rzundel

I have a '06 C4s with 19x11 305/30/19 tires/wheels in the rear. This is a standard setup for this car. I recently installed the new Turbo Wheels in the rear. I've posted pictures of the car in an earlier posting. The wheels look great. The offset is the same as the Carrera S wheels that came with the car.

I purchased the wheels through Wheel Enhancement. They encouraged me to install the Porsche 17mm spacers in the rear. This fills out the fender nicely but I wonder if it is too much? I also wonder what this added spacer weight is doing to me if anything?

Who has experience with these spacers that can give me some direction on the right size spacer for my car? I know Porsche makes a 5mm spacer but Wheel Enhancement told me that it was not worth installing. They also told me that they sell a 15mm aftermarket spacer but the difference is only 2mm.

2mm might not be much to them but I think 17mm is too much spacer for my setup. Has anyone else installed the 17mm spacers on their new wide rear C4s?

jhbrennan

I thought that the C4S with Sport wheels came stock with the 17mm spacers. The rear offset for the Sport is 67mm while the rear offset for all the other Porsche C4S 19 inch wheels is 51mm, hence the need for the 17mm spacer. The Sport is also 11.5 width. Don't know the specs on the Turbo wheels but I have a lot of faith in the advice that Wheel Enhancment provides.

gota911

Rzudel - here is a link to a wheel offset calculator. You can enter your original wheel dimensions (width and offset) on the top and the dimensions of the new Turbo wheels on the bottom to find out the potential impact of the change. Since you didn't list the effective offsets of the two wheel types, I couldn't do the calcs for you.

http://www.1010tires.com/WheelOffsetCalculator.asp

rzundel

My original wheels were the Carrera S wheels not the Carrera Sport wheels. Both the Carrera S wheels and the Turbo wheels are 11" W with a 51mm offset. They are identical. The reason they recommeded the 17mm spacers were to give the car are more aggressive stance. With the wider rear end, Wheel Enhancement felt that the car looked better with the wheels brought out 17mm. This would have been the same if I kept my stock Carrera S wheels. I am simply concerned that the wheels were brought out too much with the spacers. I am looking to see if anyone else uses the 17mm spacers on their new C4s or is their a better spacer that I should be using?

jhbrennan

OK - now I understand...but I don't have an answer for you - I guess it's just personl preference on looks. Someone smarter than I might have some tips on performance issues. Good luck.

rzundel

Am I the only one out there putting spacers on my C4s? Could really use some help on this?

gota911

Maybe you should post a couple of pics with the shot taken from the rear, almost (but not quite) directly down the side of the car. This will allow us to see how much the wheels and tires extend beyond the fenders, if at all.

HMS

The turbo wheels should have the same offset as the C4S...51mm. I would leave them stock and ditch the spacers. The only spacers I would go with are the 5mm factory ones sold for the GT3. Plus, 17mm is a little overkill anyway. That puts a real load on your hubs too. Stay stock buddy.

meaker

Hey rzundel, I don't know if this helps or not.These examples are all 11in wheel. The c2s has 67mm and most of the aftermarket company go with 55 -58mm on the rear(maybe even 52mm). I know 51mm looks to be to far because i have seen a C4S wheel on a C2S. Now just figure in that the rear fenders are 22mm wider on the C4S. I would think you could go with 17mm and still be OK, but would be a safe bet on the 15mm.

Coochas

Nope.
I put the 5mm Porsche set on my Carrera Classic 19" on my C4S - the only reason I did it was to just slightly fill out the fenders.
See this post: https://rennlist.com/forums/showthre...ghlight=spacer
In winter mode, I run 18" 235 front and 265 rear which necessitate putting the 17 mm spacer set just on the rears - this is solely because a 40 mm difference in tire width and a slightly greater offset with my winter wheels still makes me look like I'm running a donut...the 17 mm fixes this nicely.
For the 17mm winter combo see this post: https://rennlist.com/forums/showthre...ghlight=spacer

I don't know the details of the Sport Tech wheels.

MichaelL

Thick spacers do nothing good for the unsprung weight. The other, more serious shortcoming is the additional bending moment imposed on the wheel bolts by the longer moment arm acting on the bolt. This places a higher bending stress on the shank of the bolt, as well as greater fatigue stress. Loosening of the bolts is increased and proper bolt torque becomes more critical. A loosened bolt can yield or fracture much more easily. This localized, non-ductile failure is not evident, unless the head falls off, and will lead to a cascade failure.

Wheel spacers are a retrofit for wheels with too small an offset. If used, wheel bolt torque is critical and should be checked periodically.

Stick with the factory 5 mm or be brave.

rzundel

Thanks for the great feedback. I will try and post some close up rear pictures. I think my concerns are valid based on the feedback I am getting. 17mm might be an overkill. They do not stick our beyond the top fender well but it is close.

dstrimbu

Good point, Michael. Thanks!

ohsixx

I think spacers are a bad idea. If it is only for looks; forget it!

rzundel

Here are a couple shots of the car. Let me know what you think?