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Load on car during Dyno run?

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Old Nov 3, 2004 | 09:05 PM
  #1  
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Load on car during Dyno run?

I'm waiting for the Rtek7 1.7 ECU to arrive so I can install it along with my new GReddy 720cc secondaries. I'd like to run the car on the dyno afterwards but I have no further boost control than the stock wastegate. It's an S4 gate and it's been ported but I still get creep up to 13 psi in third gear @ WOT (should be fine with the rtek7 1.7). BUT, if/when I put the car on the dyno, will the car be under more load (has to turn those big rollers) and therefore produce MORE boost? The last thing I want is to creep further and toast my new motor.

Thanks!!

Jon
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Old Nov 3, 2004 | 09:51 PM
  #2  
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From: BC, Canada
It will be under less load than street driving, not more.
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Old Nov 4, 2004 | 08:30 AM
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Originally Posted by scathcart
It will be under less load than street driving, not more.
How is that possible...don't those big rollers equate to more rolling resistance?
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Old Nov 4, 2004 | 09:08 AM
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damn I had my wastegate ported and thing won't go past 5.5lbs for ****! Did you just port to the stock flapper or did you port past it? I don't think I would run any dyno runs until you can control your boost because hopefully you are tunning as well and if you are tuning and you are mearly tuning to a boost spike or creep and it goes past that creep level then it is going to damage the engine. Also is your boost creep relatively the same every time or is differant depending on conditions??? I don't know I would rather have a constant boost preasure than relying on boost creep.

Last edited by hondahater; Nov 4, 2004 at 09:12 AM.
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Old Nov 4, 2004 | 09:29 AM
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The boost I get is consistent...10 lbs in 2nd gear, 12 in 3rd and 13 in 4th. Outside temps have no effect (yet). I realize that aerodynamics won't be effecting the car but those rollers need more torque to move than a car on pavement, correct? And wuoldn't that equate to more load, and therefore more creep?
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Old Nov 4, 2004 | 09:35 AM
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Originally Posted by jon88se
How is that possible...don't those big rollers equate to more rolling resistance?
The roller drag represents the weight of the car, but the dyno has no equivalent of aerodynamic drag.

The torque & RPM's measure the same no matter how the load is applied.
The only difference is how long you hold the load, and how much ram air is pushed through the IC.

Last edited by SureShot; Nov 4, 2004 at 09:40 AM.
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Old Nov 4, 2004 | 07:05 PM
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From: n
It depends on the dyno...
Most DynoJets induce less resistance than driving on the road, unless it has the fancy load cell attachement.
A Mustang Dyno already has a load cell attachment as standard equipment, and this can be manipulated to put more or less load onto the vehicle.


-Ted
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