Maybe I just didn't have the right keywords... :shrug

Can someone tell me, again, the percentage we lose for drivetrain on the FWD? Is it 15%? 20%? 30%? Other?

Thanks!

Anything anyone can offer on this is just a guestimate and thus, mostly bullshit anyway. wHP is all that matters.

Indeed, but ballpark sir...?

EDIT:
Please don't kill me!

I try not to pull bullshit numbers out of the air, dude.

Try google.

yeah there are many factors on actual WHP numbers, but guesstimates that many go by are close to a 15% drivetrain loss with a MT stock flywheel, aluminum Flywheel is 10%, and AT tranny 20%. there are other things you can consider is if you lighten knifeedge your crank is less of a loss, Aluminum UP's as well(which you already have), no AC/PS pulleys being used can also give you less drivetrain losses. so there are many factors. that's why i just believe in dyno and not percentage guesstimates like Dino mentioned. but it's kinda close using those numbers just to get an idea.

Originally posted by DarKReaLity
but it's kinda close using those numbers just to get an idea.

How do you know? You might not be even remotely close. Quoting numbers is stupid because you have no real info or proof to back them up. Misinformation is bad. Do you honestly believe that an aluminum flywheel is going to net a gain of 5% ? Wanna buy some dihydrogen monoxide based latex paint thinner? $99\bottle.

Drivetrain loss in a MTX is significant.
Drivetrain loss in a ATX is really significant.

I think we should just ditch the tranny altogether and just use the crank, since HP is so much higher there. Anyone have a writeup for attaching the crank directly to the axles? What belts would I need?

Bah! Maybe I'll just have to dyno the engine separate from the car a couple times and then dyno it in the car. :P Thanks for enlightening me as to the randomness and triviality of pulling numbers out the ass this morning gentlmen.

Appreciate it. Now I know...

Originally posted by DR1665
Now I know...

...and knowing is half the badly drawn and yet incredibly engrossing cheesy cartoon battle.

Originally posted by DarkOne

Originally posted by DR1665 Now I know...

...and knowing is half the badly drawn and yet incredibly engrossing cheesy cartoon battle.

Don't make me bust out my Cobra shirt.

Originally posted by DarKReaLity
there are other things you can consider is if you lighten knifeedge your crank is less of a loss, Aluminum UP's as well(which you already have), no AC/PS pulleys being used can also give you less drivetrain losses. so there are many factors. that's why i just believe in dyno and not percentage guesstimates like Dino mentioned. but it's kinda close using those numbers just to get an idea.

Okay... drivetrain loss is only drivetrain, UDP has nothign to do with it, Crank horse power should be measured with accessories on at the crank. So any UDP, or knifeedging can increase horsepower but would but be a reduction of drivetrain loss. The drivetrain is transmission to wheels.

The only true way to measure drivetrain loss would be to pull your engine, get an engine dyno. Drop it back in , an dget a chassis dyno. Then you would have a very close estimate.



Exile Racing Technologies: http://www.exileracing.com
una salus victus
It's holding down the garage floor right now.

vt has an engine dyno. i say you pioneer this effort brian :)

I've thought about this a lot myself. The way I figured it is as unscientifically anyone. It's totally deductive.

Since most dyno's have measured 420a's to about ~115whp, in stock form, I work through that number. DSM measured crank horsepower as we all know to 140hp.

Therefore, 140chp - ~115whp = 25HP loss. 25hp from 140chp is 17%.

I would think 17% drivetrain loss as a best guess-timate. That's assuming DSM didn't BS all of us. I've seen neon's pull about the same amount in their stock dyno's as well. Does that mean Neon's with the same tranny and basic engine get a 25% loss since they're rated at 150hp?

Originally posted by soulcontroller
vt has an engine dyno. i say you pioneer this effort brian :)

GOOD IDEA! I'll pull my engine out, pay a hundred or so bucks to ship it VT (wherever the hell they are), let them dyno it, laugh, and then pay another hundred or so bucks to ship it back, reinstall it, fix the resulting bullshit problem that would result, from the engine being removed again, find a local dyno, pay them fifty bucks or so to get a couple pulls, all just to come up with something like 16.237%.

:rolleyes

I think not. I was curious, but last time I looked, there was no money falling out of my ass.

Thanks all for the input.

GI Joe ruled.

Originally posted by DR1665
I was curious, but last time I looked, there was no money falling out of my ass. Thanks all for the input. GI Joe ruled.

Money falls out of my ass, Brian and Sarah collect like 1 buck in change throughout the house everynight. :P

Hey Brian, maybe in a few weeks we can get into a Dyno Day somewhere in town. Maybe DynoComp, I liked their setup. I need to get a baseline dyno on Pika before I start turning wrenches.

here's an example on a stock base run from import tuner mag that i found...



see that it's kinda close to a 15% drivetrain loss. i'm not saying that i don't agree with you Dino, you're right. but i'm just saying that it's an idea in the sense of guesstimates. i don't go by guesstimates myself.

Originally posted by DarKReaLity
it's kinda close to a 15% drivetrain loss. i'm not saying that i don't agree with you Dino, you're right. but i'm just saying that it's an idea in the sense of guesstimates. i don't go by guesstimates myself.

"Kinda close" is not close enough for me.

In that same vein, unless anyone has actually had their car on an engine dyno, talking crank horsepower is just bench racing.

Actualy Drivetrain loss Varies A LOT depending on WHICH transmission (if auto think the best auto is like 15% ish vs some atrocious 50% loss i heard the 606 sometime produced due to bad TCM programing)

there are auto tranies out there that are known for low power loss ...but yah...what really counts is not CRANK hp but WHEEL hp.....a car with 550BHP/500WHP vs a 600Bhp/500WHP (saying powerbands are identical) should theoretically accelerate just as quick....just cause those extra 50 hp are doing nothing exept being converted to heat cause of friction loss/slipage

i see you guys basing your loss % from known whhp dyno numbers, but in reality those % your giving are on the assumption that the 420a actually does make 140hp in stock form...until someone yanks a bone stock engine from say 10 eclipses and flywheel dynos them there is no real way to know what the actual average stock HP is....so like dino said guestimating numbers is useless...get your whhp numbers and be happy with them...cause thats all that does matter...

Stock engine is rated at 140hp....stock dynos usually hit around 115hp...

Just do the math...there's your ballpark.