I know there are many posts regarding this issue but I cannot find any in which there is full agreement. Spin has posted some very good threads regarding this issue but I ask another (knowledgeable member/vendor) and they disagree with his logic.

My situation.......

2008 Z with std 3.42 gearing. D1SC set @ ~ 10 PSI, blower cam, A&A Brkt, headers, and Pfadt adj coilovers and sways, RPM level VI trans, RPS Street Twin, and Nitto Invos. I beleive all the above will or may(for PL Sam) effect traction. All this equates to approx 725 RWHP and ??? torque (maybe 600-650 ft-#).

I know I will NOT eliminate my traction "problem" but how do I minimize it?

My opinion: 1st: Change to Nitto NT05 (for street driving), 2nd: Change to 3.73, 3.90, or 4.10 differential.

Notes: I avoid driving in the rain but in South FLA that is near impossible and I want a smooth ride. The addition of the INVO's completely changed the "smoothness" of the ride for the better.
I would like to road race (Strictly as a hobby) and may bring the car to the track (until they nail me for safety equipment - I am sure the car will break "their threshold"). I also have my OEM rims which can be equipped with Toyo's for RR. I have no intention of ever selling the car so upgrades, in my mind, are not a problem, ie., a new differential, but of course, $$ doesnt grow on trees and if it is not $$ well spent then why do it.

I have received so many different opinions (all from knowledgeable sources) I am lost. Switching from INVO's to NT05 is a "no brainer". The big question is the differential.

If I change to 3.73, 3.9 or 4.1 I will be shifting more often or earlier - no problem for me. I run this through my mind and it seems I will spin in 1st no matter what, second and third are the key to the solution. Upon gaining momentum and topping out in 1st, 2nd should (?) have a greater chance of gaining traction? If this holds true then 3rd, provided I ease into it via clutch "riding" should grab and off I go (the same MAY apply in 2nd).

The option or suggestion of widening the rear rim and putting a different tire on the back has come up. This is NOT out of the question but I am already 345/30ZR19 on the rear. If I go to NT05 the size would change to 335/30ZR19. I have spent a small fortune on Forgeline rims and would rather not change.

So.............this being my dilemna, what would you do? I am strongly leaning towards giving the NT05 a chance even though they will not ride as "nice" as the INVO's and switching to either a 3.73 or 3.90 rear-end.

Does anyone have 1st hand experience between NT05 and INVO's?

I have received comments that INVO's have terrible traction but coming from run-craps the difference is definitely in favor of INVO.

 

Tires are your best option right now. Nitto's are good, but they don't make anything in a 19, so you would have to run an 18 if you wanted to go with them......It seems like nobody makes anything in a 19 drag, slick, etc.

With a Z making that much power, I'd look into running a 345-30-18 MH drag radial. I've seen what these tires can do first hand on a TT car, and they seem to be really nice.

If you are having traction issues, the last thing you want to do is put in a shorter gear, this would cause you to rev faster which means you will be spinning tires worse.

 

"If you are having traction issues, the last thing you want to do is put in a shorter gear, this would cause you to rev faster which means you will be spinning tires worse."


The above statement is exactly where the point of contention is. Many will argue on this exact theory. I am torn between whom is right or wrong as all the input I have received is from reputable and very knowledgable folks. Theoretically is sounds like a fair statement but so does the opposite.

Look at it this way. You are running race from 40 or 50mph thru 100. Are you more likely to spin from thru 2nd and 3rd if you hammer it at 40 (when the momentum is already well under way?).

The tires are going to smoke in 1st no matter what you do unless of course you proceed at a slow to moderate pace but that's not what we are talking here.

If you get THROUGH first and then shift to second the spin will moderate at 2nd. The thinking is.......the quicker you can redline 1st the quicker you get to second and the wheel spin is then manageable.

 

if you are only going to run it on the track once in awhile I would get a set of 18,s widened for that purpose and run the 19,s the rest of the time, thats what I have decided to do.

 

According to SpinMonster:
linkage:
http://forums.corvetteforum.com/c6-t...oo-tall-2.html

Of course he was talking about the A6, but I'd presume the same holds true.

 

6 speed automatic - don't think paddle shifters are an option for you now but wouldn't that be great!!

 

Well...............he (spin) is one of the knowledgeable sources I speak of ......however, I have others that disagree. This being the dilemna. Who is correct. I would rather not go out, buy an RPM differential (look at the price for a Z06 ), and then find Spin's theory does not hold true.

I see this thread as an opportunity to reach a concensus or continue the argument.

I can moderate the throttle as anyone can but I dont see that as the best option.

I dont know if there is a all encompassing answer but there has to be at least a consensus that yes or no - this "formula" will in fact - Increase Traction.

This is primarily a street car to be road raced as a hobby - I dont care if I come in last place - it would just be fun to run around a track. Being in S.Fla the only turns I see are at stop lights.

 

On the street you cause is lost. Most of the time the road is not going to be in the best conditions for you to get traction especially at that power level. I would focus on getting a tire for the track and have your fun there as 700+ hp on the street without traction is scary. MT makes a great d/r and also a great full slick. With you power level I would probably run a full slick. But ultimatley the choice is yours. Speaking from gear upgrade experience it will not make your street traction any better. The gears help place you higher in your torque curve so more of that crap is getting put down faster. They will defintely make the car scream though.

 

I want him to add his words of wisdom.

 

All I can say is this: I had a 99 Trans Am making 450 rwhp with 3.42 gears. It would spin through 3rd without a problem if I let it...It was controllable though......I then swapped to 4.10's..... It went from bad to worse...Yes, the 4.10's allowed it to rev up quicker, and from a roll it was great WHEN it would get traction......but forget 1+2 gear from a dig or any speed!......That was just 450 RWHP....I could only see your car being a whole lot worse!! I just don't see how anyone could say that switching to a shorter gear is the answer for traction.. Maybe it's me. What do I know?

 

Not presuming to talk for Guy, but the Spinmonster has >700WHP and runs 305s on an 18" wheel through 4.10s. He has a thread devoted to solving the traction issues. He doesn't have traction issues......

 

CPG1962!! I would take it 1 step at a time. Do systematic changes and go from there.

1. Tires would be my first change. Either dedicated M&H DR's like mentioned or give NT-05's a shot they have recieved great reviews!!

2. Bigger tire

3. Softer suspension

4. As far as Spinmonster goes I would like to see a in car speedo vid of him without any traction issues. I would be one of the people argueing his higher final drive theory.


OT
That is 1 thing I miss about my old EVO is traction. A friend had a 653whp EVO and it just hooked from 35mph roll I know my Z06 will never be able to do that!! If I still even minutely cared about racing on the street I would have kept the EVO. I'm older now and don't care about that stuff anymore.

I still have the video of Mike (750whp EVO) beating a 1000rwhp TT Z06 40-160mph by multiple lengths and beating a 8 second Ls1 from a dig on the street.

Bottom line it's hard to hook when you get to that 600whp+ power level.

Good luck

 

I don't yet have experience with NT05s, but I just got my INVOs and they are far, FAR better than the stock RFs. And they haven't even been broken in yet - it's still day 1.

Of course, I'm stock right now.. Guess this might be up my alley later on, though you're still going to have 200rwhp on me So maybe my INVOs will still work great

 

I guess you never had traction!!!!!!!!!!!
If you would have ,you would not be saying that!!!
my 342 a6 with DRs will not spin at all, yet if I put on my Toyo T1r's
I can spin thru 3rd, but then I used to do the same thing with my 2.56"s
so it's a traction (tire) issue!!!!!!!! not a gear issue!!!!!

 

It's not hard to hook, if you have the right tire's and wheel combo.

 

I would like to see a video of a vette not having traction issues with 700+whp using a 18" or 19" tire and a manual in 1st gear

It's all about trade offs the softer the tire, more sidewall, the better the bite, but there goes handling

 

Ever had 4.10's, a 6-speed, and over 450 RWHP????...If you did, you wouldn't be arguing my statements .......If the most you've ever had was a 3.42 gear, how can you speak for someone who is thinking about 4.10's with 750 RWHP?????

Did I hit a sore spot cause I disagreed with Spin???? God Forbid!!!!!

 

Well, do you want traction???? there is allways a trade off!!!
you can't have both, it's either a 1/4 mile car or a street car!!!

 

God is not here.
I can tell you that my car has more than 450hp
I know what hook up is!!! I've been in the 7's @ 190 so I know how it feels.
4.10 with 750rwhp is useless if you DON'T KNOW how to drive!!!!
it will never have traction if you don't have the right combo for what you are trying to achieve
KEYWORDS driver/combo

 

M&H'S tire is a 345/"35"/18.{not 30}
I just got mine and am waiting to install them!
They should give me very good traction!!