hi,
I have searched some threads but i couldnt find an exact answer. I am putting a JDM H22 in my Si so thought mightaswell change the clutch and while im at that put a new flywheel.
What my question is does changing the flywheel give more horse power at wheel ?
How much increase for that Investment ?
Im looking at a 8lb (3.6Kg) FIDANZA Flywheel. I dont want to loose any power or low end accelration or anything...so is changing the flywheel for my needs ? I dont take car to track....just the odd street drag and all...
thanks

 

Some info here

Phil

 

that is a good thread right thurre

 

no hp is gained but u might loose some TQ cuz of the light weight but you rev faster

 

what /\ said !

 

Holy crap guys, this has been discussed for waaay too long. Search for some threads on this or ask one of the HT veterans..

The deal is this: you don't lose or gain ANYTHING when you put a lightweight flywheel on. Dyno's have confirmed this. Think about it - is engine output changed at all when you slap a light flywheel on? No, the engine still has the same power characteristics, flow characteristics, camshafts, bolt-ons, etc. NOTHING changes in that department.

The effect that does occur is a slight lowering of acceleration time. This is not science, but some estimate the decrease to be similar to this formula -

For each pound the flywheel is lighter than stock * 10 = # lbs lighter your car will feel

Less power is required to spin the flywheel up to speed, therefore RPM's will raise more quickly and lower more quickly. In summary, the mod gives you the effect of weight reduction, not power increase.

Now for benefit - DO IT. I put the Fidanza in my DA with light mods a few weeks ago and I think it's probably one of the best mods for the money. The car feels a lot quicker and shifting quickly is easier and less jerky. The car feels much faster before than before, however I'll put this on you again: I nor anyone will find the power increase on a dyno.

And to answer the other statement directly - NO torque is lost either, however some say it takes more gas and more clutch slipping to make a smooth start. This might feel like a loss of torque, but it's merely less kinetic energy transferring to the transmission and wheels when you're starting off the line (8 lbs spinning at 1,000 RPM vs. 18 lbs spinning at 1,000 RPM). Once the clutch and wheels hook up, you won't notice a loss in anything because the the engine will be spinning less weight and will spin easier.