17x9 wheels with 5'' backspacing

[BuickMike231]

Hey guys, I'm looking around for some new wheels and was wondering if a 17x9'' wheel with a 5'' backspace would work for the rear of the car. I am not going to put anything huge for tires, a 275/40 would be the largest I would consider and I was already planning on rolling the fender lip to be sure. Would there be any issue with that backspace? I know it would probably be better around 4.5 or 4.75, but do you guys see any issue with the 5 inche bs? My car has the 2'' DSE lowering springs on it as well. Thanks in advance.

 

[lhbarrett]

I have Rev 17*9s on the rear with 275/40s with no issues using moog lowering springs. For a while I had Boss 338s on the rear using. Eibach lowering springs 18*9.5, 5.2 BS with 275/40s, talk about a big tire on a Turbo T, and they did not rub anywhere. but it was tight on the frame.

 

[toomanymodz]

I think it should fit easily. Might not have to roll the fender lip either.

 

[BuickMike231]

Thanks for the replies guys. I know some guys say that 4.5" be is too much in the front since it looks like its sucked under the car. The 5" in the back would be the same thing right? Does it look right with the 5" bs? Also you guys don't have any issues hitting the frame? what kind of clearance to the frame are we looking at with that size wheel and a 275/40 tire? Thanks!

 

[lhbarrett]

The wheel sizes are before the tire size. The 275/40/18 on the Boss 338s (18*9.5) had a 1/4 inch plus from the frame, but all cars are different. Get a carpenters square and a tape measure and measure twice and purchase once.

 

[49-blues]

I'm running 17 x 9.5" with 4.5" backspacing with a MT 295 x 45 x 17 drag radial - fits perfect .if you measure from the rear drum face to the frame there is about 5.5" max that's with the backspacing & sidewall bulge.

 

[toomanymodz]

I'm running 17 x 9.5" with 4.5" backspacing with a MT 295 x 45 x 17 drag radial - fits perfect .if you measure from the rear drum face to the frame there is about 5.5" max that's with the backspacing & sidewall bulge.

That's a good point. So if someone plans to run a 5 inch backspace, they can as long as the tire doesn't bulge much past the rim. Most 17 and 18 inch combos with the proper size tire doesn't have hardly any bulge, usually 1/8 to 1/4 inch. Most 15 inch combos have quite a bit of bulge, usually between .5 and 1.5 inches. It's fairly simple to calculate and it will get you close. For example: I'm running 15x9 with 4.5 backspace. My 295/55's have a total width of 11.6 inches (295 divided by 25.4). A 9 inch wide rim is measured at the bead, so it has a total width of 10 inches (a 15x7 rim has a total width of 8, and a 15x8 has a total width of 9 inches). So 11.6 - 10 = 1.6 then divide it by 2 and you get .8 which represents how much it will bulge past the rim. Add the bulge plus the backspacing, .8 + 4.5 = 5.3 On my car the drum face to frame is 5 5/8 or 5.625. 5.625 - 5.3 = .325 That is very close to my actual clearance, which is about 3/8 inch.

 

[BuickMike231]

Great info guys, thanks for that!