Dyno Readings - Facts !
Dyno Readings - Facts !
04-01-2017, 03:04 AM
Quote:I used to work in automotive testing and dynamometers, so here are the facts:-
There is only one sort of dyno that gives you engine power, and that is an engine dyno which has to be directly connected to the engine and used in an engine test cell with strictly controlled environmental conditions.
A chassis dyno (rolling road) will never ever tell you engine power. It measures power at the wheels, and is only really useful for comparing before and after when modifying.
Any engine power figures are calculated (guessed) from estimating transmission losses during spinning down the rollers.
A highly skilled operator can tweak the calculation to get very close to the figure which would be produced from an engine dyno, but you wont find them on your average industrial estate dyno shop.
Many don't even correct for atmospheric conditions (temperature, pressure and humidity).
Cheers
Bobby
Shy boys don't get sweeties.
Picked this up on another site thought it might be of interest, the guy that wrote it supplies a lot of good technical info on the RX8 site so IMO he knows his stuff, others might disagree though !
Quote:I used to work in automotive testing and dynamometers, so here are the facts:-
There is only one sort of dyno that gives you engine power, and that is an engine dyno which has to be directly connected to the engine and used in an engine test cell with strictly controlled environmental conditions.
A chassis dyno (rolling road) will never ever tell you engine power. It measures power at the wheels, and is only really useful for comparing before and after when modifying.
Any engine power figures are calculated (guessed) from estimating transmission losses during spinning down the rollers.
A highly skilled operator can tweak the calculation to get very close to the figure which would be produced from an engine dyno, but you wont find them on your average industrial estate dyno shop.
Many don't even correct for atmospheric conditions (temperature, pressure and humidity).
Cheers
Bobby
Shy boys don't get sweeties.
04-01-2017, 03:22 AM
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
FirebirdPhil
04-01-2017, 03:22 AM #3Can't disagree with the fact that an engine dyno is needed to ascertain actuate HP of an engine, but it is widely accepted that RR's are fine for getting the HP of your average road car, the calculations are usually very close, who has the money to use engine dynos??
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
04-01-2017, 03:36 AM
As you say Bobby, it's especially good if you take the car back to the same rolling road to compare before and after a mod. I've already got a "stock" figure for my car at Surrey Rolling Road, so I can take it back there and see the "after" turbo figure ! :biggrin:
![[Image: Sig-enginebay.jpg]](http://i5.photobucket.com/albums/y179/SteveHammatt/Sig-enginebay.jpg)
IS200 Turbo project now just about complete ! See my thread here and leave your comments.
Now running standalone Syvecs ECU and no stock ECU !
steviewevie
04-01-2017, 03:36 AM #5Yep, agree with 2tongues. If you go somewhere reputable it should be ok. Sure, you won't get an accurate a figure as if you took the engine out and connected it to a proper dyno, but it's the next best thing in the real world.
As you say Bobby, it's especially good if you take the car back to the same rolling road to compare before and after a mod. I've already got a "stock" figure for my car at Surrey Rolling Road, so I can take it back there and see the "after" turbo figure ! :biggrin:
IS200 Turbo project now just about complete ! See my thread here and leave your comments.
Now running standalone Syvecs ECU and no stock ECU !
04-01-2017, 03:44 AM
This goes some way to saying that RR's with good operators are fine for your average person.
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
FirebirdPhil
04-01-2017, 03:44 AM #6Surry RR and SPC's are within something like 0.1 BHP of each other, the only difference is the one at SPC has newer software.
This goes some way to saying that RR's with good operators are fine for your average person.
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
04-01-2017, 10:53 AM
40mm Lowering Springs, Re-sprayed Front, 6000K HID's, Re-furbed alloys, Bandit Induction Kit (cheers Chris), Raised boot spoiler with LED, Blue calipers with silver decals, De-badged rear, Chrome Oil Filler Cap (thanks to Chris again), White LED dash bulbs, Blue a/c control bulbs, Blue door markers and interior lights, Sony head unit, Chrome Lexus tax disc holder, TRD side skirts, Original Saloon Front Bumper re-fitted instead of Sportcross
![[Image: Lf9Nl.jpg]](http://i.imgur.com/Lf9Nl.jpg)
Wouldn't you rather know the HP at the wheels anyway so you know what power you actually have at your disposal.
40mm Lowering Springs, Re-sprayed Front, 6000K HID's, Re-furbed alloys, Bandit Induction Kit (cheers Chris), Raised boot spoiler with LED, Blue calipers with silver decals, De-badged rear, Chrome Oil Filler Cap (thanks to Chris again), White LED dash bulbs, Blue a/c control bulbs, Blue door markers and interior lights, Sony head unit, Chrome Lexus tax disc holder, TRD side skirts, Original Saloon Front Bumper re-fitted instead of Sportcross
04-01-2017, 11:34 AM
Andy-R. Wouldn't you rather know the HP at the wheels anyway so you know what power you actually have at your disposal.
In a way, yes. But the trouble is, manufacturers don't usually quote wheel bhp figures. So your starting point is normally the flywheel bhp.
IS200 Turbo project now just about complete ! See my thread here and leave your comments.
Now running standalone Syvecs ECU and no stock ECU !
steviewevie
04-01-2017, 11:34 AM #8Andy-R. Wouldn't you rather know the HP at the wheels anyway so you know what power you actually have at your disposal.
In a way, yes. But the trouble is, manufacturers don't usually quote wheel bhp figures. So your starting point is normally the flywheel bhp.
IS200 Turbo project now just about complete ! See my thread here and leave your comments.
Now running standalone Syvecs ECU and no stock ECU !
04-01-2017, 12:04 PM
40mm Lowering Springs, Re-sprayed Front, 6000K HID's, Re-furbed alloys, Bandit Induction Kit (cheers Chris), Raised boot spoiler with LED, Blue calipers with silver decals, De-badged rear, Chrome Oil Filler Cap (thanks to Chris again), White LED dash bulbs, Blue a/c control bulbs, Blue door markers and interior lights, Sony head unit, Chrome Lexus tax disc holder, TRD side skirts, Original Saloon Front Bumper re-fitted instead of Sportcross
But the flywheel figure is for showing off:laugh:
40mm Lowering Springs, Re-sprayed Front, 6000K HID's, Re-furbed alloys, Bandit Induction Kit (cheers Chris), Raised boot spoiler with LED, Blue calipers with silver decals, De-badged rear, Chrome Oil Filler Cap (thanks to Chris again), White LED dash bulbs, Blue a/c control bulbs, Blue door markers and interior lights, Sony head unit, Chrome Lexus tax disc holder, TRD side skirts, Original Saloon Front Bumper re-fitted instead of Sportcross
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