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I was thinking of higher spring rates, as I think they were planning on using a sway bar and we are not. Also the aero puts more of a load on the rear, from some photos particularly Brandons, the rear looked like it squatted at speed, that would raise the splitter and cause an aero push. I was thinking higher rates all around with less front to rear split. Just thinking outloud.
I must say, I really do like what the scoops do for it. They make it look more aggressive IMO.
I did a few little changes to the suspension over the weekend. A few adjustments, and other secret stuff.
Since I could not test last weekend (The group was full) I'm not racing at California Speedway this coming weekend. I did not want to tow 6 hours and chase my tail if things were not working right like at Buttonwillow. It kinda sucks, but on Friday I will be testing a Buttonwillow again and instructing a Gentleman with a Cayman R.
Alot of things will be getting tested (Scoops, Insulated oil cooler box, Mechie's new rear top vent, suspension). Keep your fingers crossed that the oil temps are hopefully fixed! That way I can focus on driving and tuning the suspension for once.
Lots of good stuff Chad, hopefully this time is the one.
Will you also be testing Mechie's front hood enlarged louvers?
400lb with wing, 300lb without on the back. And generally everyone applies too much downforce to start. Ask me how I know.. :rolleyes:Quote:
Originally Posted by D Clary
Stock springs at the rear are 500 with the wing. I'm higher than that now. Car was leaning way too much for me.Quote:
Originally Posted by bstuke
If you can balance it, you can use the down force. it is just easier to gain in the rear with a giant wing than with a small splitter. Keeping the splitter on the ground is the key to how much rear you can add as the wing is mounted behind the axle.
Preliminary Redneck aero-yarn-tuft test complete.
1. Mechie's rear top vent does actually suck Air in to the engine bay on a 818R. Speeds of 50-60mph. That could change going faster. Not necessarily a bad thing, I like that it can cool off my Oil cooler box behind it. (Maybe the IC core creates a low pressure under the hatch right there.) Also could be with the rear bumper vented a lot like I originally thought.
2. Kurk's Scoops are definitely scooping air. Only the very bottom of the scoop was not scooping as much, the rest was definitely working.
How I attached.
http://i.imgur.com/gviNpU6l.jpg
Screen grab from video while driving
http://i.imgur.com/WxFfNpel.jpg
http://i.imgur.com/8xDFMNXl.jpg
http://i.imgur.com/202Mt5Ol.jpg
All waxed up (first time) and ready for Friday's test. Chance of rain.... I hope not, but we sure do need it.
http://i.imgur.com/dyWLli8l.jpg
That looks killer. Hoping for a smooth and successful track day for you.
Looks great! Hope it goes well.
http://rationalwiki.org/w/images/thu...peed_Racer.jpg
Good luck, Chad!
Good luck and keep us posted!
Chad, mine is an 818S but I always look forward to your posts because you are charting new territory and a lot applies to us street-only guys.
Thanks for the R&D. And good luck this weekend!
Oh you don't have Craig's larger front hood louvers. Sorry about that, that you had.Quote:
Originally Posted by C.Plavan
There's nothing wrong with Red Yarn to visualize airflow.
Attachment 41952
Just got back from testing: Buttonwillow CW #1 configuration.
+'s
1. My new suspension setup was a big improvement over stock. I still need to tweak ride heights (lower front, raise rear) for better angle of attack
2. I took 1.5 degrees out of there rear wing, that helped the aero push, and increased straight line speed. I can probably take more out safely next test. (8.0 degree's)
3. Engine Coolant never got over 199 degrees on the track while beating the heck out of the car.
4. The car is faster than the Lotus 2 Eleven race car records (1:59.3) on this race track Configuration (CW #1). I pulled off a 1:58, with junk R7 practice tires with 18+ heatcycles. (Anything under 2:00 is considered really fast on this configuration)
5. I was faster than 996 based Factory Porsche Cup cars out there.
6. The IC temp never got over 114 degrees.
7. I am getting faster and faster with this car after every session.
-'s
1. While all the oil cooler improvements helped keep me on the track the whole session each time, It was still getting too hot that last few laps. I would back off, let it cool, then treat the car with no respect and wring it out again.
2. The oil cooler was getting plenty of flow with and without the fan packs on it (tried both ways). I really think we need even bigger oil coolers for racing- It cant seem to keep up. I already have a few plans up my sleeve.
3. People kept on asking if the car was a Honda, Lotus, or BMW....lol
4. Time for more oil cooler changes.....
Right on! I bet it has to be one heck of a feeling knowing youve built that car to perform the way it does.
Congrats on a successful run!
Great News Chad,Quote:
Originally Posted by C.Plavan
Sounds like you have licked the engine coolant and intake temperatures.
What temp do you consider to hot for the oil?
Thanks for the update from Plavan Engineering R&D Department.
Bob
1: that will turn in better but will lose a little drive offQuote:
Originally Posted by C.Plavan
6: Cool air into the intake is a huge deal, those are the after AWIC numbers I've seen on the dyno.
Thanks- Anything over 245 degree's for oil temp is too hot for me. Once it got over that temp, I could feel performance start to go away and I would slow up immediately.Quote:
Originally Posted by Bob_n_Cincy
Congrats and making some big leaps. Seems like you are very close to having the car fully sorted.
What size and brand oil cooler are you running? At your HP numbers, I would think you'd want something like a 25-row Setrab.
I have the Series 9, 20 row Setrab now with the fan pack (FP920M22i). It is probably fine for a street car, but not for the race car. It just cant keep up with me always in boost. When I let off to cool it down, I would try not to be in boost, it would take 3/4 of a lap to get into a comfortable temp zone again for me to floor it again. I could not cool it down like that pre scoops or oil cooler box before, so I know those are working fine. I am thinking of running a second (same model) cooler to the front of the car (Passenger side front bumper area, evacuating air in front of tire like some Porsches) and run them in a series of course.Quote:
Originally Posted by Hindsight
Where are you picking up your oil temp? Some people are getting it from the oil galley which is wrong, you should be taking it from the oil tank. Other wis you will get block temp.
I'm not sure I'm comfortable with that. I'm getting it from the back galley oil port under the turbo area. When it gets to 245ish, I can feel the performance start to suffer. It would go to 260+ if I didn't slow up. Porsche motors have the oil temp coming from the block.Quote:
Originally Posted by D Clary
Awesome Chad! Can't wait to see what you can do when you are not paranoid of the oil temp. I bet it will be fast!
If there is no oil flow around the bulb on the sender, you are getting the temp from still oil in the galley. The water temp senders extend into a passage that the water circulates by. A dead end galley will absorb the block temp with no way to dissipate the heat. There could be other reasons for the slow down as it gets warmer. If you have an infra red thermometer compare the temp in the tank to your gauge reading. The tank temp is your true oil temp. that is the temp that is returning to the engine. It seems to me that you have more than enough capacity and cooling to keep it in check.
I totally agree. Once I put the intake in its current spot, It solved the problem. It was ingesting hot air in the engine compartment.Quote:
Originally Posted by Wayne Presley
The problem with the front of the car is the front splitter. If you mount it the way FFR wants you to (which I did unfortunately) The front of the splitter it angled up almost a full inch. Not really what you want. I screwed down/extended the support struts down to flatten it out a little. It still is angled up a little bit. With my new springs doing their job, I can lower the front a little more to get the splitter parallel to the ground without rubbing the tires I believe. I can probably do that without raising the rear it looks like now.
I ordered a new sender with a longer probe. The one I put in there was not that long, but I dont know how deep that galley is. We will see what that does.Quote:
Originally Posted by D Clary
Quote:
Originally Posted by D Clary
There are two primary oil galley locations on the EJ257 blocks (that are easy to get to). The front gally plug is used by the stock pressure sensor, and the rear plug is unused stock. If you are going to measure both pressure and temperature, you should have the temperature probe in the front location. The front location has direct flow across the port from three locations, one of which is the direct feed to the #1 bearing. That is the best place to measure the real effective oil temperature inside the engine.Quote:
Originally Posted by D Clary
The rear plug is a great place to measure pressure, as it really is a dead end plug. It is cross sectioned into the primary front to rear top feed, but then drops down to a high pressure release valve (little bearing on the clutch side). Given it's location you will see any pressure drop across the crank bearings, which is what you really want to measure.
On a less theoretical side, I'm not convinced it makes that much difference. I have used all four locations, including both right before and after a cooler, and the temperature difference was not much.. I think pre cooler vs back galley was less then 10 degrees F.
I'm not sure of the direct mathematical correlation between the block temperature and the oil temperature, but certainly the are highly coupled. The oil has a large amount of surface area transfer with the block itself. While a galley plug will be influenced by the block temperature, I suspect the oil flow (at least at the front plug location) will be the most significant factor.
As for the temperature itself, it is possible and desirable to get cooler. In my WRX pre EZ30R I had a number of different engines, one of which was a built up EJ207. I revd that engine to 8700 rpm, and racing at Portland International Raceway I had significant oil temperature problems. After about 5 laps, especially on the the rear straight which would involved a long 2, 3, 4, 5 full boost pull, I would see oil temps climb from 225 to about 285. I added an oil cooler (not really that large of a one btw), that was front mounted right at the front bumper, and that fixed the problem. I would typically not get above 245. Of course being at the front of the car meant lots of lots of airflow over the cooler.
I would not feel comfortable running sustained oil temps of 270+ in an EJ motor. Heat is the killer of engines in so many ways. High engine block and combustion chamber temperatures can lead to knock, which can lead to lots of broken parts. Of course I also ran at least an extra qt of oil in the engine, and the lines and cooler held some as well.
Jeff
As I mentioned in my previous post, there is a theoretical advantage to using the front port for temperature ( and the rear for pressure ), but in practice I am not sure it makes that much difference. It would be pretty easy to swap the locations if you want to try that. Either way, I think your instinct about reducing the oil temps is a good idea.Quote:
Originally Posted by C.Plavan
Jeff
You have to find out if the problem is oil temp or oil cooling. I f the cooler is working and the oil is going in at a low tem and coming out hot there could be other issues. In order to find out if your oil cooling system works. the oil in tank temp is where you need to check. The peak oil temp inside the motor is irrelevant. It could be 300 degrees at the bearing and run forever, but if it is going into the motor at 300 that is not cooling.
I'm leaning towards cooling. I need a secondary cooler in the front. If I can back out of boost on the track, and the temp starts coming down rapidly after 3/4 of a lap, I think more cooler is what the car needs. I'm tired of chasing this problem and I'm going to hit it with a BF hammer.
Front oil cooler will be a giant step, better airflow and more capacity. I hope it solves the problem. What weight oil are you using? I am only asking as in the past we have used oil temp as kind of a diagnostic tool for the engine condition. More friction, more oil temp. I am far from an expert on Subie engines. But I was wondering what the possibility of loosing some of your main bearing clearance when the engine gets really warm. Just thinking out loud again. I feel like we should all be sending you money for what you have spent and what it has saved us. Thanks Chad.
Haha- yeah let's start a "Go Fund Me" 818R development account.Quote:
Originally Posted by D Clary
I'm using Mobil 1 15-50 (the good kind with the right additives for race motors). 5qt jugs are $23 at Walmart! Can't beat that for a good Synthetic oil.
Front oil cooler ordered and the associated bits. Lets get this car BUG FREE!
Have you considered positioning your rear oil cooler over near one of the monster side scoops you're using? Even with the ducting and having the oil cooler enclosed in a box, it seems like you could get better efficiency from positioning the cooler near one of those scoops.
Keep in mind this is coming from someone who hasn't installed the body yet. I may be way off base with thinking there is room available there.
I'm passed that. I think the cooler is too small for all that consistent boost (4500-7500) Not saying it wouldn't work, I have experience with front mounted coolers with Porsches. I know this will work for sure.Quote:
Originally Posted by metros
Alright- Hopefully this will be the last thing I have to do oil cooling wise. The R&D 818R is running without any leaks.
It's all together after channeling my Porsche Oil cooling experience (A skill I thought I would never have to use on a water cooled car :confused:). After about 30' of -12 AN hose, a couple new fittings, additional oil cooler in the front, careful trimming/cutting, big P-clamps, 3" duct hose and ducts (both bumper and cooler).... I can now remove my 25 pound ballast :/ . The car takes around 9- 9.5 qts of oil now. I'll know exactly next full oil change.
I'm thinking I'm going to take the day off on Friday and head to a track test day. I'm hoping and praying this oil cooling thing is now behind me.
http://i.imgur.com/2AnwkmFl.jpg
http://i.imgur.com/TQfPMt1l.jpg
http://i.imgur.com/ZqDSlB8l.jpg
I need to rivet my mesh on the rear.
http://i.imgur.com/cI34Zf8l.jpg
http://i.imgur.com/itiOCodl.jpg
Looks good Chad. On my late model I plumbed the dry sump with aluminum tubing from the rear to front. and used shorter pieces of braided steel. When you are sure it will work you could probably run it with the cooling pipes under the side pods. obviously a winter project. Anyway I got the tubing from McMaster Carr and just welded AN fittings to the ends. Just in case you're 818 crowd funding takes off.