Sniper EFI conversion

alignman88 · Jan 9, 2022

And after spending a couple hours looking around, 15 minutes after I posted question I find this auxiliary TPS for Sniper on the Holley forum.
Maybe a moderator can make the link sticky somewhere.

Auxillary TPS kit for Holley EFI used for auto trans or data acquistion | eBay

Condition is New.

www.ebay.com

Erik the Awful · Jan 10, 2022

alignman88 said:
My 88 ECM uses TPS, RPM and VSS as inputs to trigger lockup.

No, it doesn't. My '89 runs just fine and has TCC lockup. My TPS doesn't go to the ECU, and my ESC has been trash-canned.

alignman88 · Jan 10, 2022

Erik the Awful said:
No, it doesn't. My '89 runs just fine and has TCC lockup. My TPS doesn't go to the ECU, and my ESC has been trash-canned.

Ok then. How is torque converter lockup achieved on your vehicle?

PlayingWithTBI · Jan 10, 2022

alignman88 said:
Ok then. How is torque converter lockup achieved on your vehicle?

It appears to me the ECM relies on TPS% to unlock the TCC. CTS and MPH (in this case 51.50 and 45.00 respectively) allows it to lock up since the TPS% feedback is missing so, it's lower than the thresholds to unlock. Without TPS% feedback it relies on MPH (40.00) only to unlock. This is on my 88 with the EBL Flash-II ECM. I don't see any reference to RPM. If you step on the brake pedal it'll unlock too. YMMV

You must be registered for see images attach

alignman88 · Jan 10, 2022

PlayingWithTBI said:
It appears to me the ECM relies on TPS% to unlock the TCC. CTS and MPH (in this case 51.50 and 45.00 respectively) allows it to lock up since the TPS% feedback is missing so, it's lower than the thresholds to unlock. Without TPS% feedback it relies on MPH (40.00) only to unlock. This is on my 88 with the EBL Flash-II ECM. I don't see any reference to RPM. If you step on the brake pedal it'll unlock too. YMMV

You must be registered for see images attach

Thank you very much. So much information out there and it’s mostly conflicting . That’s why I specifically asked how it activate, I knew one of you folks had access to that software interface. I knew brake switch was the unlock, so how well does it work above 40mph decelerating from high speed without the TPS input for disengagement if just decelerating not on brake pedal? Only concerns are hard/unpleasant lower speed lock/unlock driveability damage to clutch in converter, undo stress on input shaft. If you guys say it works I believe ya, but my “condition” really wants to know the how for peace of mind. Thanks again!

So why does

PlayingWithTBI · Jan 10, 2022

alignman88 said:
Only concerns are hard/unpleasant lower speed lock/unlock driveability damage to clutch in converter, undo stress on input shaft

That's why it'll lock at 45 MPH and unlock at 40 MPH to help reduce that. Personally, I'd prefer the TPS input so I can adjust when I want it to unlock at harder accelerations and/or towing.

Erik the Awful · Jan 13, 2022

PlayingWithTBI has a better understanding of how it works than I do. I just know that the TCC lockup works flawlessly in my truck. It's factory-smooth, and appears to happen at the correct speed.

alignman88 · Jan 15, 2022

Thanks for the input everyone. I didn’t mention it’s far from stock engine setup. 388” stroker making a legit 435hp and I’m planning on driving it like I stole it. Everything else upgraded just want to keep the new stall converter alive.

Erik the Awful · Jan 15, 2022

Yup, my engine's too far from stock for the TBI. That's why I went Sniper. I'm hopeful that I'll have 400 hp, but I'll need to install the rebuilt transmission before I take it to get dyno-tuned.

alignman88 · Jan 15, 2022

Erik the Awful said:
Yup, my engine's too far from stock for the TBI. That's why I went Sniper. I'm hopeful that I'll have 400 hp, but I'll need to install the rebuilt transmission before I take it to get dyno-tuned.

Oh I’ve puked dollar bills from the radiator to the diff cover. Built 700r4 driveshaft with 1350 joints, TruTrac and Moser axles. I would hate to burn up a converter by missing something simple.

Sniper EFI conversion

alignman88

I'm Awesome

Auxillary TPS kit for Holley EFI used for auto trans or data acquistion | eBay

Erik the Awful

Supporting Member

alignman88

I'm Awesome

PlayingWithTBI

2022 Truck of the Year

alignman88

I'm Awesome

PlayingWithTBI

2022 Truck of the Year

Erik the Awful

Supporting Member

alignman88

I'm Awesome

Attachments

Erik the Awful

Supporting Member

alignman88

I'm Awesome

Similar threads

Latest posts

Staff online

Members online

Forum statistics

Share this page