Where is the point (RPM) of maximum acceleration

[Stan Weiss]

1. Cloudy, misty, or hazy.
2. Lacking definite form or limits; vague:

What next?

Stan

[MrBo]

I think the best idea in some drag racing classes is to use a lighter flywheel and spin it to the moon before launch. Get the best of both worlds.

Little story:
Some guys named Patterson built a 302 ci engine for a stick shift 1967 Camaro in Super Stock years ago. The HP peak was around 7300 rpm,torque peak around 6000. (unported heads back then & lots of camshaft)
The car left the line around 9600 rpm. Free energy before the race starts.
Troy, are you related to those Pattersons? They build lots of comp motors nowadays.

[Troy Patterson]

A massivly heavy flywheel reved to a high rpm will store copious amounts of kinetic energy. When released, it will produce a substantial surge in acceleration....momentarily until the stored energy is dissapated.

And then...if there is not sufficient torque available from the engine (through the drive train) the car will bog down until adequate force is obtained. But now the heavy flywheel becomes a power consumer as the engine rpm is increased and reduces acceleration forces.

It makes much more sense to gear the vehicle properly given the torque available, its weight, and the traction limit.

Not sure if you were responding in the absence of the other two who have not made their case, but...

Assuming the engine is developing an adequate amount of power once the vehicle is in motion to overcome load (as the engine represented in the data sheet provided above does), the differences in measured G-Force / curve between a manual trans and an automatic car will be essentially the same.

Nebulous: • (of a concept or idea) unclear, vague, or ill-defined

Vintage Super Stock is nowhere close to modern Super Stock.

Troy Patterson

[Procision-Auto]

I'm not sure what there is to discuss with respect to the auto vs. manual launch RPM.

There's not even enough information available to make a comparison (for the auto car setup)
which ultimately indicates the two subjects are not closely related.

With the t-con you have multipliers and flashing to deal with...nothing like that in a manual car.

[David Redszus]

Whether it be an auto or manual, the linear acceleration G forces will indicate how much force has been transmitted to the ground. Ultimately, it all comes down to where the rubber meets the road, not the flywheel, not the clutch, not the trans.

[MrBo]

Assuming the engine is developing an adequate amount of power once the vehicle is in motion to overcome load (as the engine represented in the data sheet provided above does), the differences in measured G-Force / curve between a manual trans and an automatic car will be essentially the same.

Nebulous: • (of a concept or idea) unclear, vague, or ill-defined

Vintage Super Stock is nowhere close to modern Super Stock.

Troy Patterson

To repeat what A. Atwood said to you earlier: You have to be kidding ….. right?
How do you think a two speed stick car would do in Super Stock or Competition Eliminator?

Many modern automatic drag cars actually can have a narrower rpm window than manual transmission cars with many more gears.
Please fill me in, maybe I am missing the big picture here.

[Troy Patterson]

Whether it be an auto or manual, the linear acceleration G forces will indicate how much force has been transmitted to the ground. Ultimately, it all comes down to where the rubber meets the road, not the flywheel, not the clutch, not the trans.

Right, with either the manual or the automatic trans the "linear acceleration G forces" will be substantially similar - post launch. If we consider why "linear acceleration G forces" are so high at launch relative to any subsequent point it clear for all to see; where max torque is produced with the greatest amount of gear multiplication highest "linear acceleration G forces" will be realized and measured.

Horsepower is still only a mathematical calculation based upon torque produced at any given RPM. Vehicle speed, wind resistance and time (relative to engine RPM) are all factors working against realization of maximum measured "linear acceleration G force" or actual work accomplished.

But, on the issue of launching at red line and the fallacy or deceptive claims of it superiority - despite the world of drag racers DO NOT launch at red line, with or without a clutch, automatic trans, trans break or footbreak - regardless the weight of the reciprocating assembly, the ONLY or should I say the MOST LIKELY reason a person would launch at such an RPM besides being manipulative and to deceive is because the engine is too weak to handle the load of the vehicle at peak RPM - which seems an OXYMORON.

I'm waiting for some of these characters to post some evidence of "modern day" drag racers with "modern day" engines who launch at red line. Of all the tracks I've been to in California and elsewhere, I've never seen nor heard of anyone launching at red line - just my $0.35 worth.

[speedtalk]

EOL

[Procision-Auto]

I tihnk the confusion may be that nobody (at least from what I've interpreted) is stating that redline is the
best RPM to launch the car.

What I've read and what I agree with, is that the car should be launched at the highest RPM possible before
traction is lost.