I'll add my 2cents...

I ran the 285 R1S's on my esp wrx for 1 season. I put them on 2-3 events before nats last year. They ran fine locally, but they hated the west course in lincoln. The sidewalls just weren't stiff enough and the car would "buck" in the showcase turn(s). I would get rollover marks halfway down the sideway and that was with 33 PSI (fronts).

The tires probably got a little over 65 runs on them before one of them corded on the inside at the CO match tour. I've gone through 3 sets of hoosiers and 1 set of v10's before and never corded a tire on basically the same setup (I had to run a bit more camber with the r1s's to combat the softer sidewall). One thing worth mentioning is the car/tires took first place PAX locally in the event before the CO match tour (Jon Newcombe was co-driving). I would say they do stay competitive longer, but when they fail, it's catastrophic (and unexpected).

The 285 r1s was about 1/3-1/2" wider (per tire) than a 285 A6 on my 10.5" rims.

I can't afford a new set of tires this late in the season, but I'll very likely be going back to A6's next year.

 

33psi seems low for the R1S's. The little I got to test with them they seemed to like the high 30psi range much better. The hoosiers on the other hand do like low 30's. This has probably more to do with the rounded shoulders on the hoosiers vs the square shoulder on the R1S.

 

Interesting. Seems like this method creates only a subtle difference in corner weights. Looks like it takes about a 10% side to side weight imbalance to cause a 1% cross weight imbalance using this method on a 60% front bias car.

You are right, it doesn't create a 50% cross weight unless the left and right sides are equal, but it is very close.

Seems like 10% side to side imbalance would likely cause handling assyemetry though regardless of cross weights. I could see how this method would work out better though as if you are chasing cross weight alone, I could see how you could get one tire way higher or lower on load compared to the other side.

 

Drew, welcome to the Evo Community and thanks for chiming in!
I have to say, this has been the exact opposite experience I've had with nearly a decade of experience running R-comps. Hoosiers have always been delicate. And even on cars like an RX-8 or Corvette that wears them fairly well. You can still cord them prematurely.

I have found the BGF's extremly durable. And now would confidently say they are as wear-durable as Kumho V710's without the drop in performance you see towards the end of Kumho's life cycle. I have ran the BFG's at Mineral Wells. Arguably one of the most abrasive sites in the country. And the worst I have ever raced on. Exposed aggregate, degrading asphault, with loose gravel and giant courses. The place is a tire eating machine.

Ran 4 drivers at the pro there this year and the tires held up remarkably well. They were 2 years old at the time. I took top pax on them a couple weekends ago. Plus I have done two test and tunes on them at MW. These tires are incredible.

I've never ran hoosiers below 35psi on 9.5 or 10.5" rims. And while I used to agree that BFG's also liked high 30's psi. Lowering them down to 32 psi two weekends ago, in conjunction with corner balancing my car transformed the way it performed. Of course we all know the real test is next week. And I look forward to comparing results with everyone else.

I was hoping to make it to the pro since I have a legitimate chance to win S1. But I was barely able to squeeze in Nats itself.

 

Funny, I experience the exact opposite. Setup differences maybe?

 

I only did 3 sessions on my R1S's at Gingerman a few weekends ago, so I didn't get much testing on them, but the Hoosiers we're for sure faster when we got to the low 30psi range. This is doing TT where I'm getting the tires up to temp unlike an autocross where you are starting out from nearly dead cold tires.

 

Oh ok. I thought you were talking about autocross.

 

Same here. At the last event I tried 35psi and let it grow to 39psi just to see if I was way under pressure. The result, the car felt a lot sharper but less grippy. At 32psi the tires feel almost a little mushy by comparison but they wont let go. Hard to explain, but its almost like the difference between Hoosiers and Kumhos as far as the swing from grip to feel.

Regardless, 32psi is faster for me.

 

I'll try the BFG's next time at low 30's. They've been my practice tire so I haven't put a lot of effort into them. Perhaps if they'd offer a contingency for NASA TT I'd switch to them full time.

 

Just looking through some pics from nationals. No shortage of lateral grip from the BFG's...



that's what 1.6g lateral looks like.

credit to Perry Bennett for the photo.

 

I don't have any of my real data to post right now, but I did some testing of the R1S's to A6's at my last TT event. I'd really put my money on the R1S's being faster. The other things I've noticed, R1S's withstand heat and lap times are very consistent. on A6's, anything over 2-3 hot laps and the lap times start to drop significantly. I've also got twice the amount of track time on my BFG's whereas the A6's only last me 1.5-2 events. (1 event = 8HC's, each HC = 3-5 total laps)

 

1.6 G sustained? you have logs showing that?

 

I wish it was sustained! the car is somewhat unstable on two wheels (ie it doesn't want to stay that way), and i haven't figured out how to get it to stay there without AWD freaking out and just generally overwhelming the front struts. It's not like that is the result of a yank at the wheel or something, that is the middle of a sweeper where the grip builds to the point it lifts off and then it'll set back down. The tires want to go there though if the suspension could handle it.

it'll do 1.3g sustained.

 

I need to get a good datalogging setup. I wonder what I can pull on the 315s...

 

^ i'd love to see the data on 315's. I've often wondered at what point does bigger not really help much if any.