Backspacing, Negative Offset, etc.

I currently have a 2004 Tacoma, everything stock. I am about to put on the OME 882 with full leaf set change out. I am also looking to step down from a 16" wheel to 15" steel wheels and want to run 33 x 15 x 10.50. What I can't seem to grasp is what back spacing, negative offset, etc. I need to have to minimize if not eliminate rubbing. Any recommendations?

 

First off, with 33's there will be rubbing. No wheel package alone will fix that.

If you run a 15x8 wheel, you need 4.5" of backspacing or less. On an 8" wide wheel, 4.5" of BS is equal to 0 mm of offset. Any more than 4.5" of BS may cause the tire to not clear the upper part of the spindle/ball joint area and it will definitely cause rubbing on the frame when you turn.

I am running 33x10.5/15s on 8" wide steelies with 3.75" of BS. This is -19 mm of offset on an 8" wheel. The less BS you have, the more it moves the tire outboard away from the frame rub when turning. However, you will still have to clearance the pinch weld (behind the mudflap) area. There is no avoiding this with 33s.

Does your Tacoma have the factory big brake package? Some '04 models came equipped that way. If so, you will not be able to run a 15" wheel. The big brakes will interfere.

 

4" BS is what I'm running. Slight rub on the frame in the front at full lock. BFH to the pinch weld was a must.

I think many people (like Mike) have had good experience with the 3.75" BS but the pinch weld mod is still required.

 

Fortunately, I don't have the big brake system. Would you recommend going with a different wheel/tire sizing or have you had pretty good luck overall with 33's?

 

Do you have the manual trans or is it an auto? v6?

IMO, 33x10.5/15s with a regear to 4.88s is perfect on my auto. Stock gearing with the 5-speed and 33s is a little more tolerable but still not ideal.

 

Manual. V6

 

anything less than a 4 inch back space will stick way out and be hell on your wheel bearings, try to stay in the 4.5-4 range with most likely a -6 or -12 offset.

Unless you're going for the Hawaiian look brah.

 

The first half of your comment is valid and has good info.

However, I don't understand why you feel the need to add the slanderous second half.

 

its a style in hawaii to have your wheels and tires stick out like 8 inches............ whats slanderous?

 

Whatever butters your biscuits.

 

Most of the "stick way out" is due to 10" and 12" wide rims. A 3.75" BS on an 8 inch rim will stick out .25" more than a 4" BS on the same width.

An FYI, here's a nice article that summarizes calculating offset from BS and vice-versa.
http://thesquealingtire.com/wheel-offset-and-backspace-explained/

 

What tires are you running? I'm leaning towards BFG KM2's.

 

Also, I'm 99% sure I don't have the large brake system that I guess they put on some of the '04s. But is there a way to verify that?

 

KM2s

I've seen threads on here but ATM I can't link you to them. Do some seaches in the 1st gen section or the Tacoma Garage.