TheSamba.com :: View topic - Pros & cons on installing lightweight flywheel on '74 su

Mon Oct 14, 2013 9:54 am

Hello! I need to buy a clutch kit, and I see car craft has a kit with a light flywheel inc for $100. I know some advantages of a light flywheel, but are there any disadvantages? Thanks!

Mon Oct 14, 2013 11:27 am

Junkyardjockey wrote: .... are there any disadvantages?
None that I have noticed.

Mon Oct 14, 2013 5:21 pm

OK thank you Bruce!

Mon Oct 14, 2013 6:17 pm

Heavier flywheels make it easier to start the vehicle in motion from a stop, by storing more enertia.

Mon Oct 14, 2013 6:32 pm

Lighter flywheels can affect idle. The heavier the flywheel the more you can turn the idle down.

Mon Oct 14, 2013 6:33 pm

Yea, I heard they give real jerky starts for a daily driver.

Mon Oct 14, 2013 6:51 pm

Does it say what weight the flywheel is?

Unless you live in a totally flat area with no hills leave the original if your engine is stock.

The lighter flywheel lets it rev out quicker so you will get acceleration improvement but it will lose momentum on hills much quicker and when you take your foot off the gas will slow down quicker than normal too.

THey are more suited to modified engines where power loss on hills isn't as noticeable.
I have a 12lb on my 1776 and wouldn't wanna go any lighter than that.

Mon Oct 14, 2013 7:06 pm

Junkyardjockey wrote: a kit with a light flywheel inc for $100.
That cheap means its a cast flywheel. Your stock one is forged and much stronger.

Cheap cast flywheels can come apart.

Mon Oct 14, 2013 8:55 pm

Kiptere wrote: Yea, I heard they give real jerky starts for a daily driver.
Only if you're just learning how to use a clutch.

Mon Oct 14, 2013 9:26 pm

light flywheels drive fine, IF

1) the driver is not a novice
2) the engine is properly tuned

If the car bucks, the driver is unskilled, or the engine tune sucks.

On properly tuned engines with drivers that know what they are doing, light flywheels have no downside and are wonderful.

Mon Jun 29, 2015 8:07 am

updated info here:
A few weeks ago I had my entire rotating assy. balanced, and I added a forged chromoly stock stroke & journal CW crank, and forged chromoly rods. Now to re-ask my original question, should I still stick to a stock weight 8 dowel flywheel for a stock daily driver, or use my new lightened 8 dowel flywheel? Thanks again guys!
Ken
Romans 10:9

Mon Jun 29, 2015 8:10 am

I'd stay STOCK.

Mon Jun 29, 2015 8:25 am

OK thanks Glenn! You helped me make up my mind! Now what flywheel material should I use?

Mon Jun 29, 2015 8:36 am

Just checked CIP1, no stock weight 8 dowel flywheel...still looking....

Mon Jun 29, 2015 8:50 am

wow....only vendor I saw that sells new stock weight 8 dowel flywheels is ACN; is there anyone else? Is a DPR chrome vanadium flywheel ok??

Mon Jun 29, 2015 3:09 pm

Junkyardjockey wrote: .. I added a forged chromoly stock stroke & journal CW crank,
The crank you are using has more rotational inertia than stock due to it's heavier weight. Because of this, I would lighten the flywheel a bit to get the entire rotating mass back down to stock.

Mon Jun 29, 2015 5:32 pm

With a heavier flywheel you won't lose speed as quickly on a grade or a hill as you will with a light flywheel....you can have any competent machine shop drill the extra holes in your stock forged flywheel for a small fee...heavy flywheels are the way to go on the street...light flywheels are primarily for racing...they get old quick...I'm speaking from experience, but not with a VW, but with a small block Chevy...light flywheels are a real pain in stop and go traffic...a heavy flywheel launches a heavy car nicely and is more relaxing to drive overall...my 2 cents is to get the stock flywheel drilled and use that.

Mon Jun 29, 2015 6:02 pm

Busdriver79 wrote: With a heavier flywheel you won't lose speed as quickly on a grade or a hill as you will with a light flywheel....you can have any competent machine shop drill the extra holes in your stock forged flywheel for a small fee...heavy flywheels are the way to go on the street...light flywheels are primarily for racing...they get old quick...I'm speaking from experience, but not with a VW, but with a small block Chevy...light flywheels are a real pain in stop and go traffic...a heavy flywheel launches a heavy car nicely and is more relaxing to drive overall...my 2 cents is to get the stock flywheel drilled and use that.
How about a light flywheel with a heavy crank pulley? Any experience with that?

Mon Jun 29, 2015 8:33 pm

This is seriously funny to me. :D So, JunkYardJockey, have you decided yet or are you sorry you asked?
-Heavier flywheels give better launches from a stop.
-Lighter flywheels rev up quicker.
-With heavier flywheels you won't lose speed as quickly on hills, but you need to reduce the weight of your rotational inertia.
-Lighter flywheels affect idle.
-Glenn, who likes just about everything stock, says go heavy, and he certainly knows his shit.
-Bruce is very knowledgeable as well and says go light.
-Joel says no lighter than 12lbs on a 1776.

](*,)

So basically do whatever the hell you want and don't worry about it.

Wed Jul 01, 2015 10:31 am

I will stick with a 8 dowel stock weight flywheel. I was hoping to get some input regarding my impending use of a counterweighted crank & a stock weight flywheel (being TOO heavy), but that didn't happpen. Do you care to give your opinion about that? Thanks!
Ken
Romans 10:9