Drivetrain loss

[Stangman]

I know obviously every car is different but let’s say my car, obviously a 9 inch and a c-6 with 3000 stall what do you think the horsepower loss is. I know a c-4 doesn’t draw as much horsepower Jay said it was a big difference. If I do the Wallace calculator it says I have about 490-507 horsepower at the rear wheels depending on the weight I put in. Was wondering what the loss is to know approximately what it was making at the crank.

[jayb]

The number I've heard for a stock C6 is 55 HP.  C4 is supposed to eat about 20-25.  Manual transmissions eat even less.  Not sure about the 9", maybe 5%-6% as a guess?

[machoneman]

Old post but the Glide is best, c-6 the worst.

https://www.460ford.com/threads/transmission-specifications-including-parasitic-hp-losses.118570/

[Tommy-T]

The poor 'ol C6.

Changing to a C4 behind your hot FE will easily net you 2-3 tenths. Proven time and again.

Thing is, you'll need the entire "guts" of the C4 to be aftermarket to hold up to 500 foot pounds of torque. Even then, 2 maybe 3 years of beating on it will do it in. It's tiny. Plenty of places willing to sell you a C4 for 3-5K. Many guys bring an "extra" to the track "just in case".

A competent stock rebuild of a C6 with a shift kit will easily handle that. Put it in your 11 second car and forget about it until you need to freshen up your motor. It'll probably still be ok. You can "rollerize" your C6 and maybe get a tenth back.

You can have your 3 tenths and I'll keep my anvil C6.

[Stangman]

thanks guys. Ya know Im not sure if Im trying to talk myself into a c-4 or not but my c-6 has been fine.
About 5 years ago would have been the time to go c-4 when I did my c-6 in.  I bought a new one from TCI
and at the time I didnt have the extra 2500 to go c-4. Im supposed to have my motor dynoed on Friday so Ive been
trying to figure out my old HP to my new HP and figure out about what I will be running. I guess its just alittle bench racing
cause Im bored as hell not having my car. Machoneman thats some list I didnt realize the powerglide was so efficient.
Not that Im gonna get one but do they make adapters for the FE. Well hopefully the motor will be good and I can get back out there.

[Falcon67]

The difference is internal rotating mass and the C6 has a lot.  Big heavy drums take power to accelerate.  Little C4 stuff spins up fast, spins up easier when rollerized.  If you set up the roller drivetrain in a C4, update the drums to 5~6 plates with bleed holes, update the oiling paths and use a 6 pinion planetary, updated input shaft and welded front drum you can really beat hell out of one.  At something like 500 lt/lbs for sure you'd probably want to look inside after every season or so, depending on how many runs.  I have a rollerized C4 that's been behind 300, 500 and currently about 460 HP motors and I haven't looked at the guts in maybe 8 years.  Clicks off gears like a clock.

If you reduce the C6 internal rotating weight in some way, then you get power back.  Just like in the driveline - a reduction in rotating mass is stated to be about 5 times more effective in freeing power than removing static weight.  Hence the carbon fiber driveshafts, lightened gears, drilled axles, super light rims, etc.

[Gaugster]

I have referenced the list that Machoneman posted. This jived with other figures I found in my research.

I'll have to look and see what I found for my 6R80. Obviously a different animal all together but they handle 650HP/TQ bone stock. A great platform to work with but a huge undertaking to convert.

[machoneman]

Going fast (or quick) costs a lot. How fast do you want to go? LOL

Had to mention this. In a hat tip to racers looking for every single and often very slight advantage, some years ago a NHRA SS class 426 Hemi Cuda showed up at a national event with a Chevy 12-bolt gears grafted into a Ford 9" rear. Since the hypoid angle is less than Ford gears, it was found that the hp required to turn those gears was measurably less, albeit not by much! All Hemi Cudas and Darts soon switched out their Dana 60's or true Ford 9" rears to the Chevy gears.

Like I said, how far one wants to go costs $$$.   

[machoneman]

Machoneman that's some list I didn't realize the powerglide was so efficient.

Someone on the old 'Net 54 Forum posted long ago pics of a Glide's disassembled internals next to either a C-4 or C-6 (think it was a 6). Anyway, the size and number or internals is dramatically different as is the weight of rotating parts. Yes, it's a 2 speed versus a 3 speed but virtually all racers who by rules run an auto or have a choice....use the Glide and for good reason. 

[Stangman]

Going fast (or quick) costs a lot. How fast do you want to go? LOL

Had to mention this. In a hat tip to racers looking for every single and often very slight advantage, some years ago a NHRA SS class 426 Hemi Cuda showed up at a national event with a Chevy 12-bolt gears grafted into a Ford 9" rear. Since the hypoid angle is less than Ford gears, it was found that the hp required to turn those gears was measurably less, albeit not by much! All Hemi Cudas and Darts soon switched out their Dana 60's or true Ford 9" rears to the Chevy gears.

Like I said, how far one wants to go costs $$$.   

well whatever I run now will be it my car isnt a race car and dont want to switch it over to one. But I was thinking if the motor has to spin a c-6 and it costs 55 horsepower
would the motor be working less if it had to spin something with 30 horsepower. Yes the car will be faster and wouldnt i be working the motor less?
Just things I was thinking about.

[Falcon67]

Technically yes - it take energy to make power to move the vehicle and any reduction in parasitic power loss will make more efficient use of the available energy.   Would you notice the difference in wear & tear on the engine over 10~15 years?  Probably not.  Would the small increase in efficiency be worth the expense of an adapter bell, custom converter, spacers, flex plate, etc, etc?  Not likely.  A C6 is a stout trans and I imagine with modern parts ad maybe a few tweaks would give good extended service.  If you want a couple more MPH and/or a few tenths reduction in ET on a drag strip, then that's whole different set of priorities.

[FrozenMerc]

Something else for you to think about.  I spent 13 years in the powersports industry (ATV's and Side x Sides).  Your typical ATV with a Kevlar Belt CVT style transmission, high angle CV joints in the halfshafts, and straight cut bevel gears in the trans and differentials will lose between 35% and 45% of the engines crankshaft power to the drivetrain before it gets to the wheels.  I.E., an 80 Hp 950 cc V-Twin on the engine dyno was putting about 48 hp to the ground on the chassis dyno.  Obviously this is on the extreme end of drivetrain in-efficiency spectrum, but that 32 hp that is lost has to go somewhere.  Generally it manifests itself as heat due to internal friction, and is a big reason why the drivetrain components where not expected to last much over 150 or 200 hrs of operation, equivalent to 5000 thousand miles at most.  Much different than the automotive side of things, but the concepts are the same.  There is a direct relationship with the amount of Energy or Power that is consumed by each drivetrain component and how long it lasts.

[TimeWarpF100]

I know obviously every car is different but let’s say my car, obviously a 9 inch and a c-6 with 3000 stall what do you think the horsepower loss is. I know a c-4 doesn’t draw as much horsepower Jay said it was a big difference. If I do the Wallace calculator it says I have about 490-507 horsepower at the rear wheels depending on the weight I put in. Was wondering what the loss is to know approximately what it was making at the crank.

Approx 25 yrs ago I did a good 1/2 dozen from engine dyno to chassis dyno combo's.  FE C6 and FE Toploader. 1 429 SCJ
In the 400-500 hp area it was almost exactly a 100 hp loss with 4 spd and a 125 hp loss with c6.   Those losses did include exhaust. Good exhaust but maybe not ideal but as un-restrictive as I could make them at the time.

[winr1]

Would the percentage lost be the same on a lower horse power or higher horse power mill ??


Ricky.

[Stangman]

A 100-125 horse is a lot of power to leave out there TimeWarp. Ya know my car doesn’t weight a lot either but it sure is hard to push. I always think if I can get it to roll easier that would pick it up also.