Legacy Z06

This is summer #2 I've had the vette (01 Z06), its used as a track car with occasional street driving. I've done 6 HPDE's and 1 autox with the NT05's from new. Cold pressure is 30lbs, here's hot readings from one of my HPDE days on a medium hot day

Front
38-37.5
Rear
38-38

Just checking with others to see if my wear is "typical". I realize I'm running higher PSI than most here, this is what I ran on my last car and it seems to work well on my vette, I can run 20-25 mins without them getting greasy. From what I"m used to, there shoul be more wear on the edges of the tires than the middle which is not the case here but this is coming from AWD experience and I never ran NT05's till now. How's my tires look ?


Both tracks I've driven run clockwise so as expected there's more wear on the driver side. Here's how they look today, I've put them Left/Right as they would be mounted on the car so the wear 'n tear is respective to the correct side in the pics :

Fronts



Driver





Passenger





Rear



Driver





Passenger

lefrog

This is a typical wear pattern for the NT05 but you are running too much pressure in them. I usually target 34/35 psi hot. I usually start them at 28 cold.

TheKomoman

On both points. Running that much pressure you're giving up a lot of grip by reducing your contact patch. Yes the outside is wearing because of sidewall roll but that center wear is your launch and you want as much rubber on the ground as possible.

Racer86

Take the next step and get a tire pyrometer. It will tell you what your tires are doing and what they want as far as camber, caster, toe, and pressure.
As posted, it looks like your pressure is to high and causing the center to wear.
do yourself a favor and learn how to tune a tire and suspension system for your style of driving. You will have many new friends at a track day that will want you to share your new found knowledge.

Chevy Nick

I see similar wear on my NT-05 tires.

SunnydayDILYSI

Had the same experience before moving to dedicated track car and NT01s, which made a big difference in grip and lap time (~1 sec on 90 sec lap).

Legacy Z06

Ok guys thanks for the input. I'm just used to my previous car which 40lbs is standard PSI. Will let some air out of these tires and hopefully I'll gain a little traction too.

For the street should I run less than the 30lbs recommended by GM ?

FASTFATBOY

The lower pressure will help, be patient and wait for temp and pressures to come up though before you start to "boogie".

Car could stand .5 more camber also, that corner wear will be much better with more camber as will grip.

Legacy Z06

Usually I do a full lap at my local track = 3 miles

c4cruiser

Starting with the factory recommendation of 30psi at all corners should be fine. When I run my NT-05's on a track, I'll start with 28 front and 26 in back.

What was your car that had a recommended 40 psi??

Legacy Z06

Subaru - street is 30-31, track use : high 30's low 40's isn't uncommon. Heck I had RA1's at 35lbs by accident one day which cause snap oversteer through a slalom section, up the pressure and no issues. Just ingrained in me after 10+ years but I need to accept this is a completely different car . AWD vs RWD.

Apocolipse

Different sidewall stiffness.

96GS#007

with all the others. Too much pressure on the track. Target 32-34 hot. Looks like there's some scrubbing so you may want to check the toe as well.

30psi on the street is fine.

Bill Dearborn

I ran 28 front and 26 rear with my NT05s. Front wear looked very similar to what yours are doing. Rears wore pretty much evenly. I got 26 track days out of them but they never did perform as well as a set of worn EMTs. They really aren't wearing more in the center of the tread (more to the outside) and the outside edge of the center block is worn off with tread depth increasing as you move inward on the tires. I suspect that type of wear is more due to scrubbing the tires in turns. The toe settings may need adjusting.

Bill

TKOGTO

I got the same wear pattern with my NT-05s and now with MPSS'. My averages come out a little lower: 35.5 34.7 35.0 34.2 (RF, LF, RR, LR respectively) but this likely due to a) I do adjust the fronts 1 or 2 psi lower (from 30) to get all 4 as close to equal as I can by the end of a session and b) I take my measurements back in the paddock.

There was another post on this a short time ago. Here it is: http://forums.corvetteforum.com/auto...ion-nt05s.html. Most suggested this wear pattern was due to psi's that were too high but a couple of very knowledgeable drivers suggested the opposite. As I am unsure which is correct, I have kept my starting levels the same and just rotated the MPSS' side to side every other track day. This has evened out the center wear enough to continue the practice.

Legacy Z06

Ok just did a track day last night. It was a short one but not much time so this is what I did. For the first session I left PSI where it was as I'm used to it and wanted to set a baseline for handling for a proper A/B comparison. Then came into the pits and checked pressure, was around 38. Dropped it all around to 33, guy with C6 was telling me according to his pyrometer to go even lower 30 but I figured lets drop it in increments.

Went out again and no weird handling thankfully . Took it easy the first full lap then started to push. It felt different , noticeably different on turn in. I'd say there was more traction (wish I had G meter instead of Butt-G meter) but I'd say it felt sharper turning in and hung more. Didn't get a chance to really push it as there was a ton of traffic then an Yaris blew a motor and dropped oil everywhere.

So ok 33 is good. Should I drop even further to 30 or is that pushing it ?

bluemagoo

I have to agree with others. Yours is a fairly typical NT05 wear pattern but it appears that your running too much pressure. Tire pressures will can vary quite a bit throughout the day as the ambient temp changes.

When I ran these tires I generally started around F28 & R27 "cold" but often needed to bleed off a little pressure as the day progressed and outside temps rose. I used the "triangles" on the shoulders of these tires as a guide and attempted to keep the wear right at the peak of the triangle. If I was short of the peak on a particular tire(s) I lowered pressure 1-2 lb and checked again after the next session.

Not as good as using a tire pyrometer however.

Supercharged111

I did 32 hot but noticed the centers wearing more than the outsides so thinking I should have dropped to 30 myself.