How many Engine HP needed for 500rwhp?

[khryslerkid]

 

[451Mopar]

The dyno is measuring both friction times acceleration, and mass times acceleration losses.
If torque was measured at a constant speed, the losses would be mostly just frictional losses, but under acceleration all the losses are multiplied by rate of change (acceleration)

 

[Mike Szadaj]

This is what I never understood about parasitic loss through the drivetrain...Lets assume you start with an engine setup that makes 400hp at the flywheel and assuming 20% drive train loss, you should expect to see 333hp at the wheels. A 67hp loss. Now, you start to mod the motor and when you are done, you are making 550hp at the flywheel. Still assuming the 20% loss, you are now making 458hp at the wheels. a loss of 93hp. Since no other changes were made to the drive train, the power loss should have remained constant at 67hp. Parasitic loss of hp through a torqueflite with a specific torque converter and dana 60 with a given set of gears should be constant regardless of the hp the engine is making. Correct?

I have absolutely no idea as to how to answer these questions. That being said I see a huge problem with this statement. You picked a completely arbitrary starting point. According to this logic, if the starting HP was 200, the loss at 20% would be 33 HP, and then that loss should not change as you modify the engine. What if you started with 100HP? 10HP? On the other end of the spectrum, what if the starting point is 1,500 HP?

 

[33 IMP]

I think the percentage of power loss would depend a great deal on which drivetrain. A 200hp frontdrive honda with a stick transaxle would have less loss than a 200 hp 283 two barrel going through a powerglide and a stock 63 belair rearend, which would have less loss than the same 283 going through a 4l80 and a nine inch ford.
And i know a motor, and also a drivetrain, has more parasitic loss as rpm goes up.
I just dont know what happens to the percentages if rpm and drivetrain does not change, but horsepower DOES, previous mentioned example, doubling power with a turbo or blower without increasing the rpm where that power is made.
Edit: i have not yet watched the physics explanation KK posted.... but i will !!

 

[Stroker68]

The dyno is measuring both friction times acceleration, and mass times acceleration losses.
If torque was measured at a constant speed, the losses would be mostly just frictional losses, but under acceleration all the losses are multiplied by rate of change (acceleration)

Hmmm. So the more power you make the more you lose because of more friction and more acceleration? The faster a guy goes the more power he loses because of greater forces of resistance? Makes sense kinda.

 

[Stroker68]

Ok. Watched the vid. Only thing I picked up was that less friction (Less rotating mass and lower inertia point) saves power? Less resistance more power. I have my flywheels turned down a little extra to lighten them up. Helps the twist. Takes off like a scalded cat. Just an expression. I like cats.

 

[HEMI-ITIS]

http://wallaceracing.com/Calculators.htm

147 MPH @ 3700 lbs...........

 

[dvw]

Hp numbers? Who cares. Find a known combo that will run the number you want at your weight. Plenty of them out there. Just copy it.
Doug

 

[Challenger340]

I have an engine/trans combo up for sale that I guarantee will make 500+ at the wheels.

So are you going to PROVE IT on an Engine Dyno before any Money exchanges hands ?

 

[1967coronet440]

So are you going to PROVE IT on an Engine Dyno before any Money exchanges hands ?

I would have, but didn’t have to it sold already.

 

[1967coronet440]

So are you going to PROVE IT on an Engine Dyno before any Money exchanges hands ?

we get it already get over yourself. you have an engine dyno at your disposal and dyno all your customers engines and I’m sure they’re happy. If you have a trusted builder and or combo a dyno isn’t needed IMO.

 

[Challenger340]

we get it already get over yourself. you have an engine dyno at your disposal and dyno all your customers engines and I’m sure they’re happy. If you have a trusted builder and or combo a dyno isn’t needed IMO.

and in my opinion only.... I guess just a "valid" as your opinion ?
what "warranty" are you giving with this UN-tested, UN-proven "claimed" (because that's ALL it is) 500+ rwhp Engine ?
just say'in...
are you offering a 100% money back Guarantee if it FAILS ? or Fails to make the 500 rwhp ?

 

[66Satellite47]

Post 21 vid is not only interesting, but fairly easy to grasp. To sum it up, the % loss is dependent on what's being driven behind the crank flange. Flex plate/flywheel, converter configuration, trans internal rotating parts, driveshaft, rear axle, wheels/tires all have rotating mass that adds to the losses. That means NO ACCURATE ANSWER AVAILABLE.

 

[Challenger340]

a 500 rwhp Engine.... so ballpark a 650 Flywheel hp Engine build, very easy and doable on pump 91 Octane.

My concern would be....
making sure the owner is cognizant of what's required for a patent install and satisfactory operation of the Engine in the CAR itself ?
as in "support" systems in the CAR itself capable of that much Engine ?

just say'in...
amazing how many guys think they can simply plunk that 650hp bullet in place of their 383 2 Barrel they just removed, hook up their 5/16" Fuel Line and junk Radiator, biatched terd 727 W/stock T/Convertor and "good to go" ?

It just ain't that simple ?
Depending on the Candidate car of course.... but assuming an Un-touched 383 Car example ?
I'm suggesting we see some guys spend easily half as much again..... as they did on the Engine ? upgrading the Car "support" systems for the 650 hp Engine ?
Rads/Cooling System, Fuel System & Pump/Tank Feed, Ignition System, Exhaust System... and we haven't even started ion a Beefy Auto/Convertor/Trans Cooler & Lines ? Diffy/Posi/Axles or Suspension, Frame Connectors and on and on ?

I mean I don't even know of a patent proven 650 hp N/A Intake Manifold that clears under hood ALL the time ? LOTS of Intake Manifolds can make 650 and LOTS more... just saying the HOLE in the Hood to clear ain't exactly "pretty" and Fibreglass Hoods /Scoops all ADDS Costs again ? Paint ?

 

[dcala84141]

I would think the biggest culprit that eats up hp. Would be the lubricants

 

[fratzog lover]

 

[Archangelgman26]

It's because a parasitic loss is determined through percentages. A 20% loss at 600 is a 20% loss at 800. The actual loss is different because the total of the percentage figured is more. BMW makes one of the most efficient drive trains boasting about a 7% loss across flywheel to the rear wheel. You can limit the loss across these points in your drivetrain, but you'll never remove them.