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Discussion Starter #1 (Edited)
So I used the program a couple of months ago to get a baseline and while they seemed low the numbers were reasonable.

I just installed a pair of ARH 1 3/4's on my RT and now the program is acting weird and giving me unrealistic values.

The logs I ran were a 0-70 and a 50-100 so its not all in one gear. I dont know if that has anything to do with it just thought I would put it out there.

I logged vehicle speed MPH rather than the x64 but I cant see how that would throw it off that much.

Any ideas?

Although I would be stoked to have these numbers I know its unrealistic for just a header install/custom tune. What really makes me not trust it is the 440hp chart on the first run..
 

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To get an accurate read with TT Dyno, it needs to be done in one gear. From my experience, 3rd gear works well. Just make sure you have a good open, deserted stretch of road; and be safe.

"Before going to wide open throttle (WOT), select a gear like second or third where you are able to hold full throttle all the way to redline (or wherever you feel comfortable running your vehicle) safely/legally."

TT Dyno User Manual
 

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Discussion Starter #4
To get an accurate read with TT Dyno, it needs to be done in one gear. From my experience, 3rd gear works well. Just make sure you have a good open, deserted stretch of road; and be safe.

"Before going to wide open throttle (WOT), select a gear like second or third where you are able to hold full throttle all the way to redline (or wherever you feel comfortable running your vehicle) safely/legally."

TT Dyno User Manual
Ya I figured it had something to do with the way I logged it.

I did a proper 2nd gear and then a 3rd gear log and got two different numbers. Which gear is supposed to be 1:1 in an auto?
 

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Ya I figured it had something to do with the way I logged it.

I did a proper 2nd gear and then a 3rd gear log and got two different numbers. Which gear is supposed to be 1:1 in an auto?

4th gear is 1:1 but it isn't safe to pull a run with that on regular roads, which makes 3rd gear ideal.

Looking at your TT Dyno post, change the following:

Frontal Area = 25.30

Also, for drivetrain loss, if you pull in 3rd gear, use 0.07 as a starting point and you should see very similar #'s to a real dyno. The 0.07 was the reference point used from the writer of TT Dyno and takes in consideration the drivetrain loss as well as the gearing difference between 3rd and 4th.
 

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Discussion Starter #6
4th gear is 1:1 but it isn't safe to pull a run with that on regular roads, which makes 3rd gear ideal.

Looking at your TT Dyno post, change the following:

Frontal Area = 25.30

Also, for drivetrain loss, if you pull in 3rd gear, use 0.07 as a starting point and you should see very similar #'s to a real dyno. The 0.07 was the reference point used from the writer of TT Dyno and takes in consideration the drivetrain loss as well as the gearing difference between 3rd and 4th.
Awesome thanks for the tip.

Since both pulls were at 0 drive train and the same frontal area I think its the best I can get for a before/after comparison, but I would love to get it as close to a real dyno as possible.
 

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hmm are you sure about the frontal area? The numbers seem a little high for the mods I have.

Edit: I see the frontal area is correct but the .07 seems to inflate the numbers a little.
The .07 is an estimate for flywheel hp/TQ. You can also go to 0.09 and that might get you in the proper flywheel range. If you leave it at zero, that will be rwhp/rwtq.


Sent from AutoGuide.com App
 
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