crate 502 into a 98 GMC 1/2ton
05-09-2006, 05:56 PM
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crate 502 into a 98 GMC 1/2ton
Hey everyone, I am in the middle of installing a 502 into a 98 Reg cab 2wd Sierra for a customer. We have ran into a few problems. One we dont know how to get the engine and tranny to communicate with the factory PCM to let the factory gauges operate and let the tranny know when to shift etc... The engine is a crate Ramjet from GM and came with its own computer.
05-09-2006, 11:03 PM
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The computer that came with the Ram Jet is a stand alone computer for the engine only. To control an electronic tranny you will need a stand alone computer for the tranny, TCI, Hughes, and PCS makes a controller for the 4L60E & 4L80E.
05-10-2006, 01:29 AM
#5
Get a Vortec 454 wiring harness, distrubutor, knock sensor, and front timing set and cover. Modify the harness to work with the right connectors for the IAC and TPS. The injector rail is exactly the same as a Vortec 454.
Reprogram the factory computer with a Vortec 454 tune. I am guessing you are using a 4L80-E. Don't even waste your time with a 4L60-E, they are weak crap. The 454 harness will be correct for a 4L80-E.
To tune it buy Jet Performance products Tuner. It is the only thing available that can tune the older PCM. You will need this to adjust for the cam, displacement, injectors, shift points, etc.
Going this route you ditch (sell for $$$) the computer it came with. The factory computer can do it all very well but it limited to 5800 RPM which is fine for a RamJet 502.
That's it!
The other alternative is to run TCI's trans controller (like I do) separately. (The tuning kit from Jet is HUNDREDS less than this TCI controller costs.) The stock PCM needs to be provided inputs for oil pressure, water temp, VSS, and tachometer through the OEM harness by splicing it into the sensors for it. You can use the water and oil senders from the stock 350 if you'd like to. I know for a fact the VSS signal can be spliced to feed both the PCM and the controller.
You've got yourself a can of worms there. Good luck.
Edit: I see you have a TH400. I guess that's the easy way out but a very solid solution. You'll need to provide it a kickdown switch, I'm sure you already know that. Scratch the TCI. Getting the speedometer to work requires some parts the F-Body guys have been using on their TH400 swaps to keep theirs working. There is a reluctor ring and pickup setup that slides into the speedometer cable bore on the transmission. I don't have any more information on that but it is findable on LS1tech.com.
Reprogram the factory computer with a Vortec 454 tune. I am guessing you are using a 4L80-E. Don't even waste your time with a 4L60-E, they are weak crap. The 454 harness will be correct for a 4L80-E.
To tune it buy Jet Performance products Tuner. It is the only thing available that can tune the older PCM. You will need this to adjust for the cam, displacement, injectors, shift points, etc.
Going this route you ditch (sell for $$$) the computer it came with. The factory computer can do it all very well but it limited to 5800 RPM which is fine for a RamJet 502.
That's it!
The other alternative is to run TCI's trans controller (like I do) separately. (The tuning kit from Jet is HUNDREDS less than this TCI controller costs.) The stock PCM needs to be provided inputs for oil pressure, water temp, VSS, and tachometer through the OEM harness by splicing it into the sensors for it. You can use the water and oil senders from the stock 350 if you'd like to. I know for a fact the VSS signal can be spliced to feed both the PCM and the controller.
You've got yourself a can of worms there. Good luck.
Edit: I see you have a TH400. I guess that's the easy way out but a very solid solution. You'll need to provide it a kickdown switch, I'm sure you already know that. Scratch the TCI. Getting the speedometer to work requires some parts the F-Body guys have been using on their TH400 swaps to keep theirs working. There is a reluctor ring and pickup setup that slides into the speedometer cable bore on the transmission. I don't have any more information on that but it is findable on LS1tech.com.
05-10-2006, 12:53 PM
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Originally Posted by James B.
Get a Vortec 454 wiring harness, distrubutor, knock sensor, and front timing set and cover. Modify the harness to work with the right connectors for the IAC and TPS. The injector rail is exactly the same as a Vortec 454.
Reprogram the factory computer with a Vortec 454 tune. I am guessing you are using a 4L80-E. Don't even waste your time with a 4L60-E, they are weak crap. The 454 harness will be correct for a 4L80-E.
To tune it buy Jet Performance products Tuner. It is the only thing available that can tune the older PCM. You will need this to adjust for the cam, displacement, injectors, shift points, etc.
Going this route you ditch (sell for $$$) the computer it came with. The factory computer can do it all very well but it limited to 5800 RPM which is fine for a RamJet 502.
That's it!
The other alternative is to run TCI's trans controller (like I do) separately. (The tuning kit from Jet is HUNDREDS less than this TCI controller costs.) The stock PCM needs to be provided inputs for oil pressure, water temp, VSS, and tachometer through the OEM harness by splicing it into the sensors for it. You can use the water and oil senders from the stock 350 if you'd like to. I know for a fact the VSS signal can be spliced to feed both the PCM and the controller.
You've got yourself a can of worms there. Good luck.
Edit: I see you have a TH400. I guess that's the easy way out but a very solid solution. You'll need to provide it a kickdown switch, I'm sure you already know that. Scratch the TCI. Getting the speedometer to work requires some parts the F-Body guys have been using on their TH400 swaps to keep theirs working. There is a reluctor ring and pickup setup that slides into the speedometer cable bore on the transmission. I don't have any more information on that but it is findable on LS1tech.com.
Reprogram the factory computer with a Vortec 454 tune. I am guessing you are using a 4L80-E. Don't even waste your time with a 4L60-E, they are weak crap. The 454 harness will be correct for a 4L80-E.
To tune it buy Jet Performance products Tuner. It is the only thing available that can tune the older PCM. You will need this to adjust for the cam, displacement, injectors, shift points, etc.
Going this route you ditch (sell for $$$) the computer it came with. The factory computer can do it all very well but it limited to 5800 RPM which is fine for a RamJet 502.
That's it!
The other alternative is to run TCI's trans controller (like I do) separately. (The tuning kit from Jet is HUNDREDS less than this TCI controller costs.) The stock PCM needs to be provided inputs for oil pressure, water temp, VSS, and tachometer through the OEM harness by splicing it into the sensors for it. You can use the water and oil senders from the stock 350 if you'd like to. I know for a fact the VSS signal can be spliced to feed both the PCM and the controller.
You've got yourself a can of worms there. Good luck.
Edit: I see you have a TH400. I guess that's the easy way out but a very solid solution. You'll need to provide it a kickdown switch, I'm sure you already know that. Scratch the TCI. Getting the speedometer to work requires some parts the F-Body guys have been using on their TH400 swaps to keep theirs working. There is a reluctor ring and pickup setup that slides into the speedometer cable bore on the transmission. I don't have any more information on that but it is findable on LS1tech.com.
Next question, is there a kit for the throttle cable available?
The other problem with the steering shaft not clearing the headers has been solved. We sent the header away to get the #5(?)cylinder primary re routed without sacraficing flow efficiency.
05-10-2006, 10:23 PM
#7
You can get a set of Hooker Super Comps for the 454SS truck (1990-1992) that will work perfectly with your 502. They have huge equal-length primaries and 3.5" collectors though. (BIG) They are designed for that chassis.
Throttle cable will be interesting. It sure would be cool if you could fabricate something that uses a stock arc for the trottle and a peg for the cruise control. Cruise would actually work run by the factory PCM.
You might also consider picking up a set of accessory brackets for the Vortec 454. The compressor won't fit due to the intake being in the way, but a plate can be made up to offset it and it will still clear the hood. (454 brakets are cast iron unfortunately)
Here's a few pictures of the way a friend of mine did the RamJet 502 in his Tahoe. This is Steve's setup: (note throttle linkage to cable)
Steve went the route of the Stand-Alone TCI trans controller due to unavailability of PCM tuner for these PCMs at the time of swap. We have had lengthy conversations about going back to the factory computer now that the stuff is available to program it.
Throttle cable will be interesting. It sure would be cool if you could fabricate something that uses a stock arc for the trottle and a peg for the cruise control. Cruise would actually work run by the factory PCM.
You might also consider picking up a set of accessory brackets for the Vortec 454. The compressor won't fit due to the intake being in the way, but a plate can be made up to offset it and it will still clear the hood. (454 brakets are cast iron unfortunately)
Here's a few pictures of the way a friend of mine did the RamJet 502 in his Tahoe. This is Steve's setup: (note throttle linkage to cable)
Steve went the route of the Stand-Alone TCI trans controller due to unavailability of PCM tuner for these PCMs at the time of swap. We have had lengthy conversations about going back to the factory computer now that the stuff is available to program it.
Last edited by James B.; 05-10-2006 at 10:36 PM.
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