Pirelli Corsas and shock settings

[Bill Pemberton]

One thing I really like about this Forum is that there are enough guys out there tracking their Bosses , that one often doesn't have to spend alot of time figuring out suspension settings or tire pressures, etc., as there is quite a bit of good advice offered right here.

Yesterday I was instructing at Mid America Motorplex in Glenwood , Iowa, and it was the first actual track time in the Boss -- so far just had chances to autocross. Since I drove down there I was on the Corsas. The car has 2.7 degrees negative camber up front with MM Camber plates, and I was running 35 front and 32 cold with the Pirellis. Temp got up to around 85, and I did notice the front end really pushing bad at the end of the sessions. A couple of corners on this track are tricky to get the push out of , but wondering how much may have been my setup -- shocks set at 5 in front and 3 in the rear. Running stock pads and rotors as have not had time to install the Carbotechs or the DBA rotors.

Now this is not a sob story as the car kicked butt, and I was running dead even or ahead of a T1 Vette, gave all the Porsche guys rides, and was thrilled with the way the Boss ran the curbing. Realize part of the push was the heat in the tires at the end of the session, part was the two corners design where some push is prevalent with many cars, but also know with many of you logging bazillion track miles by now, there might be some sound advice to alleviate some of the issue. Have no idea if the issue is primarily the tires ( can't say I am overly fond of the Pirellis so far ), shock set-up, or just a warm day where these factors often come in?

Have to say the temp gauge never went beyond half way, and the 302S grill had to help some?!

Thanks and awaiting any suggestions or just revelations that the Corsas act this way by the end of a run?

 

[CaliMR]

You have a regular Boss and the LS tires?


Based on my Boss on the regular Perellis, 35 psi cold is way too high especially on a hot day. I had to let a few psi out from the street pressure at the last track day, and at the one before that iirc I had to also and it was 55 degrees.

 

[JScheier]

Bill - First, the front pressures might have been a little high (cold)... but not all that much. You were probably wise to run them that high just to save them from eating their own sidewalls.

Second, the Pirellis are good for about 3-5 laps before they start to get hot. For the first couple of laps, front grip is great... after that it falls off quickly. The only thing I've found that will keep me out on track longer with the Pirellis is slow in (much slower than when I'm on better tires) and fast (but smooth) out. As much as I can do to not overwork the tires seems to let them hang in longer.

FWIW, in 18s, the Hankook RS-3s have been great at handling 20 minute sessions. Unfortunately, no 19" sizes for us

 

[Bill Pemberton]

Thanks for the info guys, and yes i do have Corsas on a regular Boss ( first owner replaced them). I had a nice line on the tires where they were rolling over, but JScheier you called it exactly on the button. 3-5 laps and they started getting hot and that was when the problems occurred. Was having fun chasing a T1 Vette on Hoosiers and hanging in there and in fact they finally let me by and was able to pull away. Just kept changing my arc on mainly two turns as it just felt like a snowplow. Your assessment was spot on , but the only other item I wondered about was the shock setting?

I do have a set of R6 Hoosiers on a set of Enkeis ( 18s ) and will likely be running them next and have alot more seat time with Hoosiers on other cars, just wasn't too wild about how quickly the Pirelli seemed to give up the ghost.

 

[steveespo]

Bill
I run staggered Corsas on my car too and found that 33F/32R was best pressures at VIR. I have Koni Sports and run the 80% stiff on both front and back which seems to tame the under steer but not too much for a hack like me. When I was running 35/35 and 80/60 on the shocks it plowed a lot with the Corsas and was only marginally quicker than the PZeros. I have had no chunking or greasiness with 350 track miles and the wear is good so far. Got another 100 coming up tomorrow at Pocono so will see how they do, looks like 82 air temp and sunny so track will be up around 125-130.
Steve