e36 M3 ?

[GBugg]

Is there a place for an e36 M3 to play in IT? I would have expected to see it in ITR, but that seems to stop with the older M3s.

[Ron Earp]

E36 M3 stock hp is over the limit for ITR. Or right at the limit basically. It was deemed to be beyond the performance envelope of the class.

Ron

[Doc Bro]

waiting.............

[Ron Earp]

E36 M3 stock hp is over the limit for ITR. Or right at the limit basically. It was deemed to be beyond the performance envelope of the class.

Ron

Let me clarify that a bit more. It could have fit in ITR, but it would have been at a weight that nobody would want to race.

[Knestis]

That is indeed the belief of the ITAC, but it's the topic of ongoing discussion since it's such a popular car.

K

[GBugg]

Thanks for the information. I'm just looking into options for my next toy.

[Z3_GoCar]

If you're still exploring options, I'd recommend an e-36 328. It's only 85 lbs more than the earlier 325's and 50lbs more than the Z3, but you get a better rear suspension than the Z3, and much better torque than the 325. Sounds like a possible winner to me.

James

[GBugg]

After poking around a while 2 BMWs out there look really good, but they are built to NASA specs. Since I plan to continue with our club, I'm trying to figure out where they fit. One is an E36 M3 the other is an E36 325i with M3 drive train. They are both (claimed to be) legal in BMW CCA classes and NASA classes. The best I can tell they only fit in SCCA ITE (ITO in the SEDiv).

The only reason it came up is that one owner has offered to trade me for my DSR and that got me looking at BMWs.

Any opinions?

Thanks.

[JeffYoung]

I beleive that is correct -- ITO only for the E36 M3 and the 325 with the replaced drivetrain.

[JoshS]

After poking around a while 2 BMWs out there look really good, but they are built to NASA specs. Since I plan to continue with our club, I'm trying to figure out where they fit. One is an E36 M3 the other is an E36 325i with M3 drive train. They are both (claimed to be) legal in BMW CCA classes and NASA classes. The best I can tell they only fit in SCCA ITE (ITO in the SEDiv).

The only reason it came up is that one owner has offered to trade me for my DSR and that got me looking at BMWs.

Any opinions?

Thanks.
The M3 engine has no good place to play in the SCCA.

I can personally vouch for this car: http://www.improvedtouring.com/forums/showthread.php?t=24148

It's an ITS/ITR E36 that is very very quick. It's out here in the San Francisco area but if you want a well-built and very quick BMW, I'd highly recommend it.

[M5rokit]

I'm looking at a 1999 ITR Z3 to buy but don't know much about them short of the rear end is not the best. Can you comment on your experiences with your Z3?

[JeffYoung]

It's not terrible -- it is the same as off of an E30 M3. It's independent but with semi-trailing arms. Not a-arm but still good. I have also driven a Z3 2.8 in the VIR 13 hr (ITR car) and if anything, the issue was a push, not a problem with the rear end.

If the Z3 is even slightly lower weight than the 325/328, it may be a decent platform since the brakes are awesome and the aero maybe a bit better. Certainly, the CG is probably lower.

[JoshS]

I sent you an e-mail ... assuming that the Z3 you are looking at is the one I think it is, I know both cars you are considering. E-mail back and I'll tell you what I know.

The rear suspension in the Z3 is pretty lousy for the track in stock trim, but the only thing it needs to turn into a fantastic handler is good stiff rear subframe bushings, and good springs and shocks. It becomes a totally different car. I'll tell you that my Z3 Coupe is easily the most fun race car I've ever had, and I've had more than a couple ...

[Z3_GoCar]

Some of the problems with the trailing arms are that they're not adjustable, which leads to more problems if they are made so, and there's not any good options for replacing the stock rubber arm bushings. The adjustment problem is inherate to all trailing arm cars, what I've learned is that by putting an adjustment kit on the rear, I now also change the roll center, because I'm moving the axis of the arms piviot points. Now if the objetive is to have a car that turns better in one direction than the other in a nearly unpredictable manner, then this is fine, but we need to turn both direction equally well and to have this be affected by the alignment in a new and different way is not a good thing. As for the bushing issue, you'd think that we could just replace them with the common urethan, or even delrin, but because the axis of the arms aren't lined up, the bushings have to be complient enough to allow multi-axial movement. The urethan bushings that I had installed, are made with two sleves in each bushing, so that when the piviot bolt is tightened down the tab that's welded on the subfame bends in causing binding aginst the bushing. As for the handeling, Jeff I don't think you guys had enough rake in the car, because mine's always been loose under braking, power off, or when the wrong bump unloads the rear and causes the toe to dynamically go out. This is easy enough to control in low and mid speed corners, but around triple digit speed corners, it's begging for a spin. I suspect that because of the speed dependant nature of my problem, there's some aerodynamic issues too. I'm still working on this though, both top and bottom.

James

[JoshS]

The some of the problems with the trailing arms are that they're not adjustable, which leads to more problems if they are made so, and there's not any good options for replacing the stock rubber arm bushings. The adjustment problem is inherate to all trailing arm cars, what I've learned is that by putting an adjustment kit on the rear, I now also change the roll center, because I'm moving the axis of the arms piviot points. Now if the objetive is to have a car that turns better in one direction than the other in a nearly unpredictable manner, then this is fine, but we need to turn both direction equally well and to have this be affected by the alignment in a new and different way is not a good thing. As for the busing issue, you'd think that we could just replace them with the common urethan, or even delrin, but because the axis of the arms aren't lined up, the bushings have to be complient enough to multi-axial movement. The urethan bushings that I had installed, are made with two sleves in each bushing, so that when the piviot bolt is tightened down the tab that's welded on the subfame bends in causing binding aginst the bushing. As for the handeling, Jeff I don't think you guys had enough rake in the car, because mine's always been loose under braking, power off, or when the wrong bump unloads the rear and causes the toe to dynamically go out. This is easy enough to control in low and mid speed corners, but around triple digit speed corners, it's begging for a spin. I suspect that because of the speed dependant nature of my problem, there's some aerodynamic issues too. I'm still working on this though, both top and bottom.

James
James, you need to come up here and drive my car. All Z3s are not pathological like yours. Mine is not loose, it's got tons of grip, and it's super easy to drive fast.

I don't know why you say that someone else's Z3 doesn't have enough rake, because theirs is stable and yours is too loose to drive fast. Maybe that means the one with the rake set wrong is yours?

[gpbmw]

I have a Bimmerworld build E36 for sale (presently unlisted) in the Atlanta area. Contact me if you have an interest.

G. Potts
404-791-6444

[Z3_GoCar]

James, you need to come up here and drive my car. All Z3s are not pathological like yours. Mine is not loose, it's got tons of grip, and it's super easy to drive fast.

I don't know why you say that someone else's Z3 doesn't have enough rake, because theirs is stable and yours is too loose to drive fast. Maybe that means the one with the rake set wrong is yours?

Josh,

I'll admit that maybe my rake might be too much, but I suspect it's not the rake but toe-out in the rear that's caused my problem. As you know mine isn't the only pathologial roadster out there.

Tom Bell told me that he had static toe-out on the rear. Unfortunetly, toe and camber are fixed unless one installs adjustors. Also the Z3 isn't a true power car, it's sort of in the middle of momentum and power. So, one area to conserve power to the rear wheels is not having too much toe in, like maybe 1/16". However, when the rear is unloaded, like after an upshift, the toe dynamically goes positive.

Tom also has the JP allowed rear wing to help keep the rear planted. This kills any lifting going on at the rear and keeps the the toe in, as lift at the rear causes toe out. Thus, the rake is an aerodynamic band-aid for down-force, that's there to keep the toe-in and not out. Note, I'm not asking for an allowance for rear wings, I plan on addressing this within the current rules.

I didn't say anything about the low and mid speed corners. This is strictly a high speed problem, which leads me to think it's probably aero in nature.

James

ps. Tom did warn me, same as I warn any other potential Z racers, before I pulled the trigger and sent TC the money. Oh, and in spite of my experiences, bad things happen when sliding sideways a 100+mph and I've done this sliding several times, I still enjoy racing the Z roady as it's not a cookie cutter race car. So thank you again for letting me know about it.

[mlytle]

Josh,

I'll admit that maybe my rake might be too much, but I suspect it's not the rake but toe-out in the rear that's caused my problem. As you know mine isn't the only pathologial roadster out there.

Tom Bell told me that he had static toe-out on the rear. Unfortunetly, toe and camber are fixed unless one installs adjustors. Also the Z3 isn't a true power car, it's sort of in the middle of momentum and power. So, one area to conserve power to the rear wheels is not having too much toe in, like maybe 1/16". However, when the rear is unloaded, like after an upshift, the toe dynamically goes positive.

Tom also has the JP allowed rear wing to help keep the rear planted. This kills any lifting going on at the rear and keeps the the toe in, as lift at the rear causes toe out. Thus, the rake is an aerodynamic band-aid for down-force, that's there to keep the toe-in and not out. Note, I'm not asking for an allowance for rear wings, I plan on addressing this within the current rules.

I didn't say anything about the low and mid speed corners. This is strictly a high speed problem, which leads me to think it's probably aero in nature.

James

ps. Tom did warn me, same as I warn any other potential Z racers, before I pulled the trigger and sent TC the money. Oh, and in spite of my experiences, bad things happen when sliding sideways a 100+mph and I've done this sliding several times, I still enjoy racing the Z roady as it's not a cookie cutter race car. So thank you again for letting me know about it.


i must be missing something here. the z3 has the exact same rear suspension as every e30 on the road, including the e30 M3 (the best handling car of it's time and beyond). why is the z3 depicted as such a horrible car? there are ton's of fast and successfull e30 race cars, with no wings. i owned and raced one for years. making an e30/z3 handle well is not a new form of rocket science....it has been done..a lot.

[Z3_GoCar]

Hey Marshall,

I'm not sure what exactly the differences are, except that the suspension arms are unique to the Z3. The fact remains that the Z3 roadster can be a handfull in high speed corners.

James

[JeffYoung]

We had the opposite problem. Great high speed stability, but pushed the nose in slower speed stuff. Not my car and don't know a lot about it, but it was fast and stable and a lot of fun to drive.

[Z3_GoCar]

We had the opposite problem. Great high speed stability, but pushed the nose in slower speed stuff. Not my car and don't know a lot about it, but it was fast and stable and a lot of fun to drive.

Jeff,

Did you check out my vid I posted on the rebuild thread? Notice how little steering input I need in all the cornes except for the slow Buttonhook? From the counter-clockwise direction the buttonhook is a decending decreasing radius turn with a little banking. With the original sway's I'd consistently lift the inside tire, and I expect it was still lifting with the stiffer bars too. Truely, it did handle like a kart. Except for the habbit of having the rear want to pass the front in some of the faster stuff I really enjoyed it.

James

[JeffYoung]

James, I did see that. All I can say is that Rick Thompson's car handled nothing like that. Yours sure did look twitchy.

Maybe email or pm Rick? I'd say he's closing in on having that car dialed in and may be able to help you.