Got the z dynoed today. pulled 299.2rwhp/313.6rwltlbs. overall was very happy. was hoping for near 300 to the wheels. what would this be about at the flywheel. it's a little better than the factory ratingof 305/335 only power mod was a lm catback.

 

Here is the formula for A4:

RWHP / .85 = FWHP

299.2 / .85 = 352

Here is the formula for M6:

RWHP / .80= FWHP

299.2 / .80 = 374

Nice numbers

SteveC

 

I think you're #'s are a little off. Manual trans (M6) doesn't eat up more power than the autos. I've always gone with 14% loss with M6 and 17% loss with A4. That would give you M6~348hp & A4~360hp at the crank/flywheel.

 

From what I understand, the beefed up and complex internals of the 4L60E added to the bigger torque converter drag the drivetrain loss to a total of 20-22%. The M6 is 15-18% depending on wear of the clutch assembly.

A4 (20% loss): 299.2/.80 = 374 fwhp

M6 (15% loss): 299.2/.85 = 352 fwhp

 

forgot to mention mine is a m6 so about 350 fwhp. well thats awesme. does this sound good, bad, or right on for a98 with only a catback...also after i geta new clutch what should iget... i was thinking a mti lid and then some hooker lt's...hows that sound. thanks guys and gals

 

Good numbers for the mods

My question is?
What difference does it make what the rear wheel numbers convert to in flywheel numbers?
You can't take the motor out and drive it down the road.
All that matters is how much it puts to the wheels and how quick it'll get down the track.
All of this debate over and over again about conversion factors. 14%, 15%, 18%, 20%, 22%, 25% who cares it doesn't correlate to anything in the real world.
299 horsepower to the pavement that's what counts.

 

It's nice to know how much power the engine alone makes though

 

i agree that whats at the weels counts...but when i tell mot people that i dynoed at 299/314 they are like "oh i guess its not as fst as you thought" bs so then i haveto do the whole talk about rwhp to fwhp. i just wanted a simple way to tell the ignorant mass. thanks...do my hopefully soon modssound good...

 

I agree, flywheel horsepower #'s mean nothing since our our cars real power #'s go through the rearwheels. But yeah, a lot of people have no clue what I'm talking about when I say my Z makes 325rwhp & 346rwtq. hehe! Oh well, they find out just how fast it really is as soon as I take them for a ride.

As for true drivetrain losses, well there really isn't a clear-cut answer. What people don't understand is that todays drivetrains are much more efficient than those of yesterday(i.e. a long time ago).

Our M6 is probably closer to 11-12% while the A4 is around 15% or so.

Mike

 

Most "ignorant" people make ignorant statements, and I would not continue the conversation any further. Case in point, this guy was telling me his Cadallac STS was faster than my Camaro because it had 300 horsepower. I asked him if it was FWHP or RWHP, ofcourse he did not know. I then asked him about his RWTQ?, he did not know what I was talking about, so I told him he was right, his car was faster than mine, and drove off.

My 2001 Z28 A4 (lightly modded) - 291 RWHP, 350 RWTQ (3.73's).

Alot of people do not understand that it is NOT the horsepower, as much as the torque that takes you from "Farfegnugen" to "****enmovin "

SteveC

 

You can't talk cars without talking to ignorant (or just plain stupid) people. It's part of the hobby, I guess.

 

i agree, converting is just bench racing....

 

looks about right for a auto car...You probably pulled somewhere around 290 stock

 

DAMN those LS1's are strong! 299 rwhp is awsome with only a LM..its looks like the LS1's where underated what 30-40hp?

 

Some of you amaze me at your quickness to denounce a flywheel conversion.

Since when do you hear of NHRA/IHRA telling the crowd and watchers on TV what the rwhp of their Pro Stock car is? Top Fuel Dragsters?

How about NASCAR. I haven't seen them yet strap one on to a dyno before the race to tell everyone what rwhp it made.

FWHP is just as impressive as RWHP. I make 555 FWHP. How many other people do you run into who can claim they have a street driven, grocery getting, family hauling 550+ hp car?

Yes, I think conversion numbers are just as effective and needed as dyno numbers.

Else, we could always pull our engines and throw them on an engine dyno so people don't have to worry about "numbers which are for bench racing" anyways