TRMotorsport Wheels En Route!

[JCz04Bimmer]

So I finally pulled the trigger on a new set of wheels. I've been running 19" SSR Comp-H's, which I loved both because of their looks and weight, but I felt it was time to go to something a bit more intelligent for track days and city driving.

I went with the following wheels/tires...

TRMotorsports MT1 18x8.5 +44 & 18x9.5 +35
Dunlop Star Specs 255/35/18 & 275/35/18

I was very close to going with the 18x9 +35 wheels up front but decided against that fitment because I didn't feel it would offer me any benefits. They're about .5lbs heavier, have a slightly too aggressive offset and wouldn't allow me to run any wider of a tire up front. A 255 tire seems to be the limit for the Z4MC and that size works on an 8.5" wheel. Perfecto.

I'll likely run a 5mm spacer up front to make the offset effectively 39mm but I'll have to see how the 255 tire behaves on a stock suspension with goofy-wide springs and stock alignment. I may NEED to pull those alignment pins! I may run a 5mm or 7mm spacer in the rear to make the offset either +30 or +28, respectively. But, again, I'm going to see how they bolt up and take it from there.

Stay tuned for pictures...

[03BeastCharmer]

You NEED to pull the alignment pin regardless. These car need more negative camber.
Look forward to pics of the new wheels. You will love the star specs, they grip like no other, but they do get loud!!

[JCz04Bimmer]

Originally Posted by 03BeastCharmer

You NEED to pull the alignment pin regardless. These car need more negative camber.
Look forward to pics of the new wheels. You will love the star specs, they grip like no other, but they do get loud!!

Oh I know! But I've been really determined to keeping the suspension stock in ever respect for my first season with it. I think it was a good decision because I now am very much aware of what the car does in most situations in its stock form which is useful for tuning purposes down the line. I went all season (9 track days so far) with just upgraded pads and steel lines really. Next season I'll run a TCK suspension with the 3.91 ring and pinion I have sitting next to me. Plenty of negative camber on order!

And I ran the Potenza RE01R's this season and they were AWESOME so I'm eager to see the Star Specs in action. The RE01Rs stayed very quiet even as they've worn, too! And their grip has been impressive especially for them technically being street tires. I love how they gum up like r-comps when they get hot! But the squirm marks at the center of the tread already told me just how much this car needs some negative camber!

[onelove]

Great setup, I was an plan on ordering a similar setup but threw NT05s on 19s in the meantime. Figure I'll save the 18" track wheels for when I'm ready for R compounds.

Definitely be ready for a nice suspension setup to compliment the tires in the future.

[Z4MCJJ]

Man I love those MT1s...had I not just picked up a set of SSR Comps on the cheap...I'd be all over those.

[JCz04Bimmer]

Originally Posted by Z4MCJJ

Man I love those MT1s...had I not just picked up a set of SSR Comps on the cheap...I'd be all over those.

Good choice though! I actually have no less than 11 SSR Comp-H wheels in various 19" sizings.

Great wheels and I'd definitely be sticking with them if they weren't 19". What sizes did you get? Need spare(s)?

[Z4MCJJ]

I pieced together a set of straight/unscathed SSR Comps 18x8.5 offset +42 and 18x9.5 offset +27...very light 18-19lbs a piece.

If I wasn't able to get these, I'd have gone with the MT1s

[JCz04Bimmer]

Some good news that people may find interesting. The front wheels fit!

Again, I went with the 18x8.5 with a +44 offset and 255/35/18 tires. It is EXTREMELY close on the strut side, though -- we're talking 1-2mm close -- but it isn't making contact when the tires are at 30psi cold and 38psi hot. They were shipped from TireRack with 44psi (smart move for shipping purposes) and they did scrub the plastic strut covering at this pressure.

I'm probably going to put a 3mm spacer on up front to bring the offset to +41 which should be perfect. I could probably run a 5mm spacer if I had camber plates capable of ticking the wheels in to -2deg camber or more to avoid contact with the fender but since I'm on a stock suspension, I don't think I could pull that off. I should also say that the stock front struts are super clunky so an aftermarket suspension would certainly offer you more strut-side room.

So the takeaway is that 255/35/18 tires DO fit on our cars with stock suspension components.

...pictures to follow at some point this week.

EDIT: The rears fit but are also very close to the inner fender liner because of the +35 offset. I'll probably use a +5mm spacer here to bring it to a +30 offset.

[The__J__Factor]

Any pics of the new wheels mounted?

[RussRamz]

I've been running MT-01s a while now and they are holding up very well. Nevermind they are very light and look good too!

[pal]

Looking forward to the pics Jared as I am on the fence about getting these rims as well ... thanks.

[skim]

exact setup i'm looking for.. pix up yet?

[3002 tii]

awesome, i was very close to picking these up to replace my ssr's for the same reasons you mentioned above. eventually went a diff route b/c i found a deal too good to pass up on but if i manage to get enough track time this year i'll be looking at these again.

[RussRamz]

Originally Posted by The__J__Factor

Any pics of the new wheels mounted?

Here are some shots of mine last year. The wheels are great and held up well so far.

[Eddy@ApexWheels]

It's too bad you have to get spacers for these wheels, as it means you also have to get extended lugs or convert to studs.

Note that a 245/40 or 255/35 setup is wide for an 8.5" wheel, and will result in more sidewall flex under cornering so if you only have 1-2mm of strut tube clearance when the car is static, you can get a lot of sidewall deflection and rubbing on the track. You'd really want to install spacers on that setup.

The APEX ARC-8 wheel in 18x8.5" is et38 so you wouldn't need a front spacer at all. They come in 18x9.5" et35 and 18x10" et25 as well. Knowing that the 18x10" et25 bolts on without issue, there is no point is running the 9.5's with a spacer. You don't have to run a wider tire, mount the same tire up. The above photo is a 275/35/18 on a 10" wheel. That would be ballooning even more if it were a 9.5" wheel.

it's a more direct fitment, slightly lighter/cheaper, and comes in 4 colors instead of 1

[JCz04Bimmer]

I think the Nitto NT01's pictured above might be a bit misleading. Race compound tires are almost always oversized compared to a street tire in the same sizing and I think that's definitely what you're seeing there. Also, the NT01's have a very rounded off sidewall which exaggerates the appearance ballooning, I think.

The 255/35/18 and 275/35/18 Dunlop Star Specs mounted to the 18x8.5 and 18x9.5 TRM MT1's don't show nearly as much sidewall balooning as pictured above. As mentioned, I went with the wheel setup I did with the full intention of using spacers. The fact that I've always run studs/nuts on every car I've owned made the added cost of longer bolts and whatnot irrelevant. Plus I already had the spacers laying around.

paintpro21 - I've been keeping an eye on those ARC-8's too. Are you certain that the 18x10 +25 wheel with a 275/35 will not rub on a dropped Z4M? As for the fronts, I would probably opt for the 18x9 +42 wheel. Any experience with running a 265/35 on that wheel on a Z4M? I'd be running around -2deg camber on the street and them switching to around -3deg camber on the track. I should note that I absolutely HATE the look of stretched out tires.

[RussRamz]

I'm running a 5mm spacer up front and no spacer in the rear on 9.5 inch wheels. The only rubbing I get is on the plastic fender lining which is getting pulled if my recent mods have no effect. I ended up softening the liner with a heat gun and pushed it up into the fender well as far as it will go. We'll see if it works during a few laps around the ring next week.

[Eddy@ApexWheels]

Originally Posted by JCz04Bimmer

I think the Nitto NT01's pictured above might be a bit misleading. Race compound tires are almost always oversized compared to a street tire in the same sizing and I think that's definitely what you're seeing there. Also, the NT01's have a very rounded off sidewall which exaggerates the appearance ballooning, I think.

The 255/35/18 and 275/35/18 Dunlop Star Specs mounted to the 18x8.5 and 18x9.5 TRM MT1's don't show nearly as much sidewall balooning as pictured above. As mentioned, I went with the wheel setup I did with the full intention of using spacers. The fact that I've always run studs/nuts on every car I've owned made the added cost of longer bolts and whatnot irrelevant. Plus I already had the spacers laying around.

paintpro21 - I've been keeping an eye on those ARC-8's too. Are you certain that the 18x10 +25 wheel with a 275/35 will not rub on a dropped Z4M? As for the fronts, I would probably opt for the 18x9 +42 wheel. Any experience with running a 265/35 on that wheel on a Z4M? I'd be running around -2deg camber on the street and them switching to around -3deg camber on the track. I should note that I absolutely HATE the look of stretched out tires.

I haven't done directly testing on the Z4M with a 265 up front, and you'll be hard pressed to make that fit, but I know it can be done. It's just a question of the perfect offset for each particular suspension setup, and a decent amount of camber.

I have a set of 265/35/18 star specs mounted on 18x9's in the shop that we're going to put onto a 335i along with AST 5100's. If there's someone local with camber plates and a z4 m I'd be happy to do some research.