SN95 TB VS Fox TB dyno comparo.

Venom351R

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Apr 27, 2002
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I have a dyno apt today at 4:00 PM. While this comparison wont be under ideal conditions It's the best I can do in my situation. The dyno run's will be just about one year apart but it will be during the same time of year weather wise (first run was july of 09) but as we all know weather can change drastically from day to day let alone from one year prior. Last year when I went the weather was warm and sunny, today is going to be cool and cloudy w/ a chance of showers. I'm bringing up the weather topic b/c as we all know dyno #'s can change based on this so if my numbers are different by not that much we can probably notch it up to that. If not then perhaps there is more power to be had w/ the fox TB set up. I'll list my previous and current set up and I'll post the results w/ a graph once I get back later today.

Previous set up:

95MM Velocity meter, C&L pipe, Edelbrock/BBK 75MM Throttle Body,

Dyno numbers at this time, 338RWHP 342 RWTQ


Current Set up:

PMAS 95MM Velocity Meter, Anderson 4" Power Pipe, Accufab 75MM Thottle body

Dyno Numbers : Pending......
 
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I edited the first post. I forgot I had the car tetuned as well w/ the velocity meter and it put down a little more, also that was done back in july of last year.


I have 4.10's now, before I had 3.73's. I didnt think that would make a difference in power over all numbers though.:shrug:
 
I edited the first post. I forgot I had the car tetuned as well w/ the velocity meter and it put down a little more, also that was done back in july of last year.


I have 4.10's now, before I had 3.73's. I didnt think that would make a difference in power over all numbers though.:shrug:



If it's a Mustang dyno, the gears really make no difference.
 
Not as certain about gear ratios on a dyno-jet. I've seen reference to software compensation for gear ratios on dyno-jets but don't know how accurate or uniform they are from one dyno to the next.

One reference I looked into suggested that gears have a much larger impact on HP numbers than they do on a Mustang dyno since dyno-jets measure HP based upon how quickly you get a known mass to X speed wheras the Mustang dyno applies additional (and variable) resistance throughout the pull to compensate for driveline.
 
Well, according to an article I found, numerically higher gears will actually REDUCE your hp on a chassis dyno. "Higher numerical gears tend to be more inefficient, so as gear ratios increase numerically, power levels tend to slightly drop, particularly on an inertia dyno." It goes on the explain why...

Chassis Dyno Guide - Transmissions And Final Drive Ratios - Hot Rod Magazine

Don't know how good that info is, but it is the first thing that popped up and seems to be a pretty thorough examination of the chassis dyno.
 
humm interesting stuff either way. Guess I'll just have to wait and see what the result is myself. I'll ask the tuner as well when I am there as far as if it makes a difference on his dyno
 
What were your comparos and results?

Here's the thread. The pics are gone as mustangmods went belly up and that was where I had all of my pictures hosted. The results were 9rwhp/5rwtq between a 65mm 94-95 setup with a ported elbow and a 75mm fox TB setup on the same dyno on the same day on my 331 combo.

http://www.stangnet.com/mustang-forums/753489-back-back-fox-versus-94-95-tb-dyno-results-inside.html


Edit, here is the pic that doesn't show up in the other thread:

My results:

paulriva6-13-08foxvssn95TBSTD.jpg
 
Its not going to be a good comparison if a significant increase is noticed if at all. Because not only is it a different brand T/B but you also changed to that 4" power pipe. And killercanary you also went from a 65 to a 75 so that alone could have been the bigger difference.
 
what intake do you have?

I can see getting a slight gain if you are currently using an intake elbow because those aren't actually "curved" like a stock '94/5 GT or Cobra intake, but usually angled with a sharp turn into the intake.

I'd like to see a same day comparison of a '94/5 Cobra (or stock) intake with a 65mm TB then swap to a fox style Cobra (or stock) intake and 65mm TB setup.
 
GTA_V6_Mustang said:
Because not only is it a different brand T/B but you also changed to that 4" power pipe.


Does not matter what brand throttle body it is, its the fact its the same size.

The change to the 4" power pipe goes along w/ the TB swap b/c its a comparison of of 94/95 set up to fox set up. Both set ups had the filter placed in the engine bay. This is not just for the "TB" aspect, its about the entire set up
http://en.wikipedia.org/wiki/Comparison_of_wiki_software
 
people are always ready to call BS when its not their money they are spending on multiple dyno runs.....Any info you get is good info for anyone on the fence with the swap.

It does give me a thought though for something maybe i can talk to someone at work about.