what the hell is this vibration

[Den]

Symptom of a worn guibo is a big clunk on shifting.
Not a clunk you hear, but one that you feel.
Of course, if it's so bad that it's missing chunks or something, I s'pose that could cause vibration while cruising.

[Den]

My one friend who owns a BMW Service center said to tighten down the driveshaft to the quibo and the diff, with the center bearing hanging by only a few threads. after you tighten everything else up you tighten the center bearing. Sounded like it made sense to me. that way you dont tighten the center bearing down crooked and then tighten it to the trans.

Sounds like a good tip to me.
Don't forget to preload the CSB by sliding it forward 4-6mm (1/4").

[Den]

Also check your Diff Mounting Bolts and Halfshaft Bolts. I noticed a few minor noises before and clunks getting on and off gas. For some reason the Diff Bolts worked thier way loose. Ive had this problem for a few months now i usually just tighten them back up and then 3-4 weeks later ill do it again.

I dunno what the problem is, but this is not normal. Maybe your diff mount is worn out, and is allowing stuff to vibrate loose. You may not be torquing down the bolts hard enough. I'd put some Loc-Tite on the bolts if they don't stay put.

On the Downpipe/connecting pipe thing for the exhuast. I dont know the technical name. Would cutting those Silencers out be a bad Idea? Leaving the Cat-Back Exhuast on, but I started at about 4:30pm and i dropped the exhuast, which was hot just used some welding gloves but the silencers or whatever they are. Were still rather hot almost 4 hours later when i went to put it back in. Everything else was cool but just that part was still too hot to handle for a few seconds. To me that seems kind of odd, Its shouldnt retain that much heat, I did remove the covering that was over it because it was well falling off so I did away with it. Would Cutting that section out hurt or improve performance in any way? I mean if its clogged up and blocking exhuast it would improve performance too cut it out right? but I do need some back pressure.

Are you talking about the catalytic converter? Cats run at 800-900º, but yeah, I would think that you'd be able to handle it after 4 hours of cooling. Removing it wouldn't remove all the back pressure; you still have a muffler, right? Performance would be improved by removal / replacement of a partially clogged cat, otherwise the stock exhaust system is not a limiting factor on the performance of the M20 motor.

Also If my A/C doesnt blow cold anymore, should I just remove the entire unit? Its heavy and robs some power from what I understand. Ive talked alot about fixing it and I never have. Should I just do away with it. Im really going to concentrate on the small things on my car and try to sort them out.

If it has only been defunct for a short time, you might be able to get away with just a freon charge. If it has been shot and unused for a long time, some seals probably need replacing since stuff in the freon lubricates the seals. In this case you may want to go ahead and do the conversion to use the newer cheaper 134a freon.
OTOH, removing the AC is an easy way to drop some weight from the front end, but it will hurt your resale value. I don't think the AC really uses much power when it's not turned on. If you believe it does when the compressor is not engaged, you could just remove the belt. I think it really depends on whether or not you need / want AC where you live, and whether or not you think you might ever sell the car.

The Chip in my car is pretty old. It was used I got it from TMS and it had an intermittant miss, which 1 week it will be here then its gone for 3 years then all the sudden its back. I dont know much about the performance software stuff. I have an entire ECU sitting around last three Digits are 173, I dont know what they mean but Ive heard thats a decent ECU i guess.... Anyone here know about these things. Id search online but I simply dont have the time.

Missing can be caused by many different fuel + ignition things.
173 ECU is a newer version of Motronic and is considered better than the earlier version. There are ~4 different ECU's but I don't know the #'s offhand.
TMS / JC chip is as good as it gets. Chips are different for old / new ECU's though; so if you changed from an older to a later ECU, you would not be able to swap your TMS chip. You might want to state the year and specific model of your car for some more specific answers.

[Ball325]

well i have an 87' my donor is a 90' i believe its the later e30 model. so its probably not compatible. But Im sure they have better technology for the chips now then they did in the 90's when it was put in the car.

[Den]

. . . But I'm sure they have better technology for the chips now than they did in the 90's when it was put in the car.

Don't be so sure. The actual chip itself is the same as it ever was.
What matters is the program in the chip. I doubt that Jim Conforti, who makes chips for TMS, has made any significant revisions in his M20 software recently. Some folks are saying that Mark D'Sylva is making code as good as or maybe even better than JC's. Mark D might be a good choice if you didn't already have a chip, but I think going from JC to Mark D would probably just be a lateral move. i.e. paying $200 for a different chip when you already have a JC chip would be a waste. . .unless you were doing it as part of the ECU swap, and I still doubt it'd be worth it.

well i have an 87

325e or 325i?

http://www.dsylva-tech.ca/

[Ball325]

I think some time soon im gonna update to another TMS or JC Chip since the one i have was used and has an intermitten miss, which is no fun when the entire car basically shuts off for a second. And the M30 AFM and larger Injectors. Then Ill dyno it and see how it turns out. pretty postive second time around I can break the 160whp mark.

[Den]

http://www.r3vlimited.com/phpBB2/viewtopic.php?p=143409&highlight=#143409

Read, it makes you less dumb!

http://davelength.net/car/bigsix.html

http://davelength.net/car/cai.html :twisted:

If you even ask what size filter you need......I'll fly out there and slap you. Read.

I'm giving you a "D+" on your reading assignment from the other thread.

http://davelength.net/car/bigsix.html

This guy got 145hp at the rear wheels with:
JC chip
M30 AFM
Mustang injectors
Sweet shielded air intake
$200 Adjustable FPR set at 4bar (Stock FPR = 3bar; so you kinda need this if you want to max out this little project.)
Dyno tuning

What makes you think you will see 160hp at the wheels when he only got 145hp?

If you really want to work the AFM + injector angle, you should get a programmable 'chip' like this and tune your stuff on a dyno.

http://www.gstuning.net/xodus_prod_info.asp?id=61