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Discussion Starter · #1 ·
Just borrowed one of these gizmos and did an uncalibrated run just to see what the software will do. I have down loaded the data but cannot seem to display it on a graph, as I should be able to. Has anyone used one of these and been able to do this?

Have done my coastdown figures and will do some proper runs tomorrow,
Thanks,
Andy
 

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Discussion Starter · #2 ·
had a play today, but it started raining after about half an hour.
Best 0 - 60 time was 6.43secs, but I am sure that can be improved upon when I master the 1st to 2nd change!
Showed 307bhp at 57 mph. Does this sound correct as I thought the AP22 gave power at the wheels, not the flywheel, if so this can't be right, as thats kind of the flywheel figure I would expect on a Stage 3 with high flow intercooler, Abbott intake pipe and diy airbox mod.
Used the following to calibrate :
Weight: 1500Kg
CdA : 0.95
Roll Resist .016
Does that sound accurate to anyone who has used one of these magic boxes?
 

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I think a little optimistic...
Showed 307bhp at 57 mph. Does this sound correct as I thought the AP22 gave power at the wheels,[/b]
307 atw....that what mine does !!

I would guess you are up there as far as "at the flywheel" the stock fuel/turbo is running out of steam at 300 atf ...

There are a few aero's with your kind of mods at the 300 level (atf)
 

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Andy,

Try to always have a full tank of fuel and a similar overall weight to make readings reliable between runs on different occasions.
I use a cdA of 0.87 a rolling resistance of 0.012 and found the weight of the car [which is a '93 Aero] (including a driver, a passenger and a full tank of fuel) to be 1630kg (on a local weighbridge).

HTH.
Nick.

PS. I get around 220 bhp at the wheels with these figures inputted.
 

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Discussion Starter · #5 ·
Originally posted by ylee coyote:
[qb]I think a little optimistic...
  [/qb][/b]
That's what I was trying to say, I know I havn't got that much...........yet
Just wondered which of my set up figs were wrong, though that seems to have been answered above too.
If as I expect, I am around 300 at flywheel, what should I expect to see via the AP22 ( at the wheels)?
Thanks
Andy
 

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Two things: First off, increasing the mass of the vehicle + passengers will only futher inflate the power value. The power is directly proportional to the mass.

Second, the AP22 is a dual axis accelerometer. On inherent flaw in such units is that they cannot differentiate between gravitational acceleration and acceleration due to your go pedal. If your vehicle happens to squat upon acceleration so that the rear is lower than the front, the unit will measure your actual acceleration plus a contribution due to gravity (since the rear of the car is "downhill" from the front). This will give you inflated estimates of acceleration and power.

I imagine that the users who experience the most inflated values still ride stock suspension such that the vehicle squats more under acceleration than other user's rides with stiffer springs etc.

The only solution to this problem is to use a 3-axis unit that can identify the vertical (gravitational) component of acceleration, and therefore account for vehicle squat. I guess you could also have rock-hard suspension installed
 
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