Tim, have you PM'd Rick Gilhart to see what he's running on his car?

Are you running a track-specific splitter?

Going to wider rubber to make them last longer--will you need to increase downforce up front to get enough heat in the tire to cut down on the push, and then will it realistically last more than the 235 or 245 options?

Cary probably has some interesting input for this problem. Cary, you out there?

 

curious as to why you are trying to fit larger rubber which will increase understeer?

 

What you are missing is certain manufacturer's like Fikse make their wheel widths in cetain increments. Fikse uses half inch increments. When dealin with tires of these sizes half an inch isn't close enough.

 

I have used up front both 265/35-18 MPSC's and 275/35-18 Hoosiers on Fikse 10" x 18" wheels. I have actually us in the same Fikse wheel up front in 8.5, 9.0, 9.5 and 10.0 's.

 

Oak,

One of the ways you can correct understeer is by going to larger tires up front.

 

From my experiences wider rubber up front definatly made it "tighter" with all other setting being the same. Especially if your trying to make the tires last as Color Change has mentioned I would think that the camber would be stock to minimal. Which would increase understeer.

 

Super D: Yes, I have a track splitter. Also, with 600+ ponies, getting the tires up to temp is not hard. I have real time trire monitoring and brake caliper montiroing on the car now.

I have 9.5 or 10's up front, can't remember.

Oak: What makes you think the bigger tires will increase understeer?

 

don't assume these wheel manufacturers know their offsets. they really don't. it's up to you to know.

btw, i love fikse wheels

 

Could be just the way I had interpret the increase in "tightness" which to me feels like increase with the wider rubber, I preferred how the turbo feels with an increase the neg camber to around -1.5 or maxed with the 235's MPSC. Feels much looser in quicker turn in's with less resistance, feels like less understeer esp on quicker and tighter turns.

 

cjv, I believe you can now custom order any offset through Fikse. Orginally they only offered on 1/2" increments.

 

Oak,

My bad. I was refering to wheel width.

 

You have no arguement on slower/tighter turns. I have always said a 2wd can kick my butt on those types of turns. This is where a GT2 shines.

The 265's are a great aid in eliminating the pushing and shoveling. You need to have at least a 9.0 or 9.5" inch wheel with this size tire. We have found that a slightly oversizes wheel, 12.5 on MPSC 315-18's in the rear induces less tire wall roll and makes the car respond with more understeer.

My camber is set about -2.0 up front.

 

Cewl....can you elaborate on that? Is it custom? Do tell.

 

Chad, I have read that wider tires up front gives more grip at the expense of 'feel' through the steering wheel. Have you found that to be true, or are your suspension upgrades sufficient that your steering feel is all "princess and the pea"?

 

PMac,

Not really sure how to answer your question. The awd, in my experience, has better grip when properly setup. As for "feel", the feel on KA as it relates to the front suspension isn't really much different than the feel on a stock turbo. The difference is grip .......... less pushing, shoveling and roll.

The tires are not a magic pill by themselves. Wider tires, wheels and track. GT2 parts along with a custom wheel carriers, JRZ four way adj. race shocks, monoballs, approx 850 pound springs and a stiffer/lighter front makes for good response on anything but very tight turns.

The down side is she drives like a truck or race car. Definitely not for long trips.