When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I need some new autocross tires for my r53 mini. I'm running 15x8 wheels.
I ran 205/50/15 RE71R on 16x7 wheels last year and did well in DS but the tire wear is stupid, I put on camber plates and I'm in STX now against some brz's that are pretty fast, top 3 cars are within 1/2 second, I took a 1st and a 3rd.
I need some new autocross tires for my r53 mini. I'm running 15x8 wheels.
I ran 205/50/15 RE71R on 16x7 wheels last year and did well in DS but the tire wear is stupid, I put on camber plates and I'm in STX now against some brz's that are pretty fast, top 3 cars are within 1/2 second, I took a 1st and a 3rd.
The tire to have in STX is RE-71R hands down but tire size is a compromise.
15x8 et36 will fit your R53 such as 6UL with 3mm thin spacer for the rear to clear rear lower trailing arm. 15x9 will not easily fit front unless you cut wheel arch plastic for clearance.
How much front negative camber are you running now and are your results with the camber plates or before?
Basically you need more front negative camber at least -3 if you want to use any tire for autocrossing. Otherwise you will burn through the outer edges fast. Rotating and flipping tires will help with wear but needs to be done with tread wear at about 40-50%.
Wear on the RE71R can be stupid fast since it is a very very soft rubber approaching Hoosier A7 (cold temps). This is a price of having more grip.
Unless you want a tire that wears better and gives up grip I would not consider anything beyond RE71R or maybe Dunlop Direzza ZII Star Spec, or maybe the new BFG Rival S.
Tirerack has Rival S in 225/45-15 listed as "closeout" for $115.77 each. If you want more tread then this could be worth a look.
But I have been "fooled" by early reports when the Rival first came out and I bought them to find they were only a "pretender" and the hype was more than reality. So now I like to see tires up close and I have driven and seen what the RE71R can do. Downside as you mention is tread wear.
Another thing to realize is that treadwear also has to do with driving style. If you drive more aggressively, with more slip angle and more sliding, or you brake later and tend to understeer some, then you are likely overdriving and using up more tire than you need to. Also do you check tire temps during the event to fine tune the air pressure? If not then you have no idea what would be the best tire pressures to run based on less than optimal data.
Each tire on your car is doing different things along any given course. Sure you can start cold tire pressures at a basic level but with heat building up fast on the fronts and the outer tires on faster turns you will find that the right pressures will be different for each tire. The goal being to use the most tread for each tire's situation. Only by checking tire temps inner, middle and outer treads right after you finish your runs can you determine where to be, there is no guessing.
Chalking tire shoulders is helpful to determine how much rollover you have but is no replacement for tire temps. Using a probe style pyrometer is most accurate as you want the tire temp under the surface heat.
I am running 15x8 949racing with 225/45/15 right now for the track, 10mm spacer up front and 5mm rear -2.5 camber both ends and +2 caster up front, tire wear up front is even and tire temps at the track are slightly warmer inside but not enough to add more camber.
last year I won almost every event in DS, STX and SMF on 205/50/15 re71r but they are tiny compared to the 225's and the grip on the track favors 225's quite a bit, my lap times are better with the 225's
unfortunately, re71r is not sold that big, which is why I listed the above tires.
I dont care about tire wear, only care about grip I put the camber plates on to fix the wear issue. I have a set of 225/45/15 R-S4 already for the track car I might try an autocross with them
There has already been some good advice posted but I will throw out a few more possibilities. For an R53 I like the Idea of running a 225/45/15 on 15x8 in front and a 205/50/15 in the rear on a 15x7 or 7.5. My old co-driver Courtney also favors running this tire combination. If you have a full set of 15x8's and can carry 6 wheels and tires with you I'd be tempted to carry 4, 225's and 2, 205's, for the rare occasions when the 205's in the rear just caused to much rotation. Two of the 225's you might want to keep at close to full tread, as rain tires.
Andy Hollis has already tested the Rival S 1.5 and found it to be a serious contender, with better transient response than the S. I noticed that it also has a higher load rating than the S, which was rated as LL. (low load}
Now, if you wanted to play it safe and save some $$ I'd stick with the 205/50/15 RE71R, on the 15x8's but I think you would be missing an opportunity.
I favored -2.2 to -2.5 camber up front and -1 in the rear but Courtney likes -.5 to -.25 in the rear. As for Caster, I think I have my K-Mac plates adjusted to increase caster by 1.5 or 2 degrees, more positive than oem, for the increased dynamic camber effect.
what about a 245 up front? Pretty sure they fit up there but not in the back, I could run 225 in the back
Me personally, would be nervous about trying to fit 245's up front. One, because I wouldn't want to run them on anything less than a 15x9 and then they would need to stick way out. Sorry I don't remember the needed offset but as you said, you would want to run them with 225's in the rear and once again I wouldn't want to try that, especially on an 8" wheel. I liked to run my car low and not super stiff and I think 245F with 225R would require running the car either Higher or stiffer or both to get that combination to work. I think this would be a great combination for the later turbo S. Also keep in mind that the wider the tire, the more camber sensitive the setup is too.
I like to run not more than 400 lb springs. Somewhere between 336 and 400 in front and either the same rate in the rear or 336/400. Courtney is happy with 289/336 or 336/336.
If you are looking for max grip I think the RE71R even with narrow tire size is the way to go given your alignment. I wouldn't be running so much rear negative camber, usually 1 degree less negative in the rear vs the front. For me, -3 in front and -2 in the rear with an adjustable rear swaybar set to medium.
If you don't notice much oversteer or it's controllable then you are fine. Might be good to check tire temps in the rear to see how much of the tire you are using.
As far as tire size goes, 225/45-15 is a good match for 15x8" wheels.
245/40-15 (Rival S) fits wheels 8-9.5" wide so it's workable on a 15x8" wheel albeit with a little more weight. You can also match this tire size in front with 225/45-15 on 15x8" wheels for the rear as mentioned.
I already have them sourced, Beck has them in stock, but they want 125 $ a tire, I could run the rs-4 225/45/15 until tire rack and the local shop I use has them in stock
If 15x9s are at all an option for you up front DO IT! I ran as big as 275/35/15 on 15x9 up front, no trimming required (but it's close). I tested this at full compression against the bump stops (springs removed), cleared at full steering both directions.
they are an option, I can run up to 9" wide wheels and 265 width tires but have to stay 200 tread wear. I could run hankook r-s4 in 245/40/15 those have 14 % more tread on the ground, and the 225/45/15 I already have on the back
rival S 1.5 is almost 100 $ more for just 2 tires. If I went r-s4 I could use them on the track car too I suppose
245/40-15 $173.92 each available 5/12/17
Fits rims 8-9.5" wide
"A further evolution of the BFGoodrich Rival S, the Rival S 1.5 features an updated construction process aimed at increasing the steering precision and transitional response often demanded by the drivers of smaller, lighter vehicles. The Rival S 1.5 features the same tread compound as its predecessor, which is designed to offer maximum dry and improved wet grip, as well as offer quicker warm-up in competition conditions".
ok first autocross done, the guy I was beating last year beat me by a second, he was in STU last year and his wrx runs STX this year. I was in DS last year. He was on star specs and just got re71r and I'm on 225/45/15 square r-s4's, they got faster each run, they now have 5 runs on them. They take a bit to heat up, the first 2 runs were pretty slick. This club I only get about 5 min between each runs , the tarheel club I typically get 10 min between runs
I've got a pair of 15x9 wheels in my cart (949racing) and 2 front tire options I'm not sure which to try, 245/40r15 in either the rival s 1.5 or the rs-4. The rears will be the r-s4 225's I already have.
Driving the r-s4 feels a big different the whole car slides a bit coming out of slaloms
here's a vid from the run, the new seat mount for the camera sucks, I'm off my pace I had enough for 2nd place and 50th overall that's about 10-15 spots down from where I ran last year
here's a vid from the run, the new seat mount for the camera sucks, I'm off my pace I had enough for 2nd place and 50th overall that's about 10-15 spots down from where I ran last year
04-18-2017, 06:23 AM
