Does Staggered tire set-up always= Understeer?

[kiley_sean]

I just bought a set of Fikse FM/5's (used). They are 17x8 front and 17x9.

I already have a set of staggered 18" wheels, and really wanted to pickup a set of non-staggered 17" wheels for autoxing, and as a spare for when I send my 18"s to get straightenend (Don't buy MAS Italy wheels, they are weak).

Anyways, I couldn't resist the bargain on these Fikse, and snapped them up.

I have a 330ti that has alot of weight upfront. I know it is not 50/50 balance anymore since I still haven't pulled the battery out of the engine bay, and added a 6-cyl. radiator and electir fan.

My question is :Would running a slightly staggered tire setup- say a 225/40/17 front and a 235/40/17 balance things out..... or does the F/R weight distribution not have such an effect as the tires?

I am just going to be Autoxing, not tracking (yet ).

Second option, would be to throw 235/40's on both front and rear. Yeah, I know I won't be able to rotate them, but that doesn't matter to me. Does the 1" difference in rim width play any effect on anything?

Third option. Try and trade 2 of my Fikse FM/5's to another owner so we can both have matching sets.

4th Option. Maybe I should just STFU and just deal with it!!! That will probably be the most likely answer from you guys!!!

Anyways, thanks for any oncoming advice.

[Matthew C Smith]

A staggered setup typically will mean more understeer, but it could be worked out with a suspension setup. Really though, unless you've got monster power, the way to go is the same size tire all around. If you've got the staggered wheels, your best bet it to try and go with the same thing all around despite not being able to get the best footprint possible out of both tires.

I suspect your car is a little front heavy at this point, but it couldn't be too terrible. Is the ti's wheelbase shorter?

[kiley_sean]

No, it's the same wheelbase as the E36, like ~108", if I remember correctly. If with the M44 318ti achieved 50/50, then with an extra 100-150lbs of an S50 (some past the front hubs), M3 front suspension &brakes, and a heavier radiator setup & electric fan (which is way at the front of the vehicle), I can see this mother easily being 60/40 F/R., no BS!!!

I plan on weighing it at my work sometime soon to get the actual C/B of it. There just isn't enough meat behind the rear axles. A full tank of fuel, and a 45lb weight strapped in might do the trick though!!!

I guess I will be going for a 235/45 all around then. I am not looking for a perfectly "neutral" handler, just not too much of either side-affect.

I understand that Autoxing is more driver skills than anything else and that a good driver can overcome alot of problems. I just want to go in there with somewhat of a "balanced" car.

So will the different wheel widths will play a role in the footprint?

Anyways, thanks for the advice, Matt.

[MrPayne]

4 x 235 is not neccessarily faster than 4 x 225...

[Matthew C Smith]

Why the 235 45? Most people and the M3 came with 235 40 17's

Anyways, If you put something like a 255 on say a 17x8" wheel you're going to balloon out the tire basically, so the footprint of the tire's not going to be very square. If you were to go with something like a 205 on the same wheel, it's going to really be stretched over the wheel.

I wouldn't worry too much about the 60/40 weight distribution. You'll have lots of extra power that'll help the car to rotate anyways.

[kiley_sean]

I wish I could go to 235/40s, but because of my Darn MAShaw front bumper, my 225/40/18' fronts are barely tall enough to get me over most of the bumps and drvieways, etc. If I went to a 235/40/17, I would be hitting all kinds of crap, especially my driveway (yes, I come in at an angle).

I also have bent 3 of my MAS italys, so I kind of want to get a little more tire on the rims. I am just tired of having to keep the car under 80mph because of the "shakes".

I am most likely going to go with the 235/45 all around and see where that gets me. I am not a pro at AutoX, so it's not really that big of deal, like you said.

Now that I think about it, the big thing hurting me is my non-LSDifferential and it's short final drive of 3.45. I hope I can control that beast exiting the turns but I am expecting to spin out a couple of times (Noob). Anybody want to go see a guy spin his car out?


Thanks for the advice.

[Matthew C Smith]

Good luck with it and I know what you mean about minimal ground clearance.

Let me know if I can do anything to help.