Wheel recommendation for track

[danishmkvgti]

Well, if the B16 springs go on the OEM plates it would seem logical to me for them to have the same upper diameter as stock ! From what I see, there are several choices on the market like K-mac, H2sport and K-sport (these are made for their own coils but seem to also work with others). K-mac goes for about 500$ while H2sport are half that (i don't know why this big difference). TT lower arms in my country are about 750 Euro (1000$) including ball joints, bolts, bushings...  The 2 options :

1) Camber plates > will pull the upper part of the damper towards the interior of the car, creating more negative camber and more room for the wheel to go well under the fender/arch, especially if the wheel is much wider than stock. From what I've read the ride with those + coilovers is harsher than only coilovers
2) TT arms > will pull the lower part of the damper towards the exterior of the car, creating more negative camber and a wider track between the front wheels but will not help much with the wheel going under the fender/arch. The ride is same as with the OEm arms so these have an advantage on bad roads

Those said above represent my logic and may be innacurate. Can anyone comment on them ?

you have to take into account the cars roll center, i'm no expert, Jonny C may be able to ellaborate more on this, i recall him writing about this before somewhere inhere, but this is from the american forum:



 

[fuscobal]

Very good articles. Just found on youtube the video of a guy with an STI WR1 with 317HP/432NM and just 1330KG. The car surpassed just about every car at Hungaroring (including me and some M3, GT3 RS...) and made a lap time of 2'07" on Michelin Cup 24/64x18 slicks >

. The time is absolutely phenomenal for a street car considering that on the same day (09.08.2010), the fastest lap was made by a Leon WTCC > 2'05" !

24/64x18 is approx. equivalent to 245/40/18 !

[RedRobin]

you have to take into account the cars roll center, i'm no expert, Jonny C may be able to ellaborate more on this, i recall him writing about this before somewhere inhere, but this is from the american forum:



 

....Do you have a link to that American forum thread, Jake? 

[danishmkvgti]

you have to take into account the cars roll center, i'm no expert, Jonny C may be able to ellaborate more on this, i recall him writing about this before somewhere inhere, but this is from the american forum:



 

....Do you have a link to that American forum thread, Jake? 

i have looked, but so far without luck, i'll keep searching though RR 

[Janner_Sy]

that guy in the BMW at first is well and truly shocking behind the wheel.

[fuscobal]

I looked again at R888 recommendations > http://www.toyomotorsport.eu/tiredetail.php?tireconcept_id=20&id=3 and I've seen now that a 7.5x17" (OEM rim) would take 235/45/17 at the limit. They say :

- permitted rims : 7.5" - 9"
- measuring rim : 8"

I don't know exactly what they mean by "measuring rim". Is this the recommended rim width ? Is there any risk in running a 235 on my 7.5" wide rim if the car is so heavy ? (1700kg)

If there's no problem, it would be the cheapest option as I only need the tires and don't have to buy rims as well !

[Top Cat]

I looked again at R888 recommendations > http://www.toyomotorsport.eu/tiredetail.php?tireconcept_id=20&id=3 and I've seen now that a 7.5x17" (OEM rim) would take 235/45/17 at the limit. They say :

- permitted rims : 7.5" - 9"
- measuring rim : 8"

I don't know exactly what they mean by "measuring rim". Is this the recommended rim width ? Is there any risk in running a 235 on my 7.5" wide rim if the car is so heavy ? (1700kg)

If there's no problem, it would be the cheapest option as I only need the tires and don't have to buy rims as well !

I run my semi slick tyres which are 225 on a 7.5 rim with no problems, that includes a trip to the ring, so i think you would be fine with 235. 

[fuscobal]

That's what I want to know...if going from 225 to 235 would be a problem. I've also run 235 street tires on 7.5" on the street but that can't compare to track use ! If there's any chance of the tire failing or going off the rim, I'd stay with 225 !

[RedRobin]

^^^^
Depending on how low slung your suspension is set up, wouldn't you have to possibly make some adjustments to stop 235 tyres rubbing?

[Hurdy]

Stick with the 225's on a 7.5 x 17 rim

My Team dynamics Pro race 1.2's were 8" wide and on 225's and still looked very chunky on the alloy rim (see pic below). No danger of scrubbing and you can get on with the job at hand on track.

[fuscobal]

I will stay with 225 then. My camber is currently lower than -1 wich is not that great. If I'll have the money, I will probably install the TT lower arms. Hurdy, in the pics it looks like you have a lot of negative camber. How did you get that much ?

[Hurdy]

That may just be the fact that the car was parked on an angle at the time I took the pics. The car is lowered and running Bilstein PSS10's and that is all that could affect camber.

[fuscobal]

I just had a terrific track day at hungaroring with the TT arms wich gave me -2.3 of negative camber and the 225/45/17 Kumho V70a. The improvement was of 11secs/lap wich is huge !!!

[Top Cat]

I just had a terrific track day at hungaroring with the TT arms wich gave me -2.3 of negative camber and the 225/45/17 Kumho V70a. The improvement was of 11secs/lap wich is huge !!!

Am i getting confused. I thought that the TT arms only give an extra 0.5 degree of camber.  2.3 sounds like the morego jobbies.

[RedRobin]

I just had a terrific track day at hungaroring with the TT arms wich gave me -2.3 of negative camber

Am i getting confused. I thought that the TT arms only give an extra 0.5 degree of camber.  2.3 sounds like the morego jobbies.
 

....Perhaps his car starts off with -1.8 degrees and the TT arms add the 0.5 extra to give -2.3