[offroadr35]

For those of you that have tracked the car, what pressures worked well? What are you running them at on the street?

 

[eliseowner2b]

OffRoadR:

I am running mine 26f/28r on the street. At Road Atlanta a few weeks ago I found that 23f/25r was great. The temperatures were mild so keep this in mind. I started off the day with a few more psi all around but after inspecting the wear marks I took some out. It looked as though I could have taken them down another psi but they felt great the way they were. I am heading to Altanta in a few minutes and plan on autocrossing tomorrow (for the first time in years) so it's going to be an experimental day for me. Perhaps the guys who have autocrossed already should chime in on their experiences in this dept. When I get back tomorrow night, Ill post my results.

 

[offroadr35]

are those numbers cold or hot?

 

[Surferjer]

I'm running 28-29 on the street, cold. For autoXing, Stan (I believe) stated 26-28 worked well. Based on the above post, I may try 25-27 or 24-27 cold on autoX (to help me with oversteer).

 

[Randy Chase]

I will have to give those pressures a try. We ran 36 rear and 34 front Sunday and the car felt great. That was cold, so I expect the pressures were a bit higher, we never cared enough to check.

 

[meat]

28 hot is where you want to be.

 

[offroadr35]

28 hot is where you want to be.

you run that all around?

 

[meat]

Yep - that is my starting point. Get the car there and then adjust as you need to. 1lb changes can be noticed pretty easily if you are in tune with the car.

Keep in mind that the 48's take time to get up to temp so you may experience a push until the fronts get warm on turn-in and then the back will be twitchy on exit.

Last weekend in 45-50 degree weather and overcast skies, it was taking me about 3 laps to get the tires up to full temp.

When these tires are warm and your pressure/alignment is set right they grip like no tomorrow. Pretty amazing actually.

 

[offroadr35]

meat, what alignment settings do you use? I assume you are referring to your Exige?

I have heard that the factory alignment on the Fed Elise should be pretty well suited to road course work. Any thoughts? I guess i'll know better on monday.

-Steve

 

[meat]

I'm running the full Motorsport alignment/ride height. I don't have the specs in front of me, but something like -1.8 degrees camber up front, -3 in the rear. Caster is -3.8 degrees I think. Toe out in the front .1mm total (so almost straight) and toe-in 2.5mm PER Wheel in the rear. Basically, the car is set-up to go straight ahead and responds to steering input just like the car was wired to your brain. Really amazing.

Ride height is set at 100mm up front and 110 in the rear with 1/2 tank of fuel and 160lbs in the driver seat.

Yes - this is on the Exige

Please note and this may be different in the S2 cars, but in the S1 cars alignment was not real good from the factory.

 

[Randy Chase]

That is pretty close to the alignment I went with on my car. Works much better than whatever it was set at.

 

[meat]

Randy - you are at stock ride height though - correct? So that is somewhere around 140mm?

I am running on Dynamic 2-way adjustable dampers with 375lb springs up front and 400 in the rear. I will be moving to 550-600lb springs when I switch to the full slicks.

I also have my front swaybar set at the middle setting.

 

[Surferjer]

I good luck today with a lot lower pressures.

 

[meat]

What pressure hot were you running?

 

[eliseowner2b]

I took Randy's advice this weekend and started my tires off 34f/36r (hot). After one run I took 2 psi out of each corner. The wear indicators seemed to be right on after this change. Please keep in mind that the pavement was wet, it was still misting/drizzling a little and the temps never went over 70 degrees. This is my first autocross with the Elise but it would seem that if I lowered the psi any more the tires would be rolling over too much.

 

[Surferjer]

Please indicate what tires you were running. The pressures will be very different.

Yesterday I ran the AO48s at 28-29 cold on my first run, then dropped them to 24-26 cold, and had much better grip. If we had actually HAD afternoon runs, I would have lowered the pressures to 23-25. I had no tire roll, and it was so cold and wet the pressures changed very little during the runs.

I ran the AD07s at 27-31 cold two meets ago with good success, then tried them higher at the last meet with less success.

 

[eliseowner2b]

Please indicate what tires you were running. The pressures will be very different.

Surferjer, your pressures seem very low. I'm running the same tires as you. Im going to take some close up photo's of my tires in a little while and post them. Maybe I was had too much p.s.i.? I haven't autocrossed this car and haven't autocrossed in several years so I'm probably way off.

 

[Stan]

Remember that the Elise is *light*. Under 1900 on gummies and light wheels, low fuel...

Try the old Europa test. Grab a front tire at 9 and 3 o'clock and "steer" the thing. Watch the steering wheel in the car spin until it locks if the key is out. This can astound onlookers who drive big iron!! What other contemporary car can do this besides the Elise? There is little weight to deal with.

Folks are still playing around with things like tire pressures. End of the season NE autocrosses get pretty cold. At least in some other cars it can be best to run a bit low on pressures when it's cold such that some increased heat is built up to more than compensate since it can help the rubber begin to soften up. I used a pyrometer at a cold, dry autocross recently. Right after a run on the AO48s my tire temps were around 65 F and the track temp was about 55 F in the sunny areas. That is way below where the tire can best do it's thing.

 

[meat]

I generally start with the tires at about 22f/23r and that gets me close to 28 hot depending on the temperature.

Sometimes I think I should just go buy a tank of Nitrogen and be done with it.

 

[eliseowner2b]

Thanks for the info guys. I completely understand the lack of weight/lack of p.s.i concept. Ill have to try a different approach at the next event.