Tire Suggestions for Crisper Turn-In?

[Number9]

Just had the car aligned. I'm running Michelin Pilot Sports 245/40's all around with about -2.5 deg front camber, -1.8 rear camber and roughly 0 front toe. The Pilots stick pretty well for street tires and are pretty quiet, possibly because they have relatively flexible sidewalls. Unfortunately, as a result, the turn in isn't nearly as crisp as I'd like - there's just a little bit of latency in the response from turning the wheel to the car actually turning in. Any tire (or suspension) recommendations to get more immediate turn-in? BTW, Thunderhill is the intended application...

[Enigma]

You have a number of options.

If you have two sets of rims then I would get a set of R compound tires. You will get vastly better turn in and grip. I currently run Kumho V700 Escta's.

For street / Track tires then you may want to look at an BFG KD, S03, or the new Toyo.

You can also improve the turn in a bit by softening the front struts if that will not cause you other handling problems.

[///Mracer]

Besides the tire change, try the OEM X-brace, this is a nice and cheap upgrade that actually works. A little bit of toe helps in the rear also for turn in (.1 to .2).

[jayhudson]

You can also try some spacers up front to get a litle more track width. Jay

[Kos-motate139]

You can always start a little toe-out, that'll get that sucker turning. For street tires, you can play with pressures a little bit to optimize their stiffness, but you'll probably end up with less overall grip doing that.

The other thing is more technique-related. If you coodinate your braking along with your turning, you'll have more traction on the front wheels, and can turn in much harder since there will be more weight on them.

I drove my M3 at Thunderhill for the first time a few weeks ago. Let us know how things go!

[frayed]

Originally posted by Kos-motate139
You can always start a little toe-out, that'll get that sucker turning.

Holy crap, I was running .25 toe out for a while, and the car would dive into a corner like a go-kart. It was incredible.

One other note, to maximize turn in, run wheels that are at the max of the width range of the given tire size you are running. Running 8.5" rims with Kumho V700 Rcomps in the 235 width provides other-worldly turn-in response. The wider the rim, the higher the effective stiffness of the sidewall . . .

[Number9]

Thanks guys, lot's of great suggestions. For those of you who have tried toe out up front, how did that affect high speed stability? (Cheaper to adjust the alignment than to replace a set of relatively new tires!)

[Kos-motate139]

Originally posted by frayed


One other note, to maximize turn in, run wheels that are at the max of the width range of the given tire size you are running. Running 8.5" rims with Kumho V700 Rcomps in the 235 width provides other-worldly turn-in response. The wider the rim, the higher the effective stiffness of the sidewall . . .

My 318 runs 215/45x16s with 16x8s. Nice and stiff.

Toe-out will effect high-speed stability, but it's not too hard to change it at the track.

Has anyone tried reducing caster to help turn-in? There's theoretically some value to be had here, also at the expense of high-speed stability. :

[Jim O.]

I don't know what car you have or what mods you've done, but you can also try stiffening up the rear sway bar, or adding a little more spring in the back. Less rebound in the rear shocks, or more compression in the front should help, too.

Jim

[frayed]

Less rebound in the rear?

[Number9]

Originally posted by Jim O.
I don't know what car you have or what mods you've done, but you can also try stiffening up the rear sway bar, or adding a little more spring in the back. Less rebound in the rear shocks, or more compression in the front should help, too.

Jim

It's a 95 M3 Dinan S3 signature vehicle (stage 3 Dinan suspension with fr. camber plate, front strut bar, X-brace, Fikse wheels, short shifter, tranmission brace, and SC+aftercooler). Full soft front sway and full stiff rear sway settings already. I'll be running with the NSX club and those things have really good turn-in because of their stock front toe-out, stiff sidewall rubber, low polar moment, and not much mass up front...

[Cannon]

Is that Enigma from LS1.COM?

Chris (former Incon TT Z28 owner)

[Jim O.]

Originally posted by frayed
Less rebound in the rear?

Yup. My thinking is that under braking the back end will come up faster (since less rebound will let the rear springs extend faster), putting more weight on the front wheels.

Jim

[jayhudson]

Originally posted by Number9
Thanks guys, lot's of great suggestions. For those of you who have tried toe out up front, how did that affect high speed stability? (Cheaper to adjust the alignment than to replace a set of relatively new tires!)

You'll be replacing those tires sooner than you want if you run toe out. Toe out will scrub the inside edges off those tires big time. Unless, you reset toe after your track events. Jay