18x10 square setup for F80... offset?

[Reach]

I'm interested in picking up a track wheel setup of 18x10 "square" wheels. I've used Apex wheels in the past and like them well enough. It seems like they've only got the EC-7 style that will clear our brake calipers in 18". I'm not interested in 19" setups.

The car will have stock adaptive suspension with camber plates. Not anticipating lowering, at least in the near term.

So, the 18x10 EC-7 is made in ET (offset) of +25, +33, and +43. Keeping price out of the issue, which would you pick and why? I will have studs on the car, so changing and using spacers won't be an issue. I see many people choosing the +25 on the forum, but that seems a bit aggressive in the front. Do people use the +33 fitment as well? If not, why not?

I'm looking for a good utilitarian wheel setup that I can buy 4 or even 6 of to keep fresh tires available and just rotate, rotate, rotate. What's the forum opinion on what to go with and why?

[CanAutM3]

I ran an 18x10ET25 square setup last year. The reason I went with the ET25 is because I did not want to bother with spacers and different bolt length and also because the ET33 where not included as part of the group buy options at the time I purchased.

ET25 is just about perfect in the front. The 275/35R18 NT01 tires just about clear the struts. ET25 is just a 4mm decrease in offset (8mm wider track) in the front. ET25 is quite aggressive in the rear though and the wide rear r-comp tires tend to poke out a fair bit. ET25 is a 15mm decrease in offset for the rear (30mm wider track).

Folks that run 18x10ET33 square usually run 5mm~10mm spacers in front to clear the strut but it results in a better fit in the rear.

I have since purchased a pair of 18x11ET44 EC7 for the rear. I figure that, paired with wider tires, they will help me better put the power down coming out of corners.

[Reach]

Thanks CanAutM3 , this is what I'm wondering, if +33 in the rear is a better fitment, and I can run a 10mm spacer in the front for an effective +23 and good fitment as well. If I could get away with 5mm, even better. I've got 10, 12, 15, and 18mm spacers hanging around from old setups.

Any other thoughts on the +33 as the one to go with?

[Dweezil]

I run EC-7 19x10 et 25 square with Toyo R888 265/30 tires with no spacers, no rubbing, no issues.


I do find that the MDM is a little more intrusive without the front/rear diameters proportionate to stock.


Since I have CCB, I have wanted the 19x11 Ec-7 but alas not yet available. How does the 18x11 compare to stock? Sorry to digress.

[CanAutM3]

Originally Posted by Dweezil

How does the 18x11 compare to stock? Sorry to digress.

My brand spanking new 18x11 wheels are stored in the basement patiently waiting for the track season to start. I am waiting less patiently though .

I'll provide feedback as soon as I get a chance to wring them out .

[tchiers]

I've run the 18x11 rear - Fits a 305 tire beautifully. That S55 can still light 'em up though

[Flying Low]

I am running EC-7 18X10" with 43mm offset. In the back I run a 295/18 R7 Hoosier and in the front I run a 285/18 R7 Hoosier with an 18mm spacer. No rubbing anywhere and I'm at stock height with camber plates set at 3 degrees. When I wear out the rear 295's I plan to go to EC-7 18X11" wheels with the same offset and a 315/18 Hoosier.

But if you want a square setup you could do 285 all around. This car needs a big tire in the rear though.

[1sickm2]

Here is a pic of an 18x10 et 33 EC7 setup on my M4. Car has 275/35/18 Conti slicks which are rebranded Hoosier R7s. I have a 10mm spacer in the front. Car is lowered on MCS coilovers.

[Reach]

Thanks for that Flying Low. Do you feel the +43 fitment in the rear is a better match than the +33? Are the rear wheels even with the fronts when you look down the side of the car?

Since you're using a +43 with a 18mm spacer it does sound like that 25mm equivalent offset in the front is what most people go with.

[Reach]

This offset calculator has been helpful as I consider this: https://www.1010tires.com/Tools/Whee...et-Calculator#

I'm leaning towards the +33's at the moment. A big question now is, what is the least amount of spacer I would need to clear the struts with the 18x10 + 33 in the front? Does anyone know? (Will less than 10mm do it? How much? 5mm? 7.5mm?)

[1sickm2]

Ill try and get under the car tonight to grab some pics and get a "rough" idea of how much smaller of a spacer can be run. Are you running stock suspension?

[Reach]

Originally Posted by 2009nj335i

Ill try and get under the car tonight to grab some pics and get a "rough" idea of how much smaller of a spacer can be run. Are you running stock suspension?

That would be a huge help.

Stock adaptive suspension. I'm awaiting camber plates once the Vorshlag's hit the market.

[CanAutM3]

Originally Posted by Reach

Thanks for that Flying Low. Do you feel the +43 fitment in the rear is a better match than the +33? Are the rear wheels even with the fronts when you look down the side of the car?

Since you're using a +43 with a 18mm spacer it does sound like that 25mm equivalent offset in the front is what most people go with.

I figure that a wider rear track (through smaller offset) will help better put the power down coming out of corners due to less weight transfer on the rear axle. Just my theory...

[Dweezil]

Originally Posted by Reach

Thanks for that Flying Low. Do you feel the +43 fitment in the rear is a better match than the +33? Are the rear wheels even with the fronts when you look down the side of the car?

Since you're using a +43 with a 18mm spacer it does sound like that 25mm equivalent offset in the front is what most people go with.

Agree on 11" rears with wider track being better for F80 torque. Would love to have them once they come out. If going square, running the ET 25 means no need for spacers at all front or rear. If you call Apex they will recommend this for square 10" setup for F8x.

[Flying Low]

Originally Posted by Reach

Thanks for that Flying Low. Do you feel the +43 fitment in the rear is a better match than the +33? Are the rear wheels even with the fronts when you look down the side of the car?

Since you're using a +43 with a 18mm spacer it does sound like that 25mm equivalent offset in the front is what most people go with.

I haven't looked at the track tires on the car for a few months but I do remember that there is still room in front and the rear as far as the fender lips are concerned. I knew early on that the 43mm offset would be the best for the rear for getting the biggest tire possible. A friend had special wheels machined and that company came up with 43 mm offset for biggest tire possible and now Apex has arrived at almost exactly the same conclusion. I don't think there is anything odd about the look except with stock height there is major fender gap between arc of fender and top of tire. I was never really concerned about the front to back look but I think it is fine with 285 front and 295 rear. It will look even more aggressive with 315 in the rear.
And by the way, with the 285 in front with 18mm spacer there is only 1/8" between side of tire and strut but it never rubs there.

[notoriousjje]

I dont think a square setup is the way to go on our cars as has been the case with previous M3's. The turbo set up gives the car enough torque that you need as big of a rear tire as we can fit.

I think 305's in the rear are the ticket for serious tracking/ lap times. The car does not have a problem rotating as you can induce oversteer seemingly at any point in the corner. I found that some entry oversteer allowed me to get the car pointed towards the corner exit and thus let me put power down earlier than I would have otherwise. This was the key to my faster laps.

So having as wide a tire in the rear as you can would let you take advantage of the torque sooner. I really think a 275/285 F and 305R R-comp setup would be a 2:25 car at Sebring stock which is absurd.

[Ryan239]

I ran 33 offset all around last year with a 5mm spacer in the front. Given the stock suspension I was glad to run square as I rotated the tires halfway through each day, and this helped keep wear down. I switched to studs on the front to make swapping easier.

Only one track (NHMS) made me want more rear tire, at Mosport and Tremblant I felt like the tires were pretty well balanced. NHMS has a lot more low speed, tight corners so the second gear turns were pretty tail happy. The tires also had 8-9 events on them at that point so were fairly worn. I ran 285/30 (I think) Nittos.

The setup is for sale if you'd be interested, I am not taking the M3 to the track anymore. Feel free to PM me, I have the wheels/tires/spacers/studs and Carbotechs.

[aboulfad]

Man, this is so confusing... So if I'd like to run a square, no spacer, stock suspension, what would the offset be and for what tires? For beginners I see its best to stay with summer performance tires and stay away from "R-compound", is that like RE11, ...
-Front: Apex Ec7 18x10 ET25
-Rear: Apex Ec7 18x10 ET??

And a stupid question, if the offset is different in the rear, in order to rotate Front <-> Rear, one would have to unmount the tires in order to rotate them?

[CanAutM3]

Originally Posted by aboulfad

Man, this is so confusing... So if I'd like to run a square, no spacer, stock suspension, what would the offset be and for what tires? For beginners I see its best to stay with summer performance tires and stay away from "R-compound", is that like RE11, ...
-Front: Apex Ec7 18x10 ET25
-Rear: Apex Ec7 18x10 ET??

And a stupid question, if the offset is different in the rear, in order to rotate Front <-> Rear, one would have to unmount the tires in order to rotate them?

In summary:

If you want to take full advantage of a square setup, you should go with the same offset for all 4 wheels. It will allow you to rotate the tires without having to un-mount them and you can even do it on the fly at the track between sessions. It is the best way to get balanced wear.

If you don't want to use spacers ET25 is the way to go (that was my setup last year and it worked very well). For a better fit, go with ET33, but you'll need 5~10mm spacers up front.

[aboulfad]

Originally Posted by CanAutM3

In summary:..
If you don't want to use spacers ET25 is the way to go (that was my setup last year and it worked very well). For a better fit, go with ET33, but you'll need 5~10mm spacers up front.

Merci and for tires, any of RE11, Re071, AD08r for a beginner? 265/35 or 275/35, ... thanks for your continued patience in answering basic questions!

[CanAutM3]

Originally Posted by aboulfad

Merci and for tires, any of RE11, Re071, AD08r for a beginner? 265/35 or 275/35, ... thanks for your continued patience in answering basic questions!

All 3 are very good choices, you won't go wrong with any of them. Have a look at the Nitto NT05, it is also an interesting offering.

275/35R18 would be my recommendation. 265/35R18 is a bit small for the rear.

[dk38]

Originally Posted by aboulfad

for tires, any of RE11, Re071, AD08r for a beginner? 265/35 or 275/35, ... thanks for your continued patience in answering basic questions!

You can also check out the Dunlop Direzza ZII Star Spec. I have them in 275/35 mounted on four Apex EC-7 18x10 ET25 wheels for my track setup.