Motor Mount Options?

[Z3_GoCar]

Hey Greg,

Point taken, that's why I'm asking questions before pulling the trigger and buying non-alowed parts. None of these mounts that I'm researching are urethane, they're all solid rubber that remove the silicon gel damping fluid, and are built like stock mounts.

Josh, thanks for finding the part number for the group-N mount. I performend a google search looking for that and wasn't able to come up with anything. The cars a CJ33, build date of 10/96. As for aftermarket sources for parts, how about these mounts:

http://store.bimmerworld.com/shared/...t=products.asp

James

[Greg Amy]

:giles:

[Andy Bettencourt]

I guess I am confused here. ONLY STOCK motor mounts are allowed. That doesn't mean stock in Europe, it doesn't mean 'made by BMW' - it means what came on your car from the factory.

[shwah]

- it means what came on your car from the factory.

when the car was purchased new in the United States, OR a part that the manufacturer now supercedes in place of that one in the United States market.

[Greg Amy]

when the car was purchased new in the United States, OR a part that the manufacturer now supercedes in place of that one in the United States market.

...noting that, "...Documentation of the superseding parts or assemblies must be supplied to the Club Racing Department and the appropriate part numbers listed on that particular model’s specification line."

Both in same paragraph, ITCS 9.1.3.C.

[Z3_GoCar]

...noting that, "...Documentation of the superseding parts or assemblies must be supplied to the Club Racing Department and the appropriate part numbers listed on that particular model’s specification line."

Both in same paragraph, ITCS 9.1.3.C.

9.1.3.C top of page 330 "Stock replacement parts may be obtained from sources other than the manufacturer provided they are the exact equivalent of the original part." So who says whats the "exact equivalent?" For anyone who can go down to NAPA to purchase such parts, do you run a frequency analysis spectrum to make sure the Chinese made part has the same polymer/cure ratio as your old part? Or do you just look at it and say, "Well it generally looks like the stock part, the holes are in the right spot, and it looks like it'll fit." If you were to even perform a simple test like a durometer on the rubber, what kind of value and more importantly what kind of error range would there be, and how does it change over time?

Remember, I'm not talking about orange poly's... I'd think the earlier list and documentation would only apply to the factory parts. On my car I could supply about a dozen or so of those superseeded part numbers, but they're not on the spec line right now.... Then multiply that across all the different cars, and our spec lines will grow much longer. I don't think the ITAC wants to get in the bussiness of part number management, not when you're getting ready to even get rid of the model (vin) numbers you have under your control now. I think the test is, "Does it look stock?" is about as close as we're going to get. Aluminum?? No, Orange/Yellow/Green/Black Poly?? No, These?? you tell me.

James

[Greg Amy]

Hoo-boy...here we go...

[JLawton]

9.1.3.C top of page 330 "Stock replacement parts may be obtained from sources other than the manufacturer provided they are the exact equivalent of the original part." So who says whats the "exact equivalent?" For anyone who can go down to NAPA to purchase such parts, do you run a frequency analysis spectrum to make sure the Chinese made part has the same polymer/cure ratio as your old part? Or do you just look at it and say, "Well it generally looks like the stock part, the holes are in the right spot, and it looks like it'll fit." If you were to even perform a simple test like a durometer on the rubber, what kind of value and more importantly what kind of error range would there be, and how does it change over time?

Remember, I'm not talking about orange poly's... I'd think the earlier list and documentation would only apply to the factory parts. On my car I could supply about a dozen or so of those superseeded part numbers, but they're not on the spec line right now.... Then multiply that across all the different cars, and our spec lines will grow much longer. I don't think the ITAC wants to get in the bussiness of part number management, not when you're getting ready to even get rid of the model (vin) numbers you have under your control now. I think the test is, "Does it look stock?" is about as close as we're going to get. Aluminum?? No, Orange/Yellow/Green/Black Poly?? No, These?? you tell me.

James

However you want to "try" and justify it...........


What do you think is the intent of the rule??

[JoshS]

...noting that, "...Documentation of the superseding parts or assemblies must be supplied to the Club Racing Department and the appropriate part numbers listed on that particular model’s specification line."

Both in same paragraph, ITCS 9.1.3.C.

That's what the rule says, but does anyone else think it's silly?

Let's see -- my car's motor mount is dead. I go to the dealer parts counter and I say, "I need a replacement motor mount for my 1999 BMW Z3". He gives me one which has a newer part number than the dead one (which was original).

Now, I go racing and someone hears that I just replaced my motor mounts and went 2 seconds faster, so I get protested for illegal motor mounts. They pull my motor mounts out of the car and read the part number off the side. They call the local BMW dealer and ask for the part number for a Z3 motor mount, and they get the same number. Pretty sure they are going to rule it legal.

Now, let's go the other way. My competitors misheard me in the paddock. What I really said was, "I'll bet if I replace these old crappy motor mounts with the new ones I just bought, I'll go 2 seconds faster!" So I get protested. They pull out my old, crappy, original motor mounts, and read off the part number. They call the local BMW dealer and ask for the part number for a motor mount. The parts guy reads off the new part number. No match. So the tech guy says, "Okay, then what's a 123456789?" Oh, that's the ORIGINAL part number. It's been superceded." Still legal.

Why do we need line item exceptions? There have been so many superceded parts on all the IT cars that the ITCS would quadruple in size. Not to mention that now, as James pointed out, we can use "stock-equivalent" parts that won't even have BMW part numbers on them.

Does anyone else agree that we should strike the rule Greg quoted?

[dj10]

That's what the rule says, but does anyone else think it's silly?

Let's see -- my car's motor mount is dead. I go to the dealer parts counter and I say, "I need a replacement motor mount for my 1999 BMW Z3". He gives me one which has a newer part number than the dead one (which was original).

Now, I go racing and someone hears that I just replaced my motor mounts and went 2 seconds faster, so I get protested for illegal motor mounts. They pull my motor mounts out of the car and read the part number off the side. They call the local BMW dealer and ask for the part number for a Z3 motor mount, and they get the same number. Pretty sure they are going to rule it legal.

Now, let's go the other way. My competitors misheard me in the paddock. What I really said was, "I'll bet if I replace these old crappy motor mounts with the new ones I just bought, I'll go 2 seconds faster!" So I get protested. They pull out my old, crappy, original motor mounts, and read off the part number. They call the local BMW dealer and ask for the part number for a motor mount. The parts guy reads off the new part number. No match. So the tech guy says, "Okay, then what's a 123456789?" Oh, that's the ORIGINAL part number. It's been superceded." Still legal.

Why do we need line item exceptions? There have been so many superceded parts on all the IT cars that the ITCS would quadruple in size. Not to mention that now, as James pointed out, we can use "stock-equivalent" parts that won't even have BMW part numbers on them.

Does anyone else agree that we should strike the rule Greg quoted?

Hey Josh!
Your making way too much out of this. Is everyone this hyper in silicone valley? Who ever you buy your mounts from, just keep the receipt with the part # on it. I you will get protested for your engine if you go 2 sec's a lap faster, not your engine mounts. Try and relax and go have a drink somewhere. Just don't drink and drive.

[Greg Amy]

Does anyone else agree that we should strike the rule Greg quoted?

The rule was created many moons ago to cover situations - such as the infamous VDub G-grind cam wars - where a lesser-performing part was superceded by the manufacturer with a better design. One can reasonably argue a performance advantage where a car is classified with one camshaft, yet when the cam goes out of production is superceded to one from another model that provides significantly more airflow.

While I highly doubt someone is going to protest a simple suffix change in a part number (it happens constantly, and changes with things as simple as a supplier change) it would be reasonable to protest a significant change in engine mount design. In that case it's the competitors' responsibility to work through the system to get it line-itemed.

There's no other reasonable way to cover it in the rules. Leave it to the competitors to prove reasonable supercession. Create a minor crack in the rules and we'll drive a truck through the resulting loophole. - GA

[Ron Earp]

Point taken, that's why I'm asking questions before pulling the trigger and buying non-alowed parts. None of these mounts that I'm researching are urethane, they're all solid rubber that remove the silicon gel damping fluid, and are built like stock mounts.

If all the stock parts have silicon gel dampening fluid, then your replacements MUST have silicone gel dampening fluid. No way around that. Sort of like that dual mass flywheel BMW (and Porsche) used on a lot of cars - if it is stock you've got to use it, can't replace it with a conventional flywheel.