I you have results (before and after) please list what type of car, flywheel, and the weight of the flywheel if known.

 

Actually I'm not sure if the flywheel will show up appreciably on the dyno (at least it wont show its true impact).

Dynos are steady state machines, which means that the engine is not accelerating as quickly as it would in real life. Since flywheels help the engines ability to accelerate not produce power then I'm certain that a typical long 4th gear pull would not show a great difference.

I could be wrong however because I have never tested this in real life.

Regards,

 

But the Dynojet measures the acceleration!!! And converts it to TQ and HP.....
The effect of the flywheel depends on the weight of the drums in a Dynojet.


[Modified by EuroITR1689, 3:49 PM 11/1/2001]

 

Yes and No. The Dynojet measures the acceleration of a massive drum, and because it takes time to accelerate this drum you will loose the dynamic improvement the flywheel achieves.

My point is that the improvement in power delivery is going to be far more apparent in 1st and 2nd gear vs the improved power delivery in 4th and 5th.

In other words if you did 1st gear pulls before and after the flywheel installation you might see 10-15 HP gains. Do the same tests in 4th gear and you might only see 2-5 HP gains.

Has the true improvement of the flywheel been illustrated in the 4th gear pull? As it has been said before here dynos can't tell you everything!

Remember that lighter flywheels free up HP when the engine is accelerating, the faster the engine can accelerate the more HP is freed up. In a quasi steady state condition like a 4th gear pull the lower engine acceleration is going to minimize this improvement.

Regards,

 

Baby NSX is correct. With a lw flywheel, your largest gains are in 1st gear and diminish exponentially after.

 

That's because the load is bigger in 4th gear, right (compared to the mass of the flywheel)?
How about the theoretical power output of the engine? Does it increase? Or is a lighter flywheel the same as reducing the weight of the car while keeping the power output of the engine?

 

Ive dyno'd with a stock flywheel and a 7.35 LB flywheel.

No differance shown on the dyno.

 

to be honest, i dont know if im any faster in any gear. it doesnt feel like it, but it revs nice and smooth,and its really easy to hold at any RPM. and now i can shift without the clutch. i always had trouble doing that, but its way easier to find the right rpm with my CM 7.5lb

 

An accelerometer dyno like a dynojet will show a difference. A power absorption dyno like a Mustang will probably not show much difference. So i've heard, anyway...

 

I drove a car wit an ACT clutch and jun flywheel, I stayed in Vtec through 1-2 2-3 and 3-4 shifts. Stock shifter! does this mean, I am an efficiant shifter or that the flywheel was not that light?

~N

 

The flywheel has nothing to do with the gearing of the tranny. What you're talking about is all about gearing. The typeRs stock gear set should allow you to stay in vtec after every shift.

For those that think the revs will drop like a stone with a really light flywheel you are mistaken. There is still plenty of mass in the engine and clutch keeping the assembly spinning while shifting. Does it drop quicker? Yes, but not as fast as some might think. If you can't keep up with the revs during shifting then learn to shift faster! I shift fast enough that even with the lightest flywheel available I am still ahead of the engine when I release the clutch. The lighter flywheel does mean that this effect does not upset the driveline that much and is easier on the car.

Regards,