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Discussion Starter · #1 ·
Had a blast everyone... just makes me want to spend more $$$ so I can see what kind of improvements I can make!


Here is my setup:

289 .030 over - original heads (ported - micro polished - tapped for rocker arms)
Comp Cams Xtreme Energy Cam - Comp Cams Pro Magnum Hydraulic Lifters
Comp Cams Aluminum Roller Rocker Arms

Holley 4160 600 CFM - Edelbrock Performer 289 intake
Hooker Comp Ceramic Headers - Custom 2 1/2" dual exhaust and X-Pipe
Flowmaster Delta flow 3 chamber

And here are the results of my four runs:
http://home.nc.rr.com/hot67ponypage/images/Dyno_run_4-22-2006_RPM.jpg



Let me know what you think,

Scott

_________________
My Pony Page

<font size=-1>[ This Message was edited by: sbrickell on 4/23/06 2:28am ]</font>
 

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On 2006-04-23 07:37, mstngjoe wrote:
Nice numbers!

What tuning changes did you make between the 1st and last run?
I'll be honest, the biggest reason for the performance jump was the fact that the first two runs were done through 4th gear; the last two were done through 3rd gear...

My gearing sucks... I am still using the original 4spd toploader and the 2.79:1 rear (great for interstate!).


Changes were as follows:

1st run was a baseline - 2nd and 3rd runs were mainly timing adjustments (I started with 39 degrees total - 13 initial, ended up with 36 degrees total) - 4th run we added the lightest secondary spring possible which opens the secondaries much earlier.

Check out the air fuel ratio and you can see the 4th run where the secondaries kicked in much quicker (at about 2,900 RPM's):

http://home.nc.rr.com/hot67ponypage/images/Dyno_run_4-22-2006_AFR.jpg

Before I went to the Dynojet, I added the softest springs possible to the distributor to open the total timing advance as quick as possilbe (the old springs were so old, it was hard to even pull them apart). I also changed the fuel filter and some other small miscellaneous things that probably made no difference.

It was recommended for me to add a 1/2 inch spacer to my Holley to cool it down a bit... I have plenty of room under my hood given the Shelby style scoops.

I have some video I hope to post this week; I need to get it from my buddy who took the shots.

Scott
 

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That's cool, we have similar builds, your heads flow better i'm sure, do you have the 1.78 int, 1.45 exh valves still or did you go bigger? Have you run the 1/4 yet? car looks great....nice #'s....
 

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On 2006-04-23 09:26, sbrickell wrote:
On 2006-04-23 07:37, mstngjoe wrote:
Nice numbers!

What tuning changes did you make between the 1st and last run?
I'll be honest, the biggest reason for the performance jump was the fact that the first two runs were done through 4th gear; the last two were done through 3rd gear...
To make accurate and valid evaluations, the ratio should be 1:1 on the gearing when on a chassis dyno.
 

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It can't be that big of a deal... would be the same as if he was running 4.10 gears instead of 3.50... the dyno should still read accurately.
 

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Right, it says always test in the SAME gear (generally 1:1), and that having a lower (numerically higher) gear reduction can decrease power readings because more inertial energy is going into accelerating the drivetrain/engine and less into the dyno. As long as you always test in the SAME gear, all variables are equal and you will still be able to optimize your tune. I think it would be more accurate to say "always dyno up to 100mph wheel speed" or something similar, than to say "always dyno in the same gear", that would give more meaningful comparisons.
 

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Technically with a lower final gear ratio, you're making less effective torque due to mechanical disadvantage to a higher ratio, but a higher numerical gear requires you be making more power to achieve the same torque.

Horsepower considers torque across a distance, torque is instantaneous.

Good numbers, I was going to say it looks like you did a bit of tuning - there was much less detonation in the later runs. Then I saw your A/F reading, and knew that was it.

Good power with those heads!
 
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