MrAWD

Since most likely SCCA will replace Stock category with Street as of the next year, so Hoos have to be replaced with street tires for the BS. What should I expect about the widest autoX street tire to be useful on EVO X?

Fedja

PSUfan1

iTrader: (2)

You could cram a 285 on an 8.5" rim. I don't autox (yet) so I can't say if you "should" do it... but I've seen it done on other cars (mustangs and RX7s come to mind). You also might need to run some sort of a small spacer to clear the suspension (I think there is something like 13mm / 0.5" of inner clearance on the stock fitment.

Iowa999

iTrader: (1)

Yep. With a max-allowed spacer, 285/30/18s fit and have been run on BS then AS Evo Xs. If you're now going to be on 140+ UTOQs tires, which are usually less square-shouldered than R-comps, I'd say that the same would be good. Depends on whether you want the gearing. If you don't want a tire that short (because you won't have the grip for the torque any more), then maybe a 275/35/18 would be better. In fact, my favorite 140+ tire is the Hankook R-S3 and they come in 275/35/18 but not in 285/30/18. Same goes for Kumho Ecsta XS and the Dunlap Direzza DZ101.

Upshot: you favorite flavor of 275/35/18 would be my suggestion.

MrAWD

Interesting! To be honest, I was not expecting to hear that we could run 285s on the stock rim. My first option for R-com were 710s, but there was no way to mount those on the stock rims. Than I got a set of used Hoos and those made it easy on stock rims. Not, since Hoosiers have less (if any) of the steel layers inside that could be the reason why there could have fit, while Kumhos would not. Looking further, I would say that typical street tire would be closer to the 710s and not Hoosiers. That would make the same problem for the other street tires as well.

Another problem is that one of mine unmounted Hooseirs when stack next to the same tire mounted on stock size rim is about an inch taller/wider in the 285 size. Due to all of that, I was expecting to hear somewhat smaller sizes for my application.

Fedja

Iowa999

iTrader: (1)

I assumed from the mention of "street tires" that you'd be moving to 'Kook R-S3s or Direzzas. These are somewhat limited in options and bending their sidewall will be more of a problem than Hoosiers. That's why I ended up suggesting 275/35/18. (I should have mentioned that everyone jamming 285s on 8.5" wheels around here are using Hoosiers, not V710s.)

You might want to get Andy Hollis' $.02 on this. Not many of us here have experience jamming wide tires onto the stock rims. If anything, around here you'll get more information about the opposite, such as the hella-stretched and hella-flush 245/40/18 on an 18x10 +15.

tee hee

Iowa999

iTrader: (1)

I had a chat with a street-tire autocrosser today and he says that the BFG Rival in 275/35/18 is the way to go on an X. "They don't mind being pinched and the 200 UTOQ is a total joke. They are the tire to have until they go on the banned list for not really being 200s."

I know that you're allowed 140+ for the next year, but he said just go to these now to get used to them.

MrAWD

The most important part for running X on street tires (aside of having a grip of course) is heat management! Due to them being very heavy for the "race car", tires will get hot much quicker and being able to handle this is crucial! Now add concrete instead of tarmac, and dual drivers and things will get out of hand pretty quickly.

As of yet I still don't know which one of those will be the best temperature wise. But, I did take a look at the numbers they have attached to them on Tire Rack site. Most of the 275s have 10.2" (10.9" for section width) of thread width (ZII's have 10.4") and my current set of 285 Hoosiers on stock rims is 10.75" of section and I guess thread width (they are rolled over a lot - unmounted section width is almost a whole inch wider) as well, so from that alone it looks like 275s should fit.

Fedja

Iowa999

iTrader: (1)

I completely agree WRT to heat, which is why I have R-S3s. I've never even driven on Rivals, so I have no clue about them, but I would ask some RT/ST folks as they come highly recommended and did win some trophies in RT at the last Nationals.

NJ Drive

iTrader: (6)

I ran 245/40/18 Z1s and 265/35/18 AD08s in RTA last year on my X.

If you're going to over tire a rim, I'd stick to using only a Z1, Z2, AD08, AD08R. The Rivals are stiff but not as stiff as these guys. The Rivals do very well on camber-challenged cars though. The RS3 definitely does NOT like to be pinched and needs camber.

In hindsight, I don't think there was much of a gain going wider since it took longer for the car to take a set in transitions. The shorter O.D. probably helped more than anything. If I were running B Street next year I'd be running 265 AD08Rs but with a GSR this time around.

MrAWD

Thanks for replay!

So far Hankook, ZII, and Rivals seem to be the choice. I will also check on those Yokos you suggested as well. I have also heard that first two are better for the heat from Rivals - at least that seem to be consensus from people running at Nationals this year.

Interesting to me is that you think GSR will be faster than SE or MR. Would you elaborate on that one?

Fedja

NJ Drive

iTrader: (6)

Fedja, I'd go with a base GSR mainly because it leaves the line a little bit harder(on stock map), more usable second gear, and 80lbs less weight to hustle around. Still a pig, but a lighter pig. I really think the Evo X 5 speed has a chance in B Street on real struts/shocks. ANZE was just finishing a Penske application right before I sold my car.

MrAWD

My suspension search for Evo X ended with Anze Penske on to top as well!

80 lb less than SE woud make GSR to be under 3330 lb! Is that what you have in mind?

As of advantages of 2nd gear, that doesn't go along with my findings. Ability of DCT to go up and down a gear whenever needed is advantage from where I stand. I might be wrong here, but from what I have seen so far, I am still on the technology side!

Launching the 5 speed the way it's needed for Pro Solo is definitely a plus. For the Solo2 I don't think it is that important. Also, from what I can see for the DCT, the main issue is in inability to launch it at the right time. Every once in a while I manage to do it right, but it is still a rare occasion and I can't rely on it for the Pro - at least not yet.

Fedja

MrAWD

Just to recap on this thread...just got 275/35/18 RS3s installed on the stock rims (well, RPF1s in stock width) and they look pretty good! Side wall is pinched in just a bit near the rim and I think/hope it will be just fine! First event is coming soon and if I ended up using them (it might be too cold for them with temps still in 40s), I will post first impressions after that!

Fedja

Iowa999

iTrader: (1)

If you get a chance to try some runs with the front bar at a setting less than full stiff, I'd be interested in your impressions. This isn't a lowered DSM. On OE springs, your roll center is high enough to not need so much front roll resistance.

MrAWD

Well, by going to full stiff seem to improve thing a lot when using Hoosiers. For the street on my 245 Kumho 4xs I went whole winter without changing the setting as well. I would be surprised to see better results with anything softer at the regular autoX day.

Why would you expect things to be better at the softer settings?

Fedja