Quick question - should one base their shift point on the Torque curve or the HP curve, or something else?

Say TQ falls off hard after 5k rpm and HP falls off hard after 7k rpm? Whick one should you be paying more attention to?

 

I think u have to factor in where u will be in the curve once u shift. Let's say u shift at 5k into 4th now u are at 3.5k with very low amount of up and torque.

Now let's flip the scenario. Let's say u shift at 7k that may put u into a better spot of your power curve in 4th. I think u need to know your power curves in all gears to find out the perfect shift points.

Or I could be completely wrong

 

Pay more attention to the HP. TQ gets you going, HP keeps you going. The load is different under drag racing compared to a dyno run anyways. Starting a dyno pull at 3000rpm is different from shifting from 2nd to 3rd at 7000rpm under WOT.

 

That's what I always heard, but when I really thought about it - in a drag race you are continuously "getting going" faster and faster, so then I got confused again.

I do have a plot of each gear vs. torque curve and also each gear vs. HP curve so I can see when power to the ground crosses from one gear to the next. Just needed to know which one to use. Sounds like the consensus is HP. Thanks!

 

What you want to try to do is keep the motor in the 'meaty' part of the power band for the entire pass.

 

Got that - just trying to figure if we were talking about "meaty" part of the TQ band or HP band. Seems like the consensus is the HP band. . .

 

Post your dyno sheet and let's analyze it together.

 

Lets use this for an example (looking at the higher TQ graph). It has a clear gap between pean TQ and peak HP.

 

1st gear 7000
2nd 7400
3rd 7500
4th complete quarter at 117-121 depending on weight of car and driver ability.

11.50's and better with 1.6x 60ft's or hire a driver!!!

 

That's about the same as what my shift-point calculator told me based on gearing and tire size. Just wanted to make sure I was in the ball park.

So far good for 60' of 1.53 and 11.000 @ 124 . . . (on my current tune - the one posted was just an example)

 

Raceweight??

Slip breakdown??

 

not bad times. what weight and tires are you on.

 

not badf at all...yess what tires

 

3100# with driver
FP Green (original version, not HTA)
Hoosier 16" QTP's on CCW 16" wheel

BEST RUN

60' ---- 1.517
330' -- 4.552
1/8 --- 7.025
mph -- 100.72
1000 - 9.173
1/4 --- 11.000
mph -- 122.76

 

^ man you alllllmost have a 10 sec car - good driving for sure!