Dyno today...Help those with dyno experience..
Thread Starter
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Dyno today...Help those with dyno experience..
Hey guys...
I am scheduled to take my car to the dyno this afternoon. I have never been to one before and the guys that are operating the equipment are new as well. They were very straight forward and explained it may take much longer than ussuall to get things set up. They said they would be flexable with how many run they let me make.
My question is how do you guys ussually test your cars? What gear/gears, etc.
Can you kinda set the stage for me so I can stop them if they are doing something stupid. I want to get the most accurate data for tuning purposes. My track times are still a bit slow, but some may be due to the fact that the track I frequent is located at ~2000ft. With DA it may be more like 3000! My best was 13.01 @ 105. Someone corrected it for the elevation and said it was actually a 12.75@106 or 107. That is more in line of what the car is capable of, but still a bit off.
I am hoping that the dyno today will pinpoint my strengths and weaknesses. From there I can correct.
Any input on the dyno process would greatly be appreciated.
Thanks guys! :cheers:
Also guesses on HP / Torque would be fun!
[Modified by ski_dwn_it, 8:44 AM 6/6/2002]
[Modified by ski_dwn_it, 8:49 AM 6/6/2002]
I am scheduled to take my car to the dyno this afternoon. I have never been to one before and the guys that are operating the equipment are new as well. They were very straight forward and explained it may take much longer than ussuall to get things set up. They said they would be flexable with how many run they let me make.
My question is how do you guys ussually test your cars? What gear/gears, etc.
Can you kinda set the stage for me so I can stop them if they are doing something stupid. I want to get the most accurate data for tuning purposes. My track times are still a bit slow, but some may be due to the fact that the track I frequent is located at ~2000ft. With DA it may be more like 3000! My best was 13.01 @ 105. Someone corrected it for the elevation and said it was actually a 12.75@106 or 107. That is more in line of what the car is capable of, but still a bit off.
I am hoping that the dyno today will pinpoint my strengths and weaknesses. From there I can correct.
Any input on the dyno process would greatly be appreciated.
Thanks guys! :cheers:
Also guesses on HP / Torque would be fun!
[Modified by ski_dwn_it, 8:44 AM 6/6/2002]
[Modified by ski_dwn_it, 8:49 AM 6/6/2002]
Melting Slicks
Joined: Oct 2000
Posts: 3,426
Likes: 4
From: Heidelberg PA
Cruise-In V Veteran
Re: Dyno today...Help those with dyno experience.. (ski_dwn_it)
If you have an auto, I am not sure I can help. But in a 4 speed -
Shift thru the gears to 3rd with the speed at 30 to 35 mph, then when operator gives you the OK, you floor it (what a great sound). Also, check your temp to keep all runs in same temp . Mine is 171.
What type of dyno? Mustang or Dynomax.
Mustang dynos tend to give lower rear wheel HP but who cares if the HP show at the track.
Under the circumstances, I would run a few HP test to get consistancy then try to adjust items on car to see effect on HP.
Relax and have fun :cheers: :cheers:
Shift thru the gears to 3rd with the speed at 30 to 35 mph, then when operator gives you the OK, you floor it (what a great sound). Also, check your temp to keep all runs in same temp . Mine is 171.
What type of dyno? Mustang or Dynomax.
Mustang dynos tend to give lower rear wheel HP but who cares if the HP show at the track.
Under the circumstances, I would run a few HP test to get consistancy then try to adjust items on car to see effect on HP.
Relax and have fun :cheers: :cheers:
Racer
Joined: Aug 2000
Posts: 491
Likes: 0
From: Houston, Texas
Re: Dyno today...Help those with dyno experience.. (ski_dwn_it)
I've watches a whole car club get dynoed. They dyno'd the standards in 4th gear 1:1. They would start the car and start accelerating slowly through the gears until they got to 4th at about 2000 RPM then he would hit the go button on the computer and hit the gas. Depending on your gearing it might take 6-10 seconds to get to your peak HP.
I've heard of some dyno's just hitting it in an auto and letting it shift through the gears (cars bouncing up and down). I would not like that. I had a manual valve body in my 86 auto and 3rd was the only gear they dyno'd.
They can also do other things. They can hook up an air/fuel ratio (wideband o2) and give you that information.
They can do things like coast down runs to determine your drivetrain loss. (I don't believe this works because you are not under power at this time, so the tranny isn't losing any power)
They should put a fan in front to keep the engine cool and they will hook up a "timing light" to your #1 plug to get your engine's RPM
The dyno calculates horsepower based on how fast the drum accelerates. Then it backs out your torque curve using your RPM information from the pick-up on #1 plug wire.
I hope this helps.
I've heard of some dyno's just hitting it in an auto and letting it shift through the gears (cars bouncing up and down). I would not like that. I had a manual valve body in my 86 auto and 3rd was the only gear they dyno'd.
They can also do other things. They can hook up an air/fuel ratio (wideband o2) and give you that information.
They can do things like coast down runs to determine your drivetrain loss. (I don't believe this works because you are not under power at this time, so the tranny isn't losing any power)
They should put a fan in front to keep the engine cool and they will hook up a "timing light" to your #1 plug to get your engine's RPM
The dyno calculates horsepower based on how fast the drum accelerates. Then it backs out your torque curve using your RPM information from the pick-up on #1 plug wire.
I hope this helps.
Drifting
Joined: Aug 2001
Posts: 1,500
Likes: 0
From: Holliston MA
Cruise-In VII Veteran
Re: Dyno today...Help those with dyno experience.. (ski_dwn_it)
With an automatic, you're going to want to manually shift through the gears into 3rd and get the wheel speed up. When you get the wheel speed up then deliberately mash the throttle. You don't want to just floor it or the car can kick down throw things off. Run it up to redline, let off the gas, and click it into neutral. Don't step on the brakes. There's a brake on the dyno to slow you down.
Log the engine data with a scanner and store after each pull. You can spend time after the car is off the dyno looking at what each change did where and figure out why later.
Get a plan together before you go on what you want to try. More timing, less timing, more fuel pressure, less fuel pressure. Different chips. Dyno time costs money, try to be as efficent as possible. You're tuning. See what the changes do. Don't worry about peak numbers on the first trip.
Log the engine data with a scanner and store after each pull. You can spend time after the car is off the dyno looking at what each change did where and figure out why later.
Get a plan together before you go on what you want to try. More timing, less timing, more fuel pressure, less fuel pressure. Different chips. Dyno time costs money, try to be as efficent as possible. You're tuning. See what the changes do. Don't worry about peak numbers on the first trip.
Melting Slicks
Joined: Aug 2000
Posts: 2,009
Likes: 1
From: Springfield MO
Re: Dyno today...Help those with dyno experience.. (SloRvette)
Mine dynoed (similar to yours) at 281 and 337#'s. But I had a tps reading of .3 and it was pig rich. I do have the stock exhaust so realistically that should give you a 30hp advantage, but then again it takes a little bit more power to operate that auto. Good luck. I'm gonna guess right at 310 and 350
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Dyno today...Help those with dyno experience.. (ski_dwn_it)
With an A4 and that TC you won't get a pull below 3,200rpm; you will tell them where to stop the pull. In my case I had them stop at 5,200rpm, sometime after the HP rolled off.
Be sure they hook up a wide band O2 sensor and get the plot, it will be your best tuning aid.
Be sure they hook up a wide band O2 sensor and get the plot, it will be your best tuning aid.
Thread Starter
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Re: Dyno today...Help those with dyno experience.. (65Z01)
Thanks guys!
I will be sure to do all the above. I just spoke with them on the phone. They said they can't wait to see the results as well.
They said they are sick of Mustangs! Coming in with 170-200 RWHP. They obviously are Chevy guys.
I have them starting a quote on a 396 for my car! I am going to start another post asking for direction from those that have done it before. I will let you know how I do today!
Keep them coming....
I will be sure to do all the above. I just spoke with them on the phone. They said they can't wait to see the results as well.
They said they are sick of Mustangs! Coming in with 170-200 RWHP. They obviously are Chevy guys.
I have them starting a quote on a 396 for my car! I am going to start another post asking for direction from those that have done it before. I will let you know how I do today!
Keep them coming....
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Safety Car
Joined: Mar 2000
Posts: 3,581
Likes: 1
From: Springfield VA
Re: Dyno today...Help those with dyno experience.. (ski_dwn_it)
As mentioned runs should be made at 1:1. For a manual (4+3, ZF 6) its fourth gear. Automatics the run should be run with the car in D(rive) Watch the redline.
Pro
Joined: Apr 1999
Posts: 533
Likes: 6
From: Poinciana Florida
Re: Dyno today...Help those with dyno experience.. (96LT1)
Make sure they have a wide band o2 sensor so you can determine A/F ratios.
Make sure you get a fuel pressure print out.
Also, make sure the garage door in front of the Dyno is left open. This makes it easier for the car
to get a clean launch when the tyedown straps break. :D
Make sure you get a fuel pressure print out.
Also, make sure the garage door in front of the Dyno is left open. This makes it easier for the car
to get a clean launch when the tyedown straps break. :D