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      02-17-2018, 06:54 AM   #89
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Great news - everything fits!

I was cautious at first and mounted them up with the 3mm spacers in place, but after looking everything over I decided that I didn’t need them. I took the spacers off and remounted everything and clearance is just fine. Even without the spacers I can still get a finger between the wheel/tire and strut in the front. Plenty of room to spare in the back.

I’ll get some pictures tomorrow - first practice event of the year. Stoked!

To recap:

Apex EC-7 18x9 ET31 front, 18x10 ET43 rear, with 275/35-18 RE-71R square.
I'm most interested in how the 275 fits the 9" wheel. Very curious how much sidewall deflection and how the contact patch stays planted. A pic of that tire on the wheel please. Good luck today.
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      02-17-2018, 09:50 AM   #90
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Originally Posted by jnoyes View Post
I'm most interested in how the 275 fits the 9" wheel. Very curious how much sidewall deflection and how the contact patch stays planted. A pic of that tire on the wheel please. Good luck today.
Fit of the 275 on the 9" wheel is better than I expected, given that RE-71Rs are known to run a bit wide.
They don't really look pinched - nothing like the 295 Hoosiers on 8" rims I used to run on my A-stock Solstice GXP

I'm skipping the practice event today as the weather has turned pretty nasty.

Some pics below.
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      02-17-2018, 06:31 PM   #91
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Originally Posted by jnoyes View Post
I'm most interested in how the 275 fits the 9" wheel. Very curious how much sidewall deflection and how the contact patch stays planted. A pic of that tire on the wheel please. Good luck today.
Fit of the 275 on the 9" wheel is better than I expected, given that RE-71Rs are known to run a bit wide.
They don't really look pinched - nothing like the 295 Hoosiers on 8" rims I used to run on my A-stock Solstice GXP

I'm skipping the practice event today as the weather has turned pretty nasty.

Some pics below.
Fit looks really good. Now I'm wondering if I shouldn't have gone 275s up front. Seems perfect on a 10, but not bad at all on a 9. And your offsets look well-matched front and rear.
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      02-21-2018, 06:59 PM   #92
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Quote:
Originally Posted by CLH View Post
Great news - everything fits!

I was cautious at first and mounted them up with the 3mm spacers in place, but after looking everything over I decided that I didn’t need them. I took the spacers off and remounted everything and clearance is just fine. Even without the spacers I can still get a finger between the wheel/tire and strut in the front. Plenty of room to spare in the back.

I’ll get some pictures tomorrow - first practice event of the year. Stoked!

To recap:

Apex EC-7 18x9 ET31 front, 18x10 ET43 rear, with 275/35-18 RE-71R square.
MUCH thanks for sharing Chris!

So... in hindsight... do you think a 285/30-18 square might have been the better choice? Perhaps on your next set?

Dave
[my 18x10xet43 anthracite rear EC-7 apex wheels on backorder(!)... I have 285/30-18 RE71's ordered to install on them... sigh] Ordered the 275/35-18x31et up front.]
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      02-21-2018, 08:03 PM   #93
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MUCH thanks for sharing Chris!

So... in hindsight... do you think a 285/30-18 square might have been the better choice? Perhaps on your next set?
Happy to help!

285/30-18 will fit all the way around (it’s been done, but not by me). Whether it’s a better choice up front than the 275 is not clear. The RE71R probably has a stiff-enough sidewall to be OK pinched that much, but the difference in footprint is going to be really small. At my level of skill I doubt it would make any tangible difference
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      02-28-2018, 07:22 PM   #94
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Rear swayswap

I have a bit of steady-state understeer in my M2 after installing slightly wider P4S tires (265/285) on stock rims. Previously, it was slip and slide power-oversteer fun. But with the wider P4S's in the rear, the front tends to run at a much greater slip angle than the rear. And the power can be easily put down.

Picked up a Dinan rear bar that should allow a slight spring rate increase in the rear that should allow tuning this out (hopefully to full neutral where both front and rears slip at similar angles in steady-state).

However... there's a local mechanic down the street from where I work, and he indicated the BMW manual calls for dropping the rear sub frame to install this(!). 8 hours. I figured it would be an easy job that wouldn't cost a lot to keep me off my garage floor.

So... anyone have experience with replacing the rear sway? And does the sub frame really need to be unbolted/realigned?? (Haven't even seen the car from below, so presumably the next step following forum inquiry)

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      03-17-2018, 09:01 AM   #95
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Quote:
Originally Posted by CLH View Post
Happy to help!

285/30-18 will fit all the way around (it’s been done, but not by me). Whether it’s a better choice up front than the 275 is not clear. The RE71R probably has a stiff-enough sidewall to be OK pinched that much, but the difference in footprint is going to be really small. At my level of skill I doubt it would make any tangible difference
Popping in to see folks interest in BS in the M2. I've been competing in a E92 M3 in FS the last three years with 19x9/18x10 setup. I've got two full sets of Apex wheels plus two additional fronts and run the Dinan adjustable front sway bar. Re: tire widths on 18" wheels -- here is my thoughts. I've run 265 square (when 275 RE71R's were on back order in 2015 briefly) 265/275, 275 square and 285/30's square. For my application, my max speed in 2nd on 275's is 68~ and 65.5~ on 285's.

My most preferred setup is 275 or 285 squared as having the wider fronts helps with understeer. 285's are very confidence inspiring in turn with virtually no tire deflection due to the shorter, stiffer sidewall, and will give you snappier gearing on slower, low speed dig out oriented courses as it has a 24.8" diameter, but suffer on Nat'l courses where speeds can easily surpass 65 mph requiring up and down shifts which makes it slower. Furthermore, the shorter sidewall will cause some unsettling of the car on bumpier surfaces, resulting in brief loss of traction at the extremes. The 285/30-18's are a total bitch for tire installers to mount on 9" fronts. Many shops can not get them on. I was one of three competitors out of 47 in FS at Nat's last year who had them as many could not get them mounted. Evidently, once they are mounted, they are easier to remount. If you pursue this, contact me and I'll explain what my installer did to get them on.

The 275's will have slightly less mid-apex grip up front but still pretty stout, and be a little less snappy in terms of dig out gearing (25.6"), but will be less prone to need for upshift and have less issue with being unsettled as the taller sidewalls will absorb surface imperfections far better than 285's with less issue. This very well may make them the faster/better choice overall as the pros may outweigh the cons. Last year, I committed to 285 square on my two sets of tires I was going to use, and felt that for everywhere except Nat'l events, it paid off, but at Nat's I ran into gearing issues which could me. I trophied in 12th but was .5 out of 5th over two days (easily could have been .8 faster the first day) and ran into rev limiter both days which probably cost me another .5-1 sec. I've finished as high as 5th. The winner last year had 285's front/275's rear which was an interesting gamble. I may try that this year I as I still have a pretty fresh set sitting around from Nat's.
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      03-17-2018, 12:25 PM   #96
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Great feedback z3papa

Any word on how those that are going 18F/19R with 305s in the back are feeling about that setup?

I did my first event in the M2 two weekends ago, and it’s a big change from the ASP Solstice GXP I’ve been driving for a few years. Once the RE71Rs scrubbed in a bit I started to get a better sense of the car, and so far I’m a fan. We have a regional practice day tomorrow...I hope to get a bunch of runs to help acclimatize to the car.
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      03-17-2018, 01:48 PM   #97
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Quote:
Originally Posted by CLH View Post
Great feedback z3papa

Any word on how those that are going 18F/19R with 305s in the back are feeling about that setup?

I did my first event in the M2 two weekends ago, and it’s a big change from the ASP Solstice GXP I’ve been driving for a few years. Once the RE71Rs scrubbed in a bit I started to get a better sense of the car, and so far I’m a fan. We have a regional practice day tomorrow...I hope to get a bunch of runs to help acclimatize to the car.
I have not heard of anyone trying that combo......yet. I have heard that BFG is contemplating larger sizes of the Rival S, possibly in the 1.5 variety, and if that were to occur, I could see people trying it providing there are not rubbing issues at the bottom of shock travel. Keep in mind the 18's really give you lower COG as compared to 19" wheels.
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      04-02-2018, 08:51 PM   #98
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Quote:
Originally Posted by CLH View Post
Fit of the 275 on the 9" wheel is better than I expected, given that RE-71Rs are known to run a bit wide.
They don't really look pinched - nothing like the 295 Hoosiers on 8" rims I used to run on my A-stock Solstice GXP

.
I wanted to get your exact setup for my M2 and I was surprised to hear back from APEX that the 275 wheel won't fit on their 9" rims, just wanted to confirm that you've run your car with the setup and that everything went fine?

He's trying to convince me to go to a square setup (ET33 18x10), which is the max allowable change in offset in stock class. I can't imagine that a 10" wheel would fit in the front without camber adjustments, which would kick me out of stock.

Thanks for your feedback
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      04-02-2018, 08:59 PM   #99
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Originally Posted by DOMs335D View Post
I wanted to get your exact setup for my M2 and I was surprised to hear back from APEX that the 275 wheel won't fit on their 9" rims, just wanted to confirm that you've run your car with the setup and that everything went fine?

He's trying to convince me to go to a square setup (ET33 18x10), which is the max allowable change in offset in stock class. I can't imagine that a 10" wheel would fit in the front without camber adjustments, which would kick me out of stock.

Thanks for your feedback
275s on the 18x9 working just fine, no issues. No problem at all sticking with the 9” front and 10” rear with 275s all around.
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      04-02-2018, 09:42 PM   #100
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Quote:
Originally Posted by jnoyes View Post
Looks great! I ended up ordering the same wheels, only with the ET33 rears. 255/275 RE71rs going on w/TPMS on Wednesday. Also a Dinan front bar and whatever my shop can do with alignment. It'll be fun to see if our subtly different approaches make a difference. Are you doing a front bar?
Why did you decide against 265/35 275/35? I would have thought wider was better?
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      04-02-2018, 09:59 PM   #101
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275s on the 18x9 working just fine, no issues. No problem at all sticking with the 9” front and 10” rear with 275s all around.
Awesome thanks!
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      04-03-2018, 05:39 AM   #102
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Originally Posted by DOMs335D View Post
I wanted to get your exact setup for my M2 and I was surprised to hear back from APEX that the 275 wheel won't fit on their 9" rims, just wanted to confirm that you've run your car with the setup and that everything went fine?

He's trying to convince me to go to a square setup (ET33 18x10), which is the max allowable change in offset in stock class. I can't imagine that a 10" wheel would fit in the front without camber adjustments, which would kick me out of stock.

Thanks for your feedback
If you're running in B-street, you're stuck with the 9" wheel width up front too...it's not just camber plates that would kick you out of stock but 10" fronts would also. As mentioned above, the 275 works ok on the 9" wheel; I've even run 275/35-18 Rivals on an 8.5" wheel with good success (stock class F-street, E90 M3).
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      04-03-2018, 08:30 AM   #103
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If you're running in B-street, you're stuck with the 9" wheel width up front too...it's not just camber plates that would kick you out of stock but 10" fronts would also. As mentioned above, the 275 works ok on the 9" wheel; I've even run 275/35-18 Rivals on an 8.5" wheel with good success (stock class F-street, E90 M3).
Thanks for the reminder! I must have thought both width and diameter are +/- 1", which of course isn't the case. I will probably copy the above setup.
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      04-03-2018, 08:34 AM   #104
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Quote:
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Looks great! I ended up ordering the same wheels, only with the ET33 rears. 255/275 RE71rs going on w/TPMS on Wednesday. Also a Dinan front bar and whatever my shop can do with alignment. It'll be fun to see if our subtly different approaches make a difference. Are you doing a front bar?
Why did you decide against 265/35 275/35? I would have thought wider was better?
I talked about this at length with my race shop. While several guys on here are going wider, my shop said they had more than one customer come back and ask to go back to 255 fronts to regain steering feel. In the past, my experience has always been that wider is better, as you said. This will be an interesting experiment to find out for this car what works best (for me, in BS, with stock camber, with re71rs, on 9" wheels, all those caveats). The fronts may cook pretty quickly anyway without additional camber, so the real question for me will be what size the SECOND set of fronts will be. I'm running SoloStorm this year, so maybe I'll have some data to support that decision. Or maybe if I go wider for the second set there will be data to do a true comparison.
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      04-04-2018, 02:07 AM   #105
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Quote:
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Quote:
Originally Posted by USANigel View Post
Quote:
Originally Posted by jnoyes View Post
Looks great! I ended up ordering the same wheels, only with the ET33 rears. 255/275 RE71rs going on w/TPMS on Wednesday. Also a Dinan front bar and whatever my shop can do with alignment. It'll be fun to see if our subtly different approaches make a difference. Are you doing a front bar?
Why did you decide against 265/35 275/35? I would have thought wider was better?
I talked about this at length with my race shop. While several guys on here are going wider, my shop said they had more than one customer come back and ask to go back to 255 fronts to regain steering feel. In the past, my experience has always been that wider is better, as you said. This will be an interesting experiment to find out for this car what works best (for me, in BS, with stock camber, with re71rs, on 9" wheels, all those caveats). The fronts may cook pretty quickly anyway without additional camber, so the real question for me will be what size the SECOND set of fronts will be. I'm running SoloStorm this year, so maybe I'll have some data to support that decision. Or maybe if I go wider for the second set there will be data to do a true comparison.
I just posted a note on last year's nationals finals in the 2018 BStreet thread I started. I polled the 4 M2 drivers. Top placed M2 ran 275/35R19 305/30R19. Others tested 285 and 265 up front and suggested 265 doesn't rub. 275s rub slightly on plastic.
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      05-29-2018, 10:11 AM   #106
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      05-29-2018, 09:17 PM   #107
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CLH - I sent you a PM.
jnoyes - I Replied by email.

As a quick update, I finally got around to installing the H&R front bar. Install was easy once I got the undertray off (not hard, just lots of fasteners to undo). I like the beefy stock aluminum sway bar brackets. Really nice. I installed the H&R bar adjusted to full stiff (innermost holes). The H&R bar is a good bit heavier than the stock bar, though I didn't weight it to see the actual difference.

I can say that having a stiffer front bar was noticeable right away at the auto-x this past weekend. The car felt more planted in transitions and didn't have near the tendency to start "over-wagging" in slaloms that it had before. One of these days I need to get the car onto an alignment rack to check the front toe and the settings in the rear.
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      05-30-2018, 06:46 AM   #108
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Quote:
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I just posted a note on last year's nationals finals in the 2018 BStreet thread I started. I polled the 4 M2 drivers. Top placed M2 ran 275/35R19 305/30R19. Others tested 285 and 265 up front and suggested 265 doesn't rub. 275s rub slightly on plastic.
Are you sure he was running 275/35-19 up front and not 275/35-18? I can't imagine the 275/35-19 fitting due to diameter size causing major rubbing, or does the M2 have *that* much room up front?

I could see running 275/35-18s up front and 305/30-19s in the rear would fit fine (diameter-wise).
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      06-12-2018, 09:37 AM   #109
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RE-71s Like night and day

I finally installed some RE-71's on my car. I went with 275/35-18's all around on Apex EC-7 wheels, 18x10 et33 in the back and 18x9 et31 in the front. The install and fit up went great, plenty of clearance room and no rubbing anywhere. I did get some 10mm spacers for the front but after test fitting them the wheels were too far out and I was worried about a rub.

I ran an autocross event this weekend and these tire are very grippy. This was my first experience with these tires. My prior experience was only with Mich PSS and Mich PS4S tires which are great for a daily but now I understand are a huge compromise for AutoX. The car was transformed and I did not hit the limits of these tires or my car with these tires and my times relative to the field improved substantially. My acceleration out of features can be harder and earlier than in the past. With the Mich tires I would slip around and have spun out a few times if I pushed too hard. (driver problem).

I have included a couple pics. My new challenge will be getting the RE71's off after AutoX days and getting the street tires back on. The tires feel great around town.

Dinan front sway bar will be installed later this week.
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      06-29-2018, 08:43 PM   #110
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\ If you pursue this, contact me and I'll explain what my installer did to get them on.
Hey Jason!

Would be interested in the 'secret' overs-sized tire mounting technicque. Please post (or PM) with the insider tricks for future reference.

Much Thanks,
Dave
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