redtopz

I finally had a chance to get both of my cars to the same track to make a comparison between a T1 setup and a ST2 setup, although it was exactly one year apart. Ironically, nobody currently races T1 or ST2 at Laguna Seca. NASA NorCal only runs at Infineon and Thunderhill. SCCA does race at Laguna Seca, but nobody in NorCal races T1, except for Chris (Sik02SS) and me (my 1st year). Hopefully the Cal Club gang will make a trip up for a T1 race here soon because it's a great track.

Anyway, I took my T1 car to LS last year and my ST2 car this year for our Corvette Challenge time trial. My T1 car was running on stock C5Z wheels with 295/315 A6's front/rear and lg coilovers. I know the coilovers are not T1 spec, but I'm finding my car to be just as fast with the T1 springs/shocks as it was with coilovers . Here is a vid from last year in that car:



This year I drove my new (to me) ST2 car which used to be a local ITE car with a big wing and ACP splitter/undertray. I swapped the stock LS6 engine and the lg coilovers from the blue car into this car a couple months ago. The ST2 car was about 1.5-2 seconds faster than the T1 car at the same hp/wt ratio. The ST2 car was running on 315/335 A6's (scrubs) and has better brakes than the T1 car too. Here is the vid from this year:



Just thought I would share since it's uncommon to see a ST2 or T1 car at Laguna Seca. Both of these days were with the 92 dB sound limit so I ran stock exhaust and short shifted to 4th at the sound station going up the hill. Each car has the potential to turn faster laps than I did, but since I was driving both about the same it shows what aero and better brakes can do. BTW, last Fall I raced the T1 car at LS with just a wing bolted on the trunk lid and did a 1:37.3, which is right between the other 2 lap times.

Short-Throw

Nice vids!

ST2 setup cars are more fun to drive as they allow a little more tinkering.

jasonberkeley

try running your T1 car with properly sized wheels and 315s all around and you'll find all the time.

The T1 car ain't a T1 car with LG coil overs on it.

2002rich

Great Video! I would not have guessed that the ST2 car would have been be able to pass sound without a serious lift and screwing up your lap time.

Olitho

Bill knows that. That first video is pretty old and he has since changed the suspension. The T1 car had to go through a few minor mods to change it over from its previous track day only role.

Bill is a very competent driver and very fast.

I like ST-2, I like all racing, but there is something to be said for having a bunch of T1 Corvettes that are nearly identical on the front row of a race group. Turn one is a blast and we usually have really close racing all the way to the checkered... at least in So Cal.

drivinhard

1/2" of wheel isn't going to pick up 2 secs IMHO. I tested a 315 A6 CCW 10/11" T1 set up at Roebling last year, back to back with 275 A6s on 10.5" speedlines, and went slower (the track had gotten hotter and slowed by about that time difference, maybe slightly less). There may have been a smidge more steady state "skidpad" grip, but the transient stuff felt terrible (to me) with the much heavier wheels/tires and the 315 stretched on a 10" wheel. IIRC the total added weight was ~40 lbs. The steering was much number and the car wasn't as light on it's feet.

The bigger tires thermal capacity during a long race is probably another debate...

Olitho

PS. I want to drive that winged wonder. I want to drive Jason's car, too.

jasonberkeley

20mm per corner is nearly four inches of rubber around the car- LOTS of grip there!

Laguna is a track I would love to drive- so jealous of you guys!

Oli- the new car is going to be great once there are some real brakes on it. The little Wilwood slimlines made the car a little hairy at 3600 lbs with gas. It looks like i'm going to put on the same Brembos that Heinricy ran and Ken Davis has on his car so I can keep my CCW Classic 17" fronts.

Bills Z06

Very nice drive!

redtopz

Yes, I enjoy the ST2 car with the full aero and the fact that I can make changes to the care as I like. It makes it fun. However, Oli is right about T1 being more fun to race around here. Having a bunch of T1 corvettes racing together is a blast and I'm learning a lot from the Cal Club guys.

redtopz

True, maybe my title is a little misleading. I was just comparing my 2 cars at the same track. And for a couple hot laps during a time trial the 295 in front doesn't really hurt compared to a 315. The coilovers are nice and I still run them on the ST2 car. However, I am finding the T1 suspension even with the sachs shocks to be just as capable.

You are welcome to drive it sometime. I think you will like the aero, the brakes, and the clutch.

jasonberkeley

At what speeds do you need to be going to really feel the downforce from the aero?

DarkMastyr

Very fast Bill. You made all those other cars look like they were just standing still.