Shift Point

[JimNolan]

Guys,
   I've got another question and it's about shift points. My car won't set the world on fire when it comes to going thru the quarter mile but since I'm bound and determined to tear it up I'd like some advice on shift point. I know I should get my car dynode but I'm scared shitless of that. I've watched a couple guys hook their cruisers up to a dyno at some of the shows and watched them call a wrecker to get them back home after the guy laid on the gas until it blew up or had a fan belt dent the hood.
  Do you look at highest average HP or average Torque to ball-park where you should shift. Or do you have to consider both. I've got two software programs that give me different HP and Torque calculations but both are the same where it comes to the graph. Other words one gives less rpm and hp calculations but both programs coincide with the curve (rpm) to get the results.
A ball park answer will suffice also. It's not like I'm shaving tenths here and I'm not getting ready to go professional. lol  Thanks guys.

[fastback 427]

I think it would depend on many things. Your going to have to find out what your car likes. If your bracket racing consistincy is key. That's why I'm not a bracket racer. If your looking for the best et that will take more than a few passes. You could start out with a lower shift point and move it up until the car slows down. I think there was a similar post a few pages back with a lot of good info......

[jayb]

Fastest way down the quarter mile is to maximize the area under the horsepower curve.  The horsepower curve always peaks at a higher RPM than the torque curve on our engines.  So, a good rule of thumb would be to shift five hundred RPM past the horsepower peak for the quickest times.  Assuming, of course, that your engine can handle that RPM level.

[JimNolan]

Jay,
   My peak power is suppose to be at 5000 rpm and that's where I've been shifting. I've got cast pistons and hydraulic valves in this engine. When I had Scott make the cam I specified 5000 because I wanted the benefit of the cast pistons and hydraulic valves gave me.

[My427stang]

Like Jay said, my hunch is shift at 5400-5500.

[machoneman]

2X to shifting a tad past max hp range. If 5K is your max, as stated 5500 should do. Still one can sneak up at it by shifting say 200 rpm higher, check the e.t., then 5400, etc. It's entirely possible too that even a 5,700 rpm point may result in the best e.t's although as also mentioned can the valve springs keep up? The e.t. slip is your best pal here. 

[fe66comet]

My first place to start would be my camshaft designed HP peak. Then adjust from there till your maximum speed is achieved. A good tuner shop can do wonders on the dyno and not grenade anything. Find a reputable engine builder in your area and go from there.......Jon