I have a choice of two sets of wheels, 6.5J x 16 or 7.5J x17, onto which I want to fit Uniroyal Rainsport 3 tyres. In the inevitable event of a wet trackday am I still better off with the wider wheels?
Funny that, was looking at Rainsport3's earlier today. Camskill gotta a killer deal on them right now. What car are they going on? And what is the normal tyre size too? Gurds
I'd be tempted to run the smaller tyres for wet weather i think, I find mine pretty scary through standing water in the wet on big 225's. However, if this is for your leon I'd think longer term about the whole car as a package. 16'' wheels will prevent you from having decent brakes further down the line, as I can absolutely promise you the 312's it has currently will not cope well once you start to develop the rest of the car. On that basis I'd go with the 17's.
I would have thought the Leon 20vT runs 305mm brakes discs on the ATE Calipers, same as a Bora/Golf 4 VR5 20v. Surely nothing a good quality brake pad cannot solve, rather than fit more unsprung weight?
As Prawn mentions, it's for the Cupra 180 - 312mm fronts and (I think) 232 solid rears. Power wise, the most I'm going for is a remap + decat + induction - so maybe 30bhp hike? I'm hopeful that the standard size brakes will do me fine (especially once the car weighs 100+kg less than it does now). I've already had EBC Yellowstuff front pads and Superblue fluid put on/in. Back to the wheels, the 6.5x16 is the factory wheel that's on there at the moment - with 205/55/16 tyres. A 7.5x17 wheel with 225/45/17 wheels is pretty much the same RR so hopefully there wouldn't be a vast change in handling when swapping between the two?
Nothing on the mk4 chassis runs a 305mm disc Eddie. only thing I can think of with 305mm brakes is the ibiza cupra R with brembo calipers. MK4 golfs / Boras had 256, 280, 288, and 312mm fronts as standard on various models. with 312's being fitted to the highest output cars. the 20vt leon in particular runs 312x25 fronts and 232x9mm rears. Sadly, no amount of brake pad / disc or cooling upgrade will make them adequate for fast track work, I've tried, and even with the car stripped back to just 1060Kg they still wern't up to the job regardless of pad choice. Simple beginner stuff they'll be OK and getting a feel for the car, but nothing more than that sadly. Of course, it all depends how fast you drive and how long you stay out on track for. The above were my findings, along with several others I know tracking the mk4 chassis
Don't go there I've been through SO many. Up until sub 300bhp levels and with semi slicks I found a good set of leon Cupra R brembo 323's with decent pads were fine so long as I added cooling. Since going considerably north of 300bhp and now using slicks they no longer cope. I've tried a few options this year with limited success, and will be running AP's this year.
I stand corrected on the size, yes that would be 312x25mm on our V5 Bora along with an ATE caliper. For a car like this @ say 1250kgs, I struggle see why this set up with an expensive brake pad cannot work for a mildly tuned 200ps/240lbft motor if driven correctly.
Yes he is correct, I made a mistake. The stock car ~180ps and about 165lbft. A remap on the stock hardware take it to ~ 200bhp and 250lbft depending on how the boost is programmed. I tend to avoid 275lbft spiking and target 1.2bar of boost or so. A decat would allow less back pressure and the potential for a bit more top end power and torque so ~ 210-220bhp at the same boost request. Induction kits, I would look at the turbo intake pipe. Bill of Badger 5 from here sells them. I am yet to try the Rainsport 3s, as my Rainsport 2s are still new. The thread pattern looks like and interesting mix of blocks to pump the water out and an areafor more contact on the out edges. I will like to know if their stiffened the side walls on the new version, which is an issue on the current when you start winding them up in semi dry conditions.
Ive just bought a set of rainsport 3s for my trackcar as a set of wets, as above camskill is doing a mega deal. Yet to try them though....
It's only a "mega" deal if you can get them fitted cheap. 225/45/17 = 72.29 x 4 = 289.16 delivered. My local tyre shop charges 10 per corner for strip/disposal/fit/valve/balance. Total = 329.16 For my local tyre shop to supply and fit = 340.80 and they can get the tyres within an hour.
After Toyotec`s recent wet weather `tyre testing` feedback I thought I`d add this for info. ... http://www.s2ki.com/home/2010/03/14/the-art-of-racing-in-the-rain/ Tires: Temperature: The tires will not heat up nearly as much due to constant cooling from water from the track. Evaporation is a very effective way of heat dissipation. And the significantly less tire deformation due to lack of grip will make this situation even worse. Meaning, the tires will never be at their optimum operating temperature, worsening overall grip even further (unless you use specialized rain tires, which work at lower temps). Pressure: Since you cannot reach optimum tire temperature, you should start with significantly higher cold tire pressures to be able to reach a hot number slightly higher than your dry optimum pressures. This pressure will maximize your contact patch. There is no magical number. But the best way to find this number, is with a tire pyrometer (which is just as important as a tire pressure gauge). But as general rule, you want to run higher wet hot pressures, maybe 5-8 psi above your dry hot pressure. Hydroplaning occurs mostly with underinflated tires, when the tire deforms and allows a center longitudinal channel of water run through the contact patch. The faster you go, the higher the chances of hydroplaning. An overinflated tire does two things. First, it decreases deflection of the tire while rounding the center. And second, it helps keep the groves of the tires open, facilitating water evacuation. These two things will help you against hydroplaning. As a side effect the contact patch, and therefore traction, is reduced. But: Its always better to have less traction than no traction at all (hydroplaning). As regards a choice of wet tyre ... depends on what you want to pay vs how you are prepared to drive ?
