How to dyno an A4???
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
How to dyno an A4???
I'd like to get my car on the rollers sometime soon to make sure my output is where it should be. Question is, what is the procedure for performing a dyno run on an A4?
In a stick-shift, you would put it in 4th (1:1) and floor it up to the limiter. However, if you do that in an automatic, it will downshift. The only gears on the A4 that won't downshift are 1st and 2nd, so do you have to do the run in either of those gears instead and then calculate-out the torque multiplication?
What about the converter being locked versus unlocked? I guess you could put it in 'D' and wait until the TCC engages (45mph), but then as soon as you floor it, the TCC will disengage and the tranny will downshift.
:confused:
Cheers,
Ian.
In a stick-shift, you would put it in 4th (1:1) and floor it up to the limiter. However, if you do that in an automatic, it will downshift. The only gears on the A4 that won't downshift are 1st and 2nd, so do you have to do the run in either of those gears instead and then calculate-out the torque multiplication?
What about the converter being locked versus unlocked? I guess you could put it in 'D' and wait until the TCC engages (45mph), but then as soon as you floor it, the TCC will disengage and the tranny will downshift.
:confused:
Cheers,
Ian.
Racer
Joined: Jul 2002
Posts: 267
Likes: 0
From: Minnetonka MN
Re: How to dyno an A4??? (i_york)
Option 1. This will yield unlocked TC results in your final numbers.
1. Turn off Traction control.
2. Shift into 3rd gear.
3. Run the car up to about 70mph so that the transmission has actually shifted into 3rd gear. At this point the dyno operator should start the run and you would must floor into until redline.
Option 2. Either of these will yield in Locked TC results.
1. Using a Tech 2 or AutoTap, set the Gear to 3rd and Lock the Converter before the run.
2. Turn off Traction Control.
3. Shift into 3rd.
4. Once you start the wheels moving, bring the car to about 2000 rpms, have the dyno operator start the run and floor it.
Regardless of which way you go, any shop who has a dyno should know the proper way to get your car tested. However some of the shops will not have have a tech 2 or autoTap software or may even know about these tools (scary thought) in order to get locked converter results.
Also, there may be other options as to the correct procedure, and maybe I am missing a step or two, so if this is the case someone please chime in. But these are the basic procedures I am aware of.
1. Turn off Traction control.
2. Shift into 3rd gear.
3. Run the car up to about 70mph so that the transmission has actually shifted into 3rd gear. At this point the dyno operator should start the run and you would must floor into until redline.
Option 2. Either of these will yield in Locked TC results.
1. Using a Tech 2 or AutoTap, set the Gear to 3rd and Lock the Converter before the run.
2. Turn off Traction Control.
3. Shift into 3rd.
4. Once you start the wheels moving, bring the car to about 2000 rpms, have the dyno operator start the run and floor it.
Regardless of which way you go, any shop who has a dyno should know the proper way to get your car tested. However some of the shops will not have have a tech 2 or autoTap software or may even know about these tools (scary thought) in order to get locked converter results.
Also, there may be other options as to the correct procedure, and maybe I am missing a step or two, so if this is the case someone please chime in. But these are the basic procedures I am aware of.
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
Re: How to dyno an A4??? (brialex42)
Option 1. This will yield unlocked TC results in your final numbers.
1. Turn off Traction control.
2. Shift into 3rd gear.
3. Run the car up to about 70mph so that the transmission has actually shifted into 3rd gear. At this point the dyno operator should start the run and you would must floor into until redline.
Option 2. Either of these will yield in Locked TC results.
1. Using a Tech 2 or AutoTap, set the Gear to 3rd and Lock the Converter before the run.
2. Turn off Traction Control.
3. Shift into 3rd.
4. Once you start the wheels moving, bring the car to about 2000 rpms, have the dyno operator start the run and floor it.
1. Turn off Traction control.
2. Shift into 3rd gear.
3. Run the car up to about 70mph so that the transmission has actually shifted into 3rd gear. At this point the dyno operator should start the run and you would must floor into until redline.
Option 2. Either of these will yield in Locked TC results.
1. Using a Tech 2 or AutoTap, set the Gear to 3rd and Lock the Converter before the run.
2. Turn off Traction Control.
3. Shift into 3rd.
4. Once you start the wheels moving, bring the car to about 2000 rpms, have the dyno operator start the run and floor it.
Cheers,
Ian.
Racer
Joined: Jul 2002
Posts: 267
Likes: 0
From: Minnetonka MN
Re: How to dyno an A4??? (i_york)
The tranny is computer controlled.
If you are using the tech 2 or autotap, you can lock in the gear you want as well as the TC mode (Locked or Unlocked)
If you are using option 1, the speed sensor will detect that you are above the 2nd gear threshold and accelerate only in 3rd gear. Depending on TC and gearing you may have to find that point. For example when my car was stock gears and TC.. this was around 70mph. Now with 3600 stall converter and 3.42 gears, this is around 80mph.
If you are using the tech 2 or autotap, you can lock in the gear you want as well as the TC mode (Locked or Unlocked)
If you are using option 1, the speed sensor will detect that you are above the 2nd gear threshold and accelerate only in 3rd gear. Depending on TC and gearing you may have to find that point. For example when my car was stock gears and TC.. this was around 70mph. Now with 3600 stall converter and 3.42 gears, this is around 80mph.
Melting Slicks
Joined: Mar 1999
Posts: 2,499
Likes: 0
Re: How to dyno an A4??? (brialex42)
The tranny is computer controlled.
If you are using the tech 2 or autotap, you can lock in the gear you want as well as the TC mode (Locked or Unlocked)
If you are using the tech 2 or autotap, you can lock in the gear you want as well as the TC mode (Locked or Unlocked)
Drifting
Joined: Dec 2002
Posts: 1,472
Likes: 1
From: Reynoldsburg oh
Re: How to dyno an A4??? (mfrnka)
The best way is to use option 1. The person with the dyno should know how to do it. If they dont, then dont dyno your car there. As in mine, they put it in 1st and took off easly, shifted to 2nd manually, then to third, kept it in 3rd till about 75ish or 3k on the rpm. By this time your car should be at a speed where its like driving on the freeway, go a certain speed and floor it and it will not downshift. Then just floor it and keep it floored until you want to shut down or you hit the rev limiter, but I wouldnt take it that far.
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
Re: How to dyno an A4??? (sprayedc5)
The best way is to use option 1. The person with the dyno should know how to do it. If they dont, then dont dyno your car there. As in mine, they put it in 1st and took off easly, shifted to 2nd manually, then to third, kept it in 3rd till about 75ish or 3k on the rpm. By this time your car should be at a speed where its like driving on the freeway, go a certain speed and floor it and it will not downshift. Then just floor it and keep it floored until you want to shut down or you hit the rev limiter, but I wouldnt take it that far.
Will this have any effect on the numbers?
Will the dyno correct for this?
Have can I correct for it?
Cheers,
Ian.
:cheers:
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