

[Rob T]

Track Day Update: I went to the track on 3/8 and stopped after the first session. There was a lot going on that day: New tires, track was cool and a bit wet, I'd rebuilt the brakes....anyway, during the first session, when I would accelerate hard or lift, the car would "step left". It was very unsettling. I was not sure what the problem was, so in an abundance of caution, I packed up for the day and came home. After talking to a few folks, I did a few things....I replaced the nuts on the rear axles and verified the torque. I had not done this since changing the hubs a ways back. I also checked the toe on the rear wheels. I found that the toe in on the right rear was about 5/8" and about 1/8" on the left rear. I made them both the same at 1/8". Then I took the car out on the local roads and it felt good. I don't know when the right toe changed, but when I think back, the car was always a little unsettling. I had chalked it up to wind impact on the wing.

Today 4/26 was another track day. I had the new tires, cool conditions, and the "repaired" toe in on the rear. The car felt "planted" and more stable than it has ever felt. As confidence built, I was able to push harder. My best time in the first session was 1:59.476. Second session was 1:53.994 and third session at 1:53.054. What was cool was the consistency in the third session: Lap 3 - 1:53.545, Lap 4 1:53.285, Lap 5 1:53.054 and Lap 6 1:53.093 The Theoretical Best Lap for Session 3 (the best time of each segment) was 1:51.885, so I know I have more to go get.

I recorded one of my fastest speeds on the track at 116.05, and was pulling 1.29g going left and 1.21g going right with 1.11g braking. It was great to be back out on the track. The three scavenge dry sump is working excellently and there is no drop in oil pressure at any point on the track.

I hope to get back out either 5/10 or 5/24, the next possible track dates.

[Hobby Racer]

Great to hear it's coming together for you!

[Rob T]

Finally made it back to the track on 8/17. Three sessions. Overall a good day. It was warm and the track was basically unused for about three weeks, but we've had a lot of rain. I will publish data, but I was a couple of seconds slower than the last session in April and figured I was just rusty. Interestingly, I talked to some of the instructors from HPDE who commented that it was their slowest day on the track by 2-3 seconds EVER, and suggested it was due to lack of rubber on the track from low use and a lot of heavy rain. Overall, car ran well. I have a nagging small coolant leak on the front of the engine under the intake manifold, passenger size. No liquid, but I can hear it when the car is hot and I come off the track. There is also some "staining" or discoloration on some of the suspension components on that side of the car. I run distilled water with water wetting. Any ideas for what might be a likely culprit? More to come.

[mikeb75]

The coolant crossover pipe? It houses both the temp sensor and a small T that I believe is used in the throttle body warming/cooling loop? There are gaskets that seal the aluminum pipe to the block in 2 places. Otherwise, have you checked your upper coolant reservoir for cracks around the pressure cap... if it's OEM (cast metal) it can hairline crack... mine did a lifetime ago.

[Rob T]

Here are some pics of the area I think the leak is. Passenger side, front of the engine. This is the general area.
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More details
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I run Red Line Water wetter and distilled water only. The leak is small... During the three sessions I lost about 1/3 of the overflow bottle. After a session, I could hear the leak, but not see anything. There is never a puddle, and the system always stays full and pulls water from the overflow bottle.

[mikeb75]

Thanks for the pics!
First pic is your upper coolant reservoir, and that's not an OEM one.
3 and 4 pics are your Intake cam ACVS solenoid (variable valve/cam timing) and that banjo bolt is connecting to an oil line/gallery. Don't think the leak is from that, as it'd be an oil leak not a water leak.
I'd focus on checking the clamps, hoses and barbs of the upper reservoir.

Also, how is the tube plumbed into the overflow bottle?

[Dave 53]

Check the turbo cooling hose. The one that has the heat shield on it. The lower end is very close to the hot turbo. It's hard to see a leak unless you look from under the car. I carry a spare of that hose to the track.

[Rob T]

Found the leak....after I pressurized the system. Here is the orienting picture..
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Here is where the leak was....
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Mounting bracket on the back of the aluminum collection box. Bad news was that it was a bugger to find. Good news is that it never would have failed catastrophically....opted for a JB weld solution first, before trying to weld the aluminum with its inherent challenges (for me). I am going to slot one of the mounting holes to allow a little movement and try to keep some of the stress down. Leak is visible on the far right of the mounting bracket. A hairline crack at the weld edge.

[Rob T]

Track day yesterday at CMP. 8 cars in my run group, so basically an open track. Car ran great. No coolant leaks. Temps in the 70's. More data to follow.

[Rob T]

Track day at CMP on 10/17. 9 cars in my run group. It was cold. About 40F for the first session, with 55 by the third session. Took about 3 laps to get the tires up to temp. The turbo loves the cool air. Coolant temp was 163F and IAT was 87F max.

[Dave 53]

Track day at CMP on 10/17. 9 cars in my run group. It was cold. About 40F for the first session, with 55 by the third session. Took about 3 laps to get the tires up to temp. The turbo loves the cool air. Coolant temp was 163F and IAT was 87F max.

What's on the post track day to-do list? I've yet to have a track day without some item that needs attention before the next track day. Curious what others are experiencing. My new clutch arrived yesterday and I'll start the installation a bit later today.

[Rob T]

Good Question. I only really had one issue. My push lock button that holds the hood on the driver's side in the back was jammed and I didn't realize it. That caused the hood to lift and cut my first session short. I am going to put a bit of oil on all of those to make sure they don't stick. I also plan to see how the repair to my coolant tank collection box is holding up. Other than that, a quick run-through of fasteners, brake pads, etc. I generally run only three sessions per outing of 20 minute duration.

[Bob_n_Cincy]

Track day at CMP on 10/17. 9 cars in my run group. It was cold. About 40F for the first session, with 55 by the third session. Took about 3 laps to get the tires up to temp. The turbo loves the cool air. Coolant temp was 163F and IAT was 87F max.

Rob, Is your IAT sensor before of after the AWIC?

[Rob T]

After. I also have a sensor in the water feed to the AWIC. Generally, I get Ambient +15 degree water temperature to the AWIC heat exchanger and +10 degrees above that For the air going to the engine after the AWIC. My car has a separate radiator in front of the engine radiator (coldest air) for the AWIC water loop. I have also T'd into the AWIC water line after the intercooler and bypass a small amount of water through a tube in shell heat exchanger that cools the 6 spd transmission. With the low flow to the tube in shell, it did not have a negative impact on the AWIC water loop temp.

[Rob T]

As an additional point, I have only seen one track session where timing was pulled (indicated on the COBB Accessport I have on the dash). It was 95F ambient with higher temps on the track. Other than that, full timing has always been available with this set up. This is also a speed density tune, running 93 Octane gas.

[Bob_n_Cincy]

As an additional point, I have only seen one track session where timing was pulled (indicated on the COBB Accessport I have on the dash). It was 95F ambient with higher temps on the track. Other than that, full timing has always been available with this set up. This is also a speed density tune, running 93 Octane gas.

Thanks for the numbers.
I only have 2 spare ECU inputs so I use them for oil pressure and temperature. (kinda important)
My air intake is snorkeled to the right side vent so my MAP/AIT sensor gives me track air temp. I can wire that temperature sensor wiring to a sensor right before the throttle body. That may affect my tune.
Here's a picture of the Sirrocco radiator I use for the AWIC.

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[Dave 53]

My air intake is at the wheel vent. Speed Density (intake temp at throttle body). AWIC. 91 octane gas. No knock detected.

107 degree day, 100% throttle, 4,771 rpm: Intake temp 196, 13.7 psi boost, timing 4.5.

54 degree day, 100% throttle, 4,786 rpm: Intake temp 122, 17.4 psi boost, timing 11.5.

I've asked my tuner at what intake temp should I limp mode. Oddly, he won't give me a hard answer. The ECU deals with it.

[Rob T]

I remember my CA 91 Octane days. Everything here is 93, so that helps. My air intake is right next to me, where the passenger's head would be if I had a passenger seat instead of a fuel cell....

[Rob T]

Getting ready for the 2025 track season: Changed oil/filter, new trans fluid, new front brake pads (bedded now) and rears were at 10-11 mm of 12 start. I have the Wilwood brakes. The fronts use 16mm pads and the rears use 12mm pads. I have been using new pads on the front and moving the "worn" front pads to the rear. Still plenty of use left in them. They are identical other than thickness. Also did full inspection of all nuts, bolts, etc.

[Rob T]

Almost a track day today. Weather was beautiful. Got back from tech and noticed a small water puddle on the trailer on the passenger side starting about 18" behind the left front wheel. I always warm the car up on the trailer, and with all the work I have done, I've not seen that before. I run water in the radiator and not antifreeze but do add some water wetter. Rather than risk a catastrophic failure on the track or putting water down in front of my rear left tire, I decided to load back up and come home. I didn't want to be "that guy" that cut a run group short. There are pipes in each of the fiberglass "side sails" outside the frame. I expect getting at the leak is going to be a challenge.

[Hobby Racer]

Sorry you didn't get on track. I have had those side pods off more times than I can count. I am so glad I did not rivet any of the body panels on my car. Makes maintenance so much easier.

[lpmagruder]

I had a junction to that corrugated hose start leaking over winter, the one driver side front inside the side panel.

I was able to cut an access panel behind the fender liner sheet metal and snake my hand in to tighten.

Next time I have the sides off (realistically, whenever I get around to painting) I'd like to replace the hose clamps with either those gates heat-shrink style, or at least double up on some wide clamps.

I remember spending a ton of time chasing down minor drips from those junctions when I first got it running, I had to get the hose clamps much tighter than I would usually tighten them.

[Hobby Racer]

... gates heat-shrink style ...

I used them exclusively and have never had a leak. I definitely recommend them!

[Rob T]

I ended up cutting a 4X4 hole in the side skirt in the front wheel well. As I was investigating, this bit of fiberglass is getting "shelled" on the track and is wearing away. Now that I have the access hole, I am going to build a sheet metal cover for this portion (to take the rock, sand and rubber hits) and make it removeable by glassing in some metal so I can use a fastener. Believe it or not, this course of action was far easier than removing the body panel. I was able to reach the hose clamps easily with the access hole.

[Rob T]

I ended up doing both sides of the car. As long as the patient was on the table.....there was another set of clamps I could not access on the passenger side. A little bit of "farm engineering" on the repair. I ended up using some 10ga aluminum sheet (could bend by hand and easy to cut) and Rivnuts. The fiberglass is variable thickness and not "flat" on the inside. I tested the Rivnuts on one of the coupons I cut out with my oscillating saw. On the thin fiberglass, I put a back up washer in. On the thicker, I did not. They are solid and do not twist. This is really not a structural application, so I hit the "easy" button and the rivnuts seem fine. I now have access AND some material that will stand up to the beating from sand, rocks and track rubber at the back of the wheel well. Note that the plate has a 90 bend on it and bends around the bottom. This added structure to the part and protects the corner.211865211866211867211868211869 I got a little smarter on the second one and made the hole a bit smaller with a bigger "frame" around the hole to attach the aluminum plate. That just made it easier to do the rivnuts. I have the "two wrench" rivnut tool, not the pneumatic one.