Negative offset and viper cuts

So,

New to having a runner and I’m about to start my build. I’m doing the basic 6112 in front and 5100 in back with just a 2” 1” set up. Simple stuff. For wheels to slap my 285’s on I was wanting a negative offset, I love me my tire poke.

I was going to get a set of affordable -18 offset wheels from discount tire but my shop said they’d need to do a viper cut with that much negative.

Is that the case? I’m not wanting to cut fender just yet and I was hoping for at most a bmc cut.

What’s the most negative I can go without cutting fender?

 

^Stock offset is +15mm, so with these wheels, the tire will be swinging on a 1.3" wider arc. You will need to trim the bumper cover (some people cutely name this "viper" cut), trim the fender flares, and do the cab mount chop. That is, unless you choose to run small tires.

 

Baaaaaalls

Would any negative offset cause this issue?

 

^Put it this way, there's a Toyota TSB for dealer techs to trim the front bumper to clear the stock tires on TRD Pro models, because the Pro wheels are +4mm and cause the tires to sometimes rub.

 

I was looking for validation and so far I’ve gotten sadness.

Would a 0 offset be okay? Not seeing much plus offsets. I’m already doing a mud flap delete and I’m okay with trimming liner and bmc.

 

^You picked the wrong platform if you wanted to run larger tires with a wide stance Should've bought a Wrangler or Bronco built by hardworking 'Mericans in 'Mericuh.

0mm offset will be slightly worse than +4mm offset but effectively the same.

 

Just do the front bumper trim. You can copy what TRDHulk did here in his build thread at the other forum .

it's barely noticeable and will also require front fender push with the help of a heat gun.

 

Had a wrangler….just got my lemon law payout…now I’m back to Toyota.

 

You don’t need a viper cut for negative offset…..but you would need to do the fender liner mod. If you look that up, you can find a bunch of step by steps. Super easy and you can perform yourself with basically a screw driver, a drill and a box cutter. It’s a very minimal trim of the corner of the fender flare. You won’t even notice it’s gone.

If you don’t want to do any of that, I’ve heard a +6 is the lowest offset you can get away with……but that’s just hearsay. I haven’t personally tested that.

 

I don't think you'll need a full viper cut to fit 33's with -18 offset. Just a lot of trimming as @michow87 mentioned. I'm not a big fan of the really high viper cut either... Many people cut about 4" higher than I did.

My cut is pretty aggressive but I didn't do it just for tire clearance. I did it to clear obstacles. I’ve also found the wide stance helps protect the body and provides some stability on off camber obstacles.










Running 34s with offset equal to 17x9 -38.

 

Alright, that doesn’t look too bad. He’s also running a bigger tire as well so if I do trim with a 0 offset it should be a bit less maybe. He didn’t list his wheel specs but those look like the standard trd wheels. If I remember those are +4

 

When you widen the track of your vehicle with wheel spacers or changes in offset you increase the scrub radius. If you widen the track with long travel suspension, you leave the scrub radius unchanged. Increasing the scrub radius contributes to an increased arc prescribed by the wheel as it turns, and it’s the increased arc, primarily, that causes the rubbing.

Here’s an accurate enough drawing for explanation. As the label denotes, it shows a stock 265/70r17 tire on a stock TRD rim:7½x17 rim with a +15mm offset:

What if we replace the stock wheel with the very popular 285 tire on the 7x17 rim with the +4mm offset?

Comparing the two drawings, notice in the second drawing that the offset is decreased and the scrub radius has increased.

Looking down from the top, we still see the dashed line prescribing the steering axis. From this view it is apparent that not only is the point of the tire’s rotation on the ground not centered on the tire laterally, it’s not centered front to back either. An effect of this is that as the tire is turned left and right, the leading outboard corner and the trailing outboard corner of the tire prescribe 2 different arcs, drawn in orange.

Now let’s swap out the 265 wheel for the 285.

The arc of the 285 wheel is purple. The arc of the 265 wheel is orange. The 285 wheel fits in the wheel well just fine. So why does it rub? Because the 4Runner is not very tolerant to changes in the diameter of this arc. It’s so intolerant, in fact that just pushing the wheel outboard of the steering axis a scant 4 tenths of an inch, (as occurs when the TRD Pro rims are fitted) causes Toyota to cut the fender at the port. It’s not merely the wheel being pushed outboard that causes the rubbing. It’s the wheel being pushed away from the steering axis that causes the trouble.

 

I'm running 17x8.5 0 offset wheels. Stock size Falken Wildpeak AT3. I only have a front level of 1". I did not have to push the fender liner or BMC. Very MINIMAL rub when steering is fully rotated to the left and reversing on a hill. On flat surfaces, no rubbing or issues.

 

What is your ultimate goal for form or function?

 

Little of both. I like the look and performance of the 285 but the negative offset is literally just visual.

 

I appreciate that info bud. I’m surprised the runner doesn’t have the same offset capacity as the taco. I ran a -10 on my 2016 with no issues. I’m just gonna do a 0 and allow a small amount of trimming if need be. I don’t want a full viper, not my thing.

 

We run a 0 offset wheel and have ran 275-70's with just a tiny rub, after the inner fender mod exactly NO rub. Thanx to Nimby! Why the sadness? wheel/tire choices should be fun!

 

TRDHulk has the Relation Race Wheels RR6 with a -25 offset.

 

Oh shit okay, then like a -10 probably wouldn’t need that much of a cut if I still went negative. I just don’t want a full viper

 

It’s not necessary for 33s and -18 offset.

Here’s an extreme example
35s with -38 offset and no viper cut. If you look close, there’s a trim to the bumper cover.

It can be done without a viper cut

 

Did you miss this post earlier?