Indeed you are not, the dynapack itself absorbs energy and you still measure the power after the kinematic chain ... its not a "engine dyno", the gearbox dissipates energy by friction, the prop shaft does, the diff does ... the bearings do, all that kinematic chain from the flywheel to the rear wheels hub dissipates energy in frictions ... and that usually is accepted to be up to 16% itself.

so losses + dynapack loss = that number.

Yes it could be corrected, ajusted so it looks "better" but whoever knows about Dynos, and a given car has been "dynapacked" knows that the raw result will be lower than other solutions. Once again, when you tune a car, the Delta is important, not the absolute raw number ...

A dynapack will read lower than an engine dyno but typically higher then a chassis dyno.

All the dynapacks i know read less than all the other dynos ....

Probably got our wires crossed. I know about wind down loss calculations and anywhere around 50bhp is possible and actually very likely. What I meant was that if there are 50bhp losses at 150whp, does not mean 300whp = 100bhp losses.

There are fixed drivetrain losses and variable drivetrain losses simultaneously occurring. Combined, they represent an overall percentage of drivetrain loss, which is definitely proportionate to power & speed.

To understand the big picture, you have to understand all the elements occurring on each "side" independently.

4 major elements on the "fixed" side of things are:
transmission gear tooth angles; more angle = more DT loss
final drive gear tooth angles; again more angle = more DT loss
[read: http://www.ehow.com/how_6513778_calc...cal-gear.html]
Trans ratios / FD ratio / tire size; less mechanical leverage = more DT loss
[dyno your car in 1st gear vs. 6th gear to see the effect of mech. leverage)
Rotating mass; more rotating mass requires more energy = more DT loss
[pick up something that weighs 1 lb, then pick up something that weighs 1000 lbs and decide which took more effort]

Gear tooth angles, weights, and ratios don't change over the course of any given RPM band (forget shifting gears) so you can consider these "fixed" or "constant" losses.

The "variable" side of DT loss changes in relation to power & speed:
Friction - input/output shaft bearings, diff bearings, wheel bearings, tire friction - all increase proportionately with speed. Low RPM = lower DT losses / High RPM = higher DT losses

You also have friction between the trans gears and FD gears. And it shouldn't be too hard to understand that the friction between two gears in a 200 HP car will be less than the friction between two gears in a 400 HP car. DT loss will be proportionate to the difference in power. Simply put; the gears are transferring more power, more power = more friction = more DT loss

RPM/Speed goes hand-in-hand with this. Higher speed = more gear tooth engagements within a given period of time = more DT loss. Again, the loss will be proportionate to speed.

There's also centrifugal losses and torque converter losses and one could write a doctorate thesis on the topic as a whole. But I just wanted to give some food for thought because DT loss isn't a fixed value. And you really need some qualifiers before you can say it's just a fixed percentage as well.

Great point.

I was about to say that power loss can't be a static value for several reasons.

Acceleration is related to a coefficient. Friction is related to a coefficient. Innertia is related to a coefficient. Distorsion/Dissipation/Rotation/Penetration are related to a coefficient too. All these are factors/coefficients/proportionality.

...aaaaanyway, just timed it tonight with DashCommand: 0-60 4.0 secs! :w00t:

Some sound of my 86:

[ame="https://www.youtube.com/watch?v=uCxxMBUN4kc"]MONSTAKA GT-86 / BRZ HKS V2 SUPERCHARGER - YouTube[/ame]

:wub::wub::thanks:

This :clap:

Aside from not using a restrictor, did you have to upgrade your injectors or fuel pump? Sorry if you've already answered this question but I didn't see any mention of it in the thread.

I think i can answer for them, no they didn't upgrade yet :) its still running on the stock fuel injection system.

Correct. Thanks HaDDeS.

I was thinking the same thing...
 

I was thinking exactly the same thing there...

If the Dyno is reading low, then do what other people do and state that, don't give the correct flywheel horsepower and the low read wheel hp together, it just gets confusing, either give the flywheel horsepower with an estimated correct BHP or just give the BHP with the caveat that the actual BHP is probably higher...

Jaden

I would really like to find out more about getting my hands on one of these kits.