Pros & Cons - E30 325i Flywheel swap into E30 318is

[mjc85]

Could someone please fill me in on the cons and pros of this swap as i am considering doing it but have only heard the pros but no cons.

Thanks
Mitch

[Rob]

cons- you have to drop the tranny. if you suck at driving, you might stall a little bit more, maybe a little bit more noise from the tranny.

[mjc85]

What so no one else has done this swap ?

[mjc85]

*bump* :?

[JHZR2]

sorry to sound dumb but could you please fill me in on the pros that youve heard regarding doing this? Would you just use a 325 flywheel, or would you have to use a 325 clutch disc as well?

As far as I know, the reason why the 318 had the dual mass flywheel was to enable smoother engagement of the clutch, I guess because the 318 doesnt have quite as much torque, so the extra mass kept it from stalling as easily, thus providing a good classic BMW transmission feel. I guess if you change it to a lighter flywheel, you run the risk of having a bit more of a clunk and a rough engagement as you let the clutch out. Its more on/off than with the dual mass, where you can let the clutch out reallly slow without stalling.

If you can drive with it ok, then youre set. If it is too harsh, you run the risk oif ruining your drivetrain and your mounts, IMO. Of course the engine will spool up a little bit faster.

This is a mod that is serious enough and has enough consequences from making a bad choice that it may warrant trying to drive another's car who has the light flywheel in the m42.

JMH

[BimmerToad]

sorry to sound dumb but could you please fill me in on the pros that youve heard regarding doing this? Would you just use a 325 flywheel, or would you have to use a 325 clutch disc as well?

As far as I know, the reason why the 318 had the dual mass flywheel was to enable smoother engagement of the clutch, I guess because the 318 doesnt have quite as much torque, so the extra mass kept it from stalling as easily, thus providing a good classic BMW transmission feel. I guess if you change it to a lighter flywheel, you run the risk of having a bit more of a clunk and a rough engagement as you let the clutch out. Its more on/off than with the dual mass, where you can let the clutch out reallly slow without stalling.

If you can drive with it ok, then youre set. If it is too harsh, you run the risk oif ruining your drivetrain and your mounts, IMO. Of course the engine will spool up a little bit faster.

This is a mod that is serious enough and has enough consequences from making a bad choice that it may warrant trying to drive another's car who has the light flywheel in the m42.

JMH

The mod uses a 325i clutch disc, pressure plate, and flywheel. A lighter flywheel will have no affect on clutch engagement, unless you're replacing a worn out clutch for a new one ;)

A lighter weight flywheel greatly improves throttle response and makes the car more fun to drive. Going from a 28lb to a 9lb in my old '95 318ti was a pretty big difference, but it didn't seem to really help in overall acceleration. It was also VERY buzzy when coasting on the freeway at around 2500-3500rpms in 5th gear. Fortunately the slightest amount of gas quited the noise. I attribute the noise to the fact that my 318ti had a solid clutch disc, and a 4 cylinder engine isn't as harmonically quiet as say a inline 6.

Fortunately, this mod uses a 325i clutch disc which has springs in the disc to absorb driveline vibrations.

[Jon325i]

Going with a lightend flywheel definately enhances the driving experience of your E30. I've had two 325i cars and did a lightend flywheel in both. No horsepower gains to speak of but the throttle response is definately improved.....which is particularly nice when matching revs during heel/toe downshifting. StuMc did a write-up on swapping out the heavy dual-mass wheel for a single mass on the M42. It sounds like a fairly straight forward job to do....no more difficult than changing a clutch. And since everything you need can be sourced up from the BMW parts bin, this is definately a cost-effective upgrade.

Jon

[Mike 91 318ic]

why not use a lightend dual mass fw and compromise... metric mechanic sells them, you can ask them for more info.

M