robbycolli

iTrader: (8)

Is there a general concenses as to the hp loss between crank and wheel with a stock 03-05 350Z? I think I dyno'ed at 235 pretty stock with my 03'. Any others dyno stock cars. Is there a better answer to this question than comparing the stock dyno numbers to the given 287 crank hp rating?

I did a search and cant find anything. ANy help would be great. Thanks.

moflow

A lot depends on what dyno you're using. But i think lots of 03-05's put down between 230 and 240hp stock. 06's usually 240-250. We dont know yet with the 07's.

robbycolli

iTrader: (8)

thanks moflow. i'm calculating 18% loss. does that seem right to you all?

OCG35

iTrader: (2)

AT or MT?... I usually calculate about 15-20% for my AT G, although I've heard some say as much as 25%...

for MT; I guess 10% or so.... If you are AT I'd say 18% is a good conservative legit percentage...

Q45tech

Frictional losses vary with rpm and lube/tire temperature, diff are extremely lossy until 10 mph and optimized for 55 mph. In fact everything is optimized for 55-65 mph to squeeze every 0.001 mpg on epa dyno test.

Tires are the highest individual component, then comes the TC, alignment [rear toe and cambers], then diff, driveshaft, AT pump, halfshafts, AT gear mesh.

The point is every car will have a different loss, give or take a few percent.

dutchboy350Z

iTrader: (5)

You'll never see a bone stock 03'-05' non revup 350Z dyno @ 259 whp (10% loss).

Most non-revup VQ dyno btw 230 to 240 whp on MTs. Which is a 16 - 20% loss. 10% is way too low.

FWIW my MT Z dynoed bone stock a 239 whp on a Mustang Dyno SAE corrected.

RBlover69

iTrader: (2)

what we need to do is find out how porshe has such a low drivetrain loss. And we the car based on a boxer have abundant drive train loss.

Resolute

iTrader: (2)

Less drivetrain. The Porsche uses a transaxle, just like a front wheel drive does. Of course, Porsche puts the engine/transaxle out back. But either way, it's a more compact set-up with fewer reciprocating parts and therefore less reciprocating mass. No seperate transmission output shafts, U-joints, drive shaft, etc.. because the transmission also contains the differential.
This is why transaxle cars like front drives and mid drives have 10-12% parasitic loss on average, and front engine-rear drives have 15% parasitic loss on average. AWD cars will have a higher parasitic loss due to more drivetrain components, on average round 20%.
I dynoed my bone stock 03 base at 239whp on a DynoJet.
Will

Sunset350ZR

iTrader: (6)

I have always heard drivetrain losses are actually greater on FWD cars.

miamifan3413

No way, power has less distance to travel to get to the ground w FWD platforms therefore less power loss

Alberto

iTrader: (14)

242whp, 240ft/lbs SAE Dynojet for me. 17% loss if my math is correct.

Dynosty

iTrader: (27)

Nissan Motorsports claims about 18% loss through the MT, which sounds right on. Numbers can vary due to variables of course.

robbycolli

iTrader: (8)

These are the numbers I am finding too. Thanks for your input.

Old School

iTrader: (28)

Most dynojets I'd say 18-20%. Ran mine on a dynapack not too long ago and was sitting at 238whp....that's with breather mods and a UTEC....so I'd say 20-25% on a properly setup dynapack. I'm at sea level btw.