Yesterday I met up with budhayes3 and creederado at TTP Performance for their monthly dyno day. The weather was bad, but we had a good time and I'm glad I finally got to meet these guys and the crew at TTP.

My first run was in 3rd gear, until the factory speed limiter kicked it at 4100 rpm - stupid stock tune

231 hp and 297 torque

The rest of the runs were done in 2nd gear up to about 5900 rpm

260 hp and 279 torque

I know that power is lost when you dyno in anything other than 3rd gear, so I'd like to convert the 2nd gear numbers so I can have a true comparison after my cam and tune. Anyone know how to do that?

I also have videos of all three trucks if someone can host them for me.

 

It was a good time.
I guess I'll throw mine in

Dyno jet-
2003 GMC EXT Cab Z71
5.3/60E 3.73 G80
265/75 16 Stockers

Mods
New Volant , TB Bypass
05 Fans
Nelson 91-93 Tune

Tire limited, stopped it at 5200 it was falling off anyway.
3rd gear, TC Locked
251 rwhp
290 rwtq at 4000.
about 60 degress
sunnoco 94

I'm going back hopefully with the step side truck after I throw an exhaust on the GMC.

 

Yea I had a blast. I'm pretty bummed about my numbers though. I had the VHP hand held cam #1 tune installed for the pulls, so I could compare with my custom tune next time around. Only managed 210 rwhp and 269 ft/lb torque. My a/f ratio went rich (12:1) at about 4100 rpm...hoping that has something to do with it, along with the 285 BFG's and autotrak transfer case. Now just gotta figure out why it went rich.

It made some speed though...they said they had it over 150 mph on the first pull (up at 6200 rpm). Surprised it didn't blow the rear tires off it!

Hope somebody can host the vid! (hope to have some better #'s next time too...gotta get to the track and see if all the $$$ I spent on cam and tune can improve on my 16.5 bolt on time from last year)

 

i dont guess the 285's killed your hp numbers..

I know with the ls1's/fbodies the bigger the tire, the worse the hp numbers will be.. you probably lost maybe 15hp there if im thinking right? I know my 285's slowed the hell outta my truck!

 

I know that power is lost when you dyno in anything other than 3rd gear, so I'd like to convert the 2nd gear numbers so I can have a true comparison after my cam and tune. Anyone know how to do that?

I had to dyno mine in 2nd gear about 1 1/2 years ago and asked the same question. Consensus was to add about 20 hp and tq to your dyno #s.

 

next question.. how are you guys making sure its in 3rd gear? just and FYI if i ever dyno my turd

 

We didn't drive em up on the dyno ourselves, the guys at TTP did. I assume that they manually shift it and hold 3rd.

 

Just put it in 3rd. Run thru the gears to 3rd. Make sure you get above the speed were it drops back to 2nd and then nail it.

 

They had to do tdrumm's runs in 2nd gear because the speed limiter kept kicking in in 3rd. Creed and I did ours in 3rd.

 

Stupid speed limiter. You can see the truck shut itself down in the video. Can't wait to get rid of that.