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Discussion Starter · #1 · (Edited)
Ok Im sure this has been asked dozens of times by now, however on the search function, amongst the PK Auto spam, I don't see anything relating to this, so I'm going to ask it (possibly again). We have a 1320 and a Scat Pack, and both of them just spin like crazy on a race track, and roads in general, even with soft compound tires. Yes I know the 1320 is set up for drag, but this family prefers a track with turns. We wanna do 315 soft compound radials on the rear. Right now, we're looking at MRR M392 11 inch rears and 9.5 fronts. The 11 inch wide rears have 24mm offsets and 6.9 inch back spacing. We are hearing several things from different people. Some say they fit fine. Some say the rear fender well needs to be cut on the inside rear edge. Some say it needs 3mm spacers. Some say it needs 25 or 30mm spacers. With wheels like this on stock suspension, do you really need spacers? I feel like they would clear the brakes just fine. Im not sure about the wheel well though. Anyone have experience with MRR M392 11'' on a scat pack or 1320? What did you do to get them to fit, if anything?
 

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24mm spacers would be the same as the wheel having a 0 offset and would stick out of the fender like crazy. Its really the tire that you have to worry about in your specific setup. I'd say MAX youd need a 5mm spacer, probably less, all depends on your tire
 

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Discussion Starter · #3 · (Edited)
24mm spacers would be the same as the wheel having a 0 offset and would stick out of the fender like crazy. Its really the tire that you have to worry about in your specific setup. I'd say MAX youd need a 5mm spacer, probably less, all depends on your tire
Ya I had red flags as soon as I saw someone call out spacers that big. That seems to be all American Muscle carries though, so I guess people might see that and think those are supposed to be used on these cars. I know the wheels will fit, they're Hellcat coffin reproductions. And from what I understand, 305 tires fit just fine. Im asking because I dont know if the 315's will. Thats gonna be an extra 7.5mm deeper into the wheel well than what I know to work. So question is... On a hellcat with 305's on coffin wheels in the back, is there 10mm of clearance behind the tire? Enough to fix the extra 7.5mm and still give the wheel well some room so it doesnt get bit? As for sticking out, I'm not worried about that. These cars are so bad at aerodynamics already that a little tire sticking out doesnt really matter much unless its a 1/2 mile speed run or something (not joking, there are quite a few SUVs out there with better drag coefficients than our cars). We have the power to pick up against the drag, at least at road course speeds. I actually like the look of tires in the back that are so wide that they dont tuck. Reminds me of late 60's / early 70's drag builds that you used to see on the street. I mean not "mexican pickup truck" levels of sticking out, but a tiny bit past the upper fender edge isnt a deal breaker. I expect the Scat Pack will end up like that with 11 inch because its not a wide body.

But getting off topic here... If you, or anyone else reading this, has 305's and coffins on the back wheels, please chime in and let me know what your tire to wheel well gap is on the inner area. Im looking for someone to confirm 10-15mm (ish), which is about 0.4-0.5 inches if that makes it easier to visualize. Or if you have 315's, has it ever bit your fender, and are you using spacers for them?
 
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