Dyno readings question

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Sep 13, 2008 | 09:24 PM

black_89_vette

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Melting Slicks

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From: Winchester Ontario

Dyno readings question

Say an engine put out numbers, but the readings were 1000 RPM off, what would change about the hp numbers?

Since hp is derived from torque calculations, if it were reading peak tq at 3200 rpm and it should have read 4200 rpm, would this change the number it gave for hp?

Thing is a friends DIY dyno gave numbers on a friends car that said 456 tq @ 3200 and 320 hp @ 4000 or close to it.

Since we believe the dyno numbers to be off by 1000 rpm, would it change the 320 hp number at all since the calculations would be 1000 rpm off?

Turbo car.

Sep 13, 2008 | 10:38 PM

Zix

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From: Phoenix AZ

Dynos read spark right from the plug-wires usually I think, so even if the tach in the car is off the dyno should still be correct.

EDIT: what's a DIY dyno?

Sep 13, 2008 | 11:07 PM

black_89_vette

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Melting Slicks

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From: Winchester Ontario

A Do it yourself dyno. Basically it's not a dynojet or mustang dyno. It's one that the guy bought and assembled.

Sep 14, 2008 | 12:17 AM

Zix

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From: Phoenix AZ

Quote:

Originally Posted by black_89_vette

A Do it yourself dyno. Basically it's not a dynojet or mustang dyno. It's one that the guy bought and assembled.

Where does it read the RPM from?

Sep 14, 2008 | 03:17 AM

65Z01

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From: SE NY

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Quote:

Say an engine put out numbers, but the readings were 1000 RPM off, what would change about the hp numbers?

Of course, since HP is simply an mathematical entity calculated from torque & RPM.

Sep 14, 2008 | 06:25 AM

black_89_vette

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Melting Slicks

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From: Winchester Ontario

That's what I figured Jim. The hp numbers seemed low, it's a tune in progress at the moment. But since hp is just a mathematical calculation from tq, I wonder if you could somehow extrapolate what the hp numbers would be.

Sep 15, 2008 | 03:59 AM

BlackHarleyMan

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From: Winchester Virginia

Quote:

Originally Posted by black_89_vette

that's what i figured jim. The hp numbers seemed low, it's a tune in progress at the moment. But since hp is just a mathematical calculation from tq, i wonder if you could somehow extrapolate what the hp numbers would be.

hp=tq*(rpm/5252)