Backspacing questions...

[nero]

OK, I think I got a grip on understanding backspacing. Is it, the more backspacing the further out the wheel will stick out? For example, a 4.5" backspacing would be more under the car than a 4"?

I'm trying to get an aggressive stance. I have GNx flares, so I'd like to have the wheels come out as far as possible without going past the flares or forcing me to use longer studs. Would these satisfy my needs on all four corners?

Cragar S/S Super Sport Wheels: CRR-617934 - summitracing.com

***If you've been following the nero-saga, I've changed it up and decided to get a two-piece rim and have the spokes powder coated to a dark gray/anthracite color before mounting.

Those cragars have a NICE and DEEP lip and the two piece design makes it easy on the powder coaters.

Thanks

 

[nero]

Here's a pic from cragar's site...

 

[Silver Fox]

Nero,

Check out this site, as it will explain what you are asking:

https://www.rsracing.com/tech-wheel.html

By the way, I am finally getting ready to do the install of the SC&C Stage 2 kit in a few hours.

Rob

 

[nero]

Fantastic!!! Let me know how it goes!!!!

 

[BlackMetal]

OK, I think I got a grip on understanding backspacing. Is it, the more backspacing the further out the wheel will stick out? For example, a 4.5" backspacing would be more under the car than a 4"?

You said it wrong the first time and then correct when you used the numbers. LESS backspacing makes the wheel stick out further, but yes, 4.5" would put more of the wheel "under" the car.

As far as using that wheel on all 4 corners, I wouldn't. 9" is way too wide for the front, and that backspacing is probably too much for the front anyway. Go for a staggered look, have a 7" or 8" wide in front. The 9" will be perfect with that backspacing for the rear, though.

I'm no expert but I have learned a lot about all these measurements just from buying new wheels for my car (just installed ANOTHER new set for this summer), so if you have any more questions feel free to ask.

 

[nero]

You said it wrong the first time and then correct when you used the numbers. LESS backspacing makes the wheel stick out further, but yes, 4.5" would put more of the wheel "under" the car.

As far as using that wheel on all 4 corners, I wouldn't. 9" is way too wide for the front, and that backspacing is probably too much for the front anyway. Go for a staggered look, have a 7" or 8" wide in front. The 9" will be perfect with that backspacing for the rear, though.

I'm no expert but I have learned a lot about all these measurements just from buying new wheels for my car (just installed ANOTHER new set for this summer), so if you have any more questions feel free to ask.

Hahahah thanks for clearing that up!! LOL

I don't want the 9" wheels to be sticking out like a hotwheels car but at the same time I don't want them to be reallllllll far under the car. I hope I'm making sense... so the 9" and 4.5" backspacing will achieve an aggressive stance that I'm describing? Awesome... 17x8 comes in 4.5 or 3.5 backspacing... which one would give me the more aggressive stance?

Thanks again T6C

 

[BlackMetal]

Yeah I'd say the 9" wide with 4.5" backspacing will achieve what you're looking for in the rear, not sticking out too much but definately not hidden under the car.

The 17x8 in front would probably look best with the 3.5" backspacing.

 

[nero]

Thanks again!!! These guys are a LOT cheaper than the others, so I'll probably be able to get them sooner, powder coated and pic posted!!!

Thanks AGAIN!!

***Last thing, what's the fattest tire that can go on those 17x9s?

 

[BlackMetal]

Well I know a few people cram 275s on stock 7" rims, you could probably get away with 295s or 315s.

You have to be careful though. If you go too wide, when you go over bumps the sidewall will flex very easily, and when it flexes it might come in contact with the frame. The tires may not rub normally, but if you start noticing wear on the inside of the tire, or hear noise over bumps, it means the sidewall is rubbing at some point.

Actually it might not be that much of a problem if you're doing 17s, since there will be less sidewall in the first place. But I know the guys who put really wide tires on their stock rims have mentioned the tires end up rubbing because they flex.

 

[nero]

Tons of valuable info you're passing to me... thanks, man! Question... the 3.5 backspacing 17x8 have more negative offset than the 4.5 backspace 17x9s... does that mean that the lip is deeper for the fronts?

 

[BlackMetal]

I guess I never really gave you a specific answer to your last question. If you want to play it safe and have tires that are a good fit for that rim I'd probably do 275s. That's what I had on my 18"x9" wheels.

Hm...that offset question has me stumped. I'm actually sitting here drawing it out on a piece of paper and can't figure it out. It looks like the front actually would have a bigger lip but about half an inch....that's stupid haha.

EDIT: Yeah...unless I'm messing up the math somewhere, it looks like the front would have a larger lip. Hm...

 

[nero]

Yea... that is kinda dumb! LOL

The only other option is the 4.5" backspacing on the 17x8s. They have a 0mm offset, deep but not as deep as the rears. Would a 17x8 4.5" backspace be too much "under" the car to keep that aggressive stance or is it a fitment issue?

 

[BlackMetal]

Ahhh my brain is spinning, I looked at it again and came up with them having about the exact same "lip". Which still might look kind of strange...but not as bad as having a larger lip in the front.

Offset is the distance from the flat mounting surface of the wheel face to the true center of the wheel (aka the width of the wheel divided in half). So you have less of an offset on the 9" wide rear wheel BUT we're working from a different center line. On the rear wheels, the mounting face of the wheel is 12mm away from true center, which would be 4.5" on a 9" wheel. The front wheels have a more negative offset of 25mm, but that's 25mm away from a center line of 4". The difference between 12mm and 25mm is about half an inch, but the centerline of the wheels also have half an inch difference. So that's why I'm now thinking the lip would look about the same. I was getting thrown off just by the idea that 25mm is more than 12mm, but we're not talking about the same size wheel.

(now that I've confused anyone else reading this haha...)

I think 4.5" in front would be BOTH a poor appearance and a fitment issue. The inside lips of the wheel would probably hit during turns.

 

[nero]

Here's a monkey wrench...

T6P Rear Tire Sizes And Pictures - t6p.com - Turbo Buick Regal Resource

Scroll to the 17s with the car that says... "Mike Jacobsen Centerline Scorpions 17x9 4.5" I'm assuming that's all four corners, but don't want a paperweight if I try to go that size for fronts too...

 

[BlackMetal]

Yeah it does seem that he has 9" for all four wheels. Not to mention it says they're 4.5" backspacing, which I thought didn't work in the front. I don't know as much about how much space there is for the front wheels, I've always worried more about rear backspacing because I like cramming huge tires in back. So maybe there really is that much room in the front, I didn't think so. I remember someone at these forums asking for opinions about 8" front wheels with 3.5" backspacing and someone said even that size could possibly cause trouble. Soooo now I'm not too sure about the front.

 

[BlackMetal]

I'm trying my best over here... hahaha

 

[nero]

Interesting... I'll do some more searches on all three forums and post a link to this thread in the other... has me doing a lot of reloading and searching! Finding the right wheels is TOUGH lol..

 

[nero]

LOL Damn!!! Thanks for the diagram hahaha... I wouldn't do 17x9s all the way around, I'd let the fronts be 17x8 4.5" so that the lip is deeper in the rear. IF and IF a 17x8 4/.5" backspace will work, I'll do it (keeping in mind I'm shooting for an aggressive non-under-the-car wheel look and stance and that my car has GNx flares)...

 

[nero]

Another monkey wrench... the car two pics below the one I spoke about a few posts back has 17x8s with 4.5" backspacing. The stance looks pretty GOOD...

 

[BlackMetal]

Another monkey wrench... the car two pics below the one I spoke about a few posts back has 17x8s with 4.5" backspacing. The stance looks pretty GOOD...

Yeah I was just looking at that car, I have no idea why it looks that way. I have 8" front wheels with only 3.75" backspacing and I think they sit too far under the car even with 3.75, I don't know how his wheels sit that far out with that much backspacing.

I was just looking through some other threads on these forums (you'll find a ton if you just search for "backspacing") and here's one quote I found about the front wheels....

"4.5" backspacing on 8" wide rim is about as far as I'd like to go and even that is too much in my opinion (3.5" to 4.0" is ideal). 4.75" backspacing on either the front or the rear would suck the wheels in too far, they wouldn't look good, and would put the tire in danger of rubbing the frame in the rear or having the rim rub the upper control arm in the front when the wheel is cut all the way."

So I guess it depends if you care about occassional rubbing. 4.5" backspacing would probably fit, but might rub on sharp turns, and will also have a small lip on the outside which might not look too attractive if you want deep wheels.