45 replies to this topic

[jameso]

Sounds like 245 is sensible option then. thx peeps

[JG]

no, 225 is the sensible option Maybe 235 at a push.

[siztenboots]

I have put a spare set of front wheels on the back to try, 195/50/16 = poor mans lower final drive

[jameso]

no, 225 is the sensible option

Maybe 235 at a push.

oi

[SteveA]

no, 225 is the sensible option

Maybe 235 at a push.

I think all of the more serious track drivers, JJJ, Cliffe, MaxR, Sizten, Joe, myself, etc, etc would disagree with you.

If you haven't driven both options I don't think you are really in a position to decide.

Edited by SteveA, 25 May 2012 - 12:26 PM.

[siztenboots]

have a much wider rim, makes a big difference to how the sidewall works, very pleased with the 9J rims

[MrSimba]

Think it's a lot more than just 235/245/255 ect as different tyres of the same rated size have VERY different profiles... A 245 V70A with its almost 90' shoulders is very different to a 245 AD08 with rounded shoulders both same size yet one would rub like a b@stard and the other won't! Camber as said make a lot of difference also, one with -2.5' will be very different to a geo set to -1' ! But lovin my 9J's on the rear with 235 AD08's and really don't think I (note the 'I'...) need any more than 205's on the front, perfect steering feel and balance with zero understeer so all good!

[GeorgeBC]

Its different for every car. My 245 v70 tyres simply dont fit. They use to foul the clam. Ive had a new geo now with another 0.5 neg camber and now it catches the tub and the shock. Ive fitted a 2mm spacer today and have a td next wrrkend to test it. Mikes car needed butchering though so if mrsimba is ok id suggest that is the size to go for. Ill be buying either 235 or 225 after the national but before the euro trip!

[MrSimba]

With 235/40/17 AD08's on a 9J rim @ 125mm ride height with -2.5' camber - absolutely no rubbing at all & that includes the high speed bend at 90mph on a Walshy day so its safe to say they aint going to rub!!! Fronts 205/45/17 AD08's on a 7.5J rim @ 115mm with 1.5' camber - no noticeable rubbing even at full lock each direction, but with the wheel removed you can see it *just* catching but it is not noticeable in any way whilst driving and the first mm that wears from the tyre it'll be gone! TBH the 9J rim is just soooooooooo W I D E as it is I'd not be wanting to start spacing it even by a couple of mm or it'll be too far out of the body for MOT / visual stops by police ect.

[Nev]

Bear in mind every clam will sit differently on each car (by several mm).

As MrSimba has insightfully stated, different tyres of the same supposed size will vary with considerably. R888s for example have a very pronounced sidewall bulge of approx 1cm static (more when under compression like a bump) and a lot of symetric feathing on both sides of the tyre. This sidewall buldge is one of the reasons I have decided to adopt a different tyre, as I would prefer less buldge and more contact surface area on the tarmac.

This kind of info is available on the internet to help you decide, eg: http://toyotires.com...mpetition-tires (click on the specification tab).

If you want maximum contact area with the tarmac, I'd generally advise swapping to a rectangular profile. The V70a tyres for instance have a mild upswept outer edge (only) that is not detectable until they are inflated, so appear rectangular on the shelf, but are in fact feathered nicely (asymetrically) for progressive break away at the limit. Subtle stuff for most of the people on here, but if you are serious about your car sticking on the road, then you will make the effort to investigate further

As an extra tit-bit, the V70a are standard issue for factory Ultima GTRs. As this car holds the world record for 'production car' 0-100-0 MPH on these tyres, that is a recommendation in itself. (The term production car is used rather losely though!!). I have also driven one of these things, and it was one of the memorable things in my life, though there are a few VX220s out there now that can match them

GL.

Edited by Nev, 04 June 2012 - 02:03 PM.

[Nev]

Here are a couple of useful links that may help you estimate the max size you can squeeze under your clam

http://www.willtheyfit.com/

http://www.tyres-pne...nce-advice.html

Good luck, I hope you get a good fit, don't forget to let the community know your findings (good or bad!).

Cheers,

Nev.

Edited by Nev, 04 June 2012 - 03:19 PM.

[Steelic]

In an ideal world you would have acess to a supplier with all the sizes, Brands, etc and a good few hours swapping about but even then it's like buying a pair of shoes and finding out there not for you after you've worn them!

[Steelic]

Personally I'd recommend Yoko AD08's, I'm running 205/45/17F and 235/45/17R no rubbing except on full front lock when reversing ect, though I have noticed rubbing at top of wheel liners but thats down to my nitron 115/125mm ride height and Dam 'B' roads.

[Steelic]

. . . and of course my driving habits!

[chrisgold]

My rear wheels are 8J ET30, with 245/40/17. No rubbing issues at all, but thats standard ride height using Exige suspension.

Indeed - So i was going to move to a 255/40/17 rear as my rear rims are wider - just trying to work out if it will still be rub free and not cause horrible understeer if the fronts are only 225

255 rear and 225 front is a good setup, ET:20 you should be fine! I'm 9j 17 255 ET:25 rear and 7.5j 17 225 ET:15 front

[krambulle]

255 rear and 225 front is a good setup, ET:20 you should be fine! I'm 9j 17 255 ET:25 rear and 7.5j 17 225 ET:15 front

What wheels/rims are you running?

//Johan

[Mike (Cliffie)]

9J rear+3 degrees neg camber +245 tyre+110 ride height=rubbage on tub and clam.

[JimmyJamJerusalem]

Had 245's on my rear for over a year now with no rubbage issues. For once my stiff springs come in useful Cliffie lad, I think most of your rubbage is down to your aero mate. You're shoving the rear of the car down and your springs just aint up to it!!

[JimmyJamJerusalem]

no, 225 is the sensible option

Maybe 235 at a push.

I think all of the more serious track drivers, JJJ, Cliffe, MaxR, Sizten, Joe, myself, etc, etc would disagree with you.

If you haven't driven both options I don't think you are really in a position to decide.

Got to agree with Steve with this one. With tuned VX's pushing more serious power the extra grip of wider tyres is a BIG help!!

I initially went over to the 245 rear as my Time Attack tyre was a normal road tyre and I needed to claim some traction against the 225 888's back by increasing the width of the tyre. Even with 888's on an exit of a bend I was still spinning up the rear tyres up when planting the throttle. All well and good but you know it's just wasted time (not to mention dangerous if you're not used to the back end moving around).

Here's a snap from the last corner at Anglesey (approaching the pit wall) and you can clearly see the rears spinning. Not the most flattering pic ever, ride heights were all over the place





Umar got it very wrong



Either way going over to 245's on semi's cured that and the rest is history

Honestly anyhting over 250bhp needs alot more tractio than a 225 offers in my opinion

[jameso]

yeah I went with 225F and 245R in the end, small rub on full lock - but need a geo reset anyway now so hopefully will get them to eliminate the rub there