Parasitic Loss

[jusbo]

The "Got the truck on the dyno..." (http://s10v8.com/viewtopic.php?topic=16109&forum=2) thread got me thinking. How can we combat the problem of parasitic loss? HP and Torque @ the flywheel are one thing but what is being put out at the other end is a completely different thing. What can be done?



But before that we have to know where its(HP & Tq.) getting lost. Having a transmission bolt right up the the engine and front wheels is where its at, unfortunately that is not possible for us.



Where in our drive line is the power sucker? Is it the gearing in the transmission? Is it the laws of physics playing a nasty joke on the drive shaft? Or is it having to convert one direction of energy into a different direction in the rear end?

Lets bring our knowledge together and maybe get a better understanding, and possibly get somewhere.

[BrandOmatic]

the first thing that comes to mind is the ford 9" rear. it's strength is it's weakness. the pinion meshing much farther down on the ring gear makes for a LOT of tooth contact and a lot of strength, but also a lot of friction. If you don't need all the strength, i think you're better off building up a 10 or 12 bolt. i believe it's a % or two difference between the 9" and the 7.5 and 8.5. but i'm sure someone else knows the exact numbers.

mechanical fans and power steering take a little too.

[wheelspin]

driveline power lose is what is. its always gonna be there. an upgraded rearend shouldnt be a concern about losing hp.for one its costly to keep rebuilding 7.5's(like I have) and it can be dangerous depending on when it blows. if you got the coin a 9 inch is the way to go, besides the majority of hp being "robbed" is in the trans anyway.

[Scotty_S-15]

Lots of logic in what Brandomatic says. Seems to be common knowledge that a 9 inch rear "eats" more power than smaller rears. Same goes for a 400TH vs. 350TH trans.

............. A lot of guys in the know consider a 9" to be overkill for anything except the most severe racing applications.

............. Regarding the rears, there's a lot of choices out there between the 9 inch and the 7.5. http://www.s10v8.com/images/smilies/icon_wink.gif There's the 12 bolt, Ford 8.8, Chevy 8.5, and even a Mopar 8-3/4. Then there's the sheer weight of the big rears to consider.

.............. Seems that any manual trans has to have less loss than any automatic. But for certain types of racing, other factors make an automatic the obvious choice.

.............. Then there is the alternator and water pump...... http://www.s10v8.com/images/smilies/icon_wink.gif http://www.s10v8.com/images/smilies/icon_biggrin.gif

[rayL]

reduce rotating mass, its simple. light flexplate, Roller bearings in the transmission, light drive shaft, lightweight ring and pinion, lightweight spool, lightweight axles, light weight rotors, light wheels......the list goes on. Add this to what everyone else says. My hang up is the percentage thing. if your motor makes 100 hp it looses 15 hp (15%) of it through the driveline.....if your motor makes 1000 hp does it loose 150 hp....??? Never liked that percentage thing.

[s10carguy]

direct drive like the funny cars... just release the clutch and hold on!



or build everything out of titanium http://www.s10v8.com/images/smilies/icon_biggrin.gif

[jusbo]

I was checking out the inner workings of a TH350 and damn, its complicated. I know if there was any way of improving it, it would have been done, but maybe it hasn't.

I will have to admit defeat at this point on.

It irks me that a honda can lay down better numbers on a dyno then our monster machines.

[redneckgames]

On 2007-10-15 11:14, jusbo wrote:

I was checking out the inner workings of a TH350 and damn, its complicated. I know if there was any way of improving it, it would have been done, but maybe it hasn't.

I will have to admit defeat at this point on.

It irks me that a honda can lay down better numbers on a dyno then our monster machines.





why? that honda motor is missing one key thing. TORQUE. Horsepower is not even a true value. its calculated.

[Scotty_S-15]

On 2007-10-15 11:14, jusbo wrote:

I was checking out the inner workings of a TH350 and damn, its complicated. I know if there was any way of improving it, it would have been done, but maybe it hasn't.

I will have to admit defeat at this point on.

It irks me that a honda can lay down better numbers on a dyno then our monster machines.

Don't get so crazy about this. the losses in a trans are something that have to be accepted. Other than a lock-up converter, they're part of life.

........... As for the rear, I suppose some of the additives available might help. But hey, if they helped a whole lot, the rears would have it in there from the factory.

.......... I guess the only thing we can do is use the trans with the least loses (smallest & weakest?) trans possible, and still have it live with the beating we plan to give it. Same goes for the rear.



BTW, I changed this whole note.....

[adh383]

No need in trying to re-invent the wheel-- build it to be dependable , and to be up to the task at hand--- here's the answer--$$$$$$$$$$$$ and WORK-- as for the hondas-- they are a different breed-- and u will spend $$$ to make em live-- and RUN-- WEIGHT is very critical to moving mass- my sons honda will stand up to most street driven cars-- 3800$ to make it that way-- and only 2200 lbs-- but its a garrett turbo-- you can make anything run with turbo or supercharger- or juice-- class yourself off with like kind- oooops excuse the sermon

[greenmachine_1]

When you have any kind friction or rotating mass you're going to have losses minimizing these things will do wonders to how much loss you have... Now that being said as you take away weight from your rotating mass (unless you uses titanium alloys) most likely you're going to lose strength so that's just a game of compromise. Then dealing with friction the best way to do that is with using a synthetic oil that's as light as possible... that could possibly harm your components if you run to light of oil so there's another compromise, but there are always going to be losses and to compare a rear wheel drive vehicle to a front wheel drive vehicle there is no comparison.... the rear wheel drive will actually be able to survive 600+ HP and the front wheel drive will start breaking parts before that point.