engine rotating mass reduction

[austrian type-R]

hi everyone!

I am trying to get my curb weigth down a bit more, but I am at the bottom now to keep the car as daily street driven (1190kg ~ 2620lb with full gas tank and w/o driver).

So I thought to reduce some rotating mass from the engine. I have oem clutch and JUN fly, but the Exedy twin carbon weights in total just 18lbs but produce noise from the flaoting discs when the car is not rolling (have this clutch on my race car and I love it).

Well, now I found that the ATS single carbon clutch only weights 18.5lbs compared to 35.5lbs stock. Thats about just half the weight for the ATS clutchkit. Anyone who has experience with this clutch?

Reducing weight via an aluminium crank pulley is not good for long terms (vibrating)

Other parts like campulleys and pulley from the alternator is also a way to go. To bad those cam sprokets are like 1000usd from comptech. I guess the diff is about 0,5kg per pulley? So this would be also 4 kg ~ 8lb in rotating mass. Worth it? For myself I have to say Yes.

 

[BBVNSX]

...

Reducing weight via an aluminium crank pulley is not good for long terms (vibrating)

Other parts like campulleys and pulley from the alternator is also a way to go. To bad those cam sprokets are like 1000usd from comptech. I guess the diff is about 0,5kg per pulley? So this would be also 4 kg ~ 8lb in rotating mass. Worth it? For myself I have to say Yes.

Can't help with the clutch as mine is OEM...

But i installed the ATI pulley and Comptech campulleys

rotating mass reduction is:

ATI dumper: - 0,79 kg

Comptech campulleys: - 1,71 Kg

you can see it here on my build thread:

http://www.nsxprime.com/forum/showt...tugal!/page2?p=1723994&viewfull=1#post1723994

 

[Mac Attack]

So I thought to reduce some rotating mass from the engine. ...
Worth it? For myself I have to say Yes.

You could also:
1) Go from big, heavy DOHC heads to simpler, lighter SOHC heads.
2) Remove a couple of pistons and corresponding mass on the crankshaft counterweights.
3) Save a few pounds by going with custom cams and eliminating the VTEC lobes/rockers/pins/LMAs.

But, I recommend the switch to a higher-technology, smaller, lighter engine like the K20 series for huge weight savings. This would probably be the cheaper route too. We now have a "J" swap, how about you make a DIY "K" swap?!

 

[MvM]

I have a '98 NSX so when my OEM clutch was giving up, I decided to go for the SOS Sport 350 Clutch.
It is better suited for higher torque than the OEM clutch.
It is also lighter than the heavy NA2 OEM clutch. The total package inluding the flywheel weighed 11.2 kg (24.7 lbs) on my scale.
It was also cheaper than the OEM NA2 clutch.

I also have the ATI damper installed, which saves some weight also, as mentioned above.

 

[A.S. Motorsport]

The real trick in this is getting the pulley, crank and flywheel dynamically balanced as one assembly.
This is how Honda does it on NSX-R rotating assemblies.

Then carefully balance out the crank counterweights, on a V6 '90 degree I'd rather stick with the OE or ATI damper than anything thinly machined out of a billet.
You must remember that there is a strong harmonic resonance in V6 especially in a 90 degree one.

 

[scammy]

After reading those articles on Speed Hunters about the Advance NSX's with their fully balanced bottom end and Toda pistons making for a 3110 litre engine with stock crank and rods makes me want to get that done.

 

[xxxdominion]

I'm a little late tot he game but I went form the OS Gilken twin disk tot he EXEDY hyper single with the chromoly flywheel. the OS gilken was around 29 LBS or so and the EXEDY was a hair over 19 if I remember. And a good price. Revs were noticeably faster as well as throttle response.

The only thing I don't like about the hyper single is its quite grabby and is basically impossible to take off with at low RPM. It likes to judder a bit, but it isn't bad. May just be my unique experience as well.

 

[austrian type-R]

Have a look into the ATS single carbon, only 18,7lbs and cheaper than the exedy twin carbon.

http://www.ppi-ats.com/Carbon_clutches/CC_ appli_Oct_ 2010_Honda&Mitsubish.pdf