Apex Arc 8 Fitment Questions!

[slowthirtysix]

http://www.m3forum.net/m3forum/showthread.php?t=428767

i read every single post of this thread, and everyone seems to be running different setups than the one posted unfortunately. i needed more information as for fender rolling and there were a plethora of different setups within that thread that didnt quite help me, which is why i created my own post. im very meticulous and want to ensure i have all necessary information before executing.

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I can tell you my setup which might help.

I have 17x9.5 Arc-8, et35
-2 rear camber (iirc), -2.5 front (shims)
245/40 htr-z iii tires
10mm front spacer to clear PSS9 (due to shims tipping the top of the wheel wheel in but not the strut. Camber plates you may not need spacers if at ET30)
Lowered almost all the way down front, maybe 5-7mm left to come down in the rear collars

I used to run 255/35 which fit as well, but had to raise the front about 1cm which altered my alignment settings when putting them on for the track so ditched them for 245s.

Rears are rolled tight, unfortunately, over the sealant as done by a previous shop, so not as good of a roll as can be. Fronts are rolled as well.

I would think you'd be fine with the 17x9 and a modest roll in the rear.

i appreciate the detailed answer, thank you. im not looking to remove the sealant, but i will if i have to. my fear is that by removing the sealant, water and debris will get in there, thus causing rust.

[TostitoBandito]

i appreciate the detailed answer, thank you. im not looking to remove the sealant, but i will if i have to. my fear is that by removing the sealant, water and debris will get in there, thus causing rust.

What you do is remove the sealant from between the fender lip, roll the fender, and then apply some sort of paint or protective undercoating on top of your freshly rolled fender (inside the wheel well, not on the body obviously). The 3M undercoating would probably work fine.

[slowthirtysix]

What you do is remove the sealant from between the fender lip, roll the fender, and then apply some sort of paint or protective undercoating on top of your freshly rolled fender (inside the wheel well, not on the body obviously). The 3M undercoating would probably work fine.

interesting. that makes sense. if it isnt too much trouble, could you supply me with a link to the 3M undercoating you're referring to?

[TostitoBandito]

https://smile.amazon.com/3M-08881-Un...dp/B0002NUO5Q/

I think that's more or less what I've had. It's useful for touchups where paint has been scraped off. It's sort of like bedliner material; kind of like paint except more durable and textured. Good for wheel wells, under the car, or anywhere else that's gonna get hit by rocks and whatnot. I used it when I spun my car at the track and took a chunk out of my x-brace, to cover up the bare metal once I cleaned it up with a grinder. I also coated my replacement fuel filter cover with it to give it a little more durability against scrapes.

[slowthirtysix]

https://smile.amazon.com/3M-08881-Un...dp/B0002NUO5Q/

I think that's more or less what I've had. It's useful for touchups where paint has been scraped off. It's sort of like bedliner material; kind of like paint except more durable and textured. Good for wheel wells, under the car, or anywhere else that's gonna get hit by rocks and whatnot. I used it when I spun my car at the track and took a chunk out of my x-brace, to cover up the bare metal once I cleaned it up with a grinder. I also coated my replacement fuel filter cover with it to give it a little more durability against scrapes.

i appreciate the info, thanks a ton.

[blckstrm]

i appreciate the info, thanks a ton.

I didn't remove the sealant (and I have the exact fitment you're looking at, down to the actual tire).

I don't think you need to remove the sealant (like you, I didn't want to remove it and open the door to rust). Again, the only place I rub is at the junction between the fender and the bumper cover, and I think a little more effort there would do the job. That is the only place I'd consider trying to scrape out the sealant if nothing else worked.

[slowthirtysix]

I didn't remove the sealant (and I have the exact fitment you're looking at, down to the actual tire).

I don't think you need to remove the sealant (like you, I didn't want to remove it and open the door to rust). Again, the only place I rub is at the junction between the fender and the bumper cover, and I think a little more effort there would do the job. That is the only place I'd consider trying to scrape out the sealant if nothing else worked.

leaning more towards rolling over the sealant now, i'll have to see what my guy recommends. are you sure you're not rubbing against your mudflaps?

[pbonsalb]

If you run stock size tires at near stock ride height and don’t heavily load the car or track it, you might be OK with mild rolling and no sealant removal on ET30 wheels. Might is the answer. It’s a lot harder to do the job right after you have done it wrong and rolled against the sealant. I suppose then you could tilt the wheels in at the top with negative camber that would be excessive for street use.

[slowthirtysix]

If you run stock size tires at near stock ride height and don’t heavily load the car or track it, you might be OK with mild rolling and no sealant removal on ET30 wheels. Might is the answer. It’s a lot harder to do the job right after you have done it wrong and rolled against the sealant. I suppose then you could tilt the wheels in at the top with negative camber that would be excessive for street use.

a couple of users said i may have some luck by using a heat gun and heating the sealant before hand, it'll allow for more flex and i can compress it thus making a tighter roll while still retaining the sealant. my biggest concern is how to efficiently get OUT the sealant without destroying your fenders, and all the additional moisture and debris that'll accumulate. not looking to have my car rust on the fenders

[blckstrm]

leaning more towards rolling over the sealant now, i'll have to see what my guy recommends. are you sure you're not rubbing against your mudflaps?

I DO rub on the mud flaps - their top connection is at the same place the bumper cover connects to the fender. The way they attach is a bit odd, too, so they don't stay in position very well. When they roll forward a little they rub worse, too.

I think getting the sealant hot and rolling it like that is the way to go. You really need a little flare at that joint anyway, so the extra couple mm you'd get from removing the sealant wouldn't really change that - and would potentially open the door to problems. I've read about people trimming the bumper cover on the inside, but I'm not going to mess with it. The tire can rub on it and push it out without hurting anything - and over time it will slowly wear down to where it doesn't rub anymore.

And I should mention again - I'm on H&R Sports with a thick 15mm E46 convertible spring pad plus the original 5 mm pad, which should put me around 1/2" lower than stock. I can't remember ever rubbing when I'm in the car alone, even on track. Having someone else in the front will occasionally cause some rubbing under a lot of compression. Kids in the back seat (and I do have a sedan) or something heavy in the trunk will cause rubbing under less severe compression.

One other thing - I really only rub on my driver's side. I've tried to loosen my subframe and center it better, tried to make sure it's the same height on both sides, but it didn't make any difference.

[PITT M3 RR]

I have 17x9.5 et35 square on 245s

pss9 with linear conversion up front (minor roll), no spacer and 1 degree on the GC street camber plates, so add that to whatever stock is.

Rear 12.5mm spacer, sealer removed, heavy roll/pull sealed with RTV, stock camber arms maxed. Minor rub on heavy entry angles. If I take off the rear spacers I have tons of room...almost looks bad. If you’re willing to put the work into the fenders, you’ll have no issues.

[adamnur]

I highly advise cutting out the sealant. Once it's rolled over, there's no going back without butchering the lip or cutting it off entirely.

My street wheels are even tighter fitment than my Apex, and because of the roll over sealant, I do not have the extra 5mm I really would have needed. As a result, the inner fender paint was burned off after one short test ride over a bump, so that had to be painted with the 3M stuff. I'd rather have covered the inner fender lip with the 3M paint than the outer. I then had to slightly pull the rear fenders to fit. I actually like how they look now more, but I'd still rather have not had to do it.

Just do it once and do it right and you'll have nothing to worry about.

[mldyanks213]

I just installed apex arc 8's 17x9 with 245/40 and front cleared fine. rears rubbed for sure. rolling fenders. i took some of the sealant off the inner fenders in the rear and sprayed it with thin coat after the roll. negative camber will definitely help but might be excessive for street but your call. i have bilstein/h&r sport lowered pretty low and fronts seem ok. could use some rustoleum spray to get between the inner lip on the rear so you can get a tighter roll. then undercoating after

[Gregarious7]

Yep I got the 9.5 Et35 in back and 9" ET30 in front. The fronts fit fine without a spacer or anything else.

However, my rears rub on hard turns such as highway entrance ramps. I just got my fenders rolled, but not all the sealant was cut out. I'm still rubbing on the hard turns.

So I figure my only option is to have a reputable body shop cut the lip out and paint it....?

Oh well, I need some other body work anyway.

P.S: I should mention I'm on stock springs and still rubbing in the rear....

[blckstrm]

Yep I got the 9.5 Et35 in back and 9" ET30 in front. The fronts fit fine without a spacer or anything else.

However, my rears rub on hard turns such as highway entrance ramps. I just got my fenders rolled, but not all the sealant was cut out. I'm still rubbing on the hard turns.

So I figure my only option is to have a reputable body shop cut the lip out and paint it....?

Oh well, I need some other body work anyway.

P.S: I should mention I'm on stock springs and still rubbing in the rear....

Did you pound out the inner fender, or just roll the lip? You didn't mention it, and it's necessary for this to fit without rubbing.

[SIIDEWAYS]

Yikes!! All this talk about pounding, hammering, rolling, cracking, etc...do none of you care about your cars?!? Wow, why not just get wheels/tires that actually FIT?? Or do you just consider your cars jalopies and you simply don't care? I guess I'm still of the mindset that these are $40K+ cars (I actually paid more than this) and would never dare take a hammer to my hooptie (just an affectionate term). A perfect example of this is the beautiful red E92 M3 on the 20" BBS LMRs on the Rides & Events page...do you think that car's owner would take a hammer and "pound" out his fenders? Lord have mercy...

[Gregarious7]

We just rolled the lip...and the dude didn't take out all the sealant. But it's already been rolled over, so no going back now unless I want to cut the lip off. Which I am considering.

And to the guy above...I seriously doubt that the guy with E92 with 20" LM's fit those without any modifications. As for why I don't just get wheels that fit...the concave ARC 8's are absolutely beautiful...that's why. Beauty is pain. And my goal is to make them fit without being able to see any fender mods from the outside of the car.

My thinking is....if you can't see the fender modification from the outside of the car...then it's still as good as stock. That's why I don't want to pull/flare the fenders.

[pbonsalb]

I took a hammer and pounded my inner liners and I rolled and pulled as hard as I could. I drive and enjoy the car. It’s not a show car. Bought it 13 years ago with 44k miles and it has 130k now. Built motor, turbocharged, coilovers, etc. Have Apex ARC8 17x9ET42 on it, now with 275/40 rear and 255/40 front. Just received my 17x10 ET25 ARC8s, so I will be cutting the arches off, pushing up the inner metal and rewelding it, and riveting on Hard flares. To me it’s just a car for my amusement. I would have zero interest in a stock E36M3 — I put a supercharger on mine less than 6 months after I bought it.

[Gregarious7]

What sort of tires should I plan on getting to help me fit these? I already have seen someone comment that the Michelin Pilot sports run large...is there a tire that runs smaller??

The plan is to go 225s on front and 245's on back.

[TostitoBandito]

Check the various tire width measurements (section width and tread width) on tirerack before you buy. They're generally pretty accurate. Make sure and read the definitions of those measurements. For example, they are made on wheels of specific sizes, so if yours are wider you may need to increase the measurements slightly (you can also find good estimates for those adjustments online).

As a general rule, the higher performance summer/track tires tend to run wider than others. I'm referring mostly to the "extreme performance" category, which is a notch above something like the Michelin Pilot Sport 4S. And of course racing slicks.

[blckstrm]

We just rolled the lip...and the dude didn't take out all the sealant. But it's already been rolled over, so no going back now unless I want to cut the lip off. Which I am considering.

And to the guy above...I seriously doubt that the guy with E92 with 20" LM's fit those without any modifications. As for why I don't just get wheels that fit...the concave ARC 8's are absolutely beautiful...that's why. Beauty is pain. And my goal is to make them fit without being able to see any fender mods from the outside of the car.

My thinking is....if you can't see the fender modification from the outside of the car...then it's still as good as stock. That's why I don't want to pull/flare the fenders.

I mentioned this on the first page of this thread.

This isn't the lip rubbing - this is the inner wall of the double-walled rear fender.

Get your car up in the air, take off your rear tires, lay down with the back of your head against your brake rotor, and look about 2-4 inches up from the lip on the inside. You'll see where you're rubbing.

Again, the rear fender is double walled, so you can pound the inner fender outward with a sledge and it will not affect anything on the outer wall / outer painted surface of the car. In fact, here is a picture of a rear fender cut (for bolt-on flares on a race car - not my car) so you can get an idea of what it looks like inside. It doesn't take much to make the rubbing stop, and there's plenty of room there.

If you're especially worried, wrap some tape around the head of your hammer and go bit by bit.

I almost guarantee this is where you're rubbing - not at the lip. No need to cut the lip.

But anyway, check this out and let me know what you find...

IMG_5637.jpg

[CblockM3]

What sort of tires should I plan on getting to help me fit these? I already have seen someone comment that the Michelin Pilot sports run large...is there a tire that runs smaller??

The plan is to go 225s on front and 245's on back.

If you are doing square concave's run square tires. The fronts are easy to fit, doesn't make sense to run a smaller tire there and lose the benefit of having a square setup.

[blckstrm]

If you are doing square concave's run square tires. The fronts are easy to fit, doesn't make sense to run a smaller tire there and lose the benefit of having a square setup.

^Amen.

[Gregarious7]

Oh....no shit blackstrm?? If that's the case then yeah....i can pound that out.
That's what she said.

Thanks for the help yall! Looking forward to hard turns without rubs.
Thats what she said.

[blckstrm]

Oh....no shit blackstrm?? If that's the case then yeah....i can pound that out.
That's what she said.

Thanks for the help yall! Looking forward to hard turns without rubs.
Thats what she said.

I did the same thing as you - kept rolling more and more, and couldn't figure out why. Finally I took the tire off and took a good, long look around and figured it out.

You've had yours on a while - there will be rub marks that will tell you where you're still rubbing.

...

Just get that rear up in the air and take a good, long look.
That's what she said.