Sponsored by The Tire Rack

[2tonik]

Just got my 17"x7.5" type 262's for the front, and Michelin Pilot Sport A/S 3's mounted all around.

Wow, big difference. The car is much more neutral, predictable, and most importantly, FUN.

Less effort at the wheel, noticeably less lock needed, more feedback at the limit, and more controllable and progressive oversteer. I can get the rear around much more easily, and at higher speeds - really enjoying this. Previously I had to use the Quaife, power, and tight turns at low speeds to bring the rear end around; now I can do it with less power but more even balance of front to rear grip.

I didn't expect quite as much change - but that's good - I may not want to do springs/shocks down the road. The M3 front control arms show up in a few days, which will complete this phase of getting rid of the stock understeer, and they may be enough.

Ever since I got the 128i, I've wanted it to handle more like my old RX-8. I'm getting closer.

[135iam]

I laughed when I read the last part, cause ever since I bought my 135 I have been trying to get it handling more like my S2000.

I swapped the stock tires for non-staggard blizzaks and loved the results as well.

Enjoy it!

[IEDEI]

my winter setup has been 225 squared on 17s and it's pretty amazing how much of a difference it makes to the rear end....the rear end is very active and very FUN! i'm not sure i would want it all year round though, as the torque on the car can light up the rears VERY easily with skinny 225s.

[BavarianN54]

Originally Posted by 135iam

I laughed when I read the last part, cause ever since I bought my 135 I have been trying to get it handling more like my S2000.

I swapped the stock tires for non-staggard blizzaks and loved the results as well.

Enjoy it!

Putting snow tires on your car improved handling, ok.

[fe1rx]

Originally Posted by 2tonik

JThe M3 front control arms show up in a few days, which will complete this phase of getting rid of the stock understeer, and they may be enough.

Square is definitely good. Have you installed M3 rear subframe bushings? If not they will rock your world. I am sure you have seen the postings that say they have a great impact on front grip - it is very true.

I speak from running square, with M3 bushings and M3 front control arms and camber plates (added in that order). Surprisingly the bushings are the biggest bang with respect to balancing the car.

The M3 control arms add some steering precision but don't really reduce understeer significantly.

I too had an RX-8. Would have been a keeper with 300 hp.

[Dafttt]

Originally Posted by BavarianN54

Putting snow tires on your car improved handling, ok.

Balance.

[BavarianN54]

I see you have M3 suspension and coil overs, that accounts for vastly more in balance, handling than your similar tire size, but you believe what you want.
Me, I have suspension work also do I'm not under steering as badly as stock.

[Olgeezer1]

Don't want the expense of changing wheels so I'm going to try 225/40/18's all around on my staggered 263 wheels. With an asymetrical max. perf. tire I'll at least be able to rotate side to side and am expecting more neutral handling.

[fe1rx]

Originally Posted by Olgeezer1

Don't want the expense of changing wheels so I'm going to try 225/40/18's all around on my staggered 263 wheels. With an asymetrical max. perf. tire I'll at least be able to rotate side to side and am expecting more neutral handling.

I can confirm that works. Also, 225 is the only width that is "correct" on both OE wheel widths.

I think you mean "symmetrical" though, because an asymmetrical tire has a defined outside edge and can't be flipped on the rim.

To flog the subframe bushing issue once again, the OE rear subframe bushings provide for passive rear steer that drives the car into understeer despite any other efforts you might make. The M3 rear subframe bushings get rid of this annoying "feature".

A car that is mass balanced front to rear should be grip balanced front to rear for neutral steady-state handling. The Nissan Deltawing is an extreme example of stagger, but the the stagger is matched to the available grip at each end of the vehicle, which is a function of mass balance. Without knowing the details it is pointless to point to other cars as arguments for stagger. Also, many mid- and rear-engined cars are not mass balanced front to rear. They need a rearward mass bias to get their power to the ground, and they need bigger rear tires in proportion to that mass balance. The reasons the 1 series was built with excessive stagger and relentless understeer are a) curb appeal and b) to try to bring the front airbags actively to the scene of the accident.

[Stohlen]

Lets get one thing straight here... A square setup creates a more balanced car, not a faster one. A novice driver benefits from a square setup because it makes the car easier to drive, and thus he/she will make quicker lap times vs. a staggered setup. A pro driver however will make quicker times with a staggered setup thanks to increased rear grip on corner exit when air pressures are setup properly.

Originally Posted by IEDEI

as the torque on the car can light up the rears VERY easily with skinny 225s.

This is moreso because they are winter tires and has little to do with the width. Width only increases straight line grip when you run a lower air pressure. Tire height is directly related to straight line grip.

[BavarianN54]

Any one, meaning expert racer/racing types stating online that support your 'theory' you'd care to post up and enlighten us with? I'd love to learn more about it.

[135iam]

Originally Posted by Daft Auto

Balance.

Exactly!

I love the comments I read about "inexperienced" drivers benefit from non staggered setups on this forum, as it's likely the farthest thing from the truth. I challenge any Internet setup guru's to spend a few years at local road courses and find the fast guys running cars with near 50/50 weight distribution. (S2000 and E36 M3, RX8, Miata) learn about trail braking, rotation. These are aspects car that are ENHANCED with a well setup suspension and non staggered wheel/tire setup. Inexperienced drivers are usually slow or spinning in neutral/oversteering car, good drivers are fast.

[Stohlen]

Originally Posted by 135iam

Exactly!

I love the comments I read about "inexperienced" drivers benefit from non staggered setups on this forum, as it's likely the farthest thing from the truth. I challenge any Internet setup guru's to spend a few years at local road courses and find the fast guys running cars with near 50/50 weight distribution. (S2000 and E36 M3, RX8, Miata) learn about trail braking, rotation. These are aspects car that are ENHANCED with a well setup suspension and non staggered wheel/tire setup. Inexperienced drivers are usually slow or spinning in neutral/oversteering car, good drivers are fast.

Absolutely there are benefits, but in a high powered rear wheel drive car they don't do enough to justify reducing rear grip. The cars you mentioned don't light up the rear tires, they aren't as extreme and don't require the added grip. In FWD or AWD where the rear tires don't handle all of the power, absolutely but not in the situation we're discussing.

[135iam]

I think it boils down to the following.....the quarter mile types aren't going to appreciate a non staggered setup, where as road course fanboys aren't going to appreciate the guys running 225 fronts and huge rears.

[imported_mega]

I've had no problem with lack of front grip, the rear however is an issue

curious if those switching to square tried swaybars first, stock leave much to be desired and I would imagine impact balance quite a bit more

[2tonik]

I think some folks may not have noticed that I'm driving a 128i. A 135i will handle differently under power compared to a 128i.

Square setups:

Just to note, the 347 horsepower 1968 Ferrari Daytona, considered a "super car" in its day, ran 215/70 tires on 15" wheels. It did pretty well.

The 240 horsepower U.S. spec E36 BMW M3 originally delivered with a "square" set up, and its handling was lauded for being brilliantly neutral. It wasn't until folks (inexperienced drivers!!!) started wrapping their E36 M3's around telephone poles that subsequent model years delivered with staggered set ups.

What I read about folks going racing with near stock versions of our cars is that square 17" set ups are fastest.

I certainly think the staggered factory set ups - with both modestly powered vehicles like the 128i (yes, 230hp/200tq is modest these days) and with the 135i are to make the cars understeer more and be less likely to oversteer. The lawyers are telling the engineers to do this. That's also why I think we're not seeing mechanical LSD's on non-M vehicles. I also think that a lot of folks like staggered set ups because they think that they look "moar" aggressive.

As for me being an "inexperienced" driver, don't know about that...

I'm 49, I've owned:

'84 Mazda RX-7 GSL-SE
'85 Mustang 5.0 Coupe (breathed upon)
'88 MR-2 (full autocross suspension set-up)
'90 Honda Civic Si
'94 BMW 325is
'94 Acura Integra GS-R
'04 Mazda RX-8
multiple non-enthusiast family and work vehicles
plus the 128i.

I've probably driven the above vehicles around 660,000 miles in the U.S.

Beyond daily driving, work trips, and fun runs, I've driven across the U.S. three times, driven in Canada, Mexico, Costa Rica, Argentina, Chile, Spain, Andorra, and France.

I'm going to say that I'm a little beyond "inexperienced" and leave it at that.

[Kgolf31]

Here is a brilliant idea for those 135i owners, Stop running tunes and boasting about power when you can't put it down.

I ran 265 rears on a Z4M and had no issues.

Square is optimal, much easier to tell the car what to do.

[mr_bean]

You are all wrong.

Proper balance comes from suspension tuning.
If your rear tires are wearing out more quickly than the fronts, go staggered and re-tune the suspension.
If all fours are wearing evenly but the balance is off, re-tune.

Also, I think a lot of the arguments here boil down to personal preferences and driving styles.
For me, my measly 128 has a square set-up with staggered rims (thanks to the PO). I can't wait to go staggered with the rubber. I've found the right amount of trail braking and I'm heavy on the throttle coming out. She's very tail happy with factory sport suspension.

[135iam]

Originally Posted by Kgolf31

Here is a brilliant idea for those 135i owners, Stop running tunes and boasting about power when you can't put it down.

I ran 265 rears on a Z4M and had no issues.

Square is optimal, much easier to tell the car what to do.

Ha, I drive a 135i with e85 and I even appreciate this post!

[fe1rx]

Originally Posted by 2tonik

I've owned:

Nice list 2tonic. You clearly have an open mind and an aversion to Kool Aid.

One other thing to consider when you go square - in the name of balance, start with matching tire pressures front and back too.

What that pressure that should be will elicit no end of opinions, so I hesitate to offer one. It does depend on what you are doing, but for driving on the street I would suggest starting at 32 and going up a bit at a time until the tires start feeling harsh over bumps, then back off a bit.

[2tonik]

To my point, the U.S. E36 M3 had a very similar power to weight ratio to the 128i.

I do plan on doing M3 rear subframe bushings, for those who are suggesting.

Another thing to keep in mind is that the 128i may be best with a square set up, but that the 135i may be better with a staggered set up to handle what is fairly ridiculous power for such a short wheelbase car. May we say that the 135i can benefit from a larger than factory spec front tire that is 215mm wide? Several of the professional reviews on the 1-series note that the 135i has perhaps too much power for its chassis. Some of those concerns may have been addressed in the 1M (LSD, 245's up front, and yes, still staggered).

Oh yeah, I forgot two vehicles on my "life list":

'85.5 944
2000 A4 Quattro Sport 6MT

I enjoyed them all, and have arrived the conclusion that a well balanced car with a straight six is my favorite.

Of course, no 911 in the list. Need to print up some more money with the Epson or win the lottery. Make mine a Singer Vehicle Design, please. YES, it will have a staggered set up.

[Kgolf31]

Originally Posted by fe1rx

Nice list 2tonic. You clearly have an open mind and an aversion to Kool Aid.

One other thing to consider when you go square - in the name of balance, start with matching tire pressures front and back too.

What that pressure that should be will elicit no end of opinions, so I hesitate to offer one. It does depend on what you are doing, but for driving on the street I would suggest starting at 32 and going up a bit at a time until the tires start feeling harsh over bumps, then back off a bit.

Pressure should be dictated by the amount of rollover you are achieving on the sidewall.

I ended dropping my pressures to around 28 front, 26 rear on the Z4M when I drove that in HPDEs