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Discussion Starter · #1 ·
dyno\'d today..sad, sad....????

I took my car to the dyno today. It was a dyno-jet that is on wheels.
Evidently these fellows take it to car shows etc. Well, the numbers are
low, and I am sad. There were a few caveats though.

I believe the car engine was heat soaked. I drove it, normally, an hour to get there. Then up on the ramp to the dyno. Because it was hot, I had the A/c
on and it stayed on throughout the dyno run. Hopefully that is worth another
80hp :rofl:

I never checked the tire pressure /images/graemlins/sad And they only had one fan, a small
carpet drying fan pointing at the oil cooler thru the fascia. The hood was only opened about 1-2" in front, and the back was closed lightly.

Take a peak at my curves and let me know if anything jumps out at you?
I was hoping to get around 420 at the wheels with the converter, catback, tubes
and filters I have .......

The dyno guy said 17% loss is usual from motor to wheels...so 392 with the loss = 472bhp on the motor. I think my math is correct. This still seems
low. Thanks.
 

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Re: dyno\'d today..sad, sad....????

A/C will shut off all by its self at WOT.

17% seems a little high for driveline loss. Anyway, we put a 1996 GTS on one of those car show traveling dynos and it too seem to dyno low. We knew what the car dyno'd at before (two times on different dynojets) and it came in under by more than a little bit.
 

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Re: dyno\'d today..sad, sad....????

Don't take the travel dynos to much to heart. They are not calibrated as often as their in ground brothers. As far as you know, the unit could have taken some hard hits while being transported. Take the car to a shop that has an in ground unit and retest it. :thumb:
 

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Re: dyno\'d today..sad, sad....????

Don't let the numbers bother you, BTW, Heffner and most others use a 15% drive line loss.

Have it dynoed on a stationary dynojet. Also allow for a cooldown, but do not test until the temperature is at normal operating range.
 

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Re: dyno\'d today..sad, sad....????

"Converting wheel bhp to flywheel bhp and vice versa
To reflect the fact that % losses are high for low powered cars and vice versa use the following equations which have been found to correlate well with real world transmission losses.
FWD cars - add 10 bhp to the wheel figure and divide the result by 0.9
RWD cars - add 10 bhp to the wheel figure and divide the result by 0.88
4WD cars - add 10bhp to the wheel figure and divide the result by 0.84

To estimate the expected wheel bhp from a known flywheel bhp just reverse the equations
FWD - multiply flywheel power by 0.9 and then deduct a further 10 bhp
RWD - multiply flywheel power by 0.88 and then deduct a further 10 bhp
4WD - multiply flywheel power by 0.84 and then deduct a further 10 bhp
 

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Discussion Starter · #7 ·
Re: dyno\'d today..sad, sad....????

Jerome said:
Joe I think you need to use 12% as the loss.

Where did you get this done at?

And off topic, nudie bar trip any time soon? /images/graemlins/smiles
Hey Jerome, how do? I got the car done at a place called xcelerated motorsports in Doylestown. With 15, 17, 12, and 10% drivetrain losses, the car is making anywhere between 440-470hp at the flywheel. Naturally, I like the 470 number the best. Not terrible, cause I think there is more there easily.

Big weekend coming up....July 4th. I am sure we can get some boobage action
in, one of the nights. Its seems club Rique is the place to be, so all we need
is the date and time, and perhaps some more fanciers of titallation... :nod:
 

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Re: dyno\'d today..sad, sad....????

With a hot motor, you will probably make in the neighborhood of 415/455 on a decent dyno. Cooling the engine for an hour prior to your pull will probably net you and additional 5-8hp/lb-ft.
 

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Re: dyno\'d today..sad, sad....????

Hard to see , but it looks like your car is getting pretty lean at the top end of your pull. Consider a VEC1 and you maybe surprised at the results.
 
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