LS1 PCM used for older EFI conversion?
LS1 PCM used for older EFI conversion? Hello,
I've been lurkng here and doing research for an LS1 conversion I will be doing on my '55 Chevy.
Already have the motor/trans for that setup.
It will be a 5.3/4L80 setup (later upgrade to more motor).
However,
I will be buying HPTuners to do this conversion.
I also have a '69 Chevelle with a 427, that I plan to install a 4L80E.
I will need a TPS to run a controller for the 4L80E, and in my mind this has already snowballed into a EFI conversion..
If I used an intake/throttlebody setup similar to a Edelbrock Pro-Flo, could I use a LS1 PCM and harness to control the 4L80 and aftermarket style EFI?
I know it would be "dumbing down" the LS1 PCM, speed density only, no coil on plug ignition, but is this worth the time?
Or would I be better off with an aftermarket EFI controller and a seperate trans controller...
I know the Big Stuff controller will do both, but I'm looking at the cost factor.
I will have the HP tuners to edit already, the intake system is not a problem, I could also go with Mega squirt for the EFI control...
Just looking for input.
Thanks
I've been lurkng here and doing research for an LS1 conversion I will be doing on my '55 Chevy.
Already have the motor/trans for that setup.
It will be a 5.3/4L80 setup (later upgrade to more motor).
However,
I will be buying HPTuners to do this conversion.
I also have a '69 Chevelle with a 427, that I plan to install a 4L80E.
I will need a TPS to run a controller for the 4L80E, and in my mind this has already snowballed into a EFI conversion..
If I used an intake/throttlebody setup similar to a Edelbrock Pro-Flo, could I use a LS1 PCM and harness to control the 4L80 and aftermarket style EFI?
I know it would be "dumbing down" the LS1 PCM, speed density only, no coil on plug ignition, but is this worth the time?
Or would I be better off with an aftermarket EFI controller and a seperate trans controller...
I know the Big Stuff controller will do both, but I'm looking at the cost factor.
I will have the HP tuners to edit already, the intake system is not a problem, I could also go with Mega squirt for the EFI control...
Just looking for input.
Thanks
I'm new to the LS1 PCM thing but may be able to answer. I'm kinda in the same boat as you right now as far as deciding which route to go with regards to using a GM PCM for engine and trans management or to go aftermarket, BS3, Megasquirt, etc for engine and TCI TCU for trans control. Technically I don't see why the GM PCM couldn't be used to control your big block but the LS1 type pcm is going to look for a couple of different inputs than you would have for a big block chevy and the differences would be pretty hard to adapt to make work. There is both a crank signal (24x) and cam signal (2x) for the LS1 which would be hard to reproduce for your engine; most aftermarket setups look for a 4x crank trigger whether it be hall effect or flying magnet. I'm not sure what the new 8.1L engines use or if there is even aftermarket support for them. Ignition would be an issue as well because going from coil on plug to a computer controlled hei type distributor are two very different things and are triggered differently. For the hassle of figuring these things out, and the cost of something like Megasquirt if it is on your list, going aftermarket would probably be the more viable solution. Hopefully some of the guys here (Brains, Parish, dieselgeek) will get the trans control working with megasquirt as well and we wont have to worry about buying a $700 trans controller jut to run a 4l60/4l80. Hope this helps and if anyone else disagrees please chime in.
Max
Max
Max,
Thanks for the response.
I was thinking it may be possible to run the cam sensor off a late model distributor such as Vortec motor...
RPM signal from distributor as a cranking signal also...
The MegSquirt UMS sounds like the solution when it gets here, I was wondering if there was a way to use the HP Tuners to kill 2 birds with one stone...
I have some time jsut doing my research.
I'm working in Iraq until sometime next year, so it'll be at least January before I get serious.
Thanks Again,
Jake
Thanks for the response.
I was thinking it may be possible to run the cam sensor off a late model distributor such as Vortec motor...
RPM signal from distributor as a cranking signal also...
The MegSquirt UMS sounds like the solution when it gets here, I was wondering if there was a way to use the HP Tuners to kill 2 birds with one stone...
I have some time jsut doing my research.
I'm working in Iraq until sometime next year, so it'll be at least January before I get serious.
Thanks Again,
Jake
The cam sensor on a late model vortec big block motor with a distributor is a 1x signal compared to the 2x signal of the LS1 type setup. Another option if you want to be able to use a GM PCM is Tunercat software. They have tuning software for pre LSx trucks (around 96-98) that are the more conventional SBC and BBC engines. Both used a 1x cam sensor and 4x crank sensor. The tunercat software can control both the injection and transmission, you would just have to get the software setup for a big block/4l80 combo. There are some guys over at the Pacific Audio forum that use this software, http://www.pacificp.com/forum/viewfo...227e29dbb9fe7f , I personally don't have any experience with it but may in the future as I have a 98 chevy truck. Right now I have megasquirt controlling the injection on the truck and I like it alot.
On The Tree
Joined: Jan 2004
Posts: 133
Likes: 0
From: Omaha, NE
Originally Posted by 350SS
The cam sensor on a late model vortec big block motor with a distributor is a 1x signal compared to the 2x signal of the LS1 type setup. Another option if you want to be able to use a GM PCM is Tunercat software. They have tuning software for pre LSx trucks (around 96-98) that are the more conventional SBC and BBC engines. Both used a 1x cam sensor and 4x crank sensor. The tunercat software can control both the injection and transmission, you would just have to get the software setup for a big block/4l80 combo. There are some guys over at the Pacific Audio forum that use this software, http://www.pacificp.com/forum/viewfo...227e29dbb9fe7f , I personally don't have any experience with it but may in the future as I have a 98 chevy truck. Right now I have megasquirt controlling the injection on the truck and I like it alot.
we're working on coilpack control right now. Found out we're not the only ones working on it either!! I would expect trans control to be working by springtime. There's already a MS-II based trans controller that's been built, software is being written for it, but we're focused on the ignition control for now.
-scott
Nope, Mad Max. I'm just real interested in PCM systems, although and admitted NOOB. I've been running Megasquirt on my truck and possibly my new project - a LQ9/4L80 in a 72 chevelle w/ a GT42 turbo setup. Ive just been following 
you guys' work on the MS setup - can't wait till ignition/trans control works. I wish I knew embeded code so I could help. Someday...
Max
you guys' work on the MS setup - can't wait till ignition/trans control works. I wish I knew embeded code so I could help. Someday... Max
