GT350 Dyno Tune - JPC Racing/HP Tuners

[Nataphen]

Each dyno has a different scale for hp and tq if you look at the numbers. They do look weird, but they're accurate.

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[tdzee]

HP and TQ do not cross at 7200 RPM.

I believe they cross at 5252 when both vertical axes are scaled the same. The initial 350 dyno was scaled the same, but the others are not.

 

[flaps]

Very interesting. I never noticed that. Most of those dyno graphs look like mountain ranges. Is that because of tuning for the track or because of the characteristics of a FPC engine?

It is because the engines are set up for top end power with huge valves and high lift/duration cams. This works great at high RPM giving a ton of power but it takes away from low-end torque. At low engine speeds, big valves and high lift cause the air to enter the cylinders at lower velocity so the fuel and air can't mix as well as they can when the velocity is higher. Lower lift/duration cams and smaller valves like in a truck engine give good air/fuel mixing at low RPM giving you good torque, but can't flow as much air at high RPM taking away top-end power. Variable valve timing can help, but it can only do so much. You basically have to sacrifice your low-end torque in order to make power at 8000+ RPM.

 

[Lucky7s]

Wish Ford would develop a V-8 VTEC (I.e Split Cam, low end lobes for torque, High end lobe for high RPM breathing for top HP) but Honda owns the patents and wont release them to anyone. :rant:

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