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Index > @ the Pickup Bed (General Topics) > Thread: what tires to auto-x with?
Thread: what tires to auto-x with?
Brad


Rotorhead
Posts: 1672
posted February 16, 2006 11:42 AM

what tires to auto-x with?

So I do need R compounds to autocross with afterall. Beating up my street tires sucks. So through connections I can get some Victoracer 205/50/15's new and shaved $200 for 4. But they're slower and heavier than the current Kumho V710 which I can get for $157 EACH!!!

And of course I need new (used?) aluminum rims for this and a 15x7 is as wide as I can go for 205, 15x8 or 9 for 225. So once I buy rims I'm committed to tire size. REPU is heavy and can use the extra 20mm width.

Decisions, decisions!!!

What to do?


____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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klaus42


Rotorhead
Posts: 1877
posted February 16, 2006 12:09 PM

Budget vs. Results...

Rim/Tire size combo: To the limits of what fits... you may find that wider, hits... unfortunately.

7.5 x 15" rim with 205 50 15 worked with BFG R-1's.

8" or 9" rim might not, under hard cornering...
Light is good... sticky, better.

Shaving? That's for people who don't like to break 'em in themselves, right? :b


       
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Brad


Rotorhead
Posts: 1672
posted February 16, 2006 02:15 PM

quote:
Rim/Tire size combo: To the limits of what fits... you may find that wider, hits... unfortunately.





I have 15x7 225/50/15 Dunlop SP2000's on the front already. They stick out but only rub sway bar at full lock. They don't rub ball joints or upper a arm 3.75 backspace.


Budget vs. Results, that really is it!!!!! + my REPU was down for 2 weeks when the dunlops were on national backorder and that won't happen with dedicated auto-x tires.

Is anyone in SoCal gonna auto-x this year????? I think one or two people sounded interested. Paul's turbocharged one with rear swaybar?

The Corvair club is having one in March, @ Camarillo airport, no date set but i'll advise when it's solid.

Shaved tires is so the tread blocks won't squirm under cornering. + less circumferance. + less heat. Heat cycling is another deal.

Still not sure if I should get the Victoracers.....
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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absolut


1st Gear
Posts: 37
posted February 19, 2006 05:28 PM

combo that worked for me!

Shortly after getting my REPU I started reseaching what wheel/tire combo would work. I wanted a tire that I could drive to work on occation yet still take i to the track on the weekend and perform. Here's what I found.
I picked up a set of Discount tires "MB Motoring" wheels... Inexpensive yet still look good. I went for the Rocker 17x8. For rubber I chose the "Nitto 555" in a 255/45/17. I found that it is nearly stock diameter but much wider. That did not seem to be a problem, They only seem to rub up front when your turning hard and backing up at the same time... not often. I have Nitto tires on four vehicle now from the "Terra Grapplers" on my 4x4 to the 35 series "505's" on my lowrider S-15 and am very pleased with the performance and price. I think I spent $1100 on the whole package with warranty and all. I can honestly say if their warm and I drop the clutch on dry pavement I could swear the front tires come off the ground. Take a look at the Gallery "Brad C" group. That is what they look like and I have no clearance problems at all, and they will easily perform beyond what the truck can do in cornering.

Brad C

       
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klaus42


Rotorhead
Posts: 1877
posted February 20, 2006 11:34 AM

I would expect...

...to be finding interference with the chassis/fenders the hard way, under auto-X extremes, using a combination that big...

       
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Brad


Rotorhead
Posts: 1672
posted February 20, 2006 04:00 PM

thanks for the info!

Good priced rims, but that combo is a little big for my lowered truck.

Trying to find some light (<21lbs) rims, got an occasional lead but not always a good one. One guy is selling his mag slotted rims off chevy truck, 15x8, but the rims are bent he says. ah well... still looking.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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Absolut


1st Gear
Posts: 37
posted February 21, 2006 09:25 AM

I was going to mention...

that this combo works well for me but I wouldn't want it on a lowered truck.
Check in your area for a wheel repair shop. There is a shop near me in Seattle called "Foster's Wheel Repair" that specializes in straightening wheels. If you got the wheels for free it may be cost efective to straighten them.
I understand the concern with weight and that is something to definently consider, however in my experience when your doing alot of cornering... auto-x... The benefit of a small sidewall verses a light wheel is great. For instance if I put a 35 series wheel on my rims I'm sure I could lower it at least 2 inces, however tires are more expensive.
In looking at what everybody else was running for wheels I was suprised to find that nearly every REPU I saw had 15" wheels.

       
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klaus42


Rotorhead
Posts: 1877
posted February 21, 2006 09:27 AM
Edited By: klaus42 on 21 Feb 2006 09:29

You likely know the 'usual' issue:

...about the 'offset' being a bit too much towards the 'outside' on the front, with many/most wide(r) rims.

What works for (stiffened-up?), stock-ride-height on the street, may encounter clearance issues on the track...

Some *sticky*, stiff-sidewall tires do better on a <8" wide rim.

Different widths/offsets front vs. rear would allow stuffing more rubber under the truck, though... but then you can't rotate front-to-rear.

If the pic's legible,at all, you may want to check out the 'wheel worksheet' I posted on the MSN-site--. :)

A set of (new!) super-lightweight (not street legal) steel wheels might be the most beneficial, pound-per-$-saved option... though not nessecarily the prettiest.

       
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Brad


Rotorhead
Posts: 1672
posted February 21, 2006 11:29 AM

thanks for the info Klaus!

I've researched and the de facto auto-x rim width for a 225 tire is 8". Some even go to 9"!!!! So I'll go with common wisdon and get 8's. Easier to mount the tire compared to 9's too.

I want a 3.75" backspace, that is the same as I have on my street fronts. No clearance issues so far but I need to doublcheck if I'm bottoming out on the front bumpstops too.

There are some 15x8 3.75 BS 6 lug rims out there, just hard to find them light and reasonably priced. Still searching.

Found out that AR-23's are 25lbs in 15x8!!! Still lighter than the 29lb 15x8 steelies I have on the rear.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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