How much do you guys think the torque reduction hurts a truck in the 1/4? I'm thinking about turning mine back on (in the program) when I up my boost... anybody run their truck with and without with the same tune/conditions? A good shift kit in a car is worth about 1-2 tenths...

 

I tend to doubt that.

--Joe

 

I was watching some video I made last Friday at the track of some of my 1/4 mile runs, and the 1-2 fart sound is VERY noticable! I didn't realize how noticable it was until I watched the vid... and if the boost is also dumped at the same time, it has to have an effect on your ETs. I was going to unplug my boost dump solenoid for a comparison but forgot.

 

A shift kit and the "boost dump" are 2 completely different things. I agree boost dump will harm your ET's. But a shift kit that makes your truck shift a thousandth of a second faster is not gonna give you 1-2 tenths.

--Joe

 

A "shift kit" may only help you a thousanth or two, but what about the torque reduction (fart)? That has got to hurt your ETs by at least a tenth. I have also heard that when the torque reduction initiates, so does the boost dump.

 

Without a chip the torque reduction is always there. I doubt it would be worth 1-2 tenths, but it causes loss of momentum.

The boost dumps when you go above a certain RPM which usually doesn't happen without a chip.

 

I guess none of you boys have done much sportbike riding. If you bump the rev limiter for a split second before a shift the bike beside you will jump out 2 or 3 bike lengths before you can bat an eye. The rev limiter on a bike does the same thing as our L's. It cuts off half the cylinders.

I had a fellow racer tell me that my truck came out of the hole great but during the shift he could literally see it slow down. That was before a chip.

So the torque reduction is costing you. I would say at least a tenth but possibly more. Surely you don't believe all the time reduction that comes from a chip is all HP and TQ. When you do the math on the amount of power gained from a chip there is no way it amounts to the lower ET's gained.

 

Think of it this way ; when you stop, under which conditions do you stop the fastest?

a: all 4 wheels locked.
b: lightly depressing the brake pedal
c: Who cares, hit the GAS
d: depressing the brake pedal to the point just before ABS invocation...

If you were to up the line pressure & remove the torque reduction, you'd probably get some good 2nd gear 'breaking loose' which means, your traction budget has just been busted.

If your wheels are sliding on the pavement, forward, backward or sideways, you're either at or past your traction limit. In a 4 wheek drift, you're using 100% of your available traction. The TR cuts ingnition to 4 cylinders ? how long does that take ?

I don't know the WFOT shift point, but I seem to recal something like 5250 rpms, so I'll go with that, & let someone more in the know correct me. At 5250 / 60 = 87.5 revolutions / second, or 43.75 ignition strokes / second. We're cutting 4 strokes or 8 revolutions ? that's approximately .1 second and it's just a guess, hopefully someone more in tune will chime in.

Even if my math is horribly wrong (that is a distinct possibility), it's probably still better to leave the TR in place, than beat on your trans that much more... All that energy has to go somewhere, so it's either going to break your tires loose, or, be absorbed by the hard parts of your drive train... While the former may look cool, it's costing you time, and the latter is costing you money...

Maybe you will gain 1-2 tenths that way...

The correct answer is D...

 

Dave,

Do you have a chipped L that you have ran at the track or are you just playing with your calculator. I have 2 years of experience running mine at the track with no speculation just concrete numbers.

 

Numbers, numbers? I don't see no stinkin' numbers...

I believe that was the original question - does anyone have numbers?

 

The only way to get an exact number is to have a flip chip with the same program with no torque reduction on one side.

I picked up 4 tenths with a Superchip R9 program (no shift kit) and 5 tenths with a reburn to JDM program (no shift kit). The power gained with the chip is not enough in itself to get those ET reductions.

A chip without a shift kit of some type will give you a chirp at the most on a 1/4 mile track.

 

I know just thinking about it it might not make sense that it will improve your time but a good shift kit will make a fairly signifigant difference 1-2 tenths in the quarter. MMFF did a test on a stock aod mustang and gained similar improvements. If it just penalizes me 1-2 tenths it's worth it for peace of mind if it hurts 3-4 tenths I'm not willing to leave that much on the table...

Hey ltnbolt does the statement no shift kit mean that your torque reduction was still on with those chip programs?

 

It meant no line mod valve or factory tech valve body. These devices give you the hard shifts at WOT.

It gave me peace of mind to get rid of the torque reduction. Mine took forever to shift into second and I know there was slipping going on. I've heard the newer models aren't quite as bad as the 99 - 00 models on the shifting.

JDM doesn't up the line pressure. He makes the shift duration shorter.

 

Is there anything to gain by installing a Factory Tech valve body without eliminating the torque reduction? i.e. no chip?

 

I would say yes. When I had my chip out with the line mod valve in the trans it shifted much better that stock. It even chirped the tires in second on the street.