[moldcad]

Thanks mate. I do have quite bad buyer's remorse though; the rims weren't exactly cheap (though not as expensive as forged wheels by some luxury brands, of course) and I could get them cut precisely to my specs; by following Dinan's I ended up with what I think is sub-optimum solution . Here are my thoughts, please correct if wrong:

So, the rear offsets at 48mm make the 265mm tires very close to rubbing fenders, therefore - after I lower the car - I'll need to add some negative camber to rear wheels. This, combined with tire width being 20mm wider than OEM and their spacing - 8mm wider, will increase understeer given that the fronts are at OEM offset (ET45) and with tire width increase of just 10mm... To fight that, I'd need to either use spacers at the front (which I hate), or get into further complications and cost of camber plates or longer LCAs, which I hate even more.

Those of you guys who have the same wheels' specs (or simply have lots of experience - like @Bee Pee for one) - do chime in, and (hopefully) help me get rid of this bad feelings... TIA,

Piotr

[Bee Pee]

Hi Piotr,

Are you speculating about your setup making your car understeer more or have you experienced more understeer with your new set up ?

Are you actually getting rubbing on the rear fenders with 265 rear tyres ?

What rear camber does your car have just now ?

If your setup is now actually giving you more understeer and you don't want spacers [very wise IMHO] nor F8X LCA [brilliant oem upgrade BTW] then my advice to you would be [in order of expense]

1. Get the cars alignment checked and ask to increase rear camber to -2deg
2. If you don't want LCAs or spacers - consider fitting camber adjustable bushes into your existing LCA's this may add ~ -0.5deg of camber to the front wheels.
3. Consider changing front tyres from 235/35/19 to 245/30/19
4. Consider changing rear tyres to 255/30/19

BP

[moldcad]

Hi Bee Pee - thanks for chiming in!

Yeah, all I wrote is mostly speculation at this point - I didn't try lowering yet, nor did I drive the car on the new wheels any closer to limits than I did before...But should my worries turn up to be justified, your advise is excellent! I even considered 245/30 fronts earlier in this thread, but was sort of discouraged - a pity, as back at that time I could have done this without additional expense.

Still waiting for some input from those also having the 'Dinan specs' wheels on their M235/240i; AlpsRider in particular as he also runs Dinan springs/b-stops. I certainly hope my anxiety is unnecessary!

Piotr

[moldcad]

Looking at the picture of my car (sorry, it was dirty), which would you choose:

- H&R, lowering 15mm on both axes
- Eibach Proline, lowering 20mm on both axes
- Eibach Proline, lowering 20mm (font) and 10mm (rear)

Please advise,

Piotr

[Bee Pee]

Originally Posted by moldcad

Looking at the picture of my car (sorry, it was dirty), which would you choose:

- H&R, lowering 10mm on both axes
- Eibach Proline, lowering 20mm on both axes
- Eibach Proline, lowering 20mm (font) and 10mm (rear)

Please advise,

Piotr

H&R over eibach

[moldcad]

Does anyone know which color do the -15mm H&Rs come in?

Asking, because I'd like to keep my BMW service unaware I went with aftermarket springs (instead of their own, pricey M-P lowering kit) for as long as possible So it'd be great if the H&Rs are red!

Piotr

[x233]

Originally Posted by moldcad

Does anyone know which color do the -15mm H&Rs come in?

Matt blue.

[moldcad]

Thanks, @x233; I also have three very important questions for those of you guys who have the experience I'm lacking. Really wouldn't like to make another mistake (like the Dinan-recommended offset of the front wheels unnecessary high ET45 while I could have my BC Forged machined with ET40, or their color being rather different from what I expected ):

1. Should I also buy the "Protection Tubes" (P/N 31331137932) with the E36 M3 front bump-stops?
2. Which springs are stiffer - the -15mm H&R, or the -20mm Eibachs?
3. What the increase in negative camber induced by lowering the M235i by those 15-20mm?

Thanks & Regards

Piotr

[x233]

1. No. Just the bumpstops (go with what Dinan OEM parts uses for their kit, info available elsewhere on this forum).

2. who knows, got to read the TUV certificates for both (available online), that might give you an idea (coil thickness, number of coils, etc. H&R may feel softer because the rears are progrossive unlike Eibachs)
here:
http://web1.carparts-cat.com/default...3107001&12=130
http://web2.carparts-cat.com/default...C279001&12=130

3. up to -30 min (no more than that, perhaps less with H&R)

PS: The color is fine. Really. Love that color, how it reflects in the sun, etc. It's the wheels specs, offsets, etc., that are not exactly perfect. But I told you that before you ordered. Those look unnaturally big for the car, the whole thing, the wheels and the tires... it's not too bad but it catches one's eye. You could safely use 3 mm spacers in the front (no risk of rubbing or balance issues, no need of new lugs). 5 mm? that you'd have to try.

[moldcad]

Thanks x233 - glad you like the color However, the complete wheels aren't actually much larger than many people are running (e.g. front tire at 225/40R19, whose diameter is larger by ca. 25mm than OEM; mine are only 12mm larger) - so I guess the impression of my wheels being huge is due to the dark color of the rims; this is why I regret I didn't pick the Brushed Clear color from the BC Forged huge palette...

Piotr

PS. Also when lowering the car, my extra 12mm of diameter is a good thing - dropping will close those nasty gaps above tires, but the effective ground clearance will be 6mm higher than on OEM wheels and the same lowering distance - so less problems with high road imperfections...So -15mm with H&R will result in ca. 10mm drop on a regular car.

[moldcad]

Originally Posted by x233

You could safely use 3 mm spacers in the front (no risk of rubbing or balance issues, no need of new lugs). 5 mm? that you'd have to try.

A lame question: with 5mm spacers, will I already need longer lugs? If still not, which is the spacer thickness threshold limit?

And another one: are the camber-adjustable bushes (like Powerflex) a proven solution - don't they turn (effectively changing the camber), or fail sooner than OEM ones?

Piotr

[Anthony235]

I haven't been following this thread much so I might be off base here, but I think I see some comments that aren't true.

Like I said earlier in this thread....adding a wider tire (or track) in the back does not increase understeer. The only way you will increase understeer (speaking only of tire widths) is if you go with a narrower tire up front compared to OEM.

Adding grip to the rear (wider rear tire) does not reduce grip up front. Wider rear tire just removes a certain amount of oversteer from the car. In an extreme example you would go with a really wide rear tire and with so much grip now in the back the only thing left is understeer. You didn't add more understeer, but you added so much grip in the rear that the front is now the weak link.

Maximum grip level up front stays the same. Was not reduced.

If you're looking for maximum grip then go with the widest you can fit...front and rear.

If you want to minimize understeer then add grip up front. Don't take grip away from the rear in an effort to "balance" the car.

[Anthony235]

Originally Posted by moldcad

A lame question: with 5mm spacers, will I already need longer lugs? If still not, which is the spacer thickness threshold limit?

And another one: are the camber-adjustable bushes (like Powerflex) a proven solution - don't they turn (effectively changing the camber), or fail sooner than OEM ones?

Piotr

No, once you go 10mm is when you will want to look at longer lug bolts or swap to wheel studs.

I run studs all around.

[x233]

Originally Posted by moldcad

A lame question: with 5mm spacers, will I already need longer lugs? If still not, which is the spacer thickness threshold limit?

And another one: are the camber-adjustable bushes (like Powerflex) a proven solution - don't they turn (effectively changing the camber), or fail sooner than OEM ones?

Piotr

I've used 3 and 5 mm spacers. no need for longer lugs with 3 mm but with 5 mm it's marginal and I used longer lugs.
The reason I like 3 mm is because the wheel is still centered on the hub. With 5 mm that's marginal and I can imagine that with some wheel designs (hub) there may be issues (wheels not properly centered). I didn't have the problem but I did take notice that the part of the hub you center the wheel on is only 7 mm tall max so... there may be wheels out there that do not center properly (that is, only by lugs and that's a recipe for getting vibrations and damage). I've centered stock wheels and MAK wheels with 5 mm spacers with no issues but like I said theoretically that may be a problem with some other wheels.

[moldcad]

Originally Posted by Anthony235

Like I said earlier in this thread....adding a wider tire (or track) in the back does not increase understeer. The only way you will increase understeer (speaking only of tire widths) is if you go with a narrower tire up front compared to OEM.

Adding grip to the rear (wider rear tire) does not reduce grip up front. Wider rear tire just removes a certain amount of oversteer from the car. In an extreme example you would go with a really wide rear tire and with so much grip now in the back the only thing left is understeer. You didn't add more understeer, but you added so much grip in the rear that the front is now the weak link.

Maximum grip level up front stays the same. Was not reduced.

If you're looking for maximum grip then go with the widest you can fit...front and rear.

If you want to minimize understeer then add grip up front. Don't take grip away from the rear in an effort to "balance" the car.

Thanks Anthony. I must admit your statements sound a bit counter-intuitive to me; I'd say that while you're right that each axle's setup doesn't influence the other's, the behavior of the car as a whole must be a function of the difference between them. Meaning that with my specific offsets & tire widths (determining both their lateral stiffness & grip), the car should exhibit some increased tendency to understeer... However, my experience describe below sort of confirms your standpoint, and denies mine - then again, it's far from scientific.

Well - it so happens I've just returned from my first longer trip after my wheels upgrade; some high-speed motorway as well as twisty B-roads, all pretty aggressive driving... here are my findings which seem to confirm your opinions quoted above:

- at high speed (well over 200 km/h), the lower profile tires make the car planted especially in Sport mode with substantial improvement also in Comfort; no more instability due to strong side winds which on OEM tires required constant corrections with the steering wheel

- much better (and neutral) handling in heavy cornering on twisty B-roads; so much encouraging in fact, that one of such bends I approached at way to high speed - 10/10 braking and tossing the car into the corner - it obeyed my steering input with no traces of understeer; was expecting the rear break-away inside the curve but none happened, so I induced a deep power-slide on exit and I left the bend victorious . In this single event, my wheel upgrade investment paid off 100% as I'm sure I'd have crashed on the OEM tires (on the other hand I wouldn't drive that fast on them, but still).

- ride is a bit harsher, but nothing serious so I'm still ready for lowering the car with some shorter/stiffer springs!

It would be a very interesting discussion to try and elaborate on which standpoint is right!

Anyways, now I also wonder whether 10mm increase of the front track (by having ordered the front wheels at ET40 rather than ET45 in the first place, or using 5mm spacers now that I have what I ordered) would improve handling even further... Opinions?

Piotr

PS. After that trip, I even sort of like the looks of my wheels better now - but still think they would look better in Brushed Clear.

[moldcad]

Welcome to the discussion!

Piotr

[AlpsRider]

If you install lowering springs on your car, you should also install the shorter bump stops. This will bring the wheel/tire closer to the front fender on full suspension compression. Have you read about anyone running 245/35/19 tires on dropped suspension without camber plates etc. that don't have rubbing? As I said before, my car lowered with Dinan springs running 235/35/19 ET45 front wheel/tires have rubbed on occasion. It only makes sense that if you go up to 245/35/19 at ET40 the rubbing will be worse depending on your tire.

[Bee Pee]

Originally Posted by AlpsRider

If you install lowering springs on your car, you should also install the shorter bump stops. This will bring the wheel/tire closer to the front fender on full suspension compression. Have you read about anyone running 245/35/19 tires on dropped suspension without camber plates etc. that don't have rubbing? As I said before, my car lowered with Dinan springs running 235/35/19 ET45 front wheel/tires have rubbed on occasion. It only makes sense that if you go up to 245/35/19 at ET40 the rubbing will be worse depending on your tire.

245/30/19 tyres will be fine up front with lowered springs, std m235i lower arms and 8" et45mm wheels

[AlpsRider]

Originally Posted by Bee Pee

245/30/19 tyres will be fine up front with lowered springs, std m235i lower arms and 8" et45mm wheels

I believe you. However, "My" Dinan lowered setup with MPS4S 235/35/19 on ET45 8" wheels "with the necessary shorter bump stops" will rub the front fender lip under extreme conditions.

[moldcad]

Originally Posted by AlpsRider

If you install lowering springs on your car, you should also install the shorter bump stops. This will bring the wheel/tire closer to the front fender on full suspension compression. Have you read about anyone running 245/35/19 tires on dropped suspension without camber plates etc. that don't have rubbing? As I said before, my car lowered with Dinan springs running 235/35/19 ET45 front wheel/tires have rubbed on occasion. It only makes sense that if you go up to 245/35/19 at ET40 the rubbing will be worse depending on your tire.

Dear AlpsRider - I'm definitely not even contemplating doing both, i.e. upsizing from 235/35 to 245/35 and increasing track to ET40 per wheel with 5mm spacers. It's either one or the other - and even if the former, it'd be 245/30 not 245/35 (and only in the future after my current tires wear out). Which leaves me with only one option for now: the 5mm spacers...

As to your having rubbed on occasion: I admit I misinterpreted your warning post in this thread multiple times (yeah I know ). First I got alarmed by it; then someone else posted info about MPS4S having wider thread than MPSS tire which I mistakenly understood the other way around - and finally, after being corrected, I took this width difference as the reason for your rubbing, and felt re-assured that my MPS4S would not rub as being thinner (and this was my main mistake as obviously you were talking about MPS4S rubbing, not MPSS). If all this makes sense in my poor English ...

Anyway: please tell me where exactly do your tires rub, because I'm still unclear reading your original post; first you say about rubbing "inside", but in the next sentence you state that "Rolling the lip would probably eliminate the issue". If it was inside than adding spacers could alleviate it - but if "outside" (against the fender lip), I should forget about spacers especially if I'm going to lower my car. However, increasing negative camber might actually solve this problem, while reducing understeer (which I'm after) - both at the same time!

So again: please be more specific where exactly the rubbing occurs and under which extreme conditions (braking on the straight line? Heavy cornering?). Because I'd love to drop my car some 15mm with H&R springs, and use the E36 M3's bump stops at the front - so to avoid rubbing you experience, I'd need to increase front camber - but only if the rubbing is expected "outside"... Please clarify that for me; TIA, Bro!

Piotr

[moldcad]

Originally Posted by AlpsRider

I believe you. However, "My" Dinan lowered setup with MPS4S 235/35/19 on ET45 8" wheels "with the necessary shorter bump stops" will rub the front fender lip under extreme conditions.

BP is talking about what I was considering - and that's 245/30 (not 245/35), which has some 8 mm smaller radius than my (and your) current 235/35...

Piotr

[Bee Pee]

Originally Posted by AlpsRider

I believe you. However, "My" Dinan lowered setup with MPS4S 235/35/19 on ET45 8" wheels "with the necessary shorter bump stops" will rub the front fender lip under extreme conditions.

Yes 235/35/19 [OD 647mm] is much taller than 245/30/119 [OD 630mm) hence why you are getting a rub !!!

https://www.wheel-size.com/calc/?whe...cl=50mm&sr=0mm