Ok here is a question for you.

[Comp Orange 04]

I posted it here because I am curious as to why my dyno graph has the torque and HP curves crossing at 4500RPM? It was brought to my attention over on mach-1.org and I thought I would post here also. Most of the dynos I reviewed over there cross around 5000-5300 RPM. Any help would be appreciated.

[PapaTango]

I may be way off base here but doesn't it seem that your peak HP reading is at a rather low 4000 rpm's? I would figure that the peak would be somewhere above 5000 rpm's, especially with a DOHC. I would say that your torque numbers are right in the ballpark.

[TexasShadow]

Originally posted by PapaTango
I may be way off base here but doesn't it seem that your peak HP reading is at a rather low 4000 rpm's? I would figure that the peak would be somewhere above 5000 rpm's, especially with a DOHC. I would say that your torque numbers are right in the ballpark.

It looks to me like the power is peaking at a little past 5000 rpm. I think you were looking at the torque curve. However, I thought the Mach1s typically peaked closer to 6000. Am I wrong about that?

[hawk]

Based on this article (http://www.epi-eng.com/FND-PwrTrq.htm), they should cross at 5252 RPM.

[PapaTango]

Originally posted by TexasShadow
It looks to me like the power is peaking at a little past 5000 rpm. I think you were looking at the torque curve. However, I thought the Mach1s typically peaked closer to 6000. Am I wrong about that?

The lower curves should be the HP readouts (2 pulls). The upper curves are the torque readings and confirm the readouts (both above 300 ftlbs/tq) at the top of the graph. I still say that the HP readings are peaking a an unusually low RPM. Also note, there is a 10 HP drop between back-to-back runs, is that normal?

Comp Orange 04, am I reading the graph correctly?

[03BlkMachOne]

I believe one run is before and the other after new exhaust.

[04azuremach]

Nothing is wrong with that graph.. they are the same at 5252 RPMS... if you look the HP and Torque axis are about 50 off from each other on each side... you have to adjust for that when you read it!

[Comp Orange 04]

Originally posted by PapaTango
The lower curves should be the HP readouts (2 pulls). The upper curves are the torque readings and confirm the readouts (both above 300 ftlbs/tq) at the top of the graph. I still say that the HP readings are peaking a an unusually low RPM. Also note, there is a 10 HP drop between back-to-back runs, is that normal?

Comp Orange 04, am I reading the graph correctly?

Yes the runs were 2 months apart, lower numbers were baseline at 1200 miles and new exhaust was at 2200 miles.

I believe 04 Azure Mach has the right answer about the graph axis numbering. I will try and replot on a graph using the same axis.

[04azuremach]

with 307 ft-lbs of torque at the wheels that equates to 361 at the flywheel with 15% loss... and our transmissions only handle 360... Good luck with that!