tw0scoops123 said:
For those of you who have gotten dyno'd:
At what RPMS do you start to lose power in each gear?
Just looking for the best shift points when I go from a stop. I think I have been hearing the fuel shutoff starts kicking in around mid 5k?
HP and TORQUE whilst being somewhat different animals, both can be charted against engine RPM, which is totally independant of which gear it is in for the most part, usually you want to "dyno" in top gear (not overdrive) as this gives a good long pull to get data.
The rate at which you get to higher rpms (redline) under load is a function of HP/ TQ/ Gearing/ Mass/ Incline/ Internal Frictional Losses/ Drag/ Hookup/ etc...
That said, all stock 2005 V-8's (not sure of V-6's, prolly similar just shifted down), have basically the same dyno signatures. Building max HP at just about 6,000 rpm and falling off after that due to many factors mostly being in the stock tune (ie, fuel shutoff after 6125 rpm, etc), and building max TQ at about 5,000-5,500 rpm, falling off right after.
I get my best shift "fun" at 5,500 and shift as fast as I can, and am able to spin the tires in 2nd and chirp them in 3rd (max TQ). For all out acceleration, I would shift at 6,000 rpm to get the last bit of accel from the HP curve (max HP) at that rpm; running an ET or "racing" a strip of street for example. This is for my manual shifts. For an automatic, I would assume you can use the same philosophy except expect more losses in the rw hp/ tq curves. An after market tuner will help you do this customizing regarding shift points optimizing.
For those with superchargers, their HP/ TQ curves are very similar except shifted up and usually HP overtakes TQ, with the additional ability to custom tune the software to get upwards of 7,000 rpm and build more HP, bypassing the shutoff assuming they have aftermarket injectors/ MAF to allow for the extra "$ucking". :shiny: