LS1 PCM on LT1.
12-31-2006, 06:27 AM
#1
TECH Regular
Thread Starter
LS1 PCM on LT1. Been thinking about the possibility of using an LS1 pcm on the LT1. I’ve worked with HP tuners and the LS1 pcm is much more than the LT1. One of the main reasons people go with aftermarket computers is the higher rpm capability, the LS1 is capable of 8k rpm and can be had for much cheaper.
The only obstacle I see is the signal from the camshaft sensor on the LS1, but this can could be had maybe through a converter from the opti sensor.
The only obstacle I see is the signal from the camshaft sensor on the LS1, but this can could be had maybe through a converter from the opti sensor.
12-31-2006, 06:57 AM
#4
TECH Regular
Thread Starter
Originally Posted by blackdogz
The LT1 PCM connecters are not the same as the LS1 PCM connectors.
12-31-2006, 08:41 AM
#5
I am not saying this to discourage just saying here is another detail to work out.
In discussions about doing the 4-7 swap on an LT1 the problem arrises that you need to leave the injector with it's proper bank and have it be out of sequence firing which would take away some of the smoothness and make those two cylinder batch fire. If you swap them then you have injectors firing on the wrong bank which will screwup O2 feedback if the afr needs any signifigant adjustment.
I would suggest you consider doing the 4-7 cam swap with this pcm if you determine you can make all the other stuff work.
Another benifit I see here is the wider/higher frequency range the LSX MAF/pcm support, the better resolution should have a positive effect on drivability. The LS6 MAF used on a LT1 pcm maxes out the LT1 pcms ability to understand frequency at 360gps, my little heads cam motor moves more than that. \
I have not wrenched on an LSx yet, the cam position sensor, is it a single point sensor or multiple?
In discussions about doing the 4-7 swap on an LT1 the problem arrises that you need to leave the injector with it's proper bank and have it be out of sequence firing which would take away some of the smoothness and make those two cylinder batch fire. If you swap them then you have injectors firing on the wrong bank which will screwup O2 feedback if the afr needs any signifigant adjustment.
I would suggest you consider doing the 4-7 cam swap with this pcm if you determine you can make all the other stuff work.
Another benifit I see here is the wider/higher frequency range the LSX MAF/pcm support, the better resolution should have a positive effect on drivability. The LS6 MAF used on a LT1 pcm maxes out the LT1 pcms ability to understand frequency at 360gps, my little heads cam motor moves more than that. \
I have not wrenched on an LSx yet, the cam position sensor, is it a single point sensor or multiple?
12-31-2006, 11:12 AM
#6
Originally Posted by 96capricemgr
I am not saying this to discourage just saying here is another detail to work out.
In discussions about doing the 4-7 swap on an LT1 the problem arrises that you need to leave the injector with it's proper bank and have it be out of sequence firing which would take away some of the smoothness and make those two cylinder batch fire. If you swap them then you have injectors firing on the wrong bank which will screwup O2 feedback if the afr needs any signifigant adjustment.
I would suggest you consider doing the 4-7 cam swap with this pcm if you determine you can make all the other stuff work.
Another benifit I see here is the wider/higher frequency range the LSX MAF/pcm support, the better resolution should have a positive effect on drivability. The LS6 MAF used on a LT1 pcm maxes out the LT1 pcms ability to understand frequency at 360gps, my little heads cam motor moves more than that. \
I have not wrenched on an LSx yet, the cam position sensor, is it a single point sensor or multiple?
In discussions about doing the 4-7 swap on an LT1 the problem arrises that you need to leave the injector with it's proper bank and have it be out of sequence firing which would take away some of the smoothness and make those two cylinder batch fire. If you swap them then you have injectors firing on the wrong bank which will screwup O2 feedback if the afr needs any signifigant adjustment.
I would suggest you consider doing the 4-7 cam swap with this pcm if you determine you can make all the other stuff work.
Another benifit I see here is the wider/higher frequency range the LSX MAF/pcm support, the better resolution should have a positive effect on drivability. The LS6 MAF used on a LT1 pcm maxes out the LT1 pcms ability to understand frequency at 360gps, my little heads cam motor moves more than that. \
I have not wrenched on an LSx yet, the cam position sensor, is it a single point sensor or multiple?
To do the 4-7 swap on a factory PCM LT1 you just need (in addition to crossing plug wires) to swap the injector wires at the PCM to put the injectors back in sync with the cam & ignition. No 02 problems we have been able to find. The LS1 already has the 4-7 swap, in addition to swapping 2 & 3, if my memory is correct. Not sure how the LS1 box would interpret the signal from an Opti. Btw, depending on your tuning software, the LS1 box will run past 8K. The cam signal is triggered by a flat machined into the rear cam journal.
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12-31-2006, 11:52 AM
#8
Ed, I knew the LSx had the different firing order and that is why I mentioned doing it too the LT1 using an LS1 pcm, forgot about the 2-3 though.
On the O2 thing my concern was should a problem develop the pcm adjusting injectors per bank and no onger understanding what bank an injector was on, I understand this would only be an issue if a mechanical problem developed.
With just a singal flat on the cam being the trigger for the cam sensor I wonder if the opti would work if you just made a new wheel with a singal slot for the lot resolution pickup.
Just thinking out loud here as I said never wrenched on an LSx.
On the O2 thing my concern was should a problem develop the pcm adjusting injectors per bank and no onger understanding what bank an injector was on, I understand this would only be an issue if a mechanical problem developed.
With just a singal flat on the cam being the trigger for the cam sensor I wonder if the opti would work if you just made a new wheel with a singal slot for the lot resolution pickup.
Just thinking out loud here as I said never wrenched on an LSx.
01-01-2007, 01:42 PM
#9
TECH Regular
Thread Starter
In the end it's required to control the spark and fuel for another V8. I'm already running the LTCC setup with LS1 coils, and will eventually go with a single plane and solid roller. The LS1 PCM will be able to support high rpm and a big TB. Also LS1 PCM and wiring can be had much cheaper than an aftermarket computer which will have to be run with the stock computer to control the tranny and other things.
01-01-2007, 10:32 PM
#11
What some are doing to their 3rd gens is going to the 411 computer with OBDll. These are used on the Vortec powered Chevy Express Vans preferably the 2000 and up models. Not hard at all to do if you are also going to swap in the 4L60E transmission.
So the 4-7 swap can be done on a regular crank? What about the cam? (sorry 'bout the hijack) 
01-02-2007, 06:12 PM
#18
Originally Posted by 1989GTA
What some are doing to their 3rd gens is going to the 411 computer with OBDll. These are used on the Vortec powered Chevy Express Vans preferably the 2000 and up models. Not hard at all to do if you are also going to swap in the 4L60E transmission.
01-02-2007, 08:09 PM
#20
Definetely interesting. I know the Vans retained the Gen 1 Vortec motor much longer than the trucks, this must be the pcm you are speaking of???
Tunercat for OBD2 happen to work on those??? If not bet TC would be willing to work on it he is a great guy to do buisiness with.
Tunercat for OBD2 happen to work on those??? If not bet TC would be willing to work on it he is a great guy to do buisiness with.