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I have all ready 5 mm front and rear, my car is a C4S, original size wheels and tires?, I would like to go wider.
If so I would have to buy new bolts?
many thanks for the info.
Since wheel and tire sizes can vary, it is difficult to say for sure which size is correct without measuring. We recommend measuring the car to make sure which size best suits your needs. We have a chart on our site that shows how and were to measure here:
I've read that with the bigger spacers in the rear, the car tends to kick up a lot more dirt onto the rear quarter panels. That could be a consideration.
The further out the wheels are in the wheel well, the closer they come to the edges of the fenders, the more tire is exposed at the bottom of the wheel and yes, lots more stuff kicks up onto the sides of the car.
Similar to the GMP advice to measure, but different in method since their general advice is measuring to the inner edge of the fender and normally with our cars with are measuring to the outer edge of the fender for the rear wheels only. Here's my advice (again for the rear tires only!) since the degree of spacer you'd want can vary depending upon the tire you are using (their side profiles vary some) and tire width you have.
Note that when I went from 295 rears to 305 rears, I had to remove my prior 14mm spacers since they made the tires stick out due to the wider tires, an alignment change for less aggressive camber in the rear, and the possiblity that the PSS sidewall shape profile sticks out further than my prior Bridgestones. I now need an even smaller spacer on the rears than I expected to bring the tires out flush... only 5mm. I may just leave them where they are.
If you want truly flush at the top of the tire, take a straight edge and place it horizontally adjacent to where the tire sticks outwards the most, resting the straight edge against the front edge and back edge of the outside of the fender (being very careful not to scratch the paint). Then simply take a ruler of some sort and measure the inward distance to the edge of the tire. A spacer this width will make the tire flush as long as you keep the same tire make and width and camber settings. Here is a photo (yeah, another slow day here...)
Edit: A couple of extra notes:
If you don't want completely flush, you just do the above above and subtract out how ever many millimeters you want to leave the tire sitting inset.
In the photo the tire is inset 5mm, but you can't see that reading unless you are looking straight down on the ruler. Be careful not the read the inset at an angle since you may get too high a number. It be even safer to put the ruler underneath the straight edge and look straight down to read it since you can't read it at an angle that way.
Last edited by StormRune; Jan 25, 2016 at 01:12 PM.
I can't tell if that's a widebody. Do you get stuff kicked up on the rear fenders due to the outboard position of the tires?
Looks GREAT btw.
Hint: You can tell it is a wide body since there is a visible ledge along the outside of the tail light in the first photo. This is there because the cars use the same tail lights but the 4's fender flares out further, effectively causing the outside of the tail light to be more inset. On non-4's the outer tail light edge is almost flush with the fender.
Last edited by StormRune; Jan 29, 2016 at 09:19 PM.
Reason: Wording correction to "almost flush"
Hint: You can tell it is a wide body since there is a visible ledge along the outside of the tail light in the first photo. This is there because the cars use the same tail lights but the 4's fender flares out further, effectively causing the outside of the tail light to be more inset. On non-4's the outer tail light edge is flush with the fender.
Using the method I described back in post #9, I installed my new spacers today. With my reduced rear camber to -1.4 degrees and wider 305 tires I only needed 5mm spacers to get the top of the tire flush with the fender now so I went ahead and just used official Porsche spacers. As expected the top outermost edge of the tire is now flush. Previously I was using 14mm spacers to get a flush alignment but with the new setup they were sticking out almost 10mm too far! (BTW, I'll be posting the prior 7mm/14mm spacer set for sale on the Rennlist classifieds tomorrow along with appropriately longer bolts).
The first photo is looking straight ahead from behind the car so that the camera angle is perfectly aligned with the front and rear edges of the fender. If the tire jutted out any you would see it here. The second is another photo front behind the center of the car showing that the stance looks good and the tires don't feel too far out.
