VT_Z06

Hey all!

New Vette, new member, loving it a ton! But, I've got lots of questions too and one that I haven't found an answer for yet is traction, so here it goes.

Currently running 385whp/360wtq on 335/30/18 rear tires (BFGoodrich g-Force T/A KDW-2) and I've been having problems getting the car to hook. Now, I'm not launching it like a nut or smashing it from a slow roll, but it just seems like the car is more than happy to break the tires loose and it has me a little concerned about adding a cam down the line and increasing power by 60-80hp/tq if it's already tough to put it down.

I figured tires that wide and sticky would help a lot, but are there suspension mods I need to do as well? (current on stock stuff, but lowered) OR, am I simply expecting too much and the car is going to spin if I hit it in first and second.

Cliffs: Car should hook better with 335 width tires, or am I expecting too much and I need to accept it/drive lighter.

Thanks guys!

-VT_Z06

scramblerman

iTrader: (16)

The KDW2 tires are pretty decent tires for a stock Z06. I had a 02 Z06 with a big cam/440rwhp. The KDW's wouldn't hook in 1st into half of second gear. I had nitto 555r2 drag radials and those would hook in second, spin a little in first. I had stock size rear tires, kdw's were 295's and would run 28 psi in them. The nittos were about 26psi. Now this was on pretty warm days. Upper 70's to upper 80's. If it was in the low to mid 50's, then the kdw's wouldn't hook at all. The nitto's didn't hook till they got pretty warm.

How much psi are you running in the rear tires.

btw welcome to ls1tech and post some pic's of the Z06.

VT_Z06

Thanks for the welcome!

Currently running 30psi all four corners, but it sounds like a few less would help? I will admit that this has all been judged in 50 and 60 degree weather (dry of course) so we'll see what happens when it hits 70+ again. I just didn't expect to slip the clutch at 1500 rpm and have wheel spin, or go 30% throttle in second and get spin, lol. I don't think I really want to run DRs all the time and go through a couple sets per year!!

Buckwheat

iTrader: (13)

Being lowered isn't giving you any weight transfer so the rear can squat and hook. Even unlowered though I start off in second a lot when it's cool out.

MPM IV

iTrader: (3)

Typed a bunch of possibilities and then saw the temps. Try again when it's warmer and you should have better results.

brians91formula

iTrader: (12)

^ I agree. Once the temperature drops, traction becomes a huge problem.

V-seriesTech

iTrader: (5)

drag radials are your friend,.....or, toyo RA1's, which are exceptional handling and launching tires. C5's are a man's car,...as in they take alot of skill to drop the hammer and keep it moving/accelerating hard, and straight. C6's on the other hand, are simpleto launch, in comparison.

ambient temp, is obviously an issue but, j think a warm drag radial would help,...alot.

Welcome to the Corvette section of tech, and congratulations on your ride. Have fun!

SCM_Crash

iTrader: (2)

How old are the tires? Did you buy the car with the tires? If they're old, they get dry and don't track well at all. I had KDWs on my LT1 and they hardly held the power. I haven't tried the KDW2s though.

I don't know where you're located, but honestly, in this cold weather right now, I'd be surprised if brand new KDWs or even brand new RA1s could hold first or second gear right now... I have T1Rs on my car right now which are a step down from the RA1s, and I can break them loose in 3rd on the freeway with our weather lately.

With 335/30/18s, you should be able to find a decent performance tire that can hold the power. I don't know what your purpose for the car is, but if you're just daily driving the car, you should look at some Nitto Invos or NT05s. Those are good daily driveable tires with decent all-weather track. The NT05's will definitely hold the power at a 335 width. If you're not going to drive in the rain, either the Toyo RA1s or the Nitto NT01s would be a good pick. Those hold lots more power but wear much quicker. I think the RA1s are 200 tread wear and the NT01s are 100. But a lower tread wear rating means it's a softer stickier tire.

EDIT: Not 100% sure if those tires all come in that size. Good luck with the hunt.

TheHitman

iTrader: (2)

If traction gets bad you can always go to an R Comp tire. (R888, PS2)

VT_Z06

Haha, TheHitman, I see you on Supraforums just about every day reading the Other Cars section. I've been on there for 7 years now, talk about a small world!!

Thanks guys, all the info is really helpful. I do suspect the temps to be somewhat of an issue, so I guess I won't know until this summer.

I'll be sort of DDing this car when it's warm and dry, though. Why buy a fun car if you aren't going to drive it? Probably 8-10k miles per year. DRs are probably going to wear out too quick and the cost of getting 2 sets a year might be annoying, but I'll definitely check on the other alternatives mentioned. The biggest issue so far, has been finding them in 335/30. I could probably find more available in 315/30 and it might not make that much of a difference.

Quick pic of the car, while I'm here

ysb02

Do you have it mini-tubbed to fit the 335s in back?

VT_Z06

Yes, it was. Pretty hard to tell though.

dudeiwin86

iTrader: (1)

see if you can jack the car up and get a good look at your contact patch on the tires.

i had an issue in my dodge (with IRS and lowered) where it would squat and only the insides of the tires were touching the pavement.

adding a little + to your camber will help if that is the case, but not too much, it can adversely effect cornering.

--

regardless of the above... i would just suck it up and get an R compound tire.
NT555R's or NT05R's.
at least for the rear... ive also heard good things about the Toyo TQ tires on the street too.

these are "drag radials" but more for street than the track IMO. and will last about 10k miles unless youre smoking them regularly.

SCM_Crash

iTrader: (2)

Yeah... The Z06s had a pretty aggressive track camber / alignment from the factory for cornering. I forgot all about that. Front tires and back. The base coupe and verts didn't come nearly as aggressive.

Are the NT05Rs OK for handling? They're a drag radial from what I've seen. The NT05's are a decent daily driveable road-race type. But the NT05Rs I can't recall being good for road racing.

scramblerman

iTrader: (16)

Good point about the camber, forgot all about that. On the Z06's I believe they were set at -2 degrees camber. When I lowered my car I had them put the camber to 0 degree's camber. Made a big difference in the contact patch. No more fade from the inside to the outside of the tire.

ctd

iTrader: (1)

I have a set of KDW II's, I rate them as junk. Hard & horrible road noise. I switched them for PS2's, much improved, as long as the air temp's are warm.

My alignment is -1* in the rear & -1.8 in the front, slight toe in rear & slight toe out front. I still like to go around the occasional corner @ excessive speed.

Tires are only good for about 2 years regardless of tread, rubber goes hard.

VT_Z06

CTD: You really don't like those tires, huh? I wouldn't rate them as the best I've used, but they were on the wheels, so there they will stay until used up. However, should I decide to get some Toyos, or NT05s, or something similar, the KDWs might find themselves wearing out a little quicker than normal

I'm still in the learning phase with this car and probably will be for all of next year as well. We have some great twisty mountain roads that I go through at 100% with the WRX. However, in the Vette I imagine I'll putter through at about 40% until I can feel out how it handles.

I appreciate the suggestions so far guys, definitely some good food for thought.

VT_Z06

Just found some NT555r in 335/30/18 for $280 each, not bad.

ctd

iTrader: (1)

Awesome to have a fellow mountain rider. Were abouts are you?

VT_Z06

Currently in the frozen tundra of Vermont, but within a year I'll be headed to - hopefully - Texas