dyno metre.

[mdsb3]

dyno metre..with one the most accurate:
dyno jet or dyno dynamic
TQ

 

[shiroitenshi]

Dynojet is Inertial Dyno, Dyno Dynamics is Load Dyno (or so I've heard)

The way they calculate torque is different and due to external factors the hp numbers will differ slightly.

One question of 'accuracy'.

Is 'true' HP output can be seen without evaluating the car's drag co-efficiency? (a.k.a. wind drag)

Dynometers are giant torque measuring equipment.. they measure torque. And due to the different methods that they use to obtain the numbers, there's always slight deviations due to air pressure, temperature, which all relates to air-density.

In fact, your car's ECU changes the fuelling based on it's many sensors, so that actually compounds the slight inaccuracies you have when doing multiple runs on the dyno.

Your first run, and your tenth run will yield differing results as the engine bay heats up, and changes your intake temperature, in turn changing your fuelling.

 

[JINEIL2EN]

so important meh..??

 

[eddie_vtec]

dyno metre..with one the most accurate:
dyno jet or dyno dynamic
TQ

if u dyno at dyno jet u get 200whp...then u dyno at dyno dynamic u get 180++whp...

 

[ccibai]

same brand different dyno might also give different value due to factors such as the condition the dyno is in ( the ability to load the car up ), how the car is strap down, wat gear the dyno was ran in, ambient temperature all those (dyno dynamics has shootout mode so tat the temp value etc those is corrected to a set of predetermined value so as to make a better comparison)

dyno is more liek a tuning tool, where it is unsafe for u to go to redline in fourth gear on the rd.

 

[shiroitenshi]

Something like eddie vtec said, but you have to be reminded that multiple runs at different times of the day can get you differing range of results as well, even on the same dyno.

 

[mdsb3]

i dyno and tune vafc2 only, my car use dyno dynamic 195 on engine hp and 183 at the wheel hp.that is small different only 12hp.is this logic or some
'magic' with the computer tuner(adjust) the graf.

 

[shiroitenshi]

Depends.. are you using lightened pulleys/lightened crank/no aircond/no powersteering? That's a VERY minimal transmission loss.

Actually from what I understand, the dynos measure torque, then use SAE correction and calculation to get horsepower. How's the torque curves for engine and wheel?

 

[mdsb3]

all dyno run in 3rd gear only.
my car use power steering,aircond belt but not on,no lighten pulley.
just gear final drive 4.785

max torque 189.1nm@6370rpm and start drop untill 167nm@8500rpm at engine.
max torque 170nm@6370rpm and start drop untill 151nm@8500rpm at wheel.

 

[shiroitenshi]

The torque numbers are quite impressive. B18C right?

Well, in that case, how many runs?

When I did mine, I had two seperate runs made. One for engine readout, and one for on wheel readout. He even added an extra run after the first run went past the 170hp mark to make sure.

But it's really confusing.. 12hp loss only? that's on the 'Wow!' scale for me... if it's true. Did the dyno guy run another pass to confirm?

I think you'd have to confirm back with him. 12hp of transmission loss is way too amazing for a non-lightened pulley setup IMO.

Best record so I've seen so far is 20hp drivetrain loss from engine to wheel, on a 200whp B18C.

I think chris2000's managed even lower, but I forget the numbers he posted last time.. I think it's around 20hp as well..

 

[mdsb3]

oopp sori.. b18c1 my crank and conrod lighten balance and new ACL bearing.
4-6 run coz tune vafc too.
i,m comfuse too 12hp loss to drive train
that why ask logic or not.
next time i'll try dyno use dynojet.

 

[shiroitenshi]

hmm.. I didn't think lightening the conrod would do that much difference, but if you dyno again, then probably can know for sure.