M3 Driveshaft Upgrade/// Anything Better???

[kenika65]

Is the M3 Driveshaft the best upgrade for the M20 driveshaft?

Time for a new driveshaft so wondering what is best to buy and where to find it!

The drive shaft will be going in my 86 325es, the transmission in the 86 is from a 89 325i

[matt]

Well, considering it won't fit, it's not a very good upgrade.

[jlevie]

The driveshaft is somewhat over built for a stock M20B27 enigne. So there's no need for an "upgraded" unit. A new or reman driveshaft will serve you up for the next 100-150k.

[kenika65]

Thanks for your reply's...

Im looking for a better drive shaft that is lighter and stronger or just stronger I figure if I am going to buy something might as well upgrade to something better!!!!

I thought it would bolt up hum!?

My 2.7 has all 89 325i 1.3 motronic parts except the i head so the 2.7 see's 6800rpms often and the rest of the es is not stock by any means...

[SpecM]

-e30 m3's have a totaly different tranny, so no the driveshaft wouldn't even fit. And I'm not so sure it's even all that much stronger.

-And your 2.7 has, what, like 140 hp?

[JGood]

There is no upgrade unless you go custom and spend who knows how much. A used, known good driveshaft with a new CSB and guibo will last a very long time. I've never heard of anyone damage a drive shaft with less then 300hp anyway, the axles usually break first from what I understand.

What makes you say it's "time for a new drive shaft"? Do you have a vibration? Have you looked at the CSB or guibo?

If you must "upgrade" something, I would get the bigger output flange from a later eta, the bigger guibo, and a matching driveshaft/CSB.

[Garageaholic]

I have the stock E30 driveshaft in my 335i turbo and it holds 300rwhp easily w/ no vibration. Honestly, no need to upgrade driveshafts....

[kenika65]

There is no upgrade unless you go custom and spend who knows how much. A used, known good driveshaft with a new CSB and guibo will last a very long time. I've never heard of anyone damage a drive shaft with less then 300hp anyway, the axles usually break first from what I understand.

What makes you say it's "time for a new drive shaft"? Do you have a vibration? Have you looked at the CSB or guibo?

If you must "upgrade" something, I would get the bigger output flange from a later eta, the bigger guibo, and a matching driveshaft/CSB.

Good news! thanks for the help everyone...

I have new CSB, Vibration damper and Guibo from bavauto. I have both 1986es, 1989i drive shaft and transmissions...

I am running motronic 1.3 so I can use either transmission.

Now I have noticed that I can not use the i drive shaft yolk in the e transmission for the flange is different and vise versa.

Does the 86es have the bigger output flange? (well after reading I guess not because the guibo is the same size as the 89i... hum so I should find a 84,85 driveshaft!!! then make it new..idk)))

If so im thinking about putting the 89i transmission in because of the updated shifter and putting the 86es (larger output shaft???) in the 89i transmission, which i would still have to use the 86es drive shaft which needs new u-joints hummmmm....

[SpecM]

to use the 86es drive shaft which needs new u-joints hummmmm....

-Can't replace e30 u-joints. Sorry.

[MR 325]

A stock driveshaft is fine.

[kenika65]

-Can't replace e30 u-joints. Sorry.

Can't I drill them out and cut a grove for C clips so that I can use replaceable u-joints???

Also where is a good place to buy ready to go drive-shafts???

[NC325iC]

get a driveshaft that was made for your car

[JGood]

You can put new u-joints in, I think BMP still stocks them.

I just don't understand your desire to do this. I'm not trying to tell you where to spend your money, but you could spend a lot on modifying the stock setup, and the only thing you are doing is increasing the likeliness of failure.

Guys running 11's and 12's with turbo M20's use stock driveshafts.

You start modifying the u-joints or whatever, and you are taking a bulletproof stock unit and throwing in the possibility of aftermarket part failure.

[JGood]

Also where is a good place to buy ready to go drive-shafts???

Bavauto, BMA, BMP, etc.. Probably $400+

Or used, for around $75, from a reputable member parting a car that claims it has no rough spots. That will likely last longer then your car.

[DSP74]

I wish the trans had a slip yoke so we could dump the guibo and swap in a much lighter one piece aluminum shaft