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[sKruPz]

Hello, I am currently running oem size wheels and installed M3 front and rear bumpers, which leave the wheel gap even larger. VMR told me that for my car (e90 330xi sedan) can run this:

Front: 19x8.5 ET35 // 235/35/19
Rear: 19x9.5 ET45 // 265/30/19

But this doesn't account for the bumpers that enlarge the wheel gap. Also, my speedometer will be off when I change wheels, so what do you recommend I do? Is that something only a dealer can help me fix? Thank you

[IllSic_Design]

Uhhhmm, your wheel gap will not get any bigger because of the m3 bumpers, they will still be the same distance away from the fender. The m3 bumpers still follow the same wheel arch of your stock fenders, impossible for the gap to the wheels to get bigger.

About your speedometer, your new rim size might be bigger, but you compensate that by getting a smaller sidewall tire which keeps your overall diameter the same size as stock/previous.

[Pinscher]

I had 19x8.5 ET +28 and 19x10 ET +30 on my 328 xi, on problem.

Tires get pretty skinny though, and I'm dodging pot holes on known bad roads with these 19".

As far as I know, the over all circumference of your new setup needs to be nearly identical to your original setup. keep circumference difference do an absolute minimal as you do have an X drive and you do not want to break your Differential. If you don't change your circumference much, then your speedo will be accurate enough. also, I don't think it's re-programmable as your speed is tied into many other carly functions.

[sKruPz]

Okay, thank you guys. I think by wheel gap I mean width of the wheel "area"? The bumpers have a wider arch than the OEM. I wish I had a photo of before/after, but it's definitely noticeable.

[sKruPz]

Originally Posted by Pinscher

I had 19x8.5 ET +28 and 19x10 ET +30 on my 328 xi, on problem.

Tires get pretty skinny though, and I'm dodging pot holes on known bad roads with these 19".

As far as I know, the over all circumference of your new setup needs to be nearly identical to your original setup. keep circumference difference do an absolute minimal as you do have an X drive and you do not want to break your Differential. If you don't change your circumference much, then your speedo will be accurate enough. also, I don't think it's re-programmable as your speed is tied into many other carly functions.

What do you mean by breaking my differential? My original setup is pretty small and I'd definitely like to increase circumference, but I didn't know there would be issues

[Pinscher]

Originally Posted by sKruPz

What do you mean by breaking my differential? My original setup is pretty small and I'd definitely like to increase circumference, but I didn't know there would be issues

Well if the rolling distance of your rear wheels is greater than the front then the rate the differentials spin at are not in sync. Sorry for lack of technical terms here, but basically your XI will not compensate for large discrepancy, and you can basically ruin your differential or transfer case.

This is why XI come with a Square wheel/tire setup, though it's possible to go staggered, provided the rolling distance of your F to R tires is within 5% or so.

[b92]

Front & rear bumpers won't increase the area under your wheel arches, unless you also have M3 fenders installed. Pics would help, super easy to upload to imgur and post the link here.

Since you have an XI, you will need to make sure your front & rear rolling diameters are within 3% of each other. The sizes you listed will be fine (647.1mm vs 641.6mm, 0.86% difference).

Assuming you are running the stock 18" tire sizes (225/40 and 255/35), you will only be increasing your rolling diameter by 1-1.5%, so your speedometer will read 1-1.5% slower which is negligible (100mph will read as 99mph..)

[sKruPz]

Originally Posted by b92

Front & rear bumpers won't increase the area under your wheel arches, unless you also have M3 fenders installed. Pics would help, super easy to upload to imgur and post the link here.

Since you have an XI, you will need to make sure your front & rear rolling diameters are within 3% of each other. The sizes you listed will be fine (647.1mm vs 641.6mm, 0.86% difference).

Assuming you are running the stock 18" tire sizes (225/40 and 255/35), you will only be increasing your rolling diameter by 1-1.5%, so your speedometer will read 1-1.5% slower which is negligible (100mph will read as 99mph..)

I will take photos and upload this weekend, I am at school so I can't right now. My stock wheels are 17x8 square with 225/45R17 sized tires. The speedometer thing seems okay then!

[sKruPz]

Originally Posted by Pinscher

Well if the rolling distance of your rear wheels is greater than the front then the rate the differentials spin at are not in sync. Sorry for lack of technical terms here, but basically your XI will not compensate for large discrepancy, and you can basically ruin your differential or transfer case.

This is why XI come with a Square wheel/tire setup, though it's possible to go staggered, provided the rolling distance of your F to R tires is within 5% or so.

I would go square if necessary, but I think I'd prefer a staggered setup. I'll keep them at around 3%

[sKruPz]

Here is a photo of my gigantic wheel gap. So I'd be OK with these tire sizes and maybe lowering springs?

Front: 19x8.5 ET35 // 235/35/19
Rear: 19x9.5 ET45 // 265/30/19

[Pinscher]

I think most people around here would advise to get a proper coil over setup and adjust to your liking. I know little about suspension, sorry .

looks like you have stock base line stuff. an upgrade will do wonders for your drive quality if those are anything like the stock i had an a 328..bouncing all over the place, socially with 19" on there.

FYI, it's outside diameter that matters, not the staggered width. I think you got that point though.

[sKruPz]

Originally Posted by Pinscher

I think most people around here would advise to get a proper coil over setup and adjust to your liking. I know little about suspension, sorry .

looks like you have stock base line stuff. an upgrade will do wonders for your drive quality if those are anything like the stock i had an a 328..bouncing all over the place, socially with 19" on there.

FYI, it's outside diameter that matters, not the staggered width. I think you got that point though.

Yes, I had been reading opinions of others as well as looking at some videos that advise against simply buying lowering springs. There's a member here selling a Bilstein B12 suspension kit that I'm really interested in buying. I don't want to go the cheap & easy route of just springs if the ride feels poor (much like I went the cheap route going with a muffler delete instead of a new exhaust)

[Pinscher]

Originally Posted by sKruPz

Yes, I had been reading opinions of others as well as looking at some videos that advise against simply buying lowering springs. There's a member here selling a Bilstein B12 suspension kit that I'm really interested in buying. I don't want to go the cheap & easy route of just springs if the ride feels poor (much like I went the cheap route going with a muffler delete instead of a new exhaust)

The PE Exhaust mod is wonderful with the resonator delete (attached). I hear that bilstein B12 are like the best.

[sKruPz]

Originally Posted by Pinscher

The PE Exhaust mod is wonderful with the resonator delete (attached). I hear that bilstein B12 are like the best.

Although I believe you, there's no way I'd be able to do that myself. I am not great with car stuff & don't even have anything to cut that with!

[Pinscher]

Originally Posted by sKruPz

Although I believe you, there's no way I'd be able to do that myself. I am not great with car stuff & don't even have anything to cut that with!

I'm mechanically inclined which I understand isn't the same for all people, and buying the tool is more often cheaper than paying someone to do the work. I actually paid an american to do my mod since he has done it a bunch of times already and I currently have zero welding skills.

Though, It really helps to have a house where you can do all this stuff.

From there it's a matter of just being handy in that way. some are, some are not. Anyone with welding skills can do the exhaust mod, on problem. it's pretty straight forward welding. Grinders are easily found at a pawn shop.

Anyways, you get the point, good luck with your car.

[sKruPz]

Originally Posted by Pinscher

I'm mechanically inclined which I understand isn't the same for all people, and buying the tool is more often cheaper than paying someone to do the work. I actually paid an american to do my mod since he has done it a bunch of times already and I currently have zero welding skills.

Though, It really helps to have a house where you can do all this stuff.

From there it's a matter of just being handy in that way. some are, some are not. Anyone with welding skills can do the exhaust mod, on problem. it's pretty straight forward welding. Grinders are easily found at a pawn shop.

Anyways, you get the point, good luck with your car.

Thank you. I'm definitely going with the B12 kit, which means I won't have to buy lowering springs as well, correct? Just not sure on wheel size still

[TheMidnightNarwhal]

Originally Posted by Pinscher

I'm mechanically inclined which I understand isn't the same for all people, and buying the tool is more often cheaper than paying someone to do the work. I actually paid an american to do my mod since he has done it a bunch of times already and I currently have zero welding skills.

Though, It really helps to have a house where you can do all this stuff.

From there it's a matter of just being handy in that way. some are, some are not. Anyone with welding skills can do the exhaust mod, on problem. it's pretty straight forward welding. Grinders are easily found at a pawn shop.

Anyways, you get the point, good luck with your car.

Lmao I just bought a welder and grinder at x mas for 2nd cat delete and possibly mod the muffler box.

Holy shit welding learning curve is pretty steep uh haha! It's a MIG gasless wire.

[b92]

Originally Posted by TheMidnightNarwhal

Lmao I just bought a welder and grinder at x mas for 2nd cat delete and possibly mod the muffler box.

Holy shit welding learning curve is pretty steep uh haha! It's a MIG gasless wire.

What were you going to mod in the 335is mufflers? As far as I know, the popular muffler mods are for the stock 335 exhausts.

[IllSic_Design]

Originally Posted by TheMidnightNarwhal

Lmao I just bought a welder and grinder at x mas for 2nd cat delete and possibly mod the muffler box.

Holy shit welding learning curve is pretty steep uh haha! It's a MIG gasless wire.

Technically not MIG if its gasless, but I know what you mean. Flux core wire mig welding is harder than actual MIG welding(with gas) in my opinion.

[TheMidnightNarwhal]

Originally Posted by b92

What were you going to mod in the 335is mufflers? As far as I know, the popular muffler mods are for the stock 335 exhausts.

From my understanding the 335is muffler box was between PE and stock.

But what I wanted to possibly do was straight pipe the left side and have the valve be remote control so I can choose if I want it super loud or normal. But I don't think I'll do that.

Originally Posted by IllSic_Design

Technically not MIG if its gasless, but I know what you mean. Flux core wire mig welding is harder than actual MIG welding(with gas) in my opinion.

Right, gas less flux core. Yeah it's not easy! But I think I'm getting the hang of it. I need to practice on stainless steel now.

[IllSic_Design]

Originally Posted by TheMidnightNarwhal

From my understanding the 335is muffler box was between PE and stock.

But what I wanted to possibly do was straight pipe the left side and have the valve be remote control so I can choose if I want it super loud or normal. But I don't think I'll do that.



Right, gas less flux core. Yeah it's not easy! But I think I'm getting the hang of it. I need to practice on stainless steel now.

Stainless is even harder because it takes a lot more heat to weld it, and you have to watch the puddle a lot more. Make sure you have the right wire also for stainless, although you CAN use regular it will rust at the weld.

[TheMidnightNarwhal]

Originally Posted by IllSic_Design

Stainless is even harder because it takes a lot more heat to weld it, and you have to watch the puddle a lot more. Make sure you have the right wire also for stainless, although you CAN use regular it will rust at the weld.

Yeah I've been told though if you then use paint over it should be fine and avoid rusting?

Is there a wire I can just buy that won't rust at all?