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Ok guys, I've done most of my research on my swap and still need a little more info if anyone can help. I talked with S&P and they have the fuel rails and vette regulator with dual lines, the return lines and custom bent headers. My question is this, If I use their wiring harness they say I have to keep the 97 ECM in tact to run the ABS and I'd rather not have 2 computers if I don't need them. What do I want to do to keep just the 02 LS1 computer and still run the ABS. They say their harness is quick, easy and I shouldn't even try to take the original computer out. Does anyone have any suggestions? GMCwantsLS1, RedHearBeat or farmtruc? Can you guys help me out?
Thanks, Lance
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I don't know if you have the DRAC unit behind the glove box or not but it feeds data to the ABS unit for rear end speed. The two wires that run from the speedometer run through it and then feeds the cruise control, speedometer and ABS. You must keep data coming to that sensor or else you lose the ABS in my truck, at least. 97 is too new for me. I run the old 92 stuff.
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If you want to keep the ABS I think you'll have to use the old computer linked to the new one. You will need to keep you old ALDL connector in place too for ABS diagnostics.
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The LS1 computer has two programmable VSS outputs. The output for the ABS is by default the same pulses per mile for the ABS unit in my 95 pickup for example as for the 2002 ABS unit. If you verify the number of pulses per mile your ABS unit is expecting as an input you can program the VSS output on the new PCM to match that. One snag in the OBS trucks is the speedo operates at 2000 PPM and the radio, cruise control, etc. use 4000 PPM. There are only two VSS outputs on the LS1 PCM so you cannot drive ABS, speedo, and cruise simultaneously. You will need a converter box for the cruise or speedo.
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Excellent information here guys!! I guess it would be easier to keep the old unit on board.
PSWired, what type of converter box would you use or do you think I should keep the old computer?
RedHeartBeat, I don't think I have that unit behind the glove box but I could be wrong. I think that was only until 94 or 95.
GMCwantsLS1, What you mentioned is pretty much what S&P said. They're sending me a complete DVD of the install on the 98 Chevy truck they built. Hopefully I can get us some more info out of there for the forum. If anyone has anymore ideas, please feel free to comment.
Thanks, Lance
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I will be doing a simililar swap as well when I can rustle up the cash. The ABS was a concern of mine as well. I am curious to see how yours pans out. I will learn from your mistakes :lol:
-Mike
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"I will learn from your mistakes" I heard that!! LOL Hopefully there will be no mistakes. I talked with a guy up around Denton that put an LS1 in his 97 SWB and the reason the custom bend S&P headers wouldn't fit was because the eccentrics for alignment were facing straight up. He did use 5/8" adapter plates to raise the engine up a little higher for header clearance and then ground off the eccentric on the passenger side only. I'm going over to GForce today to talk with Jay on a 97 install he did. The only problem he has is the tach won't work. I asked if he had the tach calibrated for a 4 cylinder and he said yes so I"m not sure what his problem is. It's a show truck and the guy doesn't care anyways he said.
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Ok, here's the info I've gathered so far for my swap, I'm using a 2002 LS1 with 4L60E tranny:
This is for a 97 GMC ext cab truck
S&P Type III custom bent headers. $520.00
Thunder Racing "Old Man" Truck cam. They said this would be close to a 35 hp increase. $429.00
New springs with titanium retainers and new steel pushrods.
97 corvette fuel rails and 58# regulator with return line. $165.00
S&P Custom made fuel return lines to fuel filter. $125.00
Stainless 316 motor mount adapters I made myself.
Will reuse original computer for ABS and a few other features I'm still looking into and will install the LS1 computer on the passenger fender well.
Autotech will calibrate my tach for a 4 cylinder engine for the correct pulse. $30.00 plus shipping
Not sure on the wiring harness, I'm either going to modify the LS1 harness or order a custom made so there are no problems.
I'm not sure on the tune yet because I want to be able to Dyno at the same time. I'll keep you guys posted.
If anyone has some better suggestions, feel free to comment here. I'm not purchasing anything until Monday.
Thanks, Lance
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Lance, contact www.BakerElectronix.com for a tach module to adapt to your truck. He made one for me and it works awesome. It's really cheap and you just add in inline.
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Cool! Thanks for the advice. I'll check'em out. That's easier than sending them my cluster.
