I'm running the SLP billet flywheel with a Cartek clutch. The car bogs some with the lightened flywheel. I read on the Ram clutch page that if you have enough rear gear you can transition better and reduce/eliminate the bogging. My question is: In our cars is it talking about the rear differential gearing ratio? And would I want to move it up or down? I have the stock gearing back there right now.

 

Lightened flywheels are not the best for off the line performance.Deeper gears help with this problem,Like 4.10 or 4.30's for M6's.

 

Yeah, so I've noticed! I'll probably go with some 4.10s, I was considering them as a future mod anyway. I guess this gives me a good excuse to get them now <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

Yeah, I've got a huge problem with this myself as I have 3.73's and I run slicks!

I'm going to switch to 4.30's I think <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

I do not get it. Less rotational mass=more power for launch?

 

No, less rotational mass = less STORED energy for launching.

Think about it, you're sitting there at the line with the tach sitting on 6000 waiting for the tree to fall. If your flywheel is heavy it's going to be hard to slow down when the clutch is dropped. It's holding ALOT of energy with all that mass spinning so fast.

Now, same situation with a much lighter flywheel. It's holding alot less energy and will be easier to slow down when the clutch is dropped. Hence, the dreaded bog.

Bottow line is lightweight flywheels suck *** for launching.

 

Exactly Colonel!

There is a time and place for everything, and in high (read 1000 plus) hp drag cars with unlimited tranny gearing choices, aluminum flywheels are perfect.

 

Thanks for the insight. I was not thinking of it that way. I was thinking of a loaded engine trying to spin up.

 

Withya on the above.

How would a lighter damper affect the above?
Ordered a new alum ATI Super Damper. Supposedly 2.5# lighter than stock...

 

Yup, launching on my car blows right now. But I just put on a new torque arm and a stronger driveshaft which for whatever reason helped transitioning, so hopefully the 4.10s will get me back to a nice smooth launch and no bogging.

 

but on the flip side i love my fidanza <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
when you are just driving it creates an incredible felling to here the engine rev so quick. Not to mention better gas, more top end power,
so like me when you live in bumble you have to interstate race cause there is no 1/4 only a crappy 1/8th no one will go to cause you can't slow down at it is cooler having topend

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MelloYellow:
<strong>Withya on the above.

How would a lighter damper affect the above?
Ordered a new alum ATI Super Damper. Supposedly 2.5# lighter than stock...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The same applies.

 

Does this same reasoning apply to automatics with converter weight? I am thinking stored energy is less of an issue due to the torgue multiplication effect of the converter.

 

Well, given that this is a daily driver and I sit in rush hour traffic on the Washington, DC beltway, driving with the lightened flywheel sucks. On rare occassion do I really get to let my baby lose and enjoy the lightened flywheel.

Speaking of revving faster, I wonder how quickly the car will rev up if I put on the ASP crank pulley.

 

How much weight difference on the stock fly vs. the Alum fly?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wm_sorg:
<strong>Does this same reasoning apply to automatics with converter weight? I am thinking stored energy is less of an issue due to the torgue multiplication effect of the converter.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">No. You're NOT talking about the car pulling the converter speed down in this case. The RPM will only go UP once the hammer is dropped in which case accelerating a lighter converter is easier for the engine to do.

<small>[ November 23, 2002, 01:12 AM: Message edited by: Colonel ]</small>

 

from what i have read....
stock f-body flywheel for ls1 30lbs
stock z06(flywheel supplied with ls1motorsports clutch pressure plate and flywheel sets) 25lbs
and a fidanza aluminum with steel friction surface (what i have) 12.5lbs

 

I have the Fidanza Flywheel. When I first put it on I was running on BFG DRs and the car reved so much faster that I kept going up in smoke. I now had to roll into the gas. Got a set of ET drags. Went to the track and every pass I made that night the car would almost stall when I dumped the clutch. Made about 10 passes that night and on the last I one broke the tranny. I had seen a lot of post about boging with a light flywheel and the tranny was coming out anyways so the steel went back. Took it back to the track and had the same problem. I had broken my battery holder on my first pass with ET drags and that was my boging problem. So I fixed the battery holder and headed back to the track (with steel flywheel). Made about 10 passes that night with 1.69 to 1.72 60s. DA that night was around +1000. I put the Fidanza back in and headed back the next week. DA was +1500. My 60s were 1.71 to 1.73 and traps were a little over 1 mph faster and ET was a tenth better also. So I have gained ET and MPH with the Fidanza and drag tires. But when running on DRs it is very hard to keep the tires from going up in smoke.

 

Yeah, rev up higher with the light flywheel on launch.

It will be above your peak torque, and the launch
will pull down your rpm across your power band.
It's tricky but it can result in better track numbers
overall.

It helps to have a lighter car and make a little
more power(bog eliminators), and of course traction
to stick the launch.
It all works in conjunction with what a lighter
flywheel is characteristically doing.

The lighter flywheel has a number of benefits but
it will require some new attention to the launches.

It seems to be a no-question mod for autocrossers
and highway racers.

Jay Johnson

<small>[ November 24, 2002, 01:05 PM: Message edited by: Jay Johnson ]</small>

 

Didnt we tell you they are no good for drag racing (and launching the car on street in general because they dont hld the inertia of the motor) when you were at the shop?