Will a car with a 245 width tire in front and a 275 in the rear turn a faster autocross or road race lap time than the same car with a 245 front and a 245 rear tire combo?

Reason I am asking is because I am looking at new wheels and I like the SLP ZR1 wheels for third gens because they look nice, are not too expensive, and dont require any spacers. The only down side to them is that they are only eight inches wide. I like them, but want to autocross the car eventually and dont want to screw myself.

Any input is appreciated. Thanks.

 

technically on a slp 17x8 you could run a maximum of 265/40/17 according to the tire guides at my workplace. I have the SLP rims and run 255/45/17. hope this helps

 

[QUOTE=1991 RS/SS]Will a car with a 245 width tire in front and a 275 in the rear turn a faster autocross or road race lap time than the same car with a 245 front and a 245 rear tire combo?[QUOTE]

Maybe, maybe not. Wider tires in the rear will make the car less likely to oversteer, but if the car already pushes in turns it will puch more with wider rears.

 

yeah there are other variables involved other than just tires. shocks/spring rates and sway bar sizes also play a role.

 

Depends on what class you plan on running in. Stock class , the best rims are the firebird 16 x 8" rims with 255/50-16 Kumho 710's . Street Prepared, 17 x 9.5" rims with Kumho 275/40-17's

 

you will want to run good tires, so I suggest getting the SLP's for the street tires and some 16x8 wheels for some good race rubber.
There is a world of difference with street tires and race tires.
the one disadvantage of running race tires is that you may over-drive your car on the street with the street tires and possibly wreck your car (if you drive aggressive on the street).
I sometimes play around on off/onramps and I can go a lot faster with my race rubber than street rubber so just keep that in mind and drive safe.

 

That would work for me to get the SLP's and use my stockers for race rubber. My stock wheels are the 91 Z28 16x8. I could also run a 255 or 265 I guess on the SLP wheels. I didnt know they could take wider than a 245. Thanks for all the quick responses. What are some more good racing tires? RWB likes the Kumhos I see, which I do as well. I currently have the Kumho Ecsta Supras for the street, which I am very pleased with for such an inexpensive tire.

 

Basic rule of thumb on a 3rd gen is keep the same size rear tire as you have in the front.

Why?

These cars have a notorious push upon corner entry. As Axiod already stated, the wider the rear tire, the more push you will get on corner entry.

Autox is better to carry your speed through the entire course rather than slow down to turn and then try and lay down big power with fatter rear tires. Best to use throttle pedal control and keep the rears the same width as the fronts.

 

the only race tires I've used are the Nitto 555RII, but they don't come in sizes smaller than 17".
For street tires, I like my Nitto 555's and BFG G-Force T/A KDW.
I've had Kumho Supra 712's but I am not too fond of them, they are too skinny, too hard when it's cold outside, and don't have all that good traction, but they are cheap, less than $120ea last time I bought a set in the 275/40/17 size.

 

I have to respectfully disagree here. I currently have had KDW tires on my Camaro for about a year now and they do not hold a candle to the comfort zone I had with the Goodyear GS-D3's. Above 85mph, the KDW's are a piece of crap to put it bluntly. I can't wait till these thing wear out. In the mean time I hardly drive it because they feel so lousy. Its the wifes car and I'll just let her wear them out.

 

Are you positive they are KDW and not KDWS? they are two totally different tires with very similiar names.
this is a KDW,


and this is a KDWS,

 

I have KDW not KDWS. They are terrible. The GS-D3's felt like I had twice the tire under me. These things feel skinny and unpredictable. Above 85 (actually about 88mph to be exact) they become very unstable and uncomfortable feeling like the car starts to dance around and is too responsive at speed. I was going to give them away to my mother-in-law for her to put on her Toyota Avalon but her tires are still almost brand new- she hardly drives it. BFG is not what it used to be. The only decent tires they still make are the KD's.

I have owned (seriously) about 40 different sets of BFG's in my lifetime.

You can see it here in this current picture. Trust me when I say they are crap compoared to the feel and security of the GS-D3's

 

i've had nothing but good experiences with the 5 sets I've had in the 16 and 17 inch sizes. nice and grippy at all speeds, nice and stable and predictable at 175mph. they also make a very loud squeal when you burn them up too.
i've never used the GS-D3's so I can't compare them to those.

 

No ands, ifs, or buts... I am definately putting another set of GS-D3's on this car next time.

They feel like twice the tire. I only bought the KDW's off of recommendations from everyone that has tried them on this board- I wish I new better before I wasted my money. Not to sound snipe or arrogant- Just an honest statement- most have never tried a really good tire on their car so these would feel great to most.

I am surprised you like them since you have run racing rubber on the car. Although, I did read you state:"There is a world of difference with street tires and race tires" and this is true for the most part, but you would be pleasantly surprised the feel, confidence, and predictability of both the GS-D3's and the surprisingly discontinued Firestone SZ50EP's BOth are world class tires for street rubber. I promise you that if you buy a set you will be pleased and never in a lifetime go back to the crappy KDW's. I seriously HATE driving this car right now because of them. My wife even hates them and she is not an aggresive driver. Her comment was "why does the car turn so easily now, the steering feels loose" and she was comparing the steering feel to my "77 ElCamino that has 235/70-15 Goodyear passenger car tires on it- it just does not steer solidly and there is not the grip level.

The only little glich with DS-G3's is a very,very,very slight no-mans-land feel to them on initial turn response and then wham!- they grip and turn. It is a very slight querk to the tires that upon initial testing you will barely notice but it goes away very quickly when you take a few turns an get use to them- A month on them and you forget you ever felt it. They noticibly out brake the KDW's also ESPECIALLY IN WET CONDITIONS- that goes for out cornering by far in wet also. And you've seen my brakes

 

I've heard good things about the GS-D3's and will probably give them a shot next time I buy tires.
how much tread is left on the KDW's? you can always give them to me.

for the next event on the 18th, I am thinking about running race tires up front and street tires out back so I can try my hand at drifting around the corners since it looks like a lot of fun and looks good on video.

 

Since your a beginner the race tires that I would recommend are Kumho Victoracers. On 16x8s you can fir 165/45-16, but I would advise going with 245/45-16. The Victoracers relatively inexpensive and have a good compromise of grip vs. wear, I usually got about 24 events out of a set (2 years worth). I'm currently running Kumho v710s, they have more grip but will be worn out in one year and are more sensitive to air pressure and temperature than Victoracers.

 

Cool. Thanks again for all of the opinions. It is always good to get alot of different peoples experiences.

 

Another good tire for beginners is the Toyo RA-1s. They're also good when there's rain at an event since they have decent thread.

 

If you buy 17 x 8 wheels I like the Falken Azenis RT615. Great for autocross and decent on the road. A set delivered to me was 500.