Backmarker

Hi there

I have a few sets of HRE wheels for my narrow body GT3 and am thinking about running a set on my wide body 997.1 C4s. Otherwise they just sit in the garage...

The wheels I have are HRE 547Rs with these specs:

18x8.5 ET 43mm
18x11 ET 65mm

Looking at wheels in this size new from TireRack for the 997.1 C4S it suggests the following:

18x8.5 ET 53mm
18x11 ET 45mm

Am I correct in think that I can run the fronts with a 10mm spacer, and on the rears I would need a 20mm spacer? I have never run spacers so not sure how smart of an idea this is. It's a 100% street car, and I have rennline studs on it that are long enough to accommodate the wheels+spacers.

Anyone have experience doing something like this?

Petza914

For the same width wheels, a smaller offset value means the wheel actually sticks out more. If you take an et43 wheel and run it with a 10mm spacer, that's like having an et33 wheel, not a 53. If the fronts you have work on your GT3, then they should also work on your C4S (front setup of almost all 997s is the same whether NB or WB) though that's a pretty aggressive offset. Your statement on the rears is correct about using a 20mm spacer, but IMO when you get to a 15mm spacer or thicker, you're better off with the H&R DRM type where the spacer bolts to the hub with special bolts and then your wheel bolts to the spacer with your current bolts, but this type of spacer doesn't work with wheel studs. Studs long enough to accommodate a 20mm spacer are going to have a lot of forces acting on the outer ends of them and I'm not sure how safe this would be.

Go to www.willtheyfit.com and punch in your current and new wheel sizes and it will explain the difference. Any spacers should be hub centric with the centering flange on them.

Backmarker

Thanks, I was concerned I had it backwards

Probably easier for me to just find a WB specific set of wheels and leave the spare HREs in the garage as decoration

PelicanParts.com

If you're interested in a great, basic guide on fitment, spacing/offset; take a look at the link below.

Wheel Fitment & Spacing Guide

Backmarker

Thanks, I stand educated ;-)