Rob T's 818R Build Thread

[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..
IMG_8567.jpg

Here is where the leak was....
IMG_8578.jpgIMG_8579.jpg

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.

awic rad.jpg

[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.IMG_8985.jpgIMG_8986.jpgIMG_8989.jpgIMG_8990.jpgIMG_8991.jpg 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.

[Rob T]

4/10/25 - Had a successful track day at Carolina Motorsports Park. Weather conditions were perfect. 15 cars in my run group. It's been a while since I have been to the track, so was working out some of the kinks. Car ran well. More to follow. It was the very beginning of a "Gridlife" weekend. Lots of interesting cars and people not normally at this track were in town.

[Rob T]

5/23/25 - The track day that almost was....Had the car loaded ready to go, heading down road at 4:45am (still very dark). At the first stop sign, 1/4 mile from my house, all the lights on the trailer went dead. No way I was going to drive with a blacked out trailer. Today will be troubleshooting mode to find the short(s). Bummer. The weather was going to be perfect, and it was test/tune day, so 30 minute sessions sorted by engine size.....Keep reminding myself that everything happens for a reason.

[Rob T]

Update: Dug into the trailer wiring. Found almost the entire back section (2 left marker lights, 3 center marker lights, 2 right marker lights) wire melted, along with the two prong plugs on the lights. Looks like one of the plugs came out and dead shorted. Not sure why the wire burned/melted, but most of the insulation is gone from the copper. Parts ordered to rewire the entire back of the trailer....

[Sgt.Gator]

Well that's a bummer. If it had been mine there would have been 50 gallons of race gas next to it!

[J R Jones]

Two years ago I bought a used Honda Ridgeline. Some time later I rebuilt a trailer dolly to pull behind our RV. I attempted to test the new dolly lighting with the Ridgeline. Not all the features worked and after rechecking my installation I found a lack of power on the Ridgeline seven pin socket. With a Google search the Honda schematic revealed an accessory fuse block in the engine compartment, devoted to the trailer plug so that a trailer wiring failure would not take out the truck fuses. My accessory fuses were (previously) blown. In your case I do not know how that level of shorting did not take out your fuses, or did it?
jim

[Rob T]

This was very curious, but a case of ignoring some warning signs...A few month ago the running lights didn't work. Found a blown 7.5A fuse. Replaced it as a "one off". Trailer lights worked fine for several trips. This time when I hooked up the trailer, no lights at all. Went to the Aux fuse box, the 20A fuse next to the 7.5 was "exploded" - like it burned up. Also partially melted the fuse box plug in point itself. Also the 7.5 blew. the 7.5 is for the running lights. The 20A is for brake and turn lights - all just the trailer. My working theory is that a plug came out of the marker light on the right side of the trailer (running light) and caused a partial short. Not enough all the time to blow the 7.5 fuse, but enough to heat things up. Ultimately, the wire melted/burned away, but also impacted the turn signal light (a three prong plug) and caused that to dead short. The insulation was gone from the running light feed wire all the way across the back of the trailer. So....solution is new plugs, new wire across the back of the trailer....that work is in progress.

[J R Jones]

Rob, In my experience 20amp fuses are for motor, solenoid and brake devices. That is high amp for lighting. The intension is to sacrifice the fuse and save the wire harness.
Are your electric brakes OK or is that circuit powering your lights?
jim

[Rob T]

Brakes were OK. There is another fuse for the brakes.

[Rob T]

Track day today at CMP. Went well. I did three sessions. Start temp was 75, but it was 90 by the third session. Oil temp was 210. My AWIC feed water was 102 and I was seeing 118-124 temps after the intercooler. Highest coolant temp was 205. It looks like I got all my slow coolant leaks taken care of. I shadowed a Miata the first session to see how he drove some of the corners I was struggling with. They have to carry momentum to be fast. The next session, I kept that line, but didn't follow the Miata and dropped almost 6 seconds off my time shadowing the Miata. Got within a couple of seconds of my fastest time ever. Last track day was April, so I was a bit rusty. Also, 90 degrees in sun, a helmet and full race suit (no cooling) is HOT.

[Hobby Racer]

... Also, 90 degrees in sun, a helmet and full race suit (no cooling) is HOT.

I was suprised at the amount of cooling I got @ VIR in the 90+ weather. So long as I was moving I did not got hot. As soon as I came into the pit though, meltdown...

[Rob T]

Yeah...too much to concentrate on while on the track to feel hot. It really hit when you stopped driving.

[Rob T]

Some stats from my time at CMP:
Best lap: 1:53.232 - I had a few of the best laps I've had in a while.
Braking G max: 1.13
Accel G max: 0.61 (power a little off in the heat)
Left turn G max: 1.32
Right turn G max: 1.35
Max speed: 112.5

Won't be able to get back out until September. But I'll be ready and excited to go.

[Rob T]

Here is a link to two good laps from 6-28-25 session at CMP. I spent the first session and the first several laps of this session shadowing a Miata running around 1:58 or so, but learning the line he was using. I passed him just before this video begins:

https://youtu.be/xKy7vFE9LHI

[Rob T]

9-12-25: Made it back to CMP today. Weather was perfect. Car ran great. I forgot the SIM card for my Traqmate data logger, so no video or lap timing. I used that to really focus on the driving. I feel like I made some progress on a few of the turns that have been plaguing me. Overall a great day. I did my typical 3 sessions. There is another opportunity in two weeks, weather permitting.

[Rob T]

Had a great track day today at Carolina Motorsports Park. Weather was perfect. In the third session (of the three I drove), I bested my best lap time every by a few hundredths of a second. Car was running great. I am experimenting with tire pressures. Next time out I will try a bit lower. Today I was 35 front, 38 rear hot temps. All of my fastest times are with this pressure. I have driven 82 twenty minute session since 6/5/20.

[Rob T]

Another track day yesterday at CMP. Again weather was perfect. 12 in my run group. There was a Challenger/Charger with the 800+ supercharged motor set up for track duty. Some interesting comparisons....His car 4,400 lbs, mine 2200 with me in it. His car 800+ horsepower, mine 285. His car 10 gallons of gas per session, my car 3.

Car ran well. Lots of power in the cool air. Worked on tire pressure to see if I could find the optimal grip. Car feels balanced. More facts and figures after I get to analyze the data.

[Hobby Racer]

... There was a Challenger/Charger with the 800+ supercharged motor set up for track duty...

I gotta ask, how quick was he?

[Rob T]

Ran away from me on the straights, but was a bit slower than me in the corners, but once past me, I could never catch him. He had done a lot of work to get this car ready for the track. No seats, completely redone suspension, lots of engine mods. It was a monster. It's just fun to see the different ways to approach speed. The penalty for big mass is high when measured in consumables (fuel, brakes, tires, etc.)

[Rob T]

I ran my best lap time ever at CMP. It was a 1:51.601. This is the quickest lap by 0.2 seconds. I started that session with hot tire pressures of 38 rear and 35 front and ended the session with 40 rear and 36 front. Here were the fastest three lap times: 1:52.766 (lap 6), 1:51.601 (lap 7), 1:51.969 (lap 8). For the third session I let some air out after the second session. This gave me a hot start pressure of 39 rear and 35 front with a finish pressure of 39 rear and 35.5 front. My three fastest lap times were: 1:54.980 (lap 3), 1:53.578 (lap 6), 1:53.748 (lap 7).

The second session had higher tire pressures by about 1 psi and all my fastest times have been at that pressure. Seems counter intuitive, and I'd like to hear some thoughts from the forum. I am running Federal FZ-201M 100 treadwear tires.

Max speed for the day was 117.1 with a calculated max HP of 249 and a max torque of 295. Left and right turn "g" of 1.25 and 0.99g of braking. I am seeing about 12 degrees of temp increase from the AWIC feed water to the IAT. Highest IAT was 110F with ambient temps around 75F.

[Bicyclops]

What size are your tires, Rob?

Ed