Stock PCM

[Tim W]

Hi yall this is my very first and I was actually referred over here from the folks at GMT 400 forum.

Let me tell you what i have going on. I have a 1994 chevy 1500 single cab step side. The motor is a professionally built mild vortec 383 stroker with a LT4 hot cam. The truck is fueled by a Holley Sniper EFI, holley Fuel pump, HyperSpark Coil, Ignition, coil, and Distributor. My built 4L60E transmission is still being controlled by my stock PCM since the sniper only controls the EFI.

In case it matters here is my transmission specs.

"High performance pump with high rpm pump rings, Torrington vanes, high output boost valve and pressure regulator assembly, special valve body and servo assembly,alloy accumulator pistons, TCC and AFL valve replacement, steel bonded apply pistons, 29 element dual cage input sprag,Borg warner low tension low sprag assembly, special modified sun gear shell, increased clutch capacity, performance servo, updated electronics, increased operating pressure and lube mods and a host of other modifications. Comes with our Street/Strip torque converter with carbon clutch, furnace brazing, hardened hub, and stall speeds up to 2600 rpm. Rated to 425HP."

In my opinion the stock PCM makes the trans shift sort of "weak" and draws 1st to 2nd out a little longer than I Like. So my question is... Is there a chip out there that will plug into my stock pcm and adjust the shift points and firmness? Im new to all of this and I'm learning as I go.

Thanks

[B52Bombardier1]

Why not a shift kit hardware change in the transmission valve body? There are no extra "chips" that plug into your PCM and though you don't mention what model of PCM you have, changes are made in the software operating system inside your PCM.

A shift kit in the valve body for firmer shifting is more direct and immediate for what I think you need.

Rick

[Tim W]

Why not a shift kit hardware change in the transmission valve body? There are no extra "chips" that plug into your PCM and though you don't mention what model of PCM you have, changes are made in the software operating system inside your PCM.

A shift kit in the valve body for firmer shifting is more direct and immediate for what I think you need.

Rick

Man i really dont want to alter the internals and void the 3 year warranty.

The PCM and the chip is stock

[Fast355]

Hi yall this is my very first and I was actually referred over here from the folks at GMT 400 forum.

Let me tell you what i have going on. I have a 1994 chevy 1500 single cab step side. The motor is a professionally built mild vortec 383 stroker with a LT4 hot cam. The truck is fueled by a Holley Sniper EFI, holley Fuel pump, HyperSpark Coil, Ignition, coil, and Distributor. My built 4L60E transmission is still being controlled by my stock PCM since the sniper only controls the EFI.

In case it matters here is my transmission specs.

"High performance pump with high rpm pump rings, Torrington vanes, high output boost valve and pressure regulator assembly, special valve body and servo assembly,alloy accumulator pistons, TCC and AFL valve replacement, steel bonded apply pistons, 29 element dual cage input sprag,Borg warner low tension low sprag assembly, special modified sun gear shell, increased clutch capacity, performance servo, updated electronics, increased operating pressure and lube mods and a host of other modifications. Comes with our Street/Strip torque converter with carbon clutch, furnace brazing, hardened hub, and stall speeds up to 2600 rpm. Rated to 425HP."

In my opinion the stock PCM makes the trans shift sort of "weak" and draws 1st to 2nd out a little longer than I Like. So my question is... Is there a chip out there that will plug into my stock pcm and adjust the shift points and firmness? Im new to all of this and I'm learning as I go.

Thanks

Nobody is going to have an off the shelf chip to do it. Also the TBI PCM will need all the correct inputs to shift normally. TPS, MAP, RPM, ECT, etc. Would have been better off upgrading to a big block TBI and tuning the TBI PCM to start with. Other than that it is possible. Just need chip burning stuff to make the changes and disable the engine trouble codes to make the PCM operate error free as a trans controller.

[Tim W]

Nobody is going to have an off the shelf chip to do it. Also the TBI PCM will need all the correct inputs to shift normally. TPS, MAP, RPM, ECT, etc. Would have been better off upgrading to a big block TBI and tuning the TBI PCM to start with. Other than that it is possible. Just need chip burning stuff to make the changes and disable the engine trouble codes to make the PCM operate error free as a trans controller.

That was my orginal plan. I have no computer skills much less tuning skills so I contacted TBI chips, sent him my engine build sheet and told me he wouldn't be able to burn my chip with out extensive data logging pics of spark plugs ect ect. He said it would take about 3 to 6 chips to get close. That would get expensive real fast.. So he actually recommended going with an EFI so I did. My truck is professionally tuned and runs great. my trans shifts ok i just want it firmer if that makes sense.