d walker

The total weight on the #7 car is about the same as yours, at the end of a 50min sprint race we weigh 2806 with 168lbs of driver. Some of our base setup, using the required Pirelli tires is:

fnt:
toe- 1/16th out
camber- - 1.7
castor- 5-6 deg
middle sway bar position (three piece bar)
Springs- 500lb

Rear-
toe 1/16th toe in
camber- 1.5deg
rear sway bar, stock
Springs, 400lb

We put in about 1deg rake, ride height is low but not ridiculously so, shock setting are meaningless unless you have the same valving etc. we shoot for 50% cross and I would dearly love to be able to get more rear weight bias, but there is literally nothing else we can move to the rear of the car.

I have no idea without seeing your car what your right turn issue might be, but maybe the setup info will help.

Highway8

iTrader: (11)

Not a ton of front Negitive Camber. I have seen/heard of others running well over 2. Is that all you can get or is it just what works best?

I heard those Pirelli Tires are fast and they dont fall off as fast as the Hoosiers.

Wheat size do you run 245?s I would love to get a set of 275/35/18 takeoff pirelli tires.

d walker

I can get a lot more if I need to, but this is what is working with those tires and the shock/springs. We might try a little more neg camber at mid-ohio, but not sure yet, thats what testign is for.

sblethen

iTrader: (3)

Some follow-up on the RX8...
I came in because the car started to sputter and wasn't running well at all. I could smell fuel and thought I had a bad leak or something... Not the case. The car had a 3/4 of a tank of fuel. We did drop out and replace the tank today and found the source of the smell. I did run it out of gas on Friday and it acted the same as it did in the race which is why I thought I may have had the gas issue. I did have bad plugs which I have now replaced. I also replaced the fuel pumps just in case those were an issue. I am really hoping it runs better, I am heading up to NHMS to do some testing this week. If anyone has any ideas on the sputter issues (after 20min at race speed) let me know.

The other issue with what feels like wheel spin is still a bit of a mystery and my largest concern at this point. I see tons of $$ being spent to figure out what the issue is and I am hoping to figure it out before all that $$ is gone! I am hopefully dropping of the "racing" rear-end on Monday to be looked at. At this point I have no idea what could be wrong with the car. We put it on the lift today and double checked all the suspension and everything appears to be fine. We also did cross weights and they all came out good. I did not drop out the transmission since I didn't have time ao I have not checked the clutch. If the diff comes back without any known issues then I will try to look at that then. I would love it If a few of you wouldn't mind watching a lap or so of the attached video and give me a few ideas on what may be wrong.

Just added a Youtube video of a few laps of me during qualifying. I was chasing down Dad Please don't give me a hard time about driving! This was only my third time driving the car and only the third session the car was ever on track!
http://www.youtube.com/watch?v=Sz4oo...layer_embedded

Stephen

sblethen

iTrader: (3)

We ran -2.8 for camber (Max that one side had and we wanted to start out with them equal.) I did notice these cars are much different than the Audis we ran and the adjustments change drastically with just a fine touch of the wrench!

Stephen

sblethen

iTrader: (3)

Another update Rear Wheel spin issue has been resolved! It DID have to do with the "droop" of the rear not being equal. If you know what I am talking about then you think I am idiot for not checking this closer at the track that first weekend out with the car. If you don't know what I am talking about I can explain if you need or want to know! Just to be clear today was the first day back out on track and that issue is resolved!

I also got rid of the sputter by replacing the Primary fuel pump! I purchased the aeromotive one that fits into the stock setup. HOWEVER... After a short period of time the car will stop running, as if I hit the kill switch but everything stays on... Fuel Pressure drops to zero and the engine stops running. I have to let my foot of the gas and wait several seconds.. the pressure will then go imediatly back up to 60 and the car will be running again as if nothing happened. Under normal conditions the fuel pressure is at 60 under full throttle or just idling. Except when the car seems to turn off it instantly goes to zero. I will remind you that when you turn the car off in the paddock the fuel pressure stays up and takes a while to drop... as any pressurized system would. Do you think I am getting air, do you think a bad regulator could cause this, or is it possible that for some reason the pump is turning off? I have checked all wires, fuses and relays. nothing is loose and they all seem to functioning properly. Does anyone know if the RX8 has a sensor that may be faulty that sends a signal to the computer to turn off the fuel pump. Kinda like an inertia switch?

Any advice is appreciated,
Stephen

d walker

The ECU varies voltage to the pump, its one of the ways it controls fuel pressure without a bypass fuel pressure regulator. Your Aeromotive pump may be drawing too much current and the ecu is getting unhappy about it. Not sure what ECU setup you have, so cannot speculate much more.
I use the "standard issue" Walbro 255HP pump and it works great so far.

BRODA

iTrader: (7)

Stephen, I heard you were able to resolve the fuel issue. How was the rest of the weekend?

TeamRX8

iTrader: (25)

The ECU has no input on amp draw. For low engine speeds (idle) the ECU routes the fuel pump electrical power through a resistor circuit to reduce supply voltage and slow the pump down. You will not engage this when racing.

There is a bypass regulator. It is located on the fuel pump housing internal to the the fuel tank. Bypassed fuel also goes through a siphon assembly to pull over fuel from the RH side of the saddle fuel tank into the LH side.

If anything I would suspect either a power wiring/connection issue or the more common issue of uncovering the pump suction in high lateral load turns and sucking air instead of fuel. Or if there is too much flow/pressure you will blow off the bypass regulator cap from the fuel pump housing. At which point the pump is flowing freely back into the tank rather than supplying adequate fuel pressure to the engine.

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/fuel-pump-solution-all-failure-modes-176491/



.

sblethen

iTrader: (3)

So I think we resolved the fuel issue We have a quick fill system in the car that uses 2 of the locations on the top of the tank that was used for venting. (Both part of the rollover safety feature) I think that the tank has 3 spots for venting... (Going from memory here!) I know they all merge into 1 small tube that goes into the subframe in the rear and then other lines go into the charcoal canister. Basically in short we cut off some of the venting with our quickfill drybreak system. We had them blocked with a loop because we are not using them at this time. This created negative pressure in the tank with not enough venting into the tank itself. No venting of air into the tank creates more and more of an issue as the session goes on and makes it impossible for the pump to get gas out! With the car completly stuffed with fuel it would make it about 25 minutes before we had issues.

Other than that the weekend went well. I still don't have my front sway bar yet which is frustrating since I am running the stock front bar. The car handles like it's on ice with TONS of oversteer. I was still getting taken pretty bad out of the corners since I really had to ease on the gas. (Nothing like before with those wheel spin issues from the droop though) Since I have raced front wheel drive for so many years I think it helped driving the car like this. I really had to be so easy on the gas and I got to learn so much about the balance of the car. I was sideways at least once in every turn on that track! Looped it twice as well

Overall I was pleased and came in 4th. I ran 3rd for a majority of the race but spun and got passed by an M3. The first 2 cars I couldn't catch (E30 and and Z3coupe) I think once I get that bar installed it will be much better coming out of the slow turns which NHMS has so many of!

Oh... I did run over on DB (101) and had to stick a 90 degree elbo out the back facing the other direction, not a big deal but made the car look a bit funny!

Stephen

PS: Here is a very short video (2min) from when I rear ended a car I was lapping and then a spin about a 1/2 lap later when I gave up 3rd to the M3. I apologized to the girl I hit, I was shocked at how much she slowed down and didn't expect it at all. She braked WAY earlier than I had planned and then stayed on the brakes much longer than I ever expected. I just couldn't slow down any more. Sadly it crackd the front bumper cover and bent in the crash bar enough to dent the AEM intake. Didn't damage the headlight though, thank god as those things are so damned expensive!

http://youtu.be/wBJ19GwAAL4

9krpmrx8

iTrader: (46)

Cool vid, was she pissed? Seems like a good smack.

MagnusRacing

iTrader: (2)

Hmmm... this doesn't seem normal. Even with a "stock" front sway bar (I run stock bars on my car). I'd take a good look at the suspension set up and alignment.

I watched your video and it seemed like maybe the track was a bit rough and upset your car before you spun? Hard to tell. How stiff is your suspension and how low are you?

sblethen

iTrader: (3)

Not really, I was expecting a point buy to be honest since my closing rate was so fast. It never came which is why I did hesitate. I then planned to go right since normally you would track further left entering this turn. The closing rate, no space, coupled with me thinking she would carry much more speed resulted in the incident. As she said "No worries, we both continued on!" I am thinking she probably realized she go go that much faster at entry as well and still easily make the turn . If it was qualifying I would have bagged the lap and just followed but it was the race and I was trying to catch that white car in the distance!

sblethen

iTrader: (3)

I did drive over the rumble strips at apex. Then the transition off of the Nascar track is what really did me in! I think overall I do need to get used to the car but I think the swaybars are not even close to matched up with the spring rates causing some of the issues. Car is set at 5.2" in front and 5.5" in rear measured to the rocker (NOT the seam weld on the rocker) Coilovers are not the best, purchased the spare set from an old koni RX8 (SRI) Fronts are 600lb Rears are 400lb. I am hoping as the RX8 is no longer raced professionaly that I may be able to pick up a set of Konis at 1/2 retail

I may not race the RX8 until next year when we do the entire proitseries.com We are going to recheck the toe when we bring it up to the shop along with checking the rear suspension travel. I am wondering if we possibly have it to far toed out and or if we may be bottoming out the shock on the bump stop. Both would cause big issues! I wish that I had used the zip tie trick to see how far they were compressing.

Thanks again for the support!
Stephen

TeamRX8

iTrader: (25)

with those spring rates it does ....

MagnusRacing

iTrader: (2)

I run similar spring rates with no severe oversteer issues. But handling is a very complicated thing involving many factors including the driver's inputs. So who knows... but I agree a softer spring might help him out.

mikeinquincy

Just curious have you ran North-South chicane configuration at NHMS? If so what kind of times are you running?

sblethen

iTrader: (3)

Softer springs or a real front sway bar? I think i may have the smallest front bar on the front compaired to anyone racing an RX8. With your spring rates did you run a big bar up front? Just curious on what others are running.

Stephen

sblethen

iTrader: (3)

Sadley SCCA no longer uses the south chicane for safety reasons. (Blind exit around the tunnel) in my slower ITB Audi with about 120hp I ran a 1:24.1. I am guessing based on relative lap times the RX8 should be in the 19's. Do you know if COM or SCDA still use it? (Or are you running with another club?)

MagnusRacing

iTrader: (2)

I use the factory "yellow dot" sway bar up front and in the rear. The is the bar that came stock on the 2004-2005 manual transmission models I believe. I think the automatics and MAYBE some of the later model cars had smaller bars? However, the only reason I use the factory bars is because I have to in my racing class. I'm sure there are alternatives out there that are better.

I run Ohlins shocks (revalved) with 725lb front and 375lb rear springs and car seems pretty neutral. Perhaps my higher spring rate in the front is helping?

TeamRX8

iTrader: (25)

Higher in the front and lower in the rear, duh .... thr RX8 chassis does not respond as linearly to rate changes as would commonly be assumed

I personally would prefer to run a lower front rate with a stiffer front bar (like the typical adjustable speedway style bar) but to each their own.

mikeinquincy

I mostly run with COM and that is the configuration they use (chicane/chicane).
Unfortunately there hasn't been another RX-8 - stock or modified run with us so it's hard to compare times.