Interesting point. Anyone have the answer?

 

My 91' 6sp has a frisbee

 

My 89 ZF-6 also HAD the frisbee.

 

mine too

It may not gain HP, but it will reduce inertia mass allowing the engine to spool up faster.

The effect being simular to underdrive pulleys



I think spool up is a factor that is often overlooked or not thought of as much as hp and torque, which are major factors, but how quick the engine gets through the rpm range is something to be considered.

 

From the CF Tech pages

"During a Q & A session at Corvettes at Carlisle 2001, I posed the question to Gordon Kellebrew as to the purpose of the "frisbee".
His response was that this disk was added by GM in 1988 to absorb vibrations
when the A/C compressor turned On/Off.
He said that they later found that this caused the serpentine belt to chirp upon sudden
changes in engine speed and so it eventually removed from engines in later years."

 

No one has mentioned how clean it looks up front with the Frisbee removed

I will complete these calculations later for the LT5/ZR-1 Technical Calculations section. Just in case this thread gets closed because of AGING sooner than I expected

But for now......Moment of Inertia I = 1/2 M x R x R
where M is mass in slugs and R is radius in feet and I is moment of inertia in lbs divided by ft /sec^2 multiplied by ft^2 or
lbs sec^2 ft

Angular acceleration is in Radians per sec^2 and there are 2 pi radians per revolutions or 6.28 radians per revolution.

Now lets just say our Frisbee weighs (I will weigh later) 5 lbs and is 1 foot diameter.
I would be 5 lbs/32 ft/sec^2 x .5 ft x .5 ft or .0195 lbs ft sec^2

Lets say our Frisbee rotates from 0 to 3,000 rpm in 1 second.
3,000 rpm would be 18,840 radians per minute or 314 radians per second accelerated in 1 second or 314 radians per sec^2

Torque would be Moment of Inertia multiplied by angular acceleration or .0195 lbs ft sec^2 multiplied by 314 radians per sec^2
Torque equals 6.13 ft lbs which is constant as the Frisbee accelerates if the acceleration is constant.

To get HP which is variable as the Frisbee accelerates angularily.....we will look at 3,000 rpm.
3,000 rpm is 314 radians per second as above. There is 550 ft lbs per second in one HP.
HP = angular velocity multiplied by Torque.
We have 314 radians per second multiplied by 6.13 ft lbs or 1,924 ft lbs per second which is approximately 3.5 hp

So the only way you get that angular acceleration of the Frisbee is rev it in neutral. Also keep in mind you have several other pullies reving at different rpms depending on their diameters. And keep in mind a couple of those pulleys (Air, Power Steering, Alternator and Water Pump) may have a torque resistance because they are doing work during constant rpms.

Also keep in mind you have ONE BIG Pulley (flywheel) which sees the same kind of angular acceleration as the rather heavy Harmonic Balancer on the front...

Let me clarify the numbers later this week and get it all straight for you
So for first go around spinning the water pump pulley from zero to 3,000 rpm or 314 radians per second in one second with a required torque of 6.13 ft lbs we would have 1,924 ft lbs per second or 3.5 hp

 

So gains or no gains, it's basically an unnecessary chunk of metal adding weight and taking up space. Does that sound about right?

 

Sounds about right to me.

How exactly did you confirm or document this "gain"? Please elaborate!

 

8 month old thread. Preparing for lockdown in 3......2......1.....

Oh Crocamonga???? Where fore art thou????? OHHHH....THERE you are....

 

This includes the L98 Frisbee HP calculations.....

Tech Info - LT5/ZR-1 Technical Calculations LT5/ZR-1 Technical Calculations

Threads may show AGE but Technical Calculations never get old

 

This one is still open? Our Fearless Leader must be at work.

 

Maybe our Fearless Leader likes Mathematics......
And Maybe our Fearless Leader does not like Questons in threads (even old threads) to go unanswered

 

I think it's relevant (for readers) to know what the potential gain/benefit is -- by removing the frisbee. Really, they should also know what can/can't be felt....IOW, that it takes more than 3.5HP for a driver to feel the difference.

Recently, I put mine back on. I was thinking about a poster who reported some vibration with the A/C running at a specific rpm. I was also thinking about harmonic balancers absorbing vibrations, the bearings in the waterpump, etc... Plus, I'd removed mine during the installation of a 383. Never tried it as a sole modification.

Now I have. Can't say I feel any difference with or without. Since the weight doesn't have an isolated inertia ring, it probably doesn't help the longevity (or vibrations of the A/C) either. But, there was one guy who said it made a difference.

So, just try it and see. It's not a big modification or deal.

Can we conclude that?

 

While this thread is still open I'll add my 2 cents.... I removed my frizbee about 4 years ago, but I can still feel the surge when my a/c cycles on and off...Luckily I almost never use my a/c so it isn't a problem, but if I used my a/c more often I would have to put it back on because the surging would drive me crazy......Through the years that I have been on here I have heard some guys say they had problems from removing the frizbee, and others have said they noticed nothing at all, so something must be different from one vehicle to another....WW

 

I'm home now...read the rules on reviving threads over 45 days old Dynomite.