Dyno Research from 2002-2011

[Chapel]

I've been researching dynos for YEARS. I think at this point I'm nearly 9 years of testing and researching.

Before I go into a ton of detail, I thought I'd share some documents and articles with you that have already been written:

Sport Compact Car - August 2004 - What's Wrong with Your Dyno?

Car and Driver - Is your Dyno Lying? - May 2004

I have another one from this month's Hot Rod Magazine doing about the same thing with a Shelby GT500 Super Snake. I'll try to get it scanned in.

I personally have had experience using:
Dynapacks
DynoJet 224s
Dynojet 248s
Dyno Dynamics
Mustang MD-1100SE
Land and Sea DynoMites

I have done some paper-only research on
MAHA LPS3000
Superflow
Rototest
Dynamic Test Systems

I'm nearly ready to complete my research and put it all into a nice written document for everyone to read.

[Dubmekanik]

Very interested to see the end result. Very interested in this topic as well!

[Dubmekanik]

[Chapel]

One more dyno day before I finish

[Vegeta Gti]

[Arizman3]

[Chapel]

ah crap... right... need to finish this don't I?

[Aguilar]

Yes please.

[Chapel]

Yes please.

if anyone has any questions they'd like to ask, maybe it'll get me through my writer's block...

[02vwgolf]

if anyone has any questions they'd like to ask, maybe it'll get me through my writer's block...

Is there any truth behind the 12% estimate in power difference between Mustang dyno's and dyno-jets? I got dyno'd last summer on a mustang dyno, and after numbers lower then I was expecting I found online that there seems to be a trend of about 12% for identical cars on either type of dyno...

If anyone knows the truth it sounds like you may be the one

[Chapel]

With my E30 BMW, I was seeing about 12% loss at the rear wheels on a DynoJet 248C and 224X. with the same car on a Mustang MD-1000 was an 18% loss (estimating approximately 170bhp)
Weather conditions were similar
This is obviously for a 2WD vehicle.

I have NEVER used a 4WD intertial Dynojet unfortunately, so I can't say.

[Dubmekanik]

Did you have the engine from this car on an engine dyno outside of the chassis?

[Chapel]

Did you have the engine from this car on an engine dyno outside of the chassis?

I did not. It's the only thing I've not done.
Though a good running E30 with some mileage with an exhaust should make about 170bhp (stock is 168bhp)

Though we assume a base estimate of crank power (in this case 170) so that when we take those baselines to another dyno, we assume the same crank and work out the information on dyno loss.

[Dubmekanik]

As you know, all engines are different. Estimated figures from manufactures are all over the map. Mileage makes a difference, too. Until someone takes an engine out and has it measured, then installs it back in the chassis and also has it measured that is the only way we can APPROACH the estimate of drivetrain loss. And then only for that particular year/make/model of vehicle..Then you would have to take an average of the top few different dyno companies, because there are differences there too. Thanks for your input, though! This thread's been dead for quite a while!

[Chapel]

As you know, all engines are different. Estimated figures from manufactures are all over the map. Mileage makes a difference, too. Until someone takes an engine out and has it measured, then installs it back in the chassis and also has it measured that is the only way we can APPROACH the estimate of drivetrain loss. And then only for that particular year/make/model of vehicle..Then you would have to take an average of the top few different dyno companies, because there are differences there too. Thanks for your input, though! This thread's been dead for quite a while!

exactly, but setting a control number still makes sense. The EXACT losses are always going to be estimated for ALL dynos.
when I say 12% for a dynojet and 18% for a Mustang... that's not ALWAYS the case. Weather conditions are important as well. Also, some dynos are calibrated differently as well.