engine and drivetrain 215Mm Vs. 228Mm Vs. Alum. Flywheel

[Sneeb]

I have read a lot of posts but still not certain what would be the best option for a daily driven 02 w/ Ireland 9.5:1 e21 pistons, 292 cam, a little bit of head work, 38/38 carb, stahl header, Ireland ss exhaust, and a 3.91 limited slip diff.

I am halfway done with the 5 speed conversion and was about to send the 228 flywheel to be lightened a bit when I read a bunch of different posts stating pros and cons of each.

It got me wondering what would actually be the best option for my setup, as a lot of the posts didn't mention to what extent their engines were built. I don't mind losing a bit of drivability (i drive it like the go kart it is) but I don't wanna have to drop the clutch at 3k to make it roll a bit in wonderful so cal. traffic.

Thanks.

[Tommy]

Do as you planned. It fits well into your setup.

 

  Tommy

[M3M3]

+1.  continue with plans.

[FB73tii]

Since I started with tii's I have always used a 228mm flywheel. When I upped the HP and began doing more track events I started using an E30 M3 sport pressure plate along with a solid-center racing clutch disk. Both sourced from IE, works great, but not street-driven. I don't think the E30 M3 pressure plate comes in a 215mm variety, so keeping the 228 setup (as mentioned above) makes sense and gives you an upgrade path.

 

I am now using a JBR 228mm aluminum flywheel with the M3 pressure plate in the '69. Very nice combo.If you can afford it go ahead, but not necessary and depends on how much you are being charged to lighten the stock flywheel.

 

My next upgrade (for the '74) is to a 140mm twin-plate setup. Just got it from VAC, the entire billet steel flywheel and Tilton clutch assembly weighs 11 lbs, far less than the 31 lb of the stock flywheel and clutch package. The new mass moment of inertia is even less than the weight drop suggests, as the mass is more concentrated toward the center. That was my Xmas present to my car

Edited January 5, 2014 by FB73tii

[Mike Self]

Yep...agree with above.  If you wish, lighten the original 228mm flywheel; cheaper than an aluminum flywheel.  Have your shop take the metal off the edges--my shop did it in "bites" around the edge between pressure plate bolt holes.  Metal removed from the edges counts for more than towards the center due to centrifugal force.

 

I wouldn't go to the smaller flywheel--experience has shown that the larger clutch lasts about twice as long as the smaller one.  Note that the factory continued to fit the 228mm flywheel to the tii in 1974 after going to the smaller 215mm flywheel to the carbureted cars.  That was for a reason.

 

mike

[Mike Self]

Yep...agree with above.  If you wish, lighten the original 228mm flywheel; cheaper than an aluminum flywheel.  Have your shop take the metal off the edges--my shop did it in "bites" around the edge between pressure plate bolt holes.  Metal removed from the edges counts for more than towards the center due to centrifugal force.

 

I wouldn't go to the smaller flywheel--experience has shown that the larger clutch lasts about twice as long as the smaller one.  Note that the factory continued to fit the 228mm flywheel to the tii in 1974 after going to the smaller 215mm flywheel to the carbureted cars.  That was for a reason.

 

mike

[Sneeb]

Nice, makes it easier then as I already have the parts. As far as a stock or sport (not race) pressure plate/clutch setup, which would be better suited for this application?

I'm thinking the stock Sachs 228 clutch kit is sufficient, but it also got me wondering if a step up in the clutch/pp combo would benefit me/car in any big noticeable way-or if it would just be overkill in a sense.

[M3M3]

stock clutch is fine.  your setup is not stressing it in any way.

[TobyB]

Yep.

 

t

[Sneeb]

Excellent, thank you gentlemen. Till my next question...