Need advice on tire size for track duty??

[BlaineWasHere]

Originally Posted by ultra

Given the info that's slowly trickling out from people on this forum who have actually tracked their cars, why on earth are people still so quick to assume that coil overs will automatically improve anything at all, let alone everything?

Because it's adjustable. Factory the car is set-up to not kill people, not be fastest around a track. Is it a great OEM set-up? for sure. Is it the best set-up for the car? Nope.

[ultra]

Originally Posted by BlaineWasHere

Because it's adjustable. Factory the car is set-up to not kill people, not be fastest around a track. Is it a great OEM set-up? for sure. Is it the best set-up for the car? Nope.

Sure, someday somebody will come out with a great set of coilovers that slash lap times and plant the car nicely (will probably involve offset bushings, camber bolts and top hats too by the looks of things).

Lots more R&D to be done before I'd consider spending any $$$ on coilovers in the name of better lap times though personally. Need to see what AST, RCE and Ohlins will come out with, never mind the serious stuff like Motons etc.

If we had somebody like Emilio from 949 racing selling custom valved and sprung Tein Monoflexes, or Robispec tuned KW V3s, that'd also change things.

Just not big on off the shelf, unproven coilers for the sake of it unless I see data.

[BlaineWasHere]

Originally Posted by ultra

Sure, someday somebody will come out with a great set of coilovers that slash lap times and plant the car nicely (will probably involve offset bushings, camber bolts and top hats too by the looks of things).

Lots more R&D to be done before I'd consider spending any $$$ on coilovers in the name of better lap times though personally. Need to see what AST, RCE and Ohlins will come out with, never mind the serious stuff like Motons etc.

If we had somebody like Emilio from 949 racing selling custom valved and sprung Tein Monoflexes, or Robispec tuned KW V3s, that'd also change things.

Just not big on off the shelf, unproven coilers for the sake of it unless I see data.

Yup, I agree. In a few months when those custom valved and sprung KWs hit the market I'll buy some! Plus I gotta feel like Moton and Penske stuff will be out pretty soon, but I can't justify spending money like that. I'm not building a time attack car!

Honistly I'd have to think the off the shelf KWs will do SOMETHING over stock, their adjustablility would allow some tuning stock does not. It's not like we are talking about raceland or FK coils here...

[track_warrior]

Originally Posted by fatoni

hes been in that discussion before. while they arent my choice, i think asking for trouble is a little extreme.

you should have decided on a tire size and picked the widest rim to accomodate. if you wanted fast (which i recall not being the biggest issue with you) then the wider the better (within reason). if you want fun, my bet would be somewhere around 215s. i guess its too late anyways so just enjoy what you have

Thanks man, i went with both sizes 245 and 235 plus i have my stockers for fun!! This car is so much fun!!

I ordered federal rs-r with 140 tread wear and hankook rs3's!!

Originally Posted by ultra

Given the info that's slowly trickling out from people on this forum who have actually tracked their cars, why on earth are people still so quick to assume that coil overs will automatically improve anything at all, let alone everything?

This isn't some Accord or TC. It's been extremely well up out of the box by all accounts I've read.

It will be tough to improve on and very easy to ruin if someone just throws parts at it.

Of course this is the Wheels, tires, brakes& suspension sub forum so some hellaflush is to be expected but this particular thread is about performance IIRC.

BTT - for competitive AutoX I'd favour maximizing the contact patch but for track duty I'd go for something that fits well even if it's thinner. I'd be more interested in getting a compound that's heat cycle friendly and not prone to overheating or getting greasy.

I can vouch for RE11s or AD08s on track but have no clue how the Kumhos perform.

Because if you take a look at my videos on my youtube channel the car rolls a bit with factory rubber, once i get sticky tires its going to roll even more and that is when the factory suspension will not cut it any more. Im taking my car to soul speed next week to play with suspension settings ( they specialize in setting up cars for the track)

[7thgear]

Originally Posted by Razz

235x40x17 is what I would pick however 245x40x17 may be okay.

Tracking and feed back is scarce on this car now.

One thing to consider when buying tires is your coilovers.

use the KW V'3 and set the car low

please disregard such posts, do not consider coilovers until you find a need to corner balance your car, and most definitely do not set it to "low"

[track_warrior]

Originally Posted by 7thgear

please disregard such posts, do not consider coilovers until you find a need to corner balance your car, and most definitely do not set it to "low"

Im not setting it low, prob just 1 inch maybe even less. Im taking it to soul speed to get it cornered balanced as soon as i install the KW'S. Soul speed is a suspension shop that sets up race cars for the track they know their stuff and they are close to me less than an hour drive.

[7thgear]

Originally Posted by pcasso87

Im not setting it low, prob just 1 inch maybe even less. Im taking it to soul speed to get it cornered balanced as soon as i install the KW'S. Soul speed is a suspension shop that sets up race cars for the track they know their stuff and they are close to me less than an hour drive.

have you ever bothered to race a stock car on good tires and brakes for a solid season?

[track_warrior]

Originally Posted by 7thgear

have you ever bothered to race a stock car on good tires and brakes for a solid season?

Sticky tires + good brakes will make this car roll. Ive tracked it twice since i got it and it rolls a bit on the stock tires the moment i go with stickier rubber its going to roll even more. Why wouldnt i upgrade the suspension? Ive already done 40+ laps trying to find out what needs upgrading, brakes are fine stock i would only change the fluid and lines they dont sponge up a lot even though i have been tracking it with outside temps over 100F.

[7thgear]

Originally Posted by pcasso87

Sticky tires + good brakes will make this car roll. Ive tracked it twice since i got it and it rolls a bit on the stock tires the moment i go with stickier rubber its going to roll even more. Why wouldnt i upgrade the suspension? Ive already done 40+ laps trying to find out what needs upgrading, brakes are fine stock i would only change the fluid and lines they dont sponge up a lot even though i have been tracking it with outside temps over 100F.

just because a car rolls doesn't mean it's not turning at breakneck speeds

if your tire is too wide and leaning on itself during a corner, try reducing the tire width or play with the geometry a bit (alignment, balljoint extenders, etc)

until you build an aero car you really don't need to worry about having it FLAT

[ultra]

Originally Posted by pcasso87

Thanks man, i went with both sizes 245 and 235 plus i have my stockers for fun!! This car is so much fun!!

I ordered federal rs-r with 140 tread wear and hankook rs3's!!





Because if you take a look at my videos on my youtube channel the car rolls a bit with factory rubber, once i get sticky tires its going to roll even more and that is when the factory suspension will not cut it any more. Im taking my car to soul speed next week to play with suspension settings ( they specialize in setting up cars for the track)

Whatever makes you happy brother, and I mean that sincerely. Being confident in the car and enjoying it is what it's all about. Everybody will have their own sweet spot setup.

Glad to see you enjoying the car and look forward to updates.

[mla163]

Tire size calculator...

http://www.1010tires.com/tiresizecalculator.asp

235/45 is 2.8% bigger diameter - you are losing some power
245/40 is 0.4% bigger - Closer to stock.

255/40 is 1.7% bigger -moar width is better. I'd go with this if you are getting coilovers and are committed to 140 TW tires

[s2kdrew]

I had 235/40/17 all around on my S2000, since I don't like the performance on 245/40/17. 235 actually feel better for me on the track.

Beside if I want to spend the money on AD08, I would spend the same amount of money on A048. Since they are the same price, or go with hankook Z214, Kumho victor racer, Nitto NT-01. Better performance, cheaper price.

[Matt Andrews]

Originally Posted by 7thgear

until you build an aero car you really don't need to worry about having it FLAT

On a double a-arm car, you are correct. As the car roles, the camber curve helps keep the contact patch on the ground. And I agree that a car that roles isn't necessarily slow.

But a strut is different. As the car roles, camber is basically static. Lots of fast strut cars are bone jarringly stiff in order to keep the proper amt of camber on the road.

I haven't had my FR-S on track yet to see where the balance is, but with a lot of tire, I suspect it will need some additional role stiffness. (either sway bar or spring)

[Matt Andrews]

Originally Posted by s2kdrew

I had 235/40/17 all around on my S2000, since I don't like the performance on 245/40/17. 235 actually feel better for me on the track.

Beside if I want to spend the money on AD08, I would spend the same amount of money on A048. Since they are the same price, or go with hankook Z214, Kumho victor racer, Nitto NT-01. Better performance, cheaper price.

AD08 is a way faster tire than the A048. (at least the ones available here in the US) Plus they don't heat cycle out. A048's get one heat cycle before they turn to rocks.