Thought I'd give a post and show the tale of the dyno from this weekend.

I have to say, for only having the mods i do, i am pretty happy.

chip, pulley, weld in mufflers, and cold air (which don't do anything on the dyno)

here they are

396rwhp and 493 rwtq



nice and safe a/f also.



before everyone asks, the reason the dyno didn't start picking up at 3000-3200 is because of the slick growing, the dyno won't register until it gets a constant

 

Great #'s for the Mods but the graphs don't match for HP or A/F.

Your HP curve looks way to flat and loses power with RPM. You should be gaining power up until 5100-5200 rpm.

Your A/F says max A/F is 17.5 yet the graph shows it hovers around 11.4 to 12.0.

You may want to ask your dyno person for an explanation and perhaps a "do-over."

 

Great #'s for the Mods but the graphs don't match for HP or A/F.

not sure what you mean

Your HP curve looks way to flat and loses power with RPM. You should be gaining power up until 5100-5200 rpm.

i think the graph looks pretty good, the fact that it's making almost 400 through the entire graph is great

Your A/F says max A/F is 17.5 yet the graph shows it hovers around 11.4 to 12.0.

i believe thats the max the dyno is set up to read a max of 17.5

 

When I look at the graph it looks like it starts at about 390 at 4100 then drops to about 380 at 4300; then it's around 370-375 at 5200. Most of the dyno's I've seen show the motor building power until around 5000 rpm.

I'm not trying to bash but it just looks a little different to me. Perhaps its the slciks or just the way it is tuned. I wish I had my dyno numbers handy; 390+ at 4100 rpm is alot of HP for that rpm.

 

thats what i'm saying, the truck is making good constant power

hell, it went 12.49 at 4820 pounds! with those mods, not too shabby, corrected density altitude was 500 ft above sea level for that pass

 

It's all good and that timeslip is really all that matters!

 

thought i'd bring this back up considering the nature of the 450/600 post

 

Hey Beefcake,
I'm right with on HP, but lack a bit in torque (see sig)

Great #'s anyway, and some very good E.Ts's at that weight.

Is there any advantage to dynoing with slicks or drag radials?

 

The thing that makes Beef's graphs "look" weird, is the scaling. Most dyno graphs are auto scaled, meaning the scale the hp and tq numbers based on maximum values. So if you look at the HP side of the graph, it may go from 0- 400 and then the torque side may go from 0-500. That's the most common way, and that gives the nice "curved" graphs. Beef's graph had both hp and tq set at 0-500, so it's flatter. BUT, since his graph is equally scaled, you can see how the curves cross at 5250, which is something that's always questioned by people (all hp and tq graphs should cross at 5250).

 

Being that the run STARTED at 4200rpm and HP/TQ went down from there, it makes me wonder how much higher the HP/TQ would have been if it was started around, say, 3800rpm. Are we to assume that the second the run was started at 4200rpm is where it makes the most power? How can we know for sure that it wasn't making more power a bit lower in the range as the graph only goes down in HP/TQ??

 

i would like to get the street tires on and dyno the truck so that it kicks in about 1000 rpms early, would be very interesting.

i was at the track racing, that's why the slicks were on the car.

it is possible that the slicks could either help or hurt, not really sure, i know the slicks are lighter, so thats less rolling resistance, but, that is the power the truck is making going down the track regardless

 

Thanks for pointing out the scale Sal. I've not seen them done like that and overlooked it.