The weather has been kinda crappy in western CO lately but I finally got a day off with the sun shining last Saturday. And the guy with the chassis dyno agreed to open up for me too. It's not often that things work out for me so I figured I best take advantage of the situation and make some noise.
For the guys that don't know here's a link to my project, 504 Highboy.
http://fepower.net/simplemachinesforum/index.php?topic=2481.0Below is the dyno sheet showing my base line pull and where I finished up after tuning. I wasn't off too far on my tune up. I went from 34 to 37-1/2 on timing. The combustion chambers in Blair's Pro-Ports don't need much timing. I tried 41 just for grins and lost 8hp. I suspect at lower elevations they would like even less than 34. The DA was 5100, which is pretty damn good for around here. In the middle of summer it's usually up around 9000.
Below is another dyno sheet showing my last 2 pulls with A/F ratio curves. The richer of the two curves was my first pull. I'm surprised at how the A/F ratio changes when the motor warms up. I took out 3 jets sizes and got just a few horses out of it.
Below is a link to a really crappy video I took. My rev limiter is set at 6500rpm. Which works out to 136mph. So you WILL hear some howling coming from my 35" BFG mudders.
Enjoy guys.
https://m.youtube.com/watch?v=ovIZPsqe__oFinal numbers to the back tires was 450 ft/lb torque and 438HP. The dyno operator had hundreds of pulls stored in his dyno computer. One thing I really enjoyed was seeing how my best curves compared to one of the guys I beat at the last mud drags. His truck is basically the GM equivalent of mine with a 620hp 572CI crate motor, except he's running a Powerglide. Our peaks were pretty similar in our curves but I beat him by half a truck.
