The difference between a 275 and 285 is a few tenths of a second on a 50 second course assuming your suspension can handle the extra grip. This difference grows to a second or so for the 245 compared to a 285.

Eric

 

I'll trust you on that one, and that's good news for me. If I can gain a second on a 50 second course just with new tires, I'll be thrilled.

I corded a 245 over the weekend, and I'm going big for my next set of tires.

In your opinion, what would be the best wheel/tire combination? I will definitely take a look at Joe's 285/30R18 on 18x10 setup at the Finale next weekend, and I may go for a similar setup myself. Tunnell is also running the 285/30R18 if I'm not mistaken. Vic Sias is running 275/40R17 on 17x10 wheels on the front of his car. The 275/40R17 is a pretty tall tire though -- might not be the best fit for the Evo, although that's probably course dependent.

 

I will be running 285/30-18's and 275/35-18's in the Pro this weekend so feel free to check them out.

 

As I recall, Vic is also running 315s on the back of his car.

Did you see Sheridan's new 285s yesterday? The fenders still need work, but it sure seemed to work going around the course.

Good to hear you're getting big meats!

 

I just mounted and properly fit some 275/40/17's over the weekend. The fit is perfect after rolling the rear fenderwells. The 275 is not much different from stock, so gearing changes are minimal.

 

For those of you running 275s and 285s, does the tire protrude past the fender lip? What kind of clearance do you have between the inner tire sidewalls and the front coilover spring and rear control arms?

 

Eric,
Are you using the 285/30 on front and 275/35 on rear? Have you actually experienced that the 285 is a few tenths faster than the 275's, and if so, do you think it is related to width or lower sidewall profile? I would like to use the 275/40/17 because of the substantial difference in wheel/tire cost, but don't want to handicap myself by a few tenths per run to save some money. I'll be in Topeka 13-15 to cheer you Evo guys on against the M3s and to try and make my final decision on wheel/tires.

Thanks for your advice,
Mark

 

The term "clearance" is subjective at best.

To use the 275 tire strictly for autocross, only mild fender rolling was required. I like to drive to the event with the race tires sometimes, so aggresive fender rolling was required.

With the right alignment, correct wheel offset, you can safely tuck the rear tires under the fender well. The key is how much negative camber you can get away with without inducing too much understeer.

Be careful rolling the fenders; it really brings out the "quality" (another subjective term) of the mitsubishi factory paint .

But at least the tires fit well enough so I can drive on the street.

There are 4 points where you have to worry about rubbing.

1. The rear trailing link
2. The rear fender well lip
3. The front coil over clearance.
4. The front fender well (just the plastic parts under full body lean)

 

I run the same size front and rear. I will be running both sizes due to the number of runs in the Pro and three drivers for Nationals. We can discuss tire performance in Topeka.

 

What offset and wheel are you running?

 

Wow! If I can run some 275/40's with just minimal rear fenderwell rolling I know what I'll be running next year. I also want to know what offsets and wheels everyone is using

 

Has anyone fit/run 275 Kuhmo 710s? Their faster, at least according to Sam Strano, than Hoosiers.

 

From what I hear, A3S05 coming soon. No idea how it will compare though.

 

The 275 Kumo 710's won't fit with out solving some rubbing issues.

First and foremost, I think the rear will fit with aggressive fender rolling / and or fender flairs

Your problem will be on the front. You will need at least 1/4" spacer (or proper rim offsets) to clear your strut or coilover. Then you run into the second problem of rubbing on the front fender (because of the sectional width and the spacer)

I have fit the 275 kumo vicoracer's with minor rubbing issues after rolling the fenders. For track / autocross use only minimal fender rolling is required, if you want to drive to the event on your race rubber (I luv air tools) then more aggressive fender rolling is required.

It might work, but I am not willing to go as far as Joe250 did on his fender rolling. Keep in mind those 285's have the same sectional width as the 275 710's.

As for my offsets....

That's a secret but they are the "common" offset used for 17x9 rims...

 

I purchased Joe250's CCW wheel/tire combo to use next season in SM and have no problem in telling everyone the backspace/spacer combo specs if it will help you figure out your setup.

Joe used a 10mm hub-centric spacer on front and no spacer on the rear. All four wheels were 18x10" with the same backspace on each, so they could be used on front or rear. When used on the rear, a small ring insert was placed in the center of the wheel to make it hub-centric. The front spacer and rear ring were custom machined by CCW. The wheels are currently in shipping from CA to TX. I will take a careful backspace measurement next week when they arrive, or the weekend that follows, and let you know. Joe also needed to use longer wheel studs and open lug nuts for them.

I was also thinking about trying to adapt the new 17x10" 5-Zigen FN01R-C for the Evo. I checked with my local Discount Tire store (DT sells 5-Zigen wheels) and their local distribution center had two of the 17x10" +35mm, 5x114.3 in stock and they are only $229 each! New CCW's are $450 each with spacers/longer studs extra. The spacer issue for the 5-Zigen would have to be worked out based on your particular coilover clearance and clearing the calipers. Caliper clearance was the issue with the CCW's that required the 10mm spacer and seems to be about the same size that ChrisW is using with his 17x9s. Fenders would require a bit more rolling than the 9-inch wheel and you could use the less expensive Kumho 275/40/17 tires. Joe250's front fender lips were rolled until near flush and then the roller tool used at a 45 degree angle to pull the fender edge up and out just a bit. I'll find out exactly how much when I roll mine.

My biggest concern was whether the 30 series or 40 series tire would be better, considering corner turn-in and acceleration out of the turns. I went with the 30 to help with turn-in, but I think a good driver can do well with either tire.

Good luck with your own setup,

Mark