96 Tahoe to LS1 conversion questions
03-01-2005, 12:04 PM
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96 Tahoe to LS1 conversion questions Hi, came across this site when investigating how to lose the Vortec crap under my hood. I really like the idea of installing an LS1 or LS6 under the hood. If I do this, I want to just have one computer running everything instead of two. I've worked out the engine mounts, engine to tranny connection, accessories, fuel injection wiring and the radiator.
What I am not sure about are the throttle body, sensors, and spark. In all of my questions, if it is just a matter of rebuilding the wiring harness it is not a concern, wiring harnesses are simple. I'd just like to know if it is possible.
1. Will the Vortec throttle body bolt to the LS1 manifold? If not, will the sensors on the LS1 talk to the Vortec computer?
2. Is there a way to make the Vortec computer that expects spark to be dealt with by the distributor work with the crank trigger of the LS1? I know how the Vortec deals with it but have no idea how the computer controls the LS1. I'm assuming that the LS1 uses the crank trigger to tell the computer where the crank is, then uses that data to tell the coils to discharge directly. I was thinking that an MSD box might work for this.
The alternative would be to use the LS1 computer. For that way:
1. Will the LS1 computer speak to my 4L60E transmission? Will it speak to a planned 4L80E with a harness rework and computer update?
2. Will the LS1 computer drive the gauges?
3. What else is controlled by the Vortec computer? Is ABS controlled? I'm really hoping that the Vortec computer only controls the engine, transmission and gauges, and nothing else on my 96.
Thanks for any help anyone can provide, if it comes down to it I can use two computers but I'd really rather have a clean, professional, unified setup under the 'ol hood. Thanks.
What I am not sure about are the throttle body, sensors, and spark. In all of my questions, if it is just a matter of rebuilding the wiring harness it is not a concern, wiring harnesses are simple. I'd just like to know if it is possible.
1. Will the Vortec throttle body bolt to the LS1 manifold? If not, will the sensors on the LS1 talk to the Vortec computer?
2. Is there a way to make the Vortec computer that expects spark to be dealt with by the distributor work with the crank trigger of the LS1? I know how the Vortec deals with it but have no idea how the computer controls the LS1. I'm assuming that the LS1 uses the crank trigger to tell the computer where the crank is, then uses that data to tell the coils to discharge directly. I was thinking that an MSD box might work for this.
The alternative would be to use the LS1 computer. For that way:
1. Will the LS1 computer speak to my 4L60E transmission? Will it speak to a planned 4L80E with a harness rework and computer update?
2. Will the LS1 computer drive the gauges?
3. What else is controlled by the Vortec computer? Is ABS controlled? I'm really hoping that the Vortec computer only controls the engine, transmission and gauges, and nothing else on my 96.
Thanks for any help anyone can provide, if it comes down to it I can use two computers but I'd really rather have a clean, professional, unified setup under the 'ol hood. Thanks.
03-02-2005, 09:04 AM
#2
Vortechhater... The problem with a '96 GM swap is that, that particular year was a change-over year from non-Vortech to Vortech & some electrical pieces are a hybrid of years '96 to '97. I am at the harness/computer stage myself, with some harness/computer suppliers telling me that the ABS brake system can be controlled by my newer 2001 F-body LS1 computer, and some telling me I might need my original V-6 Vortech engines computer to control the brakes, in tandem??? I don't know. I have made up my mind to use John@SpearTech & am patiently awaiting his response to this question in a recent E-mail. I believe, in your swap, you would be best off using the correct LS1 computer & harness that came with your engine. Gar
03-02-2005, 03:26 PM
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Yeah he is right. I am not sure about the whole abs on your truck, but you will definitely atleast need the new ls1 computer and wiring for the new engine. The vortec 350 has nothing to do electronically with the newer ls1, and the throttle body wont work either. That is the easy part though, just get a 98 or 99 f-body ls1 that has the cable driven throttle body and it will work just fine with your gas peddle, I Just needed to drill out the hole a little bit on mine to get it to fit and it snapped right in place. The 4l60e will bolt up, but Im not so sure it will work with the new harness and computer, I believe. Not 100% sure since I havent done that swap...yet. Goodluck on the swap.
Remington
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03-02-2005, 04:19 PM
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Are you sure the tranny will bolt up? The T56s have different input shafts on the LS1s than the LT1 versions. Are the autos any different on the newer motors?
03-02-2005, 05:48 PM
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THe only interface the pcm has with the abs is an output from the pcm for rear wheel speed. The harness for the abs runs into the main engine harness but all it does is piggy back ign, ground, and serial data for the abs to communicate on the databus. You can get a pinout cut the connector and then hardwire the abs with no trouble. I put a 97 350 with the abs into my 85 monte carlo. It took some time but was well worth the effort.
03-03-2005, 08:18 AM
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LT1s no good
Originally Posted by Serial Thriller
Are you sure the tranny will bolt up? The T56s have different input shafts on the LS1s than the LT1 versions. Are the autos any different on the newer motors?
03-03-2005, 08:22 AM
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I like the sound of that!
Originally Posted by 01WS6/tamu
THe only interface the pcm has with the abs is an output from the pcm for rear wheel speed. The harness for the abs runs into the main engine harness but all it does is piggy back ign, ground, and serial data for the abs to communicate on the databus. You can get a pinout cut the connector and then hardwire the abs with no trouble. I put a 97 350 with the abs into my 85 monte carlo. It took some time but was well worth the effort.
And, would there be anything else that the 96 computer drives that I need to be concerned about? I'm thinking that it only runs the engine, trans, ABS, and instrument cluster, and we have eliminated everything but the cluster at this point. Any other suprises under there? This is my main family rig I'll be doing this to, so I want to keep the down time to a minimum. While this is down, we'll have to be taking 2 cars if we go anywhere as a family. Thanks.
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03-03-2005, 08:23 AM
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Thanks, I'll await your reply, and appreciate a post NM
Originally Posted by LS1GMCTruck
The problem with a '96 GM swap is that, that particular year was a change-over year from non-Vortech to Vortech & some electrical pieces are a hybrid of years '96 to '97. I am at the harness/computer stage myself, with some harness/computer suppliers telling me that the ABS brake system can be controlled by my newer 2001 F-body LS1 computer, and some telling me I might need my original V-6 Vortech engines computer to control the brakes, in tandem??? I don't know. I have made up my mind to use John@SpearTech & am patiently awaiting his response to this question in a recent E-mail. I believe, in your swap, you would be best off using the correct LS1 computer & harness that came with your engine. Gar
03-03-2005, 08:28 AM
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Cool thanks...
Originally Posted by Remington H.
Yeah he is right. I am not sure about the whole abs on your truck, but you will definitely atleast need the new ls1 computer and wiring for the new engine. The vortec 350 has nothing to do electronically with the newer ls1, and the throttle body wont work either. That is the easy part though, just get a 98 or 99 f-body ls1 that has the cable driven throttle body and it will work just fine with your gas peddle, I Just needed to drill out the hole a little bit on mine to get it to fit and it snapped right in place. The 4l60e will bolt up, but Im not so sure it will work with the new harness and computer, I believe. Not 100% sure since I havent done that swap...yet. Goodluck on the swap.
Remington
Remington
On the trans, the 4L60E should be controllable by anything that came with one. I think there is no difference till you get to the 4L65E, and I am awaiting confirmation that a 4L80E can be controlled by the factory computer. I've heard it is possible with a repin and a reprogramming. Worse comes to worse, the TCI controller cost recently dropped to 600+ bucks from 800+, and a fellow I know that it running one is super-happy with it. I heard his run on a video, and it makes me cry to see a trans shift so well, particularly since mine shifts like crap.
03-03-2005, 12:55 PM
#10
VortecHater... John@SpearTech just E-mailed me back saying that he would have to examine my '96 GMC truck ABS & computer to see if they could be interfaced into my newer 2001 F-body LS1 computer, but did'nt see a problem. If anyone can make it happen, I think SpearTech's the place. Now I will simply communicate with John what features I need deleted, accessories I have,etc...and send them out with a credit card number! Gar
03-03-2005, 01:18 PM
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Yeah I know for a fact you can use a 4l80e with the computer and harness for the 4l60e. You will need a harness adapter that Speartech sells and you will need to just take or send your computer to a programmer like speartech and get them to take out the program for the 60e and upload the program for a 80e. I did it with my swap since the people that sold me my computer lied and said it was a 6.0/4l80e computer when in reality it was a 5.3/4l60e so I just had them reflash the computer. I had the 6.0 harness in the first place so I didnt need to change the harness.
Remington
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03-03-2005, 01:59 PM
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Cool
Originally Posted by LS1GMCTruck
John@SpearTech just E-mailed me back saying that he would have to examine my '96 GMC truck ABS & computer to see if they could be interfaced into my newer 2001 F-body LS1 computer, but did'nt see a problem. If anyone can make it happen, I think SpearTech's the place. Now I will simply communicate with John what features I need deleted, accessories I have,etc...and send them out with a credit card number! Gar
03-03-2005, 02:01 PM
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Beautiful!
Originally Posted by Remington H.
Yeah I know for a fact you can use a 4l80e with the computer and harness for the 4l60e. You will need a harness adapter that Speartech sells and you will need to just take or send your computer to a programmer like speartech and get them to take out the program for the 60e and upload the program for a 80e. I did it with my swap since the people that sold me my computer lied and said it was a 6.0/4l80e computer when in reality it was a 5.3/4l60e so I just had them reflash the computer. I had the 6.0 harness in the first place so I didnt need to change the harness.
Remington
Remington
In just a couple of days, all but one of my concerns have been addressed. Looks like there is an LS1-based 5.7L in my Tahoe's future then! Or if the funding is available, might just bite the bullet and try a Vette LS-2 6.0.
03-03-2005, 05:07 PM
#14
THe pcm does not run the abs, instrument cluster, etc. It has one output as mentioned earlier for a vss. The ins cluster uses analog inputs from the oil pressure, fuel sender, oil press and water temp. The tach i believe comes off of the coil to best of my rememberance. The ls1 or lt1 computer will still snd the correct vss signal to the speedometer, and abs module. I'll get the abs pinout from you at the shop tomorrow and post it on here so you can keep the abs and have your lt1. 1996-1997 are the simpler years of vortec pickups.
03-04-2005, 07:43 AM
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Good deal
Originally Posted by 01WS6/tamu
THe pcm does not run the abs, instrument cluster, etc. It has one output as mentioned earlier for a vss. The ins cluster uses analog inputs from the oil pressure, fuel sender, oil press and water temp. The tach i believe comes off of the coil to best of my rememberance. The ls1 or lt1 computer will still snd the correct vss signal to the speedometer, and abs module. I'll get the abs pinout from you at the shop tomorrow and post it on here so you can keep the abs and have your lt1. 1996-1997 are the simpler years of vortec pickups.
03-04-2005, 09:03 AM
#16
Thank You...
Originally Posted by 01WS6/tamu
THe pcm does not run the abs, instrument cluster, etc. It has one output as mentioned earlier for a vss. The ins cluster uses analog inputs from the oil pressure, fuel sender, oil press and water temp. The tach i believe comes off of the coil to best of my rememberance. The ls1 or lt1 computer will still snd the correct vss signal to the speedometer, and abs module. I'll get the abs pinout from you at the shop tomorrow and post it on here so you can keep the abs and have your lt1. 1996-1997 are the simpler years of vortec pickups.
03-05-2005, 08:21 AM
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I hated seeing that site!
Originally Posted by malibu9in
www.hpsalvage.com this guy knows the ins and outs on that swap.
http://www.hpsalvage.com/CM15003.jpg
This shows they had to cut a huge hole in the frame to make it fit. Anyone know anything about this, or if there is an accessory setup that'll go without cutting the frame? I will under no circumstances cut my frame!
03-05-2005, 09:16 AM
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Originally Posted by malibu9in
www.hpsalvage.com this guy knows the ins and outs on that swap.
03-05-2005, 04:36 PM
#20
Piece of cake...
Originally Posted by VortecHater
http://www.hpsalvage.com/C1500CM.jpg
http://www.hpsalvage.com/CM15003.jpg
This shows they had to cut a huge hole in the frame to make it fit. Anyone know anything about this, or if there is an accessory setup that'll go without cutting the frame? I will under no circumstances cut my frame!
http://www.hpsalvage.com/CM15003.jpg
This shows they had to cut a huge hole in the frame to make it fit. Anyone know anything about this, or if there is an accessory setup that'll go without cutting the frame? I will under no circumstances cut my frame!