Too much free time over the weekend had me thinking. I know I'm probably over thinking ways to add unneeded things to my combination but.....

Is there any way to reduce rotating mass in the primary drive without going to a belt drive? Lighter weight clutch baskets ect. I did some searching, but it seems to be an un-discussed topic when a performance thread comes up.


Edit* specifically speaking for evo models.

 

BDL compensator will save some weight I think that would be bigger savings than any clutch savings you'll get. It's substantially less weight

 

Do you know the difference in the weight between stock and BDL?

I found a couple different clutch assemblies that claim to be 2-2.5 lbs lighter then the OEM assembly.

 

I would be willing to bet it's gotta be a pound or two. I can weigh the stock set up for you if you want I have my old one missing one Belleville spring so I can figure out exactly what it weighs. Let me know and I'll check it.

Bdl should list a shipping weight or I bet they could tell you exact weight but there's nothing to it it's compact.

 

You need to find a hobby and stop this thinking business! What interests you in reducing weight? Just throw some more cubic inches in there and you'll be fine.....

 

GR is all over you with this paragraph, by the way selling 1 kidney will fund a big cube engine. Selling 1 kidney is also a 3 lb loss translating into 1 hp gained by a calculated formula, it's a win win!

Dropped 5 lbs with a Evolution Performance chrome moly trans pulley but what the hell do I know about weight loss, I weigh 280 but the 127" puts a large guy in the front, re-read GR's paragraph again.

 

KP I searched there site for a weight difference and can't seem to find one. I've also been reading some really bad reviews on the BDL unit. If it's not too much trouble I'm curious of the weight difference.

Graham. The cubic inches have recently been added. The question came about in my head the other day while talking to an old buddy. We used to build quite a bit of small block ford motors for drag/street cars. We alway used aluminum fly wheels and sfi approved fluid dampers to minimize rotating mass (always balanced with crankshaft).

In theory if you were to reduce the weight of rotating mass in the primary drive, wouldn't allow a smoother/quicker rev?

 

Honestly I was hoping to get more positive feed back from you lol, but you having the lighter trans pulley confirms your a believer in the theory.

I already built a known working 89" combo for my FXR, but I'm always looking for ways to improve things as well.

 

You are onto something, 1 HP gain for every 3 LB of rotating mass is the theory that was used in Unlimited Mudracing. My buddy runs the BDL belt system to remove rotating mass but affected his gear ratio so nothing gained and the cost of the belt drive is expensive.

The twinkies have the direct drive primary pulley but don't see them for a Evo. The best bang I did for accelleration with the smaller stroker was dropping the final gear ratio

 

There's a new design cs24a or cs25a and they get good reviews. I had one in my hand it was lighter by far but as you know it wasn't my vibration issue and was the wrong size so I shipped it back.

I'd call and get a weight from them they have to know they ship it daily. I'll weigh the stock set up for you tonight.