Lightweight flywheels For NA: Pros and Cons

[TitaniumTT]

Originally Posted by infernosg

What happens to the idle? I never noticed anything on my other car so I guess this is something unique to the rotary? Are we talking "car will randomly stall" idle effect or something like "idle is more erratic"? I suppose nothing bumping up the idle 100 RPM or so wouldn't fix?

Stock FW is what, 27 lbs? The stock ECU, I should mention that this only really relates to a stock edu'ed car, thinks you still have a 27lb flywheel and is thus tuned to rotate that mass. By removing mass you free up a little torque, so now it's taking less power to move that 9.5lb flywheel and the idle hunts around a bit, becomes irradic etc etc.

With a standalone, it's possible to get a perfectly smooth idle, it just takes time. Idle is the most difficult thing to tune. It's such a delicate balance between fuel, timing and BAC duty.

Originally Posted by jtbshaw

I love that pic

Originally Posted by jtbshaw

Again, we are talking the same thing. Didn't mean to turn this into a physics/engineering discussion Phoenix.

Well, don't ever tell an engineer that a lightweight FW adds torque because they'll jump down your throat and say you didn't add anything, you free'd it up. THen you can say, alright motherfucker, here's a stock FW dyno, heres the same car after a lighweight FW. It added torque and hp to the dyno sheets didn't it? Then they say, you dumbass, you free'd it up...... and it goes back and forth all depending on how you interprete it.

[Rotary#10]

Originally Posted by TitaniumTT

Stock FW is what, 27 lbs? The stock ECU, I should mention that this only really relates to a stock edu'ed car, thinks you still have a 27lb flywheel and is thus tuned to rotate that mass. By removing mass you free up a little torque, so now it's taking less power to move that 9.5lb flywheel and the idle hunts around a bit, becomes irradic etc etc.

With a standalone, it's possible to get a perfectly smooth idle, it just takes time. Idle is the most difficult thing to tune. It's such a delicate balance between fuel, timing and BAC duty.



I love that pic



Well, don't ever tell an engineer that a lightweight FW adds torque because they'll jump down your throat and say you didn't add anything, you free'd it up. THen you can say, alright motherfucker, here's a stock FW dyno, heres the same car after a lighweight FW. It added torque and hp to the dyno sheets didn't it? Then they say, you dumbass, you free'd it up...... and it goes back and forth all depending on how you interprete it.

Driving daily my gtus now with a RB 12lb FW and a ACT Street/ Strip clutch. Plus I do have vert wheels. Its fun to drive now, even more so with the flywheel on. I haven't really noticed my idle being erattic.
But thats what I've tell folks it just makes it easier to move what power you already have. For example you jog a block or two with two 40lbs bags of sand on your shoulders. Take the bags off the next block and jog. How do you feel? Lighter of course. Less effort for your engine to spin.
IDK about the gains in actual HP at the FW and at RWHP. That doesn't really concern me right now. I've read a few articles in theory it does. But Dnyo sheets are the evidence and facts of the matter if HP made it to the rear wheels.