Aluminum Flywheels

[kwhauck]

Ok, I need some discussion about aluminum flywheels pro and cons

setup will be getrag 282 mated to fully built 3400, 15-25lbs of boost, 01 oldsmobile alero, weekend fun car, and healthy drag race use, fx400 4 puck clutchmaster clutch

Found some info,

Well the car started out as a road course/scca solo II car for the first three years that I had the engine and flywheel in it, and then I moved over to the drag racing. The company that I got the flywheel from is no longer in business, but the same flywheel is now available from the fiero store (www.thefierostore.com) for about $400. The flywheel that would be used in a TDC set-up would be an 88 fiero V6 application (neutral balanced).

As for total use I have about 15000 miles of primarily racing on the car and the flywheel is fine (i know I just had to change a clutch). The flywheel givith and it takith away. You will see a gain in the acceleration of the engine, and it will be a little bit more free reving, but you will pay a price. First the idle quality will go down (surging and overall a bit rougher than you are used to) and second the ability to get out of the hole well will become significantly more difficult. The loss of rotational mass does not allow for the storing of as much energy as the heavier flywheel and will make the good launch zone a smaller target to hit correctly.

Overall I like the flywheel for what it helps with in my application, but if you use the car for street driving I am not sure that I would sacrifice the drivability for the small gain that would result.

Just something to think of.

thanx
Garth

[kwhauck]

anybody???

[Joseph Upson]

Use the stock 60 degree flywheel. As stated in the thread, driveability will be affected in a daily driver where it's likely to be noticed most. There was big discussion about it on the Fiero forum. If you are starting with a very heavy stock flywheel then loosing some weight isn't a bad idea and may not be accompanied by any real adverse effects at all, but when you're already using a relativly light 12-15 lb flywheel it's probably best left alone for all around performance. You probably wouldn't feel the difference if the weight change isn't significant enough and the performance change in the test I read about wasn't all that impressive and varied at certain points so that the aluminum flywheel didn't win out through the entire acceleration range.

[BMC]

We had a batch of alloy flywheels made for the RWD 60* engines. In my 1982 S10 with the L32 3.4L with full SFI system, I installed an alloy flywheel. No change in idle. When I have a trailer with my car on it (GVW S10 + MGB + Trailer + me + passenger = 6700 lbs) from an uphill start, i have to slip the clutch for Less than 2 seconds longer than with the steel flywheel.

In My MGB with the identical engine, the same results. No adverse effects upon takeoff.

Now the down side is not a slower takeoff because generally speaking, if you pop the clutch at 4,000 RPM in either vehicle, your going to smoke the tires. Nope, you slip the clutch a little around I would guess 2500 RPM as you take off. Not really faster or slower.

Now, when jamming it in to 2nd gear, you can't smash it in and get that little extra help because you didnt let go of the throttle, but that blows your gearbox up anyways. I know!!

It does allow for additional free revving and a little more top end. I know this as well too for both vehicles!

The results were 99% positive. The 1% negative is that the tires dont spin quite as easily but they still squawk in 4th gear in the MGB. The benifits are mostly felt in 2nd and 3rd gear but in 4th, the engine can reach a little higher speed before it no longer can push the weight down the road.

For the ultimate results, the alloy unit is fun but there are other items that you can do to gain power such as cam AND porting that will give similar results. Now that WITH the flywheel- Great!

-BMC.

[no_doz]

ive been successfully talked out of wanting to get one of these flywheels-i figured for a couple hundred bucks-that the gain would be much more...

[BMC]

no_doz, Not a lot of gain for the money, but start to figure out how/where the power will be used and it becomes one more piece to an expensive puzzle. All things to build power cost, but the best way to spend those limited funds are by starting with many other items unless you want simple. Simple and quick replacement is flywheel and other external items, but for the money there are plenty of better items. It was worth it for me but so are all the other improvements that will happen over time. Anywhere I can loose weight AND gain performance is another factor on top of that!

-BMC.

[1988GTU]

Aluminum Flywheels are trash. Too much risk for such little possible gain.