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[4sevens.com]

Hi everyone - I've been reminiscing about the pros and cons of a wider front - I've got lots of opinions on it but would like to know what you guys think

BTW I run 275/30/19 front, 295/30/19 rear with stock ZCP's
and 275/35/18 front, 285/35/18 rear with apex arc-8 10 and 10.5's at the track

[Richbot]

Lack of feel and worse bump steer for not much grip improvement, worse aero, its a bandaid for classes or chassis that cant be set up to rotate around a more staggered setup. Considering our cars and their unfavorable weight distribution i think a 275-ish front is a necessary evil.

[smmmurf]

Originally Posted by Richbot

Lack of feel and worse bump steer for not much grip improvement, worse aero, its a bandaid for classes or chassis that cant be set up to rotate around a more staggered setup. Considering our cars and their unfavorable weight distribution i think a 275-ish front is a necessary evil.

I am curious to drive this car with a square setup.
I don't find it that bad with the stock 245/265 in PS2 form.
However, add grip to the chassis and it starts pushing (245/265 PSS).

It may be more fun on 245 or 265 all around... DSC issues notwithstanding... hrmmm

[1MOREMOD]

I run a square set on the track. 265-30-19 and it does get rid of a lot of understeer, but still does it. Much more neutral I feel with this set up.

[smmmurf]

Originally Posted by chriszeh

I run a square set on the track. 265-30-19 and it does get rid of a lot of understeer, but still does it. Much more neutral I feel with this set up.

Good to hear! Even a very neutral car is going to understeer if you go in with too much entry speed and steady state throttle.

[bobbyd1961]

if m division thinks bigger back then i go with them . if front was better thats the way it would come.

[4sevens.com]

Originally Posted by bobbyd1961

if m division thinks bigger back then i go with them . if front was better thats the way it would come.

m division still produced the car for the street. for example I ran one lap of america (8,000 miles) this year with the car stock. It seriously needed more camber - I even removed the camber bolts to get -1.9 and it still wasn't enough. I had plates installed and am at -2.9 and to me it's much more neutral under/oversteer. But I understand why they had it -1.5 as a stock M - must more acceptable street wear but it understeered like crazy at the track when I ran one lap.

I'm planning to go with an ess kit and bump up the power to 600hp so I'm likely to go 315's in the back and keep 275's up front.

[bigjae1976]

I don't think BMW setup the camber to be adequate for serious track use. During my PCD, I noticed that the M3 I was in had pretty bad wear on the outer edges as well as the M5s that the instructors were driving.

I think wider front tires with more negative camber will usually be a given at the track for those who are pretty fast drivers.

Comparing the M3 to other cars...I think the fact that we can get almost 2 degrees in the front is pretty good.

[signes]

I run a 275 front and just switch back to my 245 front for winter. It was remarkable how much lighter and more fluid it felt. There is no mistaking the grip from a wider front (though not as much as you would expect if sticking with the stock suspension), but I kind of miss that lighter feeling with more feedback. When the 275s wear out I will likely step down to a 255/275 combo.

[smmmurf]

Originally Posted by signes

I run a 275 front and just switch back to my 245 front for winter. It was remarkable how much lighter and more fluid it felt. There is no mistaking the grip from a wider front (though not as much as you would expect if sticking with the stock suspension), but I kind of miss that lighter feeling with more feedback. When the 275s wear out I will likely step down to a 255/275 combo.

It's not just the weight of the tire, it's the fact that there is more effort to move that patch of rubber back and forth, especially at rest as the tire is stuck to the pavement (at speed it requires less effort to move the tire).

Good idea... 275 fronts are huge...

[a burrito]

A simple pros/cons would be:

Pros:
More Grip

Cons:
More Weight
Less steering wheel feel (less crispy feeling)

[BlackLight]

Would the PSS in 265-F and 285-R be a good compromise?

[signes]

Originally Posted by smmmurf

It's not just the weight of the tire, it's the fact that there is more effort to move that patch of rubber back and forth, especially at rest as the tire is stuck to the pavement (at speed it requires less effort to move the tire).

Good idea... 275 fronts are huge...

I know, just using the word to reflect feel. (Side note, if you add up the combined weight of my fronts (RAC wheels at ~20lbs and the tires) it comes out less than OEM 18s or 19s with 245s.)

It was just stark going back to a 245 front how much more feel came back through the wheel. I wish I could put the 275s out back and buy new 255 fronts but I need a 275/35 and not a 275/30.

[signes]

BlackLight, you won't get the right OD with those compared to stock (if that matters to you.)

[kmarei]

255/35front and 275/35 rear are the best compromise
at least for the street