D-Stock tire size

[MarkR171]

Looking to make the switch to race rubber for next season, trying to decide on what sizes to run. On stock suspension, would 245/35/18 Hoosier A6s all around work well on the 135? Bigger? Smaller? No fender rolling, no camber plates, stock wheels. 5mm spacer is possible, but not bigger (to stay within stock rules.)

[MarkR171]

Also looking for any input on Hoosier R6s. I can get new R6s for less than a third of the price of A6s, and half tread R6s for 50$ a tire. Are they that bad for autocross?

[DriveHard]

If im not mistaken, you cant go bigger than stock to stay in d-stock.. also i think you cant use spaces either.

rim width must not be larger than whats on the car also...

On that note, personally when i do auto-x i use my track tires.. Hankook RS3's barely leagl DOT's ( 140 tread wear )

I streatched the rules here because my car is also staggered wheel width, with corrosponding tire sizes.. I went for a square set up and used the rear tire and wheel dimensions to put on the front. That way I can rotate ( espically for tracking where one mostly turns right and the left front takes a beating)

[MarkR171]

Originally Posted by DriveHard

If im not mistaken, you cant go bigger than stock to stay in d-stock.. also i think you cant use spaces either.

rim width must not be larger than whats on the car also...

You can use any tire size so long as it fits on the stock wheel (or not more than .25" wider than stock wheel.) Spacers are legal provided the resulting offset change is less than .25". Hence 5mm spacers are legal.

[Lubo]

Originally Posted by MarkR171

You can use any tire size so long as it fits on the stock wheel (or not more than .25" wider than stock wheel.) Spacers are legal provided the resulting offset change is less than .25". Hence 5mm spacers are legal.

what are the rules about staggered wheels? Can you use 4 rears and be all good? or do you have to use 7.5 in front? 245 r-comp might be pushing it on a stock wheel.

[bluesunit]

Rims must be the same width as stock, so no rears on the front in stock class.

Mark, correct on using the 5mm spacers. I need to look at my math, but I believe that Breytons GTS-Rs have a slightly smaller offset than stock, which allows you to use a 10mm spacer to get you EXACTLY at the .25" offset variation allowed by SCCA solo-stock rules.

I've been using R6s with pretty great results (as you've seen). R6s last longer and have a wider operational temperature range than A6s. I'm estimating I'll get 100 runs on my set of R6s which had about 70% tread on them when I got them. 245's also seem easy to find on eBay which keeps the price down.

A6s, of course, have the best ultimate grip, but you might only get 30 runs out of a set. Possibly less, this car destroys front tires.

My advice, buy R6s to beat up on local competition, buy A6's when you ship your car to the mainland for Nationals

I'm running 245s square on my car. They do rub in the front (shock tower and on the front control arm at full lock). It's not enough contact to cause damage to the car or the tire.

[Amalfitano]

I think you're flipped. I'm not recalling the exacts, but if the stock offset is 52mm, and the breytons are 48mm, you lost 4mm of the stock availability. The spacers reduce the offset. If i got the offsets flipped though, then you're right, more spacer is available.

[DriveHard]

Originally Posted by MarkR171

You can use any tire size so long as it fits on the stock wheel (or not more than .25" wider than stock wheel.) Spacers are legal provided the resulting offset change is less than .25". Hence 5mm spacers are legal.

i stand corrected.. dont listen to me in this regard

carry on with the much better advice...

[MarkR171]

Originally Posted by Lubo

what are the rules about staggered wheels? Can you use 4 rears and be all good? or do you have to use 7.5 in front? 245 r-comp might be pushing it on a stock wheel.

People have stuffed 275 Hoosier A6s on the front 7.5s, but no, can't use all 4 rears.

Thanks bluesunit, what would you get in your opinion: 50% tread R6s for 50$ a tire or "full tread" R6s for 100$ a tire from the same seller?

Part of me wants to get the 50% tread to test the waters with less money, but the other part of me wants to go ahead and get the full tread tires since I'll be paying shipping to Hawaii more often if I got worn tires.

[Lubo]

Originally Posted by MarkR171

People have stuffed 275 Hoosier A6s on the front 7.5s, but no, can't use all 4 rears.

Thanks bluesunit, what would you get in your opinion: 50% tread R6s for 50$ a tire or "full tread" R6s for 100$ a tire from the same seller?

Part of me wants to get the 50% tread to test the waters with less money, but the other part of me wants to go ahead and get the full tread tires since I'll be paying shipping to Hawaii more often if I got worn tires.

Man I tried searching but couldn't find anything, do you have any pictures of that? Widest I saw was 235/40 18.

[MarkR171]

Originally Posted by Lubo

Man I tried searching but couldn't find anything, do you have any pictures of that? Widest I saw was 235/40 18.

Quote from the same thread by the 2008 DS-Ladies Nationals Champ:

At the moment we are running on 275 Hoosiers on all four corners, (this requires a 2mm spacer up front, and there is a slight rubbing issue there) Pressures starting at 45psi up front, 50psi rear.
Hoosier is coming out with a new 265 size that may be the ticket, we'll see.
Off the shelf Koni doubles from TC Kline, in dry weather the rear is maxed out stiff, both compression and rebound. On the front rebound full soft, compression 4-6 clicks stiffer than full soft.
Hotchkiss 32mm bar.
Alignment, max neg camber in front, (pins removed), nets us about -.7 deg. Rear -1 degree, 3/16 total toe out all around.

Picture is of the same car, different driver (Matt Murray.)

Link to thread: http://www.1addicts.com/forums/showthread.php?t=219124

[Lubo]

Originally Posted by MarkR171

Quote from the same thread by the 2008 DS-Ladies Nationals Champ:


Picture is of the same car, different driver (Matt Murray.)

Link to thread: http://www.1addicts.com/forums/showthread.php?t=219124

Surprisingly that doesn't look that bad. I was expecting balloon tires

[Amalfitano]

The picture does look suspect, like it was a test fit of a smaller tire up front or that the rear wheels were used up front. There doesn't seem to be much rubber spilling past the edge of the wheels, and since 7.5" = 190.5mm, or 42 mm per side, that's 1.6" per side of wider rubber than wheel. The picture doesn't look like that at all, though it could be an odd camera angle. I'd love to see the car and fitment in person for sure.

[bluesunit]

Here I am on 245s . . . under load. Car looks so goofy like it's eating the tires.

[bluesunit]

Originally Posted by Amalfitano

The picture does look suspect, like it was a test fit of a smaller tire up front or that the rear wheels were used up front. There doesn't seem to be much rubber spilling past the edge of the wheels, and since 7.5" = 190.5mm, or 42 mm per side, that's 1.6" per side of wider rubber than wheel. The picture doesn't look like that at all, though it could be an odd camera angle. I'd love to see the car and fitment in person for sure.

It's possible that most of the tire width is under the car, and the wheel is riding further out towards the edge of the tire.

But yeah, those look small.

[MarkR171]

Do you have any pictures of the tires on the car while parked? Just want to get an idea how it looks.

[bluesunit]

http://www.1addicts.com/forums/showthread.php?t=446923

Check out this thread ... Pictures when I first test fit the tires.

[MarkR171]

Yikes, that does look really close to the strut, but spacer should help. Thanks!

[BimmerMeUp]

I'm running Kumho V710s on stock sized Breyton wheels and no spacers. Fronts are 245/35-18 and rears are 285/30-18. Fits with no rubbing in competition using box stock suspension.

You have to find a special tire guy to mount up a set like those, involves "hot boxing, tons of duck butter, and hours of tag teaming".

[MarkR171]

Already have a tire guy in mind, ex-scca racer and 95% of the local SCCA region goes to him for tires/alignment/etc.

[bluesunit]

I've been using a Vietnamese used tire and lawn mower shop to mount my tires.

$7 cash per tire (no balance) and none of them has said a word about the weird sizes (although that may be a language issue). I see them mounting up 24+" donk tires all the time.