lighting flywheel

How much weight can I reduce the stock flywheel (sr20de)I now (the sock one)is something 18-9 lb if Im wrong please corrected me ,thanks

Originally posted by jprimera
How much weight can I reduce the stock flywheel (sr20de)I now (the sock one)is something 18-9 lb if Im wrong please corrected me ,thanks


The stock flywheel indeed weighs around 18 lbs.

It's possible to take about 4 lbs out of the stock flywheel safely. I've had this done in the past, however I now own aluminum flywheels for both of my SR20 powered cars.

I liked the results of the lightened flywheel. It adds a little throttle response and revs a little quicker. If you are replacing a clutch, it's a worthwhile mod to make.

THANKS GEORGE ,SO CAN I HOPE TO GET SOMETHING LIKE 2-3 HP?

Originally posted by jprimera
THANKS GEORGE ,SO CAN I HOPE TO GET SOMETHING LIKE 2-3 HP?

Honestly, I have no idea. I think it's worth it though if you are already replacing the clutch.

THANKS GEORGE ,SO CAN I HOPE TO GET SOMETHING LIKE 2-3 HP? Lightened flywheels do not increase hp as such. What they do is reduce rotational inertia so that some of the horsepower that was used in accelerating the flywheel rpm is freed up for linear (vehicle)acceleration. The clutches in F1 cars are only the size of a fist for the same reason. Your car will accelerate faster with a lightened flywheel but it won't develop/show any more power on a dyno.
I've read somewhere that 1 pound off the flywheel is like 15 pounds off the car in terms of acceleration.
Downside of lightened flywheels is that with reduced rotational or angular inertia, more revving and clutching may be required to get the vehicle moving from a standstill.
Check out this link: for more info: http://www.se-r.net/engine/light_flywheels.html

Thanks again (George-t4 primera)so I can say that its free hp ,I will do it soon Y will post the results ,and George ,it is no problem to take it out(4lb)1.6kilos from my enginne so I do it safe?thanks

Originally posted by T4 Primera
Lightened flywheels do not increase hp as such. What they do is reduce rotational inertia so that some of the horsepower that was used in accelerating the flywheel rpm is freed up for linear (vehicle)acceleration.

Most correct. On a inertial dyno like a Dynojet (popular here in The States), you will indeed read more hp, but it's not real. As you pointed out, the car will accelerate quicker though.

Originally posted by T4 Primera
Downside of lightened flywheels is that with reduced rotational or angular inertia, more revving and clutching may be required to get the vehicle moving from a standstill.

Also most correct. There are some folks who believe one shouldn't use a low mass flywheel for drag racing. That's goofy as far as I'm concerned. It just makes the launch trickier. You can create the same momentum at the flywheel by adding revs, but the rpm window for a good launch is narrower.

In real world driving I've found no downsides to the low mass flywheel. Then again, the JWT clutch is not an extremely agressive clutch. With an agressive clutch it can take some getting used to. With the JWT clutch, my wife didn't even notice the difference (other than the lighter effort) and the P10 is her car. :D

so George can I run safe without to have any problems with my clunch,taking off 4lb of my flywheel?,in advance thanks.

Originally posted by jprimera
so George can I run safe without to have any problems with my clunch,taking off 4lb of my flywheel?,in advance thanks.

Yes, of course. The cut at the back of the flywheel should be tapered. A good race shop should know what to do.

somebody have a diagram outlining where weight can be taken off ?

Originally posted by jprimera
somebody have a diagram outlining where weight can be taken off ?

:D

http://www.geocities.com/MotorCity/Show/6894/fly.html

You are the man George :cyclops: