Will these fit ?

[MpowerMike]

21x10 +17 front
21x12 +35 Rear

I’m fine with running a stretched tire but I need to know if these will clear the brakes and if they will fit at all, please help .



Thanks
Mike

[carrera2RSL]

Mike, hi

The rear should be fine, just. I would have 3-4mm clearance to the strut with 305's and a few more mm 'poke' perfect I would say. I think you could fit 305's no problem.

et 17 is too aggressive, 10mm more than you need really, my car is et28, et 25/26 on a 10 looks aggressive. Your outer rim edge would be 11mm more than my set up and the same (rim not tyre) as running 27.7mm spacers on the front of stock wheels.

[carrera2RSL]

Heres three pictures 10 et 28 with 275's and 265's and stock with 15mm spacers

[MpowerMike]

Originally Posted by carrera2RSL

Mike, hi

The rear should be fine, just. I would have 3-4mm clearance to the strut with 305's and a few more mm 'poke' perfect I would say. I think you could fit 305's no problem.

et 17 is too aggressive, 10mm more than you need really, my car is et28, et 25/26 on a 10 looks aggressive. Your outer rim edge would be 11mm more than my set up and the same (rim not tyre) as running 27.7mm spacers on the front of stock wheels.

Ok so since you confirmed the rears will fit fine , would 21x10 +25 front fit? The reason I’m going this aggressive with the offsets is because I want deep lips on the wheels , they are going to be 4” rear steplips with 21x12 +35 and I was told I can achieve a 3” steplip upfront with a 21x10 +17 but as you said it’s not going to fit. The vendor originally said I should go for +25 upfront which would give me a steplip size of 2.5” . Which I think is too small for the look I’m going for . So now I’m caught in a situation where the rears wheels will have a nice deep steplip look 4” and the fronts not so much . I really wanted 3” front and 4” rear steplips. I was told by the vendor that the only way we can achieve a 3” front lip size is if we drop to +17 offsets for the front. What do you think ? What if I go 21x10.5 will that increase the lip size ?

[m5 guy]

A 25 offset will fit just fine with a 10 inch wheel, but I wouldn't go more than that. Unless you are stretching tires you will start rubbing the bump in the liner where the bumper meets the fender.

Now you can have a lower offset and do a 9.5 wheel. That might be able to get you the lip you are after. Depends on barrel and lip sizes available at that point. Hit up an offset calculator site to determine the offset that equals a 10 inch at 25 to a 9.5 inch at X. Then talk story with the wheel company to see what they say.

Lastly if you are serious about this consider running more negative camber in the front with a lowered ride height. Will help with clearance. Plus deep dish wheels look rather silly imo at stock heights imo. Good luck!

[MpowerMike]

Originally Posted by m5 guy

A 25 offset will fit just fine with a 10 inch wheel, but I wouldn't go more than that. Unless you are stretching tires you will start rubbing the bump in the liner where the bumper meets the fender.

Now you can have a lower offset and do a 9.5 wheel. That might be able to get you the lip you are after. Depends on barrel and lip sizes available at that point. Hit up an offset calculator site to determine the offset that equals a 10 inch at 25 to a 9.5 inch at X. Then talk story with the wheel company to see what they say.

Lastly if you are serious about this consider running more negative camber in the front with a lowered ride height. Will help with clearance. Plus deep dish wheels look rather silly imo at stock heights imo. Good luck!

I’m currently slammed on kw has all the way , tire size in the front I would run either 275 or 265 . Depends on how much stretch it would be in the rear with 305 tires , I would want to equal out the tire stretch front and rear

[m5 guy]

Originally Posted by MpowerMike

I’m currently slammed on kw has all the way , tire size in the front I would run either 275 or 265 . Depends on how much stretch it would be in the rear with 305 tires , I would want to equal out the tire stretch front and rear

This will definitely be tire dependent then and a 265 will give you more stretch to match the rears. Pirelli 265 will be much narrower than the equivalent Michelin. Guys normally do 9.5/11 with 265/305 so it stands to reason a 10/11.5 would equal out stretch wise.

Doing a 10/12 will probably need to do a 255? Not sure honestly if you are trying to get the sidewalls to look the same. 255 however is not ideal at all. Unless show wheels then go for it!

Of course you could try a 10.5/12, but that will require specific firmest. Tailored levels of measuring and tire selection. I do think it's possible though as I test fit a 10 et 14 and the lip just barely went past the fender. Again though it's not the top of the fender that the issue. It's the area where the bumper meets the fender that's the problem. Solve that and you are golden.

[MpowerMike]

Well if I do go with a 305 tire in the rear and run the stretch look I will want to have the fronts stretched the same way maybe a little less. If only I can run a 325/25/21 Pzero tire in the rear and 275/30/21 Pzero tire it would match up perfectly without any stretch.

[carrera2RSL]

I’d go for 10x21 et 25 and 12x21 et 36 with the specified tyres, if you need to add a little bit more offset at the back you can fit 2 or 3mm spacers. If you go more aggressive to start you might find the tyre clips the rear arch

[MpowerMike]

Originally Posted by carrera2RSL

I’d go for 10x21 et 25 and 12x21 et 36 with the specified tyres, if you need to add a little bit more offset at the back you can fit 2 or 3mm spacers. If you go more aggressive to start you might find the tyre clips the rear arch

Which tires size would you recommend? Do you think 275 30
21 front and 325 25 21 will work?

[carrera2RSL]

Hi Mike I think you will get in 325/25 21 at the rear 275/30 at the front will be easy on et 25, may need adequate camber at the front if very low.

At the back I’m using et33 with 305’s on 11.5, here is the comparison http://www.willtheyfit.com/index.php?width=305&aspect=30&diameter=20&wheelwid th=11.5&offset=33&width2=325&aspect2=25&wheel_size =21&wheel_width=12&offset2=36

My set up will work with 3mm spacers so depending on tyre roll and bulge you should be okay. You will be close on the inside again depending on you’re bulge. But you have some inside clearance adjustment by way of small spacers

A 325/25 21, is 13.2 “ wide fitted that suggests 0.2” wider than a 12” rim which measure up circa 13.0 inches. So it will depend how the tyre sits on the rim down to the last mm.

I do think it’s not such a great idea to stretch a 305 at the back which would go in easily. I’d love to give you a definitive answer. But it will be close

I did try to get a tyre dealer to supply 325/30 20 at the same time as 305/30 but some were not keen to supply, let me fit then send back unused. I gave up pushing this when I decided against MPSC2’s

[carrera2RSL]

PS if I had been able to get MPS4S in 325/30 20 I would have tried !

[m5 guy]

Yeah I definitely think you should push for the 275/325 combo if you are up for it. Fronts easy, the rear will require precision. Seems like carrera has given you a lot of initial measurements so you have a good start. Be cool to see someone pull off a M6 fitment on a M5. Go for it!

[carrera2RSL]

Some more *** packet maths, 325’s come in at 13.2” on a 12, my and rim ar just over 12.6” at the widest so you have .6” extra to squeeze in that’s 8mm a side, I have just over 10mm on the inside at et36 you will be almost or just touching. But that’s with a 20” circumference, so I am pretty sure you will have a few mm spare. Signature quote et40 using that tyre on a 12, but that might be tight if KW are thicker than stock- not sure. On the outside et 36 will need 6mm extra, I can do 3mm easily, not 100% sure about 6mm, but this will be at the tyres widest point, not at the arch edge.

If you can get under the car you could put a straight edge along the tyre inside (upright, to give a guide in line with the camber) then see how much more room you have against the damper tube when you are 1/2 inch higher using 21’s vs 20’s

I suspect the game is to get the tyre as close as possible on the inside near the damper. You only need 2-3mm clearance, maybe less. I think your clearance will improve against the damper as the wheel goes into the arch, so minimum at ride height is okay, with droop you might find it closes a tad. But the load under droop will be in the right direction to take up any suspension compliance and move the wheel away. If you get the rim too close you can fit 2 or 3mm spacers or even have a 1mm ship manufactured - won’t cost much. One thing that’s much more difficult is to push the wheel further in. I wonder if Signature have any pictures of their 12” 21’s with 325’s and et 40 ? I think et 40 would look a little too inset visually