Printable Version of Topic

Posted by: Cheapsnake Nov 26 2008, 08:40 AM

I've changed my plans for a V8 conversion and decided to stay with a hopped up 2.0 instead. I'm considering a lightened flywheel since my impression of these engines is that they're somewhat doggy off idle. The drawback, of course is that standing starts become more of a challenge due to the lack of "flywheel effect".

In a competition environment this isn't much of an issue because hopefully you only have to do it once, but in a driver, especially in city traffic this could be an issue if you have to rev the engine and slip the clutch every time you want to get under way. Anyone got any experience with lightened flywheels in a 2.0 and want to shine some light on the issue?

Tom

Posted by: Root_Werks Nov 26 2008, 08:49 AM

The lighter your flywheel and the bigger displacement your engine is, the rougher it will idle.

Also, if you have a high torque starter and aluminum flywheel be careful. I had a starter knock a couple teeth off the flywheel.

If you don't go too light, thier great for street cars.

Posted by: Bleyseng Nov 26 2008, 09:23 AM

depends on how much lbs is taken off. Mine just revs up faster....

Posted by: Cheapsnake Nov 26 2008, 09:25 AM

Ouch! I've always wondered why, when a flywheel and starter gear clash it's always the difficult change-out flywheel that takes the hit rather than the easy change-out starter. Thanks for the response.

Tom

Posted by: Cheapsnake Nov 26 2008, 09:27 AM

do you have any machining specs?

Posted by: r_towle Nov 26 2008, 09:37 AM

Flywheel lightening is not a black art...its actually pretty straight forward.

Our flywheels are unique in one aspect. The measurement and relationship between the flange that the pressure plate bolts to and the flywheel friction surface needs to remain within specs...

I have seen many super light flywheels with a majority of the material between the pressure plate mounting bolts removed.

You get to light and you need to feather the gas pedal at idle just to keep in running.
11 Lbs is probably the limit of how low I would suggest on a street/autox car.
8-9lbs is on a race car with a race clutch.

I believe the stock flywheel is around 16lbs.

Rich

Posted by: Chris Hamilton Nov 26 2008, 09:41 AM

My flywheel is about 10lbs, and I have a sachs aluminum pressure plate. Pretty nice for street driving.

Posted by: rdauenhauer Nov 26 2008, 10:45 AM

Plug .. http://www.914world.com/bbs2/index.php?showtopic=88677

Posted by: r_towle Nov 26 2008, 11:02 AM

I also have one that I have tried to sell over the years.....and your plug is a shameless plug...but a great price for the poster...go get that one..is cheaper than the machine work to lighten it.

Rich

Posted by: Borderline Nov 26 2008, 11:12 AM

I have a lightened flywheel on my 1911 and it drives great! I highly recommend it!

Posted by: Cheapsnake Nov 26 2008, 11:29 AM

Thanks for the offers guys, but I've got a new multi-purpose machine that I've just got to use on the one I've got. Then, after I totally f**k that one up I'll be in touch.

Tom

Posted by: Mark Henry Nov 26 2008, 12:01 PM

Do not take weight off of the backside of the friction surface.

Posted by: hydroliftin Nov 26 2008, 12:04 PM

Tom,

When I rebuilt my 2.0 I had the machinist lighten the stock flywheel. Not sure how much was taken off, but not extreame. I have not noticed any issues with getting the car moving off the line, but it does rev easier. I would recomend it.

Posted by: Cheapsnake Nov 26 2008, 12:08 PM

Good to know, so everything off the friction surface?

Posted by: CliffBraun Nov 26 2008, 01:24 PM

Don't forget the clutch.... I have the same set up but with a KEP pressure plate and I love it. It rev's so nicely, I have no problem driving it even on my dying tranny.

Posted by: davep Nov 26 2008, 01:24 PM

UH, no. Most is removed from the outer ring. The working surface needs it, and the more mass removed as far from the center as possible is better.

Posted by: Mark Henry Nov 26 2008, 01:58 PM

Do NOT take weight off of the backside of the friction surface.

You run the risk of warpage if you do.

Posted by: Chris Hamilton Nov 26 2008, 02:26 PM

Of if anyone wants to go that route I've got one pre-warped they can buy, save themselves the trouble of mounting it and having to warp it themselves.