Help with stepping up to 17" wheels

[Jeff73Mach1]

offset is essentially just measuring how far the wheel hub is off center

Backspacing is how far the rear of the rim is from the hub

so a 10 rim with 5.0 back space is 0 offset

And I'm going to pick up some Craigslist 17x10.5 rear rims and 315-35-17 tires tonight for 280 bucks for the pair-if the backspacing is correct. and maybe even if it isn't!

 

[Totalled]

I've been driving it around for a little while and the ride is noticeably smoother and crisper handling than before. I believe the BFGs I had on the car previously were 20 years old! I'm not sure why the Sumitomos are so cheap, but they're excellent sticky tires. Very happy with them.

I think a front spoiler would be the cherry on top of that car. Nice ride.

 

[Mesozoic]

I've been driving it around for a little while and the ride is noticeably smoother and crisper handling than before. I believe the BFGs I had on the car previously were 20 years old! I'm not sure why the Sumitomos are so cheap, but they're excellent sticky tires. Very happy with them.

I think a front spoiler would be the cherry on top of that car. Nice ride.

Thank you! I do have a spoiler, but was thinking of painting it first before installation. What is the correct paint for the front spoiler anyway?

 

[Jeff73Mach1]

I found that my spoiler was broken today- almost all the center mounting point pulled out. Mine is a black abs and I see no reason to paint it.

That being said use washers when mounting

 

[Totalled]

^^That.

Thank you! I do have a spoiler, but was thinking of painting it first before installation. What is the correct paint for the front spoiler anyway?

'Glass or plastic? If plastic, I wouldn't paint it. If glass... probably the same as what's recommended for the hood blackout/rear spoiler.

 

[cazsper]

Do those 315's stick out beyond the fender?

 

[Mesozoic]

Do those 315's stick out beyond the fender?

No, they're a perfect fit. I think I could've gone wider with some 335s, but cost would become prohibitive at that size very fast.

 

[cazsper]

Cool. Thanks..

 

[detritusmaximus]

offset is essentially just measuring how far the wheel hub is off center

Backspacing is how far the rear of the rim is from the hub

so a 10 rim with 5.0 back space is 0 offset

And I'm going to pick up some Craigslist 17x10.5 rear rims and 315-35-17 tires tonight for 280 bucks for the pair-if the backspacing is correct. and maybe even if it isn't!

I'm not so sure on this. As I understand it, BS is measured based on total rim width, not just the width of the tire bead area. If that is so, a 10" wide rim is really like 11" wide, so BS would be more like 5.5" for a 0 offset. A 10" with 5" BS would be like a 10-15mm offset (don't recall if that is negative or positive offset).

I found that my spoiler was broken today- almost all the center mounting point pulled out. Mine is a black abs and I see no reason to paint it.

That being said use washers when mounting

I had the same problem on my Opel with a similar type spoiler. The force applied to that spoiler in the middle at highway speeds is tremendous. Mine was fiberglass and after it cracked it pulled right off the car. The flaw in the design is that it needs a support (like a fin) in the middle to prevent it from flexing backwards. Or maybe a couple of them.

 

[wrobinson]

I've been driving it around for a little while and the ride is noticeably smoother and crisper handling than before.  I believe the BFGs I had on the car previously were 20 years old!  I'm not sure why the Sumitomos are so cheap, but they're excellent sticky tires.  Very happy with them.

Mesozoic,

What suspension upgrades have you made? Interested in how much drop in front and back. I had planned on 1" drop front and rear with 17 X 8's at all four  corners wearing 245 45 R17's. Trying to visualize the stance and ride height. I want the staggered look but its my son's car. I love the stance of your car.

 

[B229218]

I've decided to step up to 17" wheels on my '71 fastback.  I'm a little concerned about backspacing and hoping I can get some help from you folks.  Here's the current situation:

Fronts: 15x7 Weld Draglites, 3.50" BS (WLD-90-57346)

Rears: 15x10 Weld Draglites, 5.50" BS (WLD-90-510350)

The rubber is a set of BFG Radial T/As in 235-60-15 up front and the rears are 295-50-15.  The stance is great, car looks good, even handles good, but since I've upgraded the suspension quite a bit lately, I want larger brakes and better handling.  I've decided on a set of 17" wheels based on size and backspacing as well: Centerline Nitro2s.

The rears are available in 17x9.5 with 5.50" BS.  The fronts are available in 17x8 with BS between 3.50" and 5.50" in steps of 0.50" increments.  What is going to be the best BS fitment and tire sizes for my '71 on 17s?  I was thinking 285-40-17 for the rear and 235/245-40/45-17 up front.

I have draglites on my car for many years, they are not designed for street handling, potholes, ect. they will start to split at center . In a straight line, there is no other lightweight drag street/strip out there. Going to 17 or even 18 inch rims puts even more shock load on a wheel at bumps due to shorter stiff sidewalls. Thtas why I went to 15 " magnum cast one-piece-for safety. THOSE wheels due come in 17" for big brakes.