Autocross - Page 2 - ZR-1 Net Registry Forums

jrtoffroad · 09-26-2011

Went to my 10th autocross for the year yesterday and the ol ZR1 made me VERY proud.

Held FTD all morning, losing it to a c5 Z06 in the afternoon, but coming out 2nd overall (raw time) in a field of 84 cars. The course was long and fast, just what the ZR-1 likes. On the back straight I was just about at the rev limiter in 2nd before braking for a 3 cone slalom leading into a sweeper.

No recent changes to the car. Surprisingly the Nitto NT-01 really hooked up well even with cooler temps. Pressures were kept at ~33 front & ~30 rear hot.

No video, but will post some pics later.

jrtoffroad · 11-02-2011

Well, had another Auto-X Sunday (10/30) and took home FTD in a field of ~60 cars!

Only change on the car was properly torquing a few very loose rear suspension components (A couple nuts were just finger tight!!!). Ran the tire pressure VERY low for this event, ~28 front and ~26 rear. Traction was great, but car felt a little loose on the edge, probably run them a touch higher at the next event.

Even cooler at this event (high of ~60), and the NT-01's still did not disappoint.

Overall great event, with a slightly smaller turn out than usual we were able to get 8 runs in (with each averaging ~50sec).

JThomas · 11-19-2011

Yep, you're hooked! Keep it up.

jrtoffroad · 04-16-2012

Here's a quick update for 2012:

Didn't have a chance to work on the car this winter (too busy building an ultra-4 racer & prepping for KOH). So, with the same configuration as last year I've now raced the Z in 3 Auto-x's this year. One of which was a 2 day event put on by the local corvette club where I got 28 runs!

The car has been doing great. I did find a little slop in the d-side lower ball joint, so the car is down right now while I replace all 4 just to be safe. Figured this is as good of time as any to throw some poly bushings in the suspension. Hopefully I can get it all done in for this weekends race! Glad I'm doing it though, some of the stock bushings are in pretty rough shape. Very excited to see if there's a noticeable change in the feel of the car.

After I get the bushings in and the ride height tweaked (plan to bring the rear down just a touch) I'll need to have the alignment checked. I did not go with the offset lower bushings. I've been pretty happy with my settings from last year and plan to stick with those for now (~-2deg front / ~-1.25deg rear, no toe front & 1/8" in rear). I don't think my street tire budget can stand any more camber, and doubt I would gain much at the track.

I've still got a little life left on the NT-01's. They don't seem to stick quite as well as they did last season (been through a lot of heat cycles now), but still are worlds better than street tires. Just for fun I ran my new NT-05 street tires at the last event to compare performance, and while they may be great street tires, my times really suffered. When the NT-01's finally cord I'll be ordering another set.

On the brakes I've been switching between my carbotech (12 front 10 rear) and hawk HPS brake pads. The carbotechs are amazing and stop MUCH better when hot, but hard to live with on the street. Unreal amount of dust. The hawks are OK and much nicer for daily driving. I find for short slower Auto-x courses the Hawks do just fine, it's really only the high speed stuff where the carbotechs make a difference. For this weekend I'll be back on the Hawk's.

Anyways, still need to shoot some more video, but the Z continues to be very competitive, pretty consistently winning BSP and usually in the top few for FTD.

09-26-2011	#11
jrtoffroad Join Date: Sep 2010 Location: Colorado Springs, CO Posts: 75	Re: Autocross Went to my 10th autocross for the year yesterday and the ol ZR1 made me VERY proud. Held FTD all morning, losing it to a c5 Z06 in the afternoon, but coming out 2nd overall (raw time) in a field of 84 cars. The course was long and fast, just what the ZR-1 likes. On the back straight I was just about at the rev limiter in 2nd before braking for a 3 cone slalom leading into a sweeper. No recent changes to the car. Surprisingly the Nitto NT-01 really hooked up well even with cooler temps. Pressures were kept at ~33 front & ~30 rear hot. No video, but will post some pics later.

11-02-2011	#12
jrtoffroad Join Date: Sep 2010 Location: Colorado Springs, CO Posts: 75	Re: Autocross Well, had another Auto-X Sunday (10/30) and took home FTD in a field of ~60 cars! Only change on the car was properly torquing a few very loose rear suspension components (A couple nuts were just finger tight!!!). Ran the tire pressure VERY low for this event, ~28 front and ~26 rear. Traction was great, but car felt a little loose on the edge, probably run them a touch higher at the next event. Even cooler at this event (high of ~60), and the NT-01's still did not disappoint. Overall great event, with a slightly smaller turn out than usual we were able to get 8 runs in (with each averaging ~50sec).

11-19-2011	#13
JThomas Join Date: May 2008 Location: Okemos, MI. Posts: 1,186	Re: Autocross Yep, you're hooked! Keep it up. __________________ Joe Thomas Corvette Club of Michigan NCRS-Michigan Chapter Member NCM Master Ambassador NCM Lifetime Member Former NCM Board Member 1991 ZR-1 Melon Copper Metallic/Black 1992 ZR-1 Bright Red/Black (Sold) 1995 ZR-1 Bright Aqua/Gray (Sold) 2012 ZR1 Super Sonic Blue / Dark Titanium

04-16-2012	#14
jrtoffroad Join Date: Sep 2010 Location: Colorado Springs, CO Posts: 75	Re: Autocross Here's a quick update for 2012: Didn't have a chance to work on the car this winter (too busy building an ultra-4 racer & prepping for KOH). So, with the same configuration as last year I've now raced the Z in 3 Auto-x's this year. One of which was a 2 day event put on by the local corvette club where I got 28 runs! The car has been doing great. I did find a little slop in the d-side lower ball joint, so the car is down right now while I replace all 4 just to be safe. Figured this is as good of time as any to throw some poly bushings in the suspension. Hopefully I can get it all done in for this weekends race! Glad I'm doing it though, some of the stock bushings are in pretty rough shape. Very excited to see if there's a noticeable change in the feel of the car. After I get the bushings in and the ride height tweaked (plan to bring the rear down just a touch) I'll need to have the alignment checked. I did not go with the offset lower bushings. I've been pretty happy with my settings from last year and plan to stick with those for now (~-2deg front / ~-1.25deg rear, no toe front & 1/8" in rear). I don't think my street tire budget can stand any more camber, and doubt I would gain much at the track. I've still got a little life left on the NT-01's. They don't seem to stick quite as well as they did last season (been through a lot of heat cycles now), but still are worlds better than street tires. Just for fun I ran my new NT-05 street tires at the last event to compare performance, and while they may be great street tires, my times really suffered. When the NT-01's finally cord I'll be ordering another set. On the brakes I've been switching between my carbotech (12 front 10 rear) and hawk HPS brake pads. The carbotechs are amazing and stop MUCH better when hot, but hard to live with on the street. Unreal amount of dust. The hawks are OK and much nicer for daily driving. I find for short slower Auto-x courses the Hawks do just fine, it's really only the high speed stuff where the carbotechs make a difference. For this weekend I'll be back on the Hawk's. Anyways, still need to shoot some more video, but the Z continues to be very competitive, pretty consistently winning BSP and usually in the top few for FTD.