X25

Yes, I planned for my track build based on the experiences of forum members and some of the vendors that prep track cars, and now that I've tested various setups myself, I think I was quite a bit mislead. I already knew that FE4 didn't work well with stickier/wider rubber, but FE3 didn't work well at all, either. I was also mislead by how great the T1 is, perhaps it really is good, but since I am not leaving the tire sizes stock or close to stock, it is a bit irrelevant. Even the Michelin race series don't go wider than 265 up front, which should have been a clue.

You could obviously try Z07 springs, but why bother, your shocks' tune would be off. Using sway bars is a good idea, but during my whole track experience with various cars, I was always told that the sways should be used to fine-tune, not fix issues, so that also feels a bit counter-productive.

This is a long discussion, and I'm sure we will have more of it : ) I have been staying a bit silent on my own build thread regarding these findings, since I would like to attend more track days first with my current setup to validate a few findings. It has been proving hard to do so, though, since fall/winter season is here : (

umiami2312

Well guys....(X25 and BaylorCorvette), I've been following you both for a while on Camaro5 and see you are now on here. I just upgraded this week from a 13' 1LE to a '14 Z51 M7. I love the track discussion (and videos) and am looking forward to seeing how your build progresses.

While I want to get a feel for the car on the street for a bit before I book a track day, I'm looking forward to feeling the difference between my former 1LE and the Corvette. Your first impressions post on this thread was very enlightening and I can't wait to see for myself.

X25

Welcome! I have to say, the new Camaros are also looking great. If I had space in the garage, I would seriously consider adding a ZL1, too. I found a manual black '17 ZL1 at $63K MSRP, on sale for $57K; incredible value!

This car is teaching me the impact of matching tire changes with suspension changes. I'm looking forward to trying my car out at my other local tracks : )

BaylorCorvette

Welcome to the club umiami2312 , you'll love the car. The Corvette is such a point and shoot vehicle (assuming the rear caster is aligned properly!)

If that isn't the truth I don't know what is! The 5th gens (at least the ZL1) was way much less sensitive to tire size changes.

AKKutz

This leaves me still in a dead spot. I've tracked the stock PSS and ate them up in three track events, which didn't lend to many miles driven. My search is on for a wheel/tire track package and all this info is making it harder to decide what to do.


I have to say, that I enjoyed the way my car handled running the LG bars and everything else being stock (mag ride).


But, I don't know what to do for wheels/tires for the track! I came close to purchasing 18x10.5/315 squares off of descartefool, but wasn't sure that was the way to go. Now, I am totally lost!

NT4HIM

Congrats on your new personal best, Baylor! Looking forward to hearing about lowering your times further with the Pirelli scrubs. You'll definitely want to install the LG sways prior to the scrubs, though, or you'll be further disappointed in the handling. Not sure about the impact on a non-mag ride car, but the LG sways reduced the roll and understeer by about 50% in my mag ride car with no other suspension changes, and with the scrubs, the car was a ton of fun!

BaylorCorvette

I'm glad that X25 came to the same conclusion as me about the car not feeling "right" on the wider tires. I thought this was all in my mind and it was really starting to frustrate me. What's even more annoying is that a set of Nitto NT01's lasted me about three days!!! It's way cheaper to run scrubs than it is to run DOT tires, which is nuts since scrubs are several seconds faster than DOTs! X25 has clearly shown (in his build thread) that on coil overs and sways the Z51 puts down some seriously impressive times with wider tires. I'd love to upgrade the sways only and see how the wider DOT tires handle but I just cannot justify the cost vs. scrubs, so unfortunately I think my DOT tire testing on anything other than OEM tire/wheels has come to a conclusion.

Thanks! It's unfortunate about the tire issue you had Sunday, but at least you get another crack at TWS this weekend.

Glad you gave feedback about scrubs on OEM sways & LG Sways. I would only assume that scrubs and OEM sways would be worse on a non mag ride car than on a mag ride car since the dampers aren't adjusting to help adept to the scrubs. I'm going to be in an interesting situation, since I'm only doing the front sway bar (to maintain SCCA eligibility), the car is going to understeer more with just the front, so I suspect that my set up is going to suck on scrubs for the road course. If that's the case I'll just do the rear sway and coil overs this time next year and just compete in the unlimited class in SCCA

X25

If I didn't insist on making 315/325 work, and revert back to 275/305, I would never know what I would be missing! Most of my confusion is coming from the feedback from forum members here, where they swear by the stellar performance they got with their 315/30/18 square NT01 or similar R7 setups, where noone could even come close to them at the track. Knowing what I know now, at least for FE3, they probably didn't realize how much better it could be, and/or their local competition was not good enough to make them realize their vulnerabilities.

It doesn't stop with the forum members, either. Take a look at this vendor post:
https://www.corvetteforum.com/forums...rformance.html
...
Reading all this, since almost everyone who use Hoosiers use wide tires, wouldn't you think that T1 works well with Hoosiers? Well, I know for a fact now that the springs these T1 shocks are designed for will be way too soft for the Hoosiers, and any other spring will not be matching the shock valving, so the answer is a big resounding NO. You might say they take sway bars into account, too. Again, the answer is still NO: T1 sway bars that I had were not able to save my handling issues.

Based on my experience, I don't think 315s would work well on stock suspension. Now, I don't know how the FE4 behaves with stickier tires, but I've already read about FE4 being even more sensitive, so I doubt it would be good. In short, yes, you can make an excellent handling car with those tires, but you will have to work on the suspension. If your car has MR, then I think you should consider LG sways (not Z07 since you want square balance), Z07 springs + DSC controller for the matching shock tune; that might make an incredibly-well-handling car.

AKKutz

Originally Posted by X25
Based on my experience, I don't think 315s would work well on stock suspension. Now, I don't know how the FE4 behaves with stickier tires, but I've already read about FE4 being even more sensitive, so I doubt it would be good. In short, yes, you can make an excellent handling car with those tires, but you will have to work on the suspension. If your car has MR, then I think you should consider LG sways (not Z07 since you want square balance), Z07 springs + DSC controller for the matching shock tune; that might make an incredibly-well-handling car.


I have the LG sways. And am waiting on the DSC controller. However, I still don't know what to do for wheels and tires! I'd like to run the NT-01. Porsche GT3 driver I know gets a ton of track miles off his. I was really surprised when I wore the inside of my PSS's to slicks after only three track days. And now reading about Baylor's experience with the NT-01 it has me guessing. It looks like wider is better... just wish there was an easy answer!

BaylorCorvette

It really is surprising that I only got three good days (~400 track miles) out of the NT01's. The instructor that I was talking to was shocked, he has an FRS and the NT01's last nearly a season for him. On my ZL1 I was getting about 5-6 days when I was running a 305 square NT01 set up.

Kamran

Could have been a bad batch. I got three days on my last set of NT01's too! I have typically been getting 4 to 4.5 days on them for the last three years, with my silly little FRS, driving pretty much at its limit! If someone told you theirs last a whole season driving an FRS, then I'd question if they are being overly gentle!

tiborrules

I am wanting to invest in a track tire & wheel combo and have been following both x25 and your threads. Any comments and help would be appreciated. I don't want to damage my fenders and I want to keep my car streetable. I will do 3-5 track days a year at Hallett Raceway. A day there is 4-5 sessions 15 minutes each. I have a 15 c7 z51 car with mag ride. Modifications so far are a procharger, catless x pipe, mgw shifter, PSS 265 / 305 tires for the street and the car has been lowered some on the stock bolts. I want to run faster times and still have a very streetable car as it is a blast to drive with the sc. I have bought z06 iron brake calipers and girodisc rotors plus ss lines for the front and rear (not installed yet). I am going to buy either a DeWitts radiator or the GM secondary radiator kit plus it sounds like I need to buy the LG sway bars.

I am thinking of buying GT2 wheels from LG that are a 18x9 and 19x10.5. I want to run as fast as possible on the track for a reasonable price and have looked at Hoosier R7, Nt01 and R888 and would consider scrubs if I can find them. I am open to both tire and wheel combo's but just want to keep a reasonable price. For track only, any suggestions?

BaylorCorvette

Really comes down to how much you want to spend on wheels and tires. I went the cheaper route and bought TSWs Corvette brand wheels which I think is Cray or something similar (I just landed in Vegas and I'm currently sitting in a restaurant eating a late lunch and then I'm driving to Spring Mountain). I'm sure LG wheel combo is great but I have no issues with my wheels, fitment or otherwise. Tire wise, like I've mentioned I'm not happy with the NT01s. I rain a faster time on the stock PSS run flats on only my second lap out with them. Mean while I had maybe 500-600 track miles on the NT01s. Point being I didn't know what to expect on the PSS and was going easier than I was on the NT01s. Now I don't know if it is because I went wider with the NT01s front and back and the car didn't like that or what. But I'm going to pick some people's brains at Spring Mountain the next couple of days.

My one piece of advise is to not run slicks until you master a DOT tire.

X25

On a related note, I think Cray Spiders (which I believe are what you have) are great wheels with low weight, much lower than LG's offering, but unfortunately they do not clear C7 Z06 iron brakes. If you intend to upgrade your brakes in future, this would be an issue.

tiborrules

Thanks for your comments and have fun at spring mountain. I was there a little over a year ago and enjoyed it. There were 7 stingrays and 4 z06's in my class. At the end of the first day I had the fastest lap times in my z51 so they put me in a group with 2 z06's. The instructors were really good at pushing us letting you drive as fast as you could as long as you were the front car.

The corvette knock offs would be the cheapest however I want a wider wheel as I would at least like to run a 275 front and 305 rear and the stock wheel width is stretching it a bit. The GT2 is a half inch wider than stock and doesn't require any spacers to clear the z06 brakes. I figure after a season on them I will consider upgrading to something like x25 has as I would like to run as wide a front tire as possible without hitting the fenders. I am bummed to hear about the NT01 as that was my first choice. I can get R888 in either a 285/30/18 or a 275/35/18 then match it with a 305/30/19. The 30 series front puts me at 1.068 ratio to the rear with the 35 series at 1.03. Some guys seem to like the R888's but some say they just stick ok the R888R is better. I ran Hoosier R6's on my c6 z06 and really liked them a lot as they stick like glue. So I am considering the R7. They are more expensive and won't last as long. I've also looked at the R888R. I have heard better remarks about them vs the R888. They are only available in a 275/35/18 or a 295/301/18 which I am worried might be too wide. For rears they also come in a 305/30/19. Maybe the R888R's in 275 and 305 would be the way to go for now and when it's time to replace the tires, consider if I want to go to the next level with slicks and more suspension mod's.

X25

Don't lose your faith in NT01s just yet. I also tried 275 / 305 NT01s, and I also didn't like the performance, as in, I could not hit times I should. When I later switched to 315/325 NT01s, the traction has increased so much, that the car started leaning substantially in corners, eventually rubbing on all 4 corners. If you think abou it, leaning too much due to traction is a good problem to have : ) Later, I switched to coilovers with stiffer springs that were adequate for these tires, and my time at the very same track dropped by 6 seconds.

Jury is still out, and I'm sure we will dig this further this next season. That said, I can tell from my and my brother's experience that R888s are vastly inferior tires, at least in our experience. I am looking forward to hearing news about the R888Rs, but some forum posts claim it's the same compound with different thread pattern, which would be disappointing. We shall see.

daleong

Has anyone just put Cup 2's in the stock Z51 sizes on and seen how that works as an option for the track?

lobsterroboto

Op, seeing your times I'm noticing that you're multiple seconds off pace of a completely stock Z51 at both TWS & MSRH.

Why would you want to be making modifications (obviously other than brake pads and cooling)

I'm not trying to be rude at all, just to get a better understanding.

ETA: I'm off pace too so im in no competition. I'm currently at 1:58 @ TWS & 1:48 @ MSRH.

Also, were you at the HPD autox this last summer I think on the 9th of september? If so I rode with you.

NT4HIM

I'm not so sure that your 1:58s on street tires at TWS are off pace. I had an instructor (Corvette driver) tell me that any sub 2 min lap on street tires was nothing to scoff at. Maybe he was just being nice to the lady driver, lol. Anyway, not sure about the OP', but I changed sway bars in my Z51 for the cost savings....OEM tires are too expensive for my track hobby and scrubs can be had at a reasonable cost. Problem is, the car isn't tuned for those tires, and the handling went away. Plus I tore up 2 splitters from scraping them and rubbed big holes in the wheel liners the car was rolling so bad. The sways cut way down on that significantly. I think the LG sways along with the DSC controller for the mag shocks would have been about all I needed for my level driving, but ended up trading the car before the controller was released.

BaylorCorvette

Anything sub two minutes at TWS is pretty good. I run with chin in the Blue Group (intermediate) which is primarily people running mid 1:50s to about 2:05s. The next level up is red group which is advanced and instructors running mid to high 1:40s to low 1:50s. The 1:58 I ended up running at TWS was effectively a stock Z51 (minus pads and fluids)

Yes that was probably me. That's about the time I started running with SCCA.