ZR1 in TT1

[racerns]

So I am thinking about running my ZR1 in TT1 some next season. This will be mainly in the NASA-MA region. I am doing this mainly for fun as I don't plan any major modifcation for the car. I will do a seat and harnesses and a set of dedicated track wheels (18" CCWs or similar). Since I don't plan any major weight reduction, the question is if I should plan on running a set of race slicks and take the point hit there or stick with an A6 (or similar tire) and bump up the HP? Stock the car will dyno in the ~540 rwhp range and I am estimating the race weight of ~3500lb (need to confim weights). I could do a minor bump in HP to the 580 rwhp range and run the slicks or bump to the 640 rwhp range and stick with DOT tires.

 

Any thoughts? (Besides you are crazy for tracking a ZR1 )

[topmover1]

Problem with slicks on that car is you'll get in peoples way while getting them warm and then once they're warm your likely to be dealing with slower traffic. A's work nicely on that car.

[jason]

Generally, the goal is 1 and done, 2 at the most. After that traffic makes it pointless.

[racerns]

Problem with slicks on that car is you'll get in peoples way while getting them warm and then once they're warm your likely to be dealing with slower traffic. A's work nicely on that car.

 

That was what I was worried about, how quick the slicks come up to temp and what the spacing/ traffic is like. On the flip side I do want to continue running HPDE and will I kill the A6s doing that?

[kbrew8991]

Problem with slicks on that car is you'll get in peoples way while getting them warm and then once they're warm your likely to be dealing with slower traffic. A's work nicely on that car.

Which slicks - I thought there were some pretty soft compounds availible from some brands

[Cobra4B]

Neil... Topmover is Joe who used to run the silver one I was telling you about.

[braknl8]

On the flip side I do want to continue running HPDE and will I kill the A6s doing that?

 

The A's can make 175-200 DE laps at Road Atlanta, maybe more. Figuring 8 laps a session, 64 per weekend, you'd be into your 4th DE event before needing to replace. That's obviously not a season on a set like some other cars can boast but three sets of tires for a DE season (keep a separate set or two for TT'ing, rotate them down when they don't have "TT stick"). It wouldn't be completely indigestible and I dare say those 200 lap A's are not too far behind anything else on track in a DE session.

[racerns]

Thanks for the tips guys. I have some things to think about. I might just put a seat and harnesses in the car and run on the stock pilot sport cups at first then decided on mods.

[jvetthead]

On the flip side I do want to continue running HPDE and will I kill the A6s doing that?

 

The A's can make 175-200 DE laps at Road Atlanta, maybe more. Figuring 8 laps a session, 64 per weekend, you'd be into your 4th DE event before needing to replace. That's obviously not a season on a set like some other cars can boast but three sets of tires for a DE season (keep a separate set or two for TT'ing, rotate them down when they don't have "TT stick"). It wouldn't be completely indigestible and I dare say those 200 lap A's are not too far behind anything else on track in a DE session.

200 laps on As....dayum.. must be gettin mine from the wrong place.

[kbrew8991]

well if you'd stop drifting all over the place Crazy Joe...

[Dizmm]

200 laps on As....dayum.. must be gettin mine from the wrong place.

 

same here. 30 some laps before I see cords.

[racerns]

200 laps on As....dayum.. must be gettin mine from the wrong place.

 

Yeah, I don't see that happening with the power and weight of the ZR1

 

I have heard of people using the Michelin Pilot Slicks for TT but I don't know if they are using a different format that might allow more tire warm up.

[drivinhardz06]

We ran a Z07 (basically a ZR1 with an LS7, minus about 165 lbs or so) at Road Atlanta for 3 days and did 150+ laps on scrub A6s. They were bought from a T1 racer with 3 heat cycles (advertised) although I have no idea how many laps were run on them before we started running them that friday. They were not flogged to the point of abuse for all those laps, but they were pushed pretty hard in DE and giving taxi cab rides.

 

Road Atlanta is one of the few tracks you could probably do this, 160 Road Atlanta laps are not 160 laps at CMP. VIR tends to be a little harder on the tire than RA as well.

 

The tires will likely make it through another 2 day weekend with some rotation/flipping

[jvetthead]

well if you'd stop drifting all over the place Crazy Joe...

But its fun..

And I heard somewhere loose is fast

 

I do seem to through rears 2/1 over fronts

[Varkwso]

ZR1 should do fine. I would keep stock HP..

[racerns]

ZR1 should do fine. I would keep stock HP..

 

I am pretty sure I will at first atleast.

[1LapSRT]

Road Atlanta is one of the few tracks you could probably do this, 160 Road Atlanta laps are not 160 laps at CMP. VIR tends to be a little harder on the tire than RA as well.

 

Don't forget it will be repaved for 2014.... That should help!

[heavychevy]

200 laps on As....dayum.. must be gettin mine from the wrong place.

 

Yeah, I don't see that happening with the power and weight of the ZR1

 

I have heard of people using the Michelin Pilot Slicks for TT but I don't know if they are using a different format that might allow more tire warm up.

 

It can happen, my car is 515 whp and has been between 3100 and 3400 lbs over the last two years I've been running A's. I still have my very first set of front tires I bought brand new from a friend. They have 26 or 27 HC on them. Mostly 2-3 Lap TT sessions, but also some double duty DE testing weekends too. The rears corded at 25 HC. Car is a 911, and quite gentle on tires. All laps at Road Atlanta.

 

HOWEVER This would by no means work at VIR. VIR (obviously not including the upcoming repave, no one knows what that will bring yet) is about 2-3x as hard on tires. You can drive tires at Road Atlanta for ages, don't think there is an easier track on tires, maybe in the country. I took a set of low lap A's with about 8 HC to VIR in July, Corded them in about 5 sessions, 2 of which were slow wet sessions with low heat and wear. Tires had a ton of tread on them when I got there, would have lasted at least 6-10 additional sessions at Road Atlanta.

 

I would not DE A6's though without cooling down after every few laps though. I've found the tire life to be significantly shorter when doing more consecutive laps vs a few and cool down. Almost has felt to me like they are as much of a lap count tire as a heat cycle tire.

[Fair]

The A's can make 175-200 DE laps at Road Atlanta, maybe more. Figuring 8 laps a session, 64 per weekend, you'd be into your 4th DE event before needing to replace. ... It wouldn't be completely indigestible and I dare say those 200 lap A's are not too far behind anything else on track in a DE session.

Wait... 200 laps on A6s??? I have to respectfully disagree on that claim - I don't want people to think they can get 200 laps on track on a Hoosier A6, because that simply isn't possible if you are driving competitively. They can and DO wear considerably faster than other, harder compound tires. Because, well, that's just physics.

 

 

I don't say this without some experience, mind you. I'm not the end all be all expert on tires but I did burn through 9 sets of new A6s this year running in TT3 with NASA. It should have been more, as I skimped at Nationals and only brought one sticker set (whereas many competitors had new sets for each day). But to compete in 7 NASA Texas weekends (and set 8 TT3 track records) it took 7 new sets of A6s as well as a few sets of R6s (which I use in practice sessions).

 

I looked and out of the 80 tires in my shop at least 30 of them are worn out A6s I used in TT3 this year

 

I'm lucky if I can get 30 laps on a sticker set of A6s. We do all sorts of tricks to make them last, like stretching a 315mm tire onto a 12" wheel, not taking more than 3 laps per session (usually only the out lap, 1 hot lap, and a cool down on the in-lap), and using a separate set of R6s to test with on Fridays or in "less than ideal" weather sessions. After one weekend (2 days of racing in TT) they have done their job and are looking pretty thin, and we usually sell the old sets to autocrossers. My first lap in each TT session is fastest and they tend to fall off a full second per lap thereafter.

 

 

We do a lot of other track events in the same car (over 25 race weekends in 2013), and often use the "no longer 100%" sets of worn A6s (and worn R6s) at HPDE days and for testing, knowing they are no longer near their peak performance. But after 60 total laps or so they are done, down to the base rubber or cords. That's just the nature of a super soft tire like the A6. Not knocking Hoosier, they have an amazingly dominant DOT legal tire that is faster than many dedicated racing slicks, but it is by no means to be thought of as a long wearing tire for HPDE, TT, W2W or other track uses.

 

This was an A6 we took down to cord, which had extremely even wear. This tire made one race weekend and one test session

 

Sorry to sound disagreeable, and I respect your opinions and experience, I just think they are highly atypical. I just don't want people to read that previous statement and think they can get 200 competitive laps on track with A6s. That's just... highly unlikely, in my experience, if you are running competitive lap times. A6s are to be driven delicately and carefully, to extract that golden lap, and are an effective tool in NASA Time Trial. If you want more laps per set get an R6 or virtually any other DOT R-compound tire, just prepare to be slower than you could be on the A6.

 

Cheers,

[braknl8]

Wait... 200 laps on A6s??? I have to respectfully disagree on that claim - I don't want people to think they can get 200 laps on track on a Hoosier A6, because that simply isn't possible if you are driving competitively.

 

 

Sorry to sound disagreeable, and I respect your opinions and experience, I just think they are highly atypical. I just don't want people to read that previous statement and think they can get 200 competitive laps on track with A6s. That's just... highly unlikely, in my experience, if you are running competitive lap times. A6s are to be driven delicately and carefully, to extract that golden lap, and are an effective tool in NASA Time Trial. If you want more laps per set get an R6 or virtually any other DOT R-compound tire, just prepare to be slower than you could be on the A6.

 

Cheers,

 

Hey Terry, I'm Chris. I've watched a lot of your videos and I appreciate all the time you took in your reply (and look forward to your E36 build thread, very high quality post!) however, I believe you may have seen the 200 laps on A6's and, as with the other two comments that weren't as respectful, but equally incorrect, allowed that statement to "cloud" the other parts of my post.

 

You see, I didn't say that you'd get 200 "competitive laps". The OP asked about getting into TT with a ZR1, while continuing to DE. What I was saying was that the A6 isn't as delicate as everyone likes to purport. IF you back it back from 110% (on a TT flyer) to slightly under 100%, the wear goes up exponentially. Yes, they are one of the softest tires out there and WILL wear accordingly. No one is trying to make them a 300 tread wear tire here but I've spent the last year doing DE's on TT'ers "trash" A6's and have learned a bit about their wear in a DE environment, .....actually, let's pause here and read that again, "a DE environment". Mind you, I also stated that the 200 laps were at RA, which is wonderful on tires.

 

Did you see Mark and Dez's posts, regarding my comment, as replies to the other two comments that were, lets call them...... "less educated sounding" than yours? I get that I'm less experienced and a fairly easy target to try to slam but do you really think they would have posted if it wasn't true? Do you think that those two don't get all that is to be had from an A6? The fact is that arguing that it can't happen is like arguing that yesterday wasn't 11/23/13 (in the USA) ...it is already in the history books....already happened. Is the red stop sign not red? Was there no green on Senna's helmet?

 

What I said was that it's not impossible to get into a revolution with your tires so that you can end up running your no longer competitive A's in DE's and not have to swap them out for new scrubs after each session. I also think that as a new TT'er it could be advantageous to run the same tire for a while, to really become intimate with it.

 

Since the question was re: TT'ing a ZR1 I, possibly incorrectly....but I don't think so , assumed that the operating budget probably isn't on the same racetrack as my, "I'll take whatever A's you have as long as I can't see air", budget.

 

Cheers,

[Fair]

Sorry Chris, I might not have read your posts (and the others) closely enough. That is why I pointed out "competitive times", which referred to the ZR1 in TT1. And while it is a good idea to run on some R compounds in HPDE before steeping into TT, I feel that an A6 is a pretty delicate tire that can really bite you if you overheat it (they bite me all the time, heh).

 

 

For more consistent feel lap after lap, and none of the heat issues, I'd recommend a Hoosier R6 (or Kumho V710 or BFG R1 or a number of other R compound DOTs) over an A6. If you are going to be buying Rs just for HPDE, A6s don't really make a lot of sense, in my opinion. But people ignore my opinions all the time, heh. Sorry for not reading your posts as completely as I should have...

 

 

As for the whole reason for this thread, a ZR1 in TT1, it can be done and has been done. Sure, there might be more cost effective cars to run in TT1, even other Corvettes (C6 Z06?), but there's no denying that a ZR1 can be brutally fast in TT. In fact, due to their boosted/heat soak nature they might work better in the 2-3 lap blast of a Time Trial session than in a full out 20-30 minute HPDE session. Coolant and oil temperatures are always worth carefully monitoring, but otherwise these are very capable TT cars.

 

 

We have a customer who runs TT1 in his ZR1 and at only his 2nd TT event he won the class (ECR, Nov 2nd, 2013). This car is nearly stock, with the majority of the mods being the safety gear we installed (Cobra seats, sliders, harness bar, Schroth harnesses), some camber adjustment kits, and good sticky Michelin slicks.

 

 

That YouTube video above is in-car video (with data) from Corey's ZR1, winning TT1 and nearly besting the old track record for the class. Again, this is in a nearly bone stock ZR1 with OEM brakes, power, and suspension + slicks and some camber. Wow! That same day I set the TT3 track record at 1:55.2 Corey ran a 1:50.4 lap in this daily drivable street car.

 

ZR1 = LEGIT

 

Cheers,

[drivinhardz06]

Sorry Chris, I might not have read your posts (and the others) closely enough. That is why I pointed out "competitive times", which referred to the ZR1 in TT1.

 

 

Actually not sure exactly how many laps these have, we know we've done 160+ laps on them ourselves. They were bought from a former NASA national champ (Corvette) with 3 HC's, so we don't know if that's three practice shake downs sessions, or 3 races. They were ran on a C6Z07 (think ZR1 with an LS7, approx 170 lbs lighter) and that car holds the current TT3 record at Road Atlanta, on those tires, and was set after WE had put 90+ laps on them in TT and DE, and the DE pace was reasonably quick.

 

They will run the Dec event and see no reason why they won't last out the weekend based on past experience.

 

RA is an easy track on tires for wear, and the C5/C6 is likely going to be much easier on tires than mac strut/camber challenged stick axle cars. Tire wear can be very driver dependent, I like to think I am easy on them and training my student who owns said Z07 to drive similarly.

 

Lots of experience with the A6 here, no illusions that is the norm, but very possible depending on the environment. Lots of other examples of sets that went a long, long time.

[skrzastek]

I will do a seat and harnesses and a set of dedicated track wheels (18" CCWs or similar).

 

I really hope you left out roll bar on accident in this initial list.......

[Cobra4B]

It's not exactly easy to do a rollbar on an aluminum chassis street car.

[heavychevy]

I think there may be confusion in semantics.

 

You aren't going to get 200 competitive laps, but ANY (and many) of those laps down to the cords can be a competitive one. It's an impossibility to get 200 straight clean laps at our pace anyways. At least 50% of the laps will be slowed by 5-10 seconds due to traffic. A's will last easily with those kinds of laps.

 

And the non competitive ones aren't intermediate DE level times either, still fast, but maybe 7-8 10ths. There is enough sampling of fast Road Atlanta regulars that prove A6's are up to the task for a long time at our home track. It's hard to imagine until you experience it, they just keep going.

 

In fact, after about 8-10 HC, the A6's (to the cords) are faster than Pirelli DH slicks on my car. Mostly due to the DH falling off badly in braking and front grip and the rears keeping more grip creating push.

 

Hope that helps. Terry, if you come to Nationals in August, I bet you won't see nearly as big of a fall off as you are used to. And for TT, that suits the life much better than racing. I was a couple thousands off my lap record on A6's with 12-15 (can't remember exactly) HC's in March. They almost put me off the track on the first lap though.

 

PS: Tell Cory to get that aero for the ZR1 so he can compete with Messer and Weather.