gumby4mayor

Quote:

Originally Posted by Butt Dyno

I was looking for this threadsince it's a better place for B-street tire discussion than the STU thread -

Oh man blast from the past! I remember that thread vividly.
Talking purely about street tires and NOT rcomps...


I ran 265 dunlops on my 11' wrx (8" wheels) did very well with the soft Dstock pax locally but in regards to the tire, it rolled pretty bad from corner to corner, by the end of the season the shoulders were completely rounded. At nats with the grip of the concrete provided by the lincoln airport, they were just simply too wide for the rim, they would move ALOT with the amount of grip in relation to support of the wheel.


So...does a massive overtire work? Sure, beneficial? I don't think so. I would not go larger than a 265 in something with a stiffsidewall like a ZII, on the 8.5" rim of the evo x, a 255 on the 8"rim of the 8's & 9's . Some may prefer the feel of even smaller tires asthe steering becomes much more crisp, but with the weight of the evo I thinkthe extra width helps with heat management.


Many conclude for street tires that tread width should match rim width, this is the ideal setup. I believe it's a good general rulefor lighter cars, but I have found the WRX and EVO benefit from a slight overtire when forced to a specific rim width. If we could use any wheel width you would want a slight pinch as it helps stabilize the sidewall. Each car andtire react differently, best way to figure out what's going to work is do yourown testing. Yes it is the expensive and the hard way, but it's also the best way with the most upside.

MrAWD

I thought that comparison between WRX on 265 and 8" rims with EVO on 275 and 8.5" rims is not right because WRX was on 17" rims, while we have 18s. Extra 1/2" of the sidewall will definitely affect thing on side loading.

Either way, I will be trying my setup pretty soon, so I will post the first impressions once that is done.

Fedja

Mario Linguini

I'll be buying 255/35R18 AD08R tires. I'm going by the Andy Hollis rule:

"Street tires don't overtire very effectively. Not at all like a Hoosier or V710. General rule of thumb is tread width no more than wheel width. Maybe 1/2" more at most, otherwise the feel just gets worse and the tire doesn't deliver anything more in grip."

I've also read some posts from Sam Strano cautioning about overtireing it (same as Andy, mushy feel and no more grip). So I've decided to pay it safe. Besides, I can only use the ADO8Rs this year.

MrAWD

Actually, since you mentioned Sam there, he with few other guys did some comparison testing and actually found out that more tire was giving more stick to the heavier car. So, it is understandable to get a bit softer feel (even to be mushy), but if that comes with more grip (and in my case, better temperature management), I could compensate for that in some other way. EVOs are very fast turning cars, so if that gets to be slowed down a bit, it will/should not affect things as much.

Just checked Weather Channel and it shows lots of 60s and some 50s for the next 10 days, so I might install those tires and see how they will fair on the street and on/of rumps even before the first event!

Fedja

Mario Linguini

Fedja,

You running at Meadowlands this weekend? 0% chance rain on Sunday (at this time) and sunny with 61-degree temps. I gotta move some place where summer doesn't begin until August ;o)

-- joe

MrAWD

Hey man,

I am in the Boston area and I don't even know where that is. Even if it is at Devens were we usually ran, I wouldn't be able to make it. 19th is the first event for me.

Fedja

wilkes.1768

Hey guys,

I just ran my first set of solo events (in the Chicago Region SCCA, we have a program called the "Learning Curve" for beginners to Solo) and was hoping to stay in BS for at least a year or two. I currently have ZERO modifications to the Evo, but was hoping to get some input from others on a few items:

I was initially running tire pressure of ~33 FR / FL and ~32.5 RR / RL; the next day I bumped the rear tire pressure up to ~35 psi because it looked like I was rolling well over the tire wear mark. After reading this thread and a few others, I'm guessing I was way way under pressure. Do you recommend any specific tire pressure set ups?

Also, with the new rule on either a new front or rear sway bar, which one would likely be more beneficial for our chassis? Given the weight distribution being still front biased, would this be a factor as well?

Thanks and look forward to having fun with this new sport!

Dallas J

iTrader: (1)

What tires? I found the ZII's do funny things around the 30psi mark and really want upper 30s or more in the case of a stock car.

AreSTG

iTrader: (4)

I just want to +1 what gumby said. I know feel is important but once you adjust to the rs3 is a great tire. And I think the "squish" is a bit overrated

ChrisV

I ran the car for the first time this weekend, Saturday at a points event, Sunday at a Test and Tune.

Setup:
2012 GSR
Revalved Bilsteins
Dunlop ZIIs, 245/40/18
K&N Filter

Saturday I ran the car as it sat. Landed down around 41 front/38 rear. The car was a blast to drive. We ran first heat (our lot gets progressively faster throughout the day), and I finished up 15/50 in my heat for pax. I landed around 50/150 (I told you the lot gets faster). In BS, we had 10 cars. It was a tale of two classes - I was third, .7 seconds out of first. Fourth was 3 or so seconds behind me. I begged the guys who finished first (Evo 9) and second (S2000) to keep coming back to our events.

Then I went and got the car aligned, and found out that I had been driving the car with almost 1/3 inch toe out in the rear - no wonder it danced so much!

We set the toe to zero front and rear, got a bunch of camber out of the front (-2.2 cross) and set the rears at -1.

Then Sunday was the Test and Tune...the car was nowhere near as much fun to drive, since the crazy oversteer was gone. We also had a long sweeper that just punished the front tires. The more I pitched and wrestled the car around, the faster it got. It really needs to be setup loose in order to be fast. To compensate I ended up running 45 front (the sweeper was killing the tires) and 50 rear. Since I either need tire-killing toe out in the rear or a big bar to get it to rotate, I'm looking for a big bar.

Any recommendations? I'm thinking Whiteline as it's the biggest and not stupid expensive for a bent piece of steel rod.

My next event will be the NJ Championship Tour (I'll be one of the worker chiefs, say hello when you check in), and I'm pumped.

Mario Linguini

Chris,

I was unable to find specifications for the Whiteline RSB. I went with a Hotchkis RSB and their heim joint end links, and they do publish specifications:

"1 1/4" (32mm) Tubular Rear Bar 3 Way Adjustable +155%, 195%, 245%"

I have seen several posts where an upgraded RSB bends/breaks the stock end links. If you do find specifications on the Whiteline RSB please post.

I haven't installed yet but will soon, our first event is not until the 1st weekend in May.

-- joe

Mario Linguini

wilkes.1768 - My 2011 Evo X MR is also untouched. I was waiting to see if the new B-Street rules would get approved. On the OEM Advan 13C and off-the-showroomfloor alignment, I had to run pressures north of 40psi front and rear to keep the tires from rolling on their side.

I've got 5 events on the car and it currently handles mostly neutral. It actually handles better with the AYC engaged (i.e. OFF-ON). Hopefully very soon I'll be able to install the Hotchkis RSB/End-Links, get a 4-wheel alignment, and the AD08Rs on it. Making so many changes at one time is not the best way forward, but...

I'll post everything I learn to this forum, even though thanks to the weather I'm way behind all of you. Hopefully, we'll see some Evo X's do well in national events.

-- joe

MrAWD

From the above it sounds like you are thinking of getting Rear sway bar to help you rotate...right? If that is wrong, disregard the rest!

I know that discussions between FSB and RSB are close to the religious debates, but I have to point few things right now. In the above text, you clearly describing that you front end is suffering tremendously due to excessive rolling of that end, but instead of thinking of fixing (or at least aiding that) you are trying to leave it intact and improve the other end instead. Bu going with stiffer bar, you are pretty much making that end to stick less than before (this is the most simple wording I can use here). So, the overall result will be less stick on the rear with hope to get faster!?

The above logic makes sense on car which has allowance to modify both shocks and springs and were you have done everything you could possible done to increase the grip on the other end. For the stock/street car that is not the case. You have lots of limitations and you have to correct the logic a bit.

So, the get back to your original issue! If you could improve the grip in the front, that would make your car much faster than it is right now or it will be if you take some of the grip from the rear to make it more loose! So, stiffer front sway bar would decrease amount of roll you get while cornering and keep geometry of the front end in a better shape. That would give you more grip and a bit less abuse on those tires. Once you increase front grip, car will become looser as the side effect and bring you back to the fun car you want to drive in the first place!

Fedja
ps. and yes, I would recommend Whiteline for the front!

wilkes.1768

I was running the stock Advans this weekend, the A13Cs. Looks like max psi is 44

wilkes.1768

Thanks! Yep, I'm thinking of upping the pressure to about 40psi all around next weekend, plus I'm getting an alignment on Friday, so hopefully I can see what those two adjustments mean in feel and results...