Reciprocating weight theory: Flex plate weights

karolko

Well-Known Member
Joined
Sep 18, 2007
would like to bounce some ideas off of some you guys about your idea of reciprocating weight, namely flex plates. what works better? Lighter or heavier flex plate.

From what i have read and theorised less reciprocating mass means the engine doesn't have to work as hard to rotate, thus less energy spent and ultimately more HP. But once you are spinning a heavier object around it should have more moment force and therefore torque, and isn't torque what we need to get a vehicle to initally move.

I have read people claiming that a heavier flex plate will yield quicker 60' times and keep shift rpm's closer together.

I also read an article that did back to back testing on a motor and all they did was change the flex plate and the end result of that test showed a nearly linear gain in Hp and torque throughout the entire RPM band. That test sort of disproves what i have read and written above, so i'm at a loss and would like some Real world Buick answers...

I'm at the point of the motor/chassis where i'm looking for the little stuff to get me those little credits in ET.

Can't afford a $4500 turbo right now, plus new torque converter.... first world problem's i know.
 
would like to bounce some ideas off of some you guys about your idea of reciprocating weight, namely flex plates. what works better? Lighter or heavier flex plate.

From what i have read and theorised less reciprocating mass means the engine doesn't have to work as hard to rotate, thus less energy spent and ultimately more HP. But once you are spinning a heavier object around it should have more moment force and therefore torque, and isn't torque what we need to get a vehicle to initally move.

I have read people claiming that a heavier flex plate will yield quicker 60' times and keep shift rpm's closer together.

I also read an article that did back to back testing on a motor and all they did was change the flex plate and the end result of that test showed a nearly linear gain in Hp and torque throughout the entire RPM band. That test sort of disproves what i have read and written above, so i'm at a loss and would like some Real world Buick answers...

I'm at the point of the motor/chassis where i'm looking for the little stuff to get me those little credits in ET.

Can't afford a $4500 turbo right now, plus new torque converter.... first world problem's i know.

I would think if the RPM band is narrow than the flexplate weight becomes more irrelevant but I could see how a heavier flexplate could help maintain RPM at the initial hit.
AG.
 
Another angle to further confuse the issue.... :confused:

Weight placement.

In theory, weight should be located as close to the center of a rotating object vs. towards the outside edge. :D

The Flywheel is a device originally required by a single cylinder, 4-stroke engine, to absorb, store & release rotational energy to carry the rotating assembly through the other 3-strokes & back to the power stroke.

As more cylinders were added & evenly spaced, the flywheel mass could be reduced.
 
Personally I wouldn't think the difference in weight between a light or heavy flex plate would be anything you could quantify in a full bodied Buick race car. Back in the day when I was a VW guy we used to lighten the flywheels in hopes of better performance. What I can tell you is light flywheel works well in a light car like a sand rail and heavy flywheel works better in a heavier vehicle like a sedan.

Neal
 
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I agree with Neal. Maybe a super stock racer that has tried several converters and flexplates could see an actual difference between the parts.


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