How much cutting do SPC uppers save for 315's?

[APhelps]

FN 17's are ET -6 or 4.5" bs. At most, I'd add a 0.5" spacer, which would be 4" bs. Def not gonna be running 3.5" bs.

Someone can correct me if I'm wrong but a 0.5" spacer is going to give you 3.0bs", not 4.0bs". A spacer should be pushing the wheel outwards, and if you want to increase backspacing you need to push the wheel inwards.

 

[Bad Luck]

Someone can correct me if I'm wrong but a 0.5" spacer is going to give you 3.0bs", not 4.0bs". A spacer should be pushing the wheel outwards, and if you want to increase backspacing you need to push the wheel inwards.

Backspacing is the distance between the back face of the wheel and the mounting surface of the wheel. He stated the wheels are 4.5" backspacing and would add a 0.5" spacer at most. 4.5" minus 0.5" equals 4.0" backspacing. How To Measure Wheel Backspace - WILD HORSES Off-Road Technical Support

 

[APhelps]

Backspacing is the distance between the back face of the wheel and the mounting surface of the wheel. He stated the wheels are 4.5" backspacing and would add a 0.5" spacer at most. 4.5" minus 0.5" equals 4.0" backspacing. How To Measure Wheel Backspace - WILD HORSES Off-Road Technical Support

Ouch. I woke up this morning and realized I completely misunderstood his post.:smash:

 

[wrench.n.wheel]

I wanted as much up-travel as could be reasonably had with 315s, since it is IFS and that upper arc is a lot of your suspension action, so I ended up with a 1" BL, lots of tubbing, SPC uppers (for tire clearance and stock UBJ positioning - caster correction here moves the tire back into the firewall) and Solo Motorsports stock-length LCAs which move the LBJ forward 1". I'm running Methods with 0 offset to keep the tire close to the spindle and minimize the steering arc that gets into the firewall (as opposed to spacers which make that interference worse). I'll still need to notch the frame a minute amount to get full range of steering, but I'm clearing the fender entirely at full stuff (I removed the bump stops and shimmed at a lower stack height to account for compression of the bump stop)

Starting to make a lot more sense why you wanted 0 offset wheels.

Did you cut up the flares in the front or no?

 

[jkeith.w]

Did you cut up the flares in the front or no?

Nope. I think I got lucky.

 

[SDmtnbkr]

I wanted as much up-travel as could be reasonably had with 315s, since it is IFS and that upper arc is a lot of your suspension action, so I ended up with a 1" BL, lots of tubbing, SPC uppers (for tire clearance and stock UBJ positioning - caster correction here moves the tire back into the firewall) and Solo Motorsports stock-length LCAs which move the LBJ forward 1". I'm running Methods with 0 offset to keep the tire close to the spindle and minimize the steering arc that gets into the firewall (as opposed to spacers which make that interference worse). I'll still need to notch the frame a minute amount to get full range of steering, but I'm clearing the fender entirely at full stuff (I removed the bump stops and shimmed at a lower stack height to account for compression of the bump stop)

Thanks so much for this post. It basically confirms what I've thought for a while, that MOST people don't understand how much is needed to reap the benefits of 35's on 3rd gens. I get most people don't care, because they're more interested in the clearance benefits, but I'm more interested in using the suspension I paid $4k for lol. Especially, since I'm mostly a desert dweller, and rarely rock crawl. I'll be sticking with the 295s!

 

[Bad Luck]

Nope. I think I got lucky.

What's your clearance between the inner edge of the fender flare and tire at stuff?

 

[jkeith.w]

What's your clearance between the inner edge of the fender flare and tire at stuff?

pretty tight. I'll probably need to trim the inner flange a bit for additional clearance.

I might be able to get another -.5" of offset out it, just trimming the inner flange - but the wheel/tire combination I have now stuffs really well in the rear.

 

[binqker]

Not sure if this would help. but thought i'd share.

 

[SDmtnbkr]

Not sure if this would help. but thought i'd share.

Thanks. I do use that chart, but not that often. Most manufactures list their offset (ET), so I find myself using this calculator much more. It's a great tool to use, especially when trying to compare different width wheels with different offsets.


Wheel Offset Calculator | 1010Tires.com Discount Online Tire and Wheel Store


And then of course, this site to compare tires... just make sure to look up the exact manufactures sizes, and not the generic listed size, for a true comparison. You can really see the minute difference in the same nominal sizes, between BFG and say, Goodyear.

Tire Size Calculator