Low end torque/HP loss with lightweight Fidanza (non-OE)flywheel?
10-08-2011, 02:05 PM
#1
Low end torque/HP loss with lightweight Fidanza (non-OE)flywheel?
I've finally upgraded my torque. Got a Fidanza flywheel and Exedy OE clutch for my 5.5. The pedal feel, off the bat, is basically broken in. I like it. The thing is, I'm not getting the same launch as before. Reving higher and still launching lighter. My upper end TQ/HP are all there, more than ever, but low end just isn't cutting it. Everything is correct. Similar experiences with lightweight flywheels after OE, or what? Again, great upper end.
10-08-2011, 02:51 PM
#3
No way, I never had that problem with my Fidanza flywheel and Spec clutch. Honestly an aftermarket flywheel is much lighter than stock so your engine can spin more freely and not have to waste as much energy turning the stock heavier flywheel. You really should be feeling more response from your engine across all rpms. I think you just not used to the mod, give it some time.
10-08-2011, 02:56 PM
#4
This makes no sense to me can you try and re-explain before I make comment.
10-08-2011, 03:16 PM
#5
How many miles have you put on the new clutch? Is it properly broken in? You're supposed to baby the clutch for 500 miles.
It sounds to me basically that your clutch isn't gripping tight enough. There should be no reason that you lose anything because you have less rotational mass. At least it doesn't make sense to me.
Did you take sandpaper and roughen the fidanza surface up? Also how come you went with the OE clutch? I think it's possible that it might have less clamping force than the OEM. I personally run a Exedy stage 1 and it feels super stock like. I'll probably get a stage 2 or act one once this one dies on me.
It sounds to me basically that your clutch isn't gripping tight enough. There should be no reason that you lose anything because you have less rotational mass. At least it doesn't make sense to me.
Did you take sandpaper and roughen the fidanza surface up? Also how come you went with the OE clutch? I think it's possible that it might have less clamping force than the OEM. I personally run a Exedy stage 1 and it feels super stock like. I'll probably get a stage 2 or act one once this one dies on me.
10-08-2011, 05:44 PM
#8
I'm at work, now, so I can't give answers to all of your questions, but, basically, I have to rev around 2000 to get going without stalling out, and when I get on the pedal I'm not launching like I did with OE everything. Once I get going, I feel tons of pull with grip. It's just blowing my mind. I'll answer questions later.
10-08-2011, 06:12 PM
#9
Yeah you will lose some low end. Essentially, the OE has more mass to get going and will have kinetic energy or whatever to keep it going which translates to more torque. The lightweight flywheel takes lesser energy for the same concept - it will speed and slow down quicker
10-08-2011, 06:14 PM
#10
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I'm at work, now, so I can't give answers to all of your questions, but, basically, I have to rev around 2000 to get going without stalling out, and when I get on the pedal I'm not launching like I did with OE everything. Once I get going, I feel tons of pull with grip. It's just blowing my mind. I'll answer questions later.
10-08-2011, 10:30 PM
#12
I think I see where you are going with this. It's possible with a lighter flywheel, you have less of what's called moment of inertia. I haven't driven a Maxima with a lightweight flywheel, but I have driven a few Porsche's with them with aftermarket clutches. I did notice that you have to give it a little extra gas upon engaging the clutch from a dead stop, but that was about it.
But I don't have to REV mine that high to get the car going. Let it break in with about 500 miles or so, BUT I don't know if that OEM replacement clutch has something to do with it either. Mine was really chattery and I stalled it out a few times during the break in period.....but as if broke in it got smoother and smoother to engage. Just give it some time.
10-09-2011, 07:05 AM
#14
My (half-azz) understanding is that the flywheel retains rotational energy so that your engine doesn't drop off right away between gears. If the rotational mass is decreased (lightweight flywheel), then you're transferring the delta between the two (OEM vs. Lightweight) back to the drivetrain. Shifting becomes more tricky to do, but that's why you usually upgrade the clutch at the same time.
Fair assessment? If so, it seems contrary to expectations that low-end power wasn't noticeably improved.
Fair assessment? If so, it seems contrary to expectations that low-end power wasn't noticeably improved.
10-09-2011, 07:35 AM
#15
10-09-2011, 01:12 PM
#16
the inertia carried by the heavier flywheel is greater than that of the lighter flywheel. In a practical example, you can notice the difference during a launch. You will not need to rev as high to launch with a heavier flywheel. Also The rotating mass of the heavier one is harder to stop than that of the lighter one.
if you have a heavy flywheel, you don't need as much precision or gas pedal application to start moving. The only problem is that all your power from your engine has to go through the flywheel- so you have to "fill" the flywheel up before you start changing speeds. Lighter flywheel = faster response, but harder to drive. Heavier flywheel = slower response, but easier to drive.
10-11-2011, 12:38 PM
#17
Totally common with a lightweight flywheel to notice a low end torque loss, especially from a dead stop, which is why I am often baffled with why anyone would want one for a street driven vehicle.
10-11-2011, 05:50 PM
#19
^WHAAAT??
That shouldn't happen bro, sounds like your clutch is sticking a bit, the idle is way too high or something else weird is going down. If you're on level ground it shouldn't matter how slow you let that clutch out, you should need to raise the RPMs.
That shouldn't happen bro, sounds like your clutch is sticking a bit, the idle is way too high or something else weird is going down. If you're on level ground it shouldn't matter how slow you let that clutch out, you should need to raise the RPMs.
10-12-2011, 08:49 AM
#20
01-23-2016, 04:40 PM
#22
You haven't actually lost any torque. It just feels that way. Imagine swinging a heavy mallet vs swinging a light hammer. The Mallet takes more energy to swing but delivers a lot of energy when it hits. The lighter hammer swings faster and easier but doesn't hit as hard. Which ever one you pick up, your arm is just as strong. If you're hammering a big spike, you need the mallet to deliver as much force as possible. If you're driving a regular nail, the hammer is enough without wasting energy swinging the mallet.
The good news is that we don't need a mallet to get our cars going. You just have to adjust the technique. Use a slightly higher RPM (more swings of the hammer) when launching AND more gas when the friction starts. Whichever flywheel you have, these cars have more than enough torque to break the tires loose. You just have to relearn the technique. Once the clutch is fully engaged, ALL the weight of the flywheel is parasitic.
A heavy flywheel is needed when a car has gobs of traction and can be launched really hard. Think RWD drag cars with slicks.
Another reason for a heavy, dual mass, flywheel like in the 3.5 cars, is that it makes the car very easy to drive. The extra weight and the sprung friction surface work to absorb any mistakes the driver makes and smooth everything out. Just about anyone can get in and drive it smoothly. Swapping to a light flywheel opens up performance but requires tighter technique. It's a classic trade off. Performance vs ease of use and comfort.
Remember that the 3.0 cars have light flywheels from the factory AND less actual torque. They drive just fine.
The good news is that we don't need a mallet to get our cars going. You just have to adjust the technique. Use a slightly higher RPM (more swings of the hammer) when launching AND more gas when the friction starts. Whichever flywheel you have, these cars have more than enough torque to break the tires loose. You just have to relearn the technique. Once the clutch is fully engaged, ALL the weight of the flywheel is parasitic.
A heavy flywheel is needed when a car has gobs of traction and can be launched really hard. Think RWD drag cars with slicks.
Another reason for a heavy, dual mass, flywheel like in the 3.5 cars, is that it makes the car very easy to drive. The extra weight and the sprung friction surface work to absorb any mistakes the driver makes and smooth everything out. Just about anyone can get in and drive it smoothly. Swapping to a light flywheel opens up performance but requires tighter technique. It's a classic trade off. Performance vs ease of use and comfort.
Remember that the 3.0 cars have light flywheels from the factory AND less actual torque. They drive just fine.
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