Pitzi

I would appreciate any input on the following problems.
My car(MY00 Classic shape Jap spec Impreza STi) will be used for track/hillclimb competitions

I am considering fitting a set of AP Racing 4-pot
I have the following problems, the car was bought with 17" OZ Superlggera`s plus I have a spare set of OZ P1 wheels. So the logical thing would be to get a set of 17" slicks, the problem is that the only slicks available in South Africa in the 17" size are 225/45/17`s, will this tyre size fit a classic shape Impreza??

My alternative is to get a set of OE 16" wheels and use the set of 205/50/16 slicks that I already have, but ehre is where the brake problems come into play. The 330mm AP Racing brakes will not fit with the 16" wheels, am I correct?? I have seen that there are 305mm AP Racing kits that are sold to fit the 16" OE wheels, are these any good??

Please I need some advice ASAP before I make any stupid decisions

Regards
Gerardo

Pitzi

Ok, ignore the tyre question, I will not be fitting 225/45`s as they require too many mods.

Can anyone advice with the brake question??

Hoppy

17in slicks are notoriously hard to find, but there are some trackday tyres available - basically cut slicks to make them road legal. Dunlop, Khumo, Michelin I think (Yoko?) though availablity is a different thing. You quote 225/45x17 which suggests you are not looking at a true slick anyway. Slicks are specc'd with their rolling diameter in mm, not the aspect ratio as a % of width. You need something like 210/605x17.

225 will probably be too wide at the back, even with the optimum off-set wheels which is 52mm so your P1 wheels will give you best clearance. Your other OZ wheels are 48mm off-set I think which will almost certainly rub.

You might get lucky with some tyres, in which case stick them on the P1 rims. But a spare set of 16in Subaru rims (off-set 53mm - don't go below 50mm to be sure of not rubbing) is the easiest route. Don't worry about fitting the AP 4-pot brake kit under them as they will still stop a train. I used to have them and did a lot of track days. Awesome. I've now got 6-pots under 17s but only because I got a mega-deal - the guy I sold the 16in kit to was doing 100-0 in 3.8 secs, as I recall, as many times as he still had the strength to hold on. That is very violent stopping indeed

Cheers,

Richard.

PS Edited to add crossed post. You've done the right thing with the 225 tyres

[Edited by Hoppy - 1/10/2004 6:03:53 PM]

Pitzi

Thanks for the input mate!!

So the 305mm AP`s are just as good then??

Hoppy

No, in theory they are not. But at Donington, the hardest circuit on brakes in the UK, my 305mm discs had enough leverage to trip the ABS at 120mph on a dry track. And they would do it lap after lap which is the real test. I have wrecked two sets of discs there, one set of standard and another pair of Group N replacements. Warped and cracked so that you could see daylight through them. Utterly useless. The APs just took it all and kept on going.

Obviously, the bigger 17in kit and-pot calipers are better. More metal for head-soak, bigger pads and I get a lighter pedal which makes me thnk I can do trail braking which, frankly, ends in a spin as often as not What I'm saying is that the 16in kit is better than I am, and that my fabulous 6-pots are just overkill unless you are very talented and race at a high and serious level.

Best,

Richard.