Dyno conversion/ crank HP question

[thom337]

So I was trying to figure out a somewhat close crank hp # for my car. I dynoed around 215 on a mustang dyno, and if what I've heard is true, thats dynojet - 12%. So that woul dbe 244.32 on a dynojet. As far as crank to whp numbers, I've heard usually about 21% on FWD cars. That would be 309.27 crank hp. Seems high to me, is some of this info I'm working off of bad? (loss percentages and conversion to dynjoet?)

x-.21x = 215
.88x = 215
215/.88 = 244.32 dynojet whp

x-.21x = 244.32
.79x = 244.32
244.32/.79 = 309.27 crank hp :dunceblock:

[gerich]

I think 21% drivetrain loss would be an auto or very efficient awd. Most people seem to figure 13-15% loss between crank and wheel hp numbers on a manual vw.

[dekroon]

Seems high to me, is some of this info I'm working off of bad? (loss percentages and conversion to dynjoet?)



Gerich is dead on about driveline loss percentages. I can't speak for evan, but I think his dyno is calibrated to read similar to a dynojet. So the 12% mustang dyno to dynojet calculation is throwing things off.

Figure for me like 226whp 253at crank (12%), 255 crank (13%), 267crank (18%)

[thom337]

Gerich is dead on about driveline loss percentages. I can't speak for evan, but I think his dyno is calibrated to read similar to a dynojet. So the 12% mustang dyno to dynojet calculation is throwing things off.


Ah ok. Thanks for the input thus far gerich and travis. I would say I wish Evan would come comment but then the rest of the Audi crew might join in and then somehow the topic of this thread would be about their homo-erotic tendencies. :eek:

[a4wdhybrid]

this thread sucks

[Ak-Abe]

it sure does... :D

[thom337]

this thread sucks

:crying::crying::crying:

[a4wdhybrid]

in a completely non-homo kind of way...:huggles:

[thom337]

:( I was just tryin to get my numbers straight for crank hp...no need to be hatin :mong:

[Yareka]

crank is bad...mmmmkay 4.

if this thread is going down...might as well hold it under water:grineyes:

[thom337]

crank is bad...mmmmkay 4.

if this thread is going down...might as well hold it under water:grineyes:

Crank is bad? So if I'm trying to figure out how much HP my car makes at the crank for comparison to some other engines thats bad....hmmm...interesting... I'm not entirely certain why you all hate this thread so much, I was just trying to figure out some drivetrain loss %s... Didn't you people ever see Bambi? If you can't say anything nice, then just don't say anything at all. :dunceblock:

[a4wdhybrid]

nobody hates this thread

only reason i posted anything was because you said something about "the audi owners"

no hating going on here...all in good fun :p :oddeye-hellyeah:

[thom337]

nobody hates this thread

only reason i posted anything was because you said something about "the audi owners"

no hating going on here...all in good fun :p :oddeye-hellyeah:

:grineyes: No worries, its late and I have a ginormous headache which may have resulted in me missing some of that illusive internet sarcasm. :smack: oh...and I just realized I quoted Bambi in my earlier post...migraines are weird. :eek:

[a4wdhybrid]

well..i can say i tihnk you def missed the "crank is bad" part :gt-bb-chongin: ;)

but its all good :D

i should have put some sort of smiley @ the end..hinting @ the sarcasm

both my parents used to get migraines...im fortunate enough to very rarely ever get headaches

[dekroon]

migranes suck. (all the pun intended) they vary alot in how they affect people. Some get sick, others light effects them some hallucinate.

When I get headaches they are often severe enough to classify as migranes.

[TurboMatt]

yep i get hallucinations, smell things, and get sick (sometimes to the point i have to go to the hospital). :( :puking: :( :puking:

[evan@absolute]

I didn't even see this thread till today or i would have posted. From what I have seen a 3rd gear pull on a 2wd car on my dyno is very close to crank hp. It is off by < 10%. A 4th gear pull is more like 15%. AWD on an S4 is around 25-28% for 4th gear. I have had cars do 195 or so in stock form to 205 with an Itg filter and cat back exhaust. I have had stock 150 hp mk4s do 140-150 to the wheels in 3rd though. A 4th gear pull on our dyno for a 4 cylinder turbo takes so long that without an upgraded intercooler the iat get too high. In my experience the difference between a mustang and other dynos in the 2wd mode is not much and certainly not consistant. I have had Subaru and mitsz tuners tell me the mustangs read 8-10% lower on average for them in awd.