Does Kennedy offer a lighter than stock flywheel for the 914? If so, is it a beneficial component for the 914 drivetrain? Thanks for any insight. -K-

I'm not using a Kennedy, but I noticed a difference in engine repsonse when I put a lightened flywheel on my 1.8.

I offer them at my store and last time I checked we had the best price of anyone....

BUT I do NOT recomend them if you have a stock engine, or an engine near stock and do a lot of freeway driving or in traffic.

Light flywheels spin down as fast as they spin up, SO the car can become hard to drive very quick if the fly is too light and the engine doesn't make the Torque of a MassIVe engine.

MPG also hurt as on the freewway you are constantly on and off the gas more without the additional rotating mass to keep the engine spinning.

You can definately tell the differences..

Hmmmm, interesting info from Jake!!!!

My D-Jet 2.0 engine is about 115 to 120-hp with a lightened flywheel. I took off about 3-lbs (plus) and added about the same to the counterweighted reground crank. I havn't noticed any driving differences like Jake mentioned. I just know my engine rev's to red line in a heart beat and acceleration is good. About the only thing I notice is coming off low idle the engine needs a little more revs. (then hang on 2nd gear comes fast).

Tom

very interesting info!. again, it's all about application/use. it's not often a parts supplier steers you away from spending more money than you need to.

k

QUOTE (Thomas J Bliznik @ Feb 19 2006, 08:32 AM)

Hmmmm, interesting info from Jake!!!! My D-Jet 2.0 engine is about 115 to 120-hp with a lightened flywheel. I took off about 3-lbs (plus) and added about the same to the counterweighted reground crank. I havn't noticed any driving differences like Jake mentioned. I just know my engine rev's to red line in a heart beat and acceleration is good. About the only thing I notice is coming off low idle the engine needs a little more revs. (then hang on 2nd gear comes fast). Tom

.....reduce rotating mass and then add it back on..... Revs faster........


WHAT!?!?!

I would imagine it's because you go from a big ass rotating disc to a 8 inch rotating crank.

QUOTE (Headrage @ Feb 19 2006, 09:01 AM)

I would imagine it's because you go from a big ass rotating disc to a 8 inch rotating crank.

Exactly....

Same advantage as going to a 5.25" clutch setup

QUOTE (Thomas J Bliznik @ Feb 19 2006, 08:32 AM)

Hmmmm, interesting info from Jake!!!! My D-Jet 2.0 engine is about 115 to 120-hp with a lightened flywheel. I took off about 3-lbs (plus) and added about the same to the counterweighted reground crank. I havn't noticed any driving differences like Jake mentioned. I just know my engine rev's to red line in a heart beat and acceleration is good. About the only thing I notice is coming off low idle the engine needs a little more revs. (then hang on 2nd gear comes fast). Tom

But it doesn't slow down faster?

It has to be a two-way street.

JAKE!!! Have you ever tryed an aluminum flywheel?

I run a lightened flywheel and the very hard to find lightened pressure plate.


KT

QUOTE (alpha434 @ Feb 19 2006, 10:24 AM)

QUOTE (Thomas J Bliznik @ Feb 19 2006, 08:32 AM) Hmmmm, interesting info from Jake!!!! My D-Jet 2.0 engine is about 115 to 120-hp with a lightened flywheel.  I took off about 3-lbs (plus) and added about the same to the counterweighted reground crank.  I havn't noticed any driving differences like Jake mentioned.  I just know my engine rev's to red line in a heart beat and acceleration is good.  About the only thing I notice is coming off low idle the engine needs a little more revs. (then hang on 2nd gear comes fast).   Tom But it doesn't slow down faster? It has to be a two-way street.

yup... look at the center of mass.....

a flywheel is big... and heavy, while a crankshaft is smaller and heavier.....

but its mass is closer to the center... less effect than a big flywheel

I did my motor a number of years ago & I was trying to find small hp. gains with internal modifications. Back then we didn't have guys like Jake to advise. Probably spent the money foolishly, but I am happy with the results & will live with it.

If I were doing my motor today I would call Jake and say here are my driving habits & how much $___??
Doctor Jake Motor Guru what do you suggest

Tom
If I only knew yesterday, what I know today

A 115-120HP is NOT stock, my post was directed toward a stock or only slightly warmed over engine lacking extra torque to overcome the mass differences.

A lightened fly DOES accelerate the revs down just as fast as up, anyone who has driven a car before and after a rotating mass change (with no other changes especiallY) will tell you this.

Its not uncommon for me to steer enthusiasts another way, even though I could monetarily benefit from it- I do it all the time because I want to sell you WHAT YOU NEED, not WHAT YOU MAY WANT! (or THINK YOU WANT!)

Thats where my experience and test work benefit everyone.

Also lighter flywheels will NOT make more HP, they do help with acceleration and getting off corners, but on the dyno you want see any gains... On a stop watch the gains you see are from the added acceleratiuon and the car getting off the corner faster, reulting in a higher trap speed on the straight.

Thanks for all your replies, and nod to Mr. Raby and his expertise in particular. So would I be correct to interpret that my car will be quicker off the line with a lightened flywheel, but I'll have to keep my foot in it for sustained higher speed runs due to the loss of inertial mass and the torque amplifying characteristics thereof? -K-

Also Lightened fly wheels "can" be tough to drive. When I drove Jake's 914 which had a VERY light flywheel with solid 6 puck disc it was different but I am good with light fast cars.

My current flywheel is 13 pounds and my hope to be soon wheels will tip the scale at 15 lbs each with Hoosier slicks @ 15 lbs.
Car @1895lbs should accelerate even better than it does.