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guys, I'm really having a hard time deceiving what to do tire-wise. I am in the process of getting the brakes wrapped up, which has always been the weak spot of the car, next to the driver and cheap tires that weren't really made for what I was doing with them. with 13" brakes up front, discs all the way around, and a new set of hp plus pads, the brakes should not be the problem anymore. I've been working pretty hard on the driver, to that leads me to tires.

 here are the specs on the car, for those that don't know:

'86 Mustang GT

Maximum Motorsports caster/camber plates

Tokico illumina struts/shocks

H&R Race Springs (800#)fronts only

Steeda 350# rear springs

Steeda 5-link-2

Cobra 13" front brakes

11.65" rear brakes

car usually runs about -2.75* camber, can't remember caster or toe, but as much as possible

oh, stock sway bars

The car has great turn-in and minimal understeer with this setup, which I like, but has limited rear traction, even with staggered size tires (245/40F, 275/40-17R). Needless to say it's a handful. I got a great deal on some 99 Gt wheels, which i plan to use for track time. They are 17x8's and I'm unsure on the backspacing. Here's what I'm contemplating: Should I go with the nt-05 street tires, or the nt-01 R-comps? should I continue to run staggered sizes? Both tires seen to do well for what they are, as well as being worlds better than what's on the car. I've gotten a really good price on both particular tires, so price is not the issue in the decision.

 

Tell me what you guys think, and anyone that has driven my car is more than welcome to chime in with their experience as well. Thanks!

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Just trying to get some Seat Time!

86 Mustang GT - maybe one day it will be fast!

forgive the way that post looks. I tried to post from my cell phone, but for whatever reason, opera and sccaforums is not agreeing. all of my spaces between my paragraphs are not there and for some reason my capital letters aren't all showing. I tried to delete the post, but the site won't let me. I'll get it all straightened out after I get to work tomorrow.

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Just trying to get some Seat Time!

86 Mustang GT - maybe one day it will be fast!

What class are you aiming for?  If nothing throws your out of an ST class (or just run street tire here in MS w/ whatever setup) grab some street tires for a season or so.  They will teach you about the limit but not cover many mistakes and it will be easier to find the vice/virutes of your setup(when/wear it understeers or oversteers)

 

The Street tires that are winning are currently:

yoko AD08 and 07

Bridgestone RE-11

Dunlop SS

Kuhmo XS

Toyo R1R

 

For the money(for the above mentioned) you can't beat the dunlops, 90% of the grip of yoks but $615/set instead of $950/set in 245's.  If you want the last bit of performance its probably going to be between bstones, yoks and possibly the toyos.  For wear as well, can't beat the dunlops, they lasted me 9 months for about 15 events, we'll see how the bstones do.

 

None of this is to say either of the Nittos will be bad, I just have no comparison and with how cheap and proven the dunlops are why pass em up?

 

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Rob P.

05' Subaru WRX--#85 STX

Grassroots Motorsports did a comparison lately at although the car that they used was a light one (Hollis' Civic, I think) they loved the Kumho XS. Tire Rack has them for $600 + shipping in those sizes. Worth looking into, anyway.

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Mississippi Region #97 STU

For now, I am running the car in ESP, so the use of street tires would only help in our region - anywhere else, I'd be blown out of the water by cars on R-comps more than likely. 

 On the dunlops, you must be really conservative on tires. You are the only person that has said anything postive about longevity with this tire. They also do not offer the sizes I need, and from what I have read, are really made for a lighter car. I would guesstimate (ASSume) that my car weighs around 3400+ without me, and I'm a pretty chunky fellow. 

Drew, I'll check the xs's out too... what are your thoughts on staggered vs same size? 

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Just trying to get some Seat Time!

86 Mustang GT - maybe one day it will be fast!

dboyles:

Grassroots Motorsports did a comparison lately at although the car that they used was a light one (Hollis' Civic, I think) they loved the Kumho XS. Tire Rack has them for $600 + shipping in those sizes. Worth looking into, anyway.

 

Most of the heavy cars are doing better with dunlops, bstones or yoks, but they're still probably worth the money, I just haven't heard any STX, STU, etc folks liking them. 

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Rob P.

05' Subaru WRX--#85 STX

Michael Melcher:

For now, I am running the car in ESP, so the use of street tires would only help in our region - anywhere else, I'd be blown out of the water by cars on R-comps more than likely. 

 On the dunlops, you must be really conservative on tires. You are the only person that has said anything postive about longevity with this tire. They also do not offer the sizes I need, and from what I have read, are really made for a lighter car. I would guesstimate (ASSume) that my car weighs around 3400+ without me, and I'm a pretty chunky fellow. 

 Here's some posts from street tire guys:

http://sccaforums.com/forums/thread/362805.aspx

BrianGT is one of the fastest guys in my class(2800lb car, compared to grassroots 2000lb car), he has done tons of testing and spends thousands on tires, so for a heavier than miata sized car on street tires there arent many better places to get data.  He also has a civic, so compares how a tire does on a light vs. a heavy car.  All of the STI's are following the same lines too(3200lb range): dunlop=$, bstone=$$ ,yoks=$$$, with only a small margin between bstone and yok and bstone offers contingency money. 

That being said, most of the data says nothing of longevity, so while those three grip well, in comparison the kuhmos may very well last longer on a heavy car, but these grip better on a heavy car.   

The Kuhmo's will probably work just fine in MS if that's where you're staying, but if they're only $15 more i'd get dunlops if it were me.  And besides, if they do wear out fast, then you'll have an excuse to be ready for rcomps

 

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Rob P.

05' Subaru WRX--#85 STX

Michael Melcher:

On the dunlops, you must be really conservative on tires. You are the only person that has said anything postive about longevity with this tire. They also do not offer the sizes I need, and from what I have read, are really made for a lighter car. I would guesstimate (ASSume) that my car weighs around 3400+ without me, and I'm a pretty chunky fellow. 

Chris and I have been running the Dunlops on his car, and I think we both have nothing but good things to say about them.  The amount of grip was very surprising.  We've only put ~25 runs on them so far between the Dixie tour and the one event in Grenada, but the wear is great so far.  I'm not sure where you read that they are only good for lighter cars because I've heard the opposite. 

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2008 Nissan 350Z

From your description it sounds like the overall balance of the car is good with the exception of a lack of rear traction on corner exit. I'd definitely stick with the staggered tires, and maybe dial a little bit of toe-in at the rear(?). At least that's what I'd do with my car, and I seem to remember the suspension dynamics being similar.

Very little rear toe-in feels good because you could get the car to rotate, but I think the ability to put power down pays bigger dividends. You may have to brake a couple of feet earlier but if you can get on the gas harder and earlier you're going to see that benefit for the entire distance until you have to brake again.

Dunlops or Kumhos, I like cheap tires because you can beat on them without feeling too bad. That said, I still sing the praises of the shaved set of Yoko AD07s that I used a couple of years ago. But back then there weren't any choices that were almost as good for $600/set.

Rob, are you going to make Grenada?

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Mississippi Region #97 STU

I don't have to report to training in Oklahoma until June 18th, but we'll be in the process of moving or visiting family at some point between now and then.  Long story short, i'm not sure...if i'm here i might make it out.

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Rob P.

05' Subaru WRX--#85 STX

Oklahoma? Where?

Do I remember incorrectly that you thought you were going to Washington state?

I did see a couple of mixed reviews on tirerack, and thought I read somewhere else that there was a couple of 350z guys who said the same thing, just not sure where. As far as Rotenberrys car, I would very much like to make a run or two in it, to help make up my mind.

 Drew, I sometimes wish very much that I could adjust my toe-in in the rear, but for now the stick axle is part of what makes the car a little difficult to setup. I am going to try and adjust the anti-squat with the 5-link, and see how it changes. I'll probably wait to buy tires till after the grenada event, and see the results I get. 

Rob, thanks for all the good info, and I'm sorry to hear you are leaving our region. I will do some further in-depth research before I make any decisions. 

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Just trying to get some Seat Time!

86 Mustang GT - maybe one day it will be fast!

Skip, you're remembering correctly, I will be stationed in Spokane, WA  following my training to fly the KC-135 Stratotanker which will be in Altus, OK from June to November.

 

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Rob P.

05' Subaru WRX--#85 STX

I feel sorry for anybody who has to drive through Oklahoma, much less live there.

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Mississippi Region #97 STU