Anyone running an E36 328is coupe with COM?...

[TroyV]

I'm not sure I'm man enough to go straight from a supercharged Mustang to a full momentum car. There need to be a few steps down......or up...depending on how you look at it.

[cfossum]

Another ST3 contenda?

[TroyV]

Who knows if it would actually contend? I co drove what I think you would call an SCCA BSP E36 M3 coupe at Devens two weeks ago, and had an awful lot of fun driving it. I managed to get within a second of the owner which isn't too bad.. I'm thinking if this 328 can even be close to that, I'd be having a good time.

[khissong]

Throw a wide body kit and a cage at that and run in P/A. I think I may have left out some stuff, but you get the picture.

[TroyV]

Here's a low brow question. The car has style 30's 16x7.. I was considering picking up a cheap set of wheels to throw some falken RT615's on and having some cheap fun with the car. The question is from the driver's perspective, and regarding the open diff, and assuming the same tire model is deployed, would it be best to stick with 16x7's and run a 205-50-16-ish sized tire, or step up to the also cheap and available 17x7 contours and run a 225-ish size tire?

[zip4zat]

Troy,
Id think that if you can get enough tire for the power the car has, stay with the 16's and get as low profile tire. I dunno if you can get 215/225-45's for 16's. 16s will be lighter and cheaper.

17's if you need or can fit more tire to offset the weight. Gearing will be affected too, not sure better or worse. My guess is worse as you go bigger with tires.

[cfossum]

I run 205s on the RX7 with 7" wheels. They're skinny enough that people notice them and then figure out that I'm cheap. I don't have the grip that some other cars have, but it is certainly not lacking. Your 328 may be a few pounds heavier than the RX7.
Regarding the open diff, mine has not really been a problem. Turn three at NHMS is the only place that I sometimes spin the inside wheel. Since our cars would be classed the same, I would assume they have a similar power to weight ratio, and would therefore assume that you shouldn't be smoking the tires much.
Anyhow, in both of your choices you are referring to a 7" wide wheel. Your dilemma of 205 or 225 widths should apply identically to either diameter.

[TroyV]

I agree, the width issue is the same for 16" and 17", but I was after the weight difference. it is obvious that 17's would be heavier, but I was trying to see if that added weight would actually help with the open diff or not.

I think it would be fun to run the car in ST3 and try to catch you, though something tells me it would be an uphill battle.

[jlwhorf]

I agree, the width issue is the same for 16" and 17", but I was after the weight difference. it is obvious that 17's would be heavier, but I was trying to see if that added weight would actually help with the open diff or not.

If all possible never add unsprung weight. You are building a race car, not a tractor. It may give you traction, but it will hurt braking, acceleration, and handling. A rule of thumb that I heared is that 10 pounds unsprung weight = 100 pounds sprung weight.

Jonathan

[gread]

E-36 likes the 17". Check out Bimmerforums.com for a large supply of used wheels available. I would recommend a 17x8 minimum. Run a 235 or 245/40/17 tire in whatever compound you like. Corner wieght and alignment will be key.
There are also plenty of used diffs on-line. An open diff will need to be addressed eventually.

[WillM]

The wheel weight will probably be insignificant to the tire weight. Often the tires are significantly heavier than the wheels. My tires are more than twice as heavy as the wheels, for example.

I'd forget about diameter and go for width. 8" minimum.

You can never go too wide.

[breakaway500]

Kumho makes a V710 in 215/40/16. 19lbs, 22.6" tall. Very sticky,doesn't hurt gearing and easy on brakes. Works well on the Focus.
Minumin rim width required is 7".

I would stop using the word "cheap" now that you own a BMW.

[TroyV]

I think I want to stick to a good street tire for this car. I already have a car that goes well with a sticky tire.

[gread]

Maybe the sticky tires are on the wrong car...

[khissong]

Maybe the sticky tires are on the wrong car...

This comes from someone who knows E36 and sticky tires.

How's it going Greg?