I have 4th gen rear and planning to run 4th gen rims all the way around, but I am still trying to figure out which spacer I need to buy from skulte.

With stock front brakes, people recommend 2", but when you do C5 conversion, C5 rotor goes on top of the 'hub' which used to be the brake, so now wheels are pushed out by the thinkness of the rotor. Right? Should I compensate for this by buying a smaller spacer? Like 1.75" (if there is one).

I just want to make sure that wallet-draining 275-40/17's with ROH rims will not rub when all is said and done.

 

You should subtract the thickness of the rotor hat from the total measurement. If the C5 rotor hats are .300" thick, then I'd go with 1.7" thick wheel adapters. We've been getting more requests for this size, so it's something I'm considering keeping in stock for the brake upgrade folks. Right now it's a custom, since we have it done on an individual order basis.

 

Andris, I think you should make it a stock size. Try to do that before the end of this month, so when I place my order they can ship right away. mmkay...

 

yeah, that's what I thought. If you decide to make it stock size, can you update us on this thread?

It already looks like I am not the only one who would be interested in those.

 

Just curious, as I have 2" spacers and will soon do the C5 upgrade.. .3"... Isn't that a tad over a quarter inch? Is it really that crutial to get new spacers? I highly doubt you could tell the difference. Please let me know if I'm missing something.

Kevin D.

 

To most it probably wouldn't be alot. But to others it'll seem like a mile.

Just personal preference.

 

i went with 1.5" spacers and ls1 brakes.. about the same as c5's.. with y2k wheels which were spec'd for a 4th gen.. i wish i would have got 1.75" as you can really tell that .25"

they do fit perfect with no rubbing tho... just not out as far as id like... nothing a new spacer wouldnt fix tho... probably will need the same for the back

 

Ace, what tire size and brand are you running and how do you like your tires

 

245/40/17 kumho estca MX, i messed up and didnt get the 245.45s so these are about 1/2 an inch shorter ... i also got the wheel on the wrong side of the car by the looks of it... they look like a nice tire, esp the rear 295/35.18s.. the cars currently on jack stands so i cant tell ya how they move yet

 

295's in the rear, eehh. Did you have to do any massaging to get those in there.

The reason I am **** about this is because I want 275's all around and up front you don't have much room left for those so every 1/4" may count.

I am thinking I can actually order rims/tires first, do some measuring and then figure out how much spacer I actually need so the tire is in the best position between the fender and the inner wall.

 

As long as you keep them relatively short and make sure that you clear the tie rod end, it’s actually easier to fit some wide meat on the front of an f-body then the rear.

 

Make that one more who will need some custom spacers for the C5 swap and 17x9.5 SS rims up front.

 

Finally got my C5's done and the new rims mounted. Found something interesting out..

I've got 4 of the same rims, same offset, etc.. 4th gen rear in the back which is 'known' to be 2" wider per side. I'm running 2" adaters up front.

I decided to measure and see exactly what spacers I should get now (assuming 1.7"). Turns out that right now, my rear track width is 1/8" bigger than my front. So in theory, my front width was off by .725" before the C5 swap and is now almost perfect.

So again, in theory, I needed 2.3" spacers before the swap and now my 2" spacers are correct.

Thoughts?

Kevin D.

 

Kevin,
I'd bolt up the wheels to the 2" adapters you have up front. The suspension wants the centerline of the tire in the same place as stock, so the scrub radius of the tire isn't changed. By moving the wheel centerline further out than stock, the tire will move forward and backwards as it's turned, and may require the plastic fender liner to get modified to clear the back of the tire at full-lock. A 1/4" won't create enough of a difference to worry about, so I'd keep what you have. I think it's pretty difficult to eyeball a 1/4" difference between front and rear. If it looks good now, and doesn't rub, I don't see any reason to go with the 1.7" adapters (which we now keep in stock as well for the LS1/C5 brake kit folks). Do you have any pictures yet?

 

In the past it seemed that a lot of people ran 2.25" spacers for "4th gen" wheels. Without problems, I assume. I run 2" adapter and had slight wheel rub on the plastic inner fender liner at full lock. I seriously considered a smaller adapter to compliment a brake upgrade. After I did the C5 swap (and new struts, springs, steering linkage, stut mounts & alum A-Arm bushings) + a tapemeasure/shadetree alignment, I had serious wheel rub. I then got a profesional alignment with a good amount of negative camber and I now have zero rub with the 2" adapter.

 

If 2.25" was the norm, then my results would be right. I'm only getting a little bit of rubbing when I'm at full-lock left, in reverse, on a 20 degree incline (seriously) when backing out of my driveway. It's little enough I can't even see where it's rubbing. Might be on the actual fender as the convertibles bottom bracing pushes the lowest bolt holes out a bit.

Here's a picture slightly off angle of the tires AFTER the C5 swap. You can see that if you were move to the right a bit to view parallel with the door, both tires would line up about perfect.

Pics of the actual car can be seen at: https://www.thirdgen.org/techbb2/sho...hreadid=304916

Kevin D.