your tach me be a little off just like mine. mine is off by about 100-300 rpm depending on where i am in the rpm range. next time have him find the limiter.

 

now at the crank is the percentage lossed calculated over a smaller lighter UDP pulley?

So the question is with an UDP is the loss greater or less at the crank? so the percentages may be greater or less then what you guys were calculating. cause the udp frees up crank hp

 

I am going to do one more dyno and that will be when the weather gets cooler in NY. Thanks for the information. Warren

 

good point. well the point of the UDP is to lessen the crank loss. sooooo, the % loss should decrease. 20% 19% 18.3765%

I only took up to Pre-Calc/Trig. This variable is beyond my mathematic abilities. Plus I'm low on advil. Someone else figure that out please.

 

Actually I've been thinking about this very thing.

In the SAE calculation, if I understand it right, all of the accessories should be in place, so the 265 should be including the stock pulley.

In that case, the WHP / 1 - drivertrain loss formula should hold and all is compensated for already.

Now, if that isn't the case (and the manufacturer's measurement is more like brake HP) then the formula would look like this:

WHP - gain from reduced parasitic loss / 1 - drive train loss

or..


221 - 7 / 1 - 0.22 = 274.36


Does this make sense?


Note that the 7 in the above calculation is a "guesstimate" of what the gain (reduction in parasitic loss) that the UDP pulley yields.

 

Is this stock? Are the numbers cited SAE corrected?

 

no i beleive it is std

 

wow, so many brains leads to more complications in trying to figure out CHP?


Another question, an UDP to me seems to take "hidden horsepower" (compensated power between the crank and the wheels) and disperse it to the wheels and crank. Maybe a 50/50 distribution.

So I'm pretty much confused now and have only figured out that I may have given my car an STD?

 

I think this has convinced me to get a 6th gen 3.5L to put in a 4th gen rather than the 5.5gen 3.5L. Wasn't the 5.5gen auto dyno'ing around 200-205whp and the 5.5gen 6spd ~215whp? What's the difference b/w the 5.5gen 3.5L and 6th gen 3.5L? The intake manifold? Is it the ECU? I know the 5.5gen ECU would run rich at high RPM's and full throttle doesn't equal full throttle at high RPM's with the 5.5gen and the E-gas.

 

UDPs have not shown any significant difference in power, or drivetrain loss...only responsiveness. The majority of the drivetrain loss comes from the transmission and the parts attached to it (not including the motor, obviously). These include, the clutches, gears, torque convertor, and driveshafts. LTW wheels, pullies, brake rotors (even when combined) havent shown even 5whp. A lot of the 3.0l guys will tell you different, but they dont have any proof besides butt dynos.

 

6 gen and 5 gen motors are virually identical. 5.5 gen autos put down ~197 and the 6mts are 204-207. Mind you, this is bone stock. Rambergs car is modded. Also, the ECM on the 6th gen is very different (and much better designed) than the 5.5 gen one. Its actually based on the one they use in the Z (32 bit vs a 5.5gen 16bit).

 

Fully modded (bolt on wise) and the #s are in STD correction

 

hmm, thanks for the info. Sounds like I should get a 6th gen ECU and a cheaper 5.5gen engine.

 

If you can wire it all up correctly (you will need a 6gen inst cluster too) go for it.

 

I've often wondered about that.

FWIW, if all goes according to plan, I will be getting my car dynoed around the end of next month.

The only performance mods will be (you guessed it) a UDP and a JWT POP charger!

We'll see how well she does.

BTW, Anyone care to suggest a good dyno shop in the Plano/Frisco (far north Dallas) TX area? If so, please PM me.

 

Looks great Ramberg.

How do you calculate torque?

 

same as hp, in that the HP # is derived from the TQ #

 

So that's 293.5 tq? That seems pretty good for burning tires on a daily basis. Is this normal for vq35; if so, then most of mods affect tq# until cams?

 

what are bone stock 6th gen 5AT's dynoing? just for reference...

 

HP=TQ*(RPM/5252) So... Cams would help torque on the right side of the tach.

 

huh ??

 

looks good man !!

 

Right side of tach = High RPM ...

 

Assume transmission loss is L (a number between 0 and 1),
wheel power is W, crankshaft power is P

Then

P*(1-L)=W

Since a typical value for L is 0.2, it follows that

P=W/0.8

 

welcome to 850000 years ago

 

Who really cares about crank hp? Just what the differnce between a bone stock whp versus the modded whp.

 

So you brought up a 3 month old thread to discuss that?

I thought ramberg had gotten on the dyno pony again and used the juice this time... damn, so disappointing...

 

Who cares about this thread, it ran its coruse. Point taken, data plotted/recorded... Now we wait until Gramps gets down to FL again.

 

I appologize it was linked to a new thread I didn't realize it was so old.