I took my Foz to a Dyno Day with the guys from Liberty.asn.au today and had a great time.

Here is a snap from my run.

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KiDo Racing - your choice for coilovers and high performance brake kits

Because STOPPING is never optional.

http://www.perth-wrx.com/vb/kido-racing/

www.kido-racing.com.au

671nm of torque?

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MY93 Impreza GX 1.8L, 0hp, 0nm

If it seems to good to be true...

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MY01 JDM EVO VII - 230KW / 430NM @ 1.6BAR

I got a laugh from it as well. The facts are that measuring engine torque on a dyno is never going to be realistic. If you want to know why there is an easy explanation. The torque figures you are used to seeing are measured on an engine dyno where direct torque measurements are easy to achieve and calibrate. Measuring torque at the wheel is likewise easy to do, and accurate. Where things fall apart is in the translation. The figure you see is a guesstimate of the engine torque based on the wheel torque readings, however the unknown factor in the equation is the gearing in the car.

Some theory..... In a static condition or almost so the torque fed into the gearbox is multiplied by the gear ratio. Same happens at the diff. So if for example the Foz generates 320nM (as quoted by Subaru in stock tune) then at the wheel we will measure engine x gear ratio x diff ratio which is 320x0.972x4.444=1382nM

Where the dyno read out falls over is that it does not know the gear ratios to do the reverse calculation. You may also notice that I have not mentioned drive train loss. In a static situation as described by the simple calculation above there is no loss, however at anything above 0 rpm of course the losses due to friction and inertia increase with speed.

Bottom line is that torque displays that try to emulate the flywheel output are not going to be very accurate.

Just to touch on the subject of power readings, I am sure you all know that some dynos read much higher or lower than others. It really doesn't matter when the dyno is used as intended, and that is as a back to back measure when adjusting a tune.

I am surprised that people want to mock something they clearly do not understand.

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KiDo Racing - your choice for coilovers and high performance brake kits

Because STOPPING is never optional.

http://www.perth-wrx.com/vb/kido-racing/

www.kido-racing.com.au

^^Thats PWRX for you!

I second this

I think that everyone "loves" a dyno fantasy figure ...

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[COLOR=Black]Liberty GT Spec B tuned 240 HP & 372 Nm at the hubs.[/COLOR] "Instead of banning high performance cars - ban low performance drivers"

Dyno Dynamics Hub dynos reverse calculate the Torque, they also don't need to take into consideration the wheel diameter (and high rpm trye bloat) unlike roller dyno's.

It works provided the operator enters the correct diff ratio & the car is run in whatever gear is 1:1 (or the closest to it)....Oh and the IAT sensor isn't hanging on a wall!

Jester Understands this btw, hence his jest.

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[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

True.
I forgot to mention the effect of tyre diameter. The IAT wont affect the torque reading displayed but can be a useful part of the tuning equipment in the right hands.

__________________
KiDo Racing - your choice for coilovers and high performance brake kits

Because STOPPING is never optional.

http://www.perth-wrx.com/vb/kido-racing/

www.kido-racing.com.au

a false IAT throws out the SAE power corrections.

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[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]