using a GM v6 ecu for a 4 cyl?
12-28-2005, 01:09 PM
#21
0.0 BAR
Join Date: Oct 2005
Posts: 0
Re: using a GM v6 ecu for a 4 cyl?
Originally Posted by Mista Bone
Spohn SFC's, LCA's and bracket, panhard bar.........
Notice a 3rd gen only on 3 stands and not twisted, the SFC's were the best mod for the money!
Notice a 3rd gen only on 3 stands and not twisted, the SFC's were the best mod for the money!
Still rocken the BADSASS LO3 and whack *** A4 for now.Dammit! I need a digital camera.
01-01-2006, 02:14 AM
#22
1.0 BAR
Thread Starter
Join Date: Oct 2005
Posts: 216
Re: using a GM v6 ecu for a 4 cyl?
Originally Posted by snm95ls
If you are worried about finding harnesses then all you would have to do is repin the harness from a truck or van to use with any of the ECMs mentioned above.
As far as the injector drivers are concerned, The TBI uses a peak and hold injector driver. And form what I have read those big *** TBI injectors only have an impedance of 1.2 ohms. So in theory you could take advantage of this circuit and run two DSM injectors per driver. The problem of firing scheme comes into play though. The TBI does not use a true batch fire scheme,. Instead of firing the injectors all at once it fires in an alternating fashion 2 times each per engine revolution. If we were to use companion cylinders to find out which driver circuit should go with cylinders, then I guess this could be sort of made into a bank to bank firing scheme.
Since we are talking about an inline 4 cylinder engine it would not truly be bank to bank, but it may work. Since each injector event is triggered by an ignition event then that would drop the 4 pulses to 2 pulses per revolution. Say we have a firing order of 1342 then 1 and 4 could receive fuel from injector 1 and 3 and 2 could receive fuel from injector 2, like in a waste spark system. Granted, the pulse timing would have to be correctly offset relative to intake valve opening. I wonder if Edelbrock did something similar to this in their MPFI conversion kits? Given an SBC with a firing order of 18436572, then possibly cylinders 1467 on 1 and 8352 on 2. This would involve grouping two pairs of companion cylinders together. Hmmm. I wonder?
If you desire to use P&H injectors then the 749 would be optimal. From what I have read, that seems to be the main hardware difference between the 730 and 749. The 730 can be used with boost if you use the mask from the 749 and tune from there.
I realize that the se ECMs can run a vehicle with twice as many ignition events, but the slowness that I am talking about is the time the computer takes to respond to what the inputs are telling it. If nothing else, trying to tune with the slow *** 160 baud ALDL stream will provide you with vague tuning information.
I also completely understand what you are saying about the abundance and cost of the 747. They are everywhere. A 730 and a727 are still in pretty high demand so they bring a much higher price from a private party. Although, the 730 was used in quite a few vehicles, so it should be fairly readily avail\able. Forget about trying to just walk into a yard and find a 749 for $20. That ---- is not going to happen.
In conclusion, I still stand by using the 730 ECM for running a MPFI with any number of cylinders. Whatever you decide make sure that you thoroughly research the GM hardware and code. One of the best sites for research is http://www.thirdgen.org/. Look around in the classifieds section and find the DIY PROM, TPI and TBI boards. I do not claim to be an expert on this subject by any means, these are merely my suggestions based on what I have read.
Hey Bone that's a CLEAN *** TA
. Any mods, times, etc?
As far as the injector drivers are concerned, The TBI uses a peak and hold injector driver. And form what I have read those big *** TBI injectors only have an impedance of 1.2 ohms. So in theory you could take advantage of this circuit and run two DSM injectors per driver. The problem of firing scheme comes into play though. The TBI does not use a true batch fire scheme,. Instead of firing the injectors all at once it fires in an alternating fashion 2 times each per engine revolution. If we were to use companion cylinders to find out which driver circuit should go with cylinders, then I guess this could be sort of made into a bank to bank firing scheme.
Since we are talking about an inline 4 cylinder engine it would not truly be bank to bank, but it may work. Since each injector event is triggered by an ignition event then that would drop the 4 pulses to 2 pulses per revolution. Say we have a firing order of 1342 then 1 and 4 could receive fuel from injector 1 and 3 and 2 could receive fuel from injector 2, like in a waste spark system. Granted, the pulse timing would have to be correctly offset relative to intake valve opening. I wonder if Edelbrock did something similar to this in their MPFI conversion kits? Given an SBC with a firing order of 18436572, then possibly cylinders 1467 on 1 and 8352 on 2. This would involve grouping two pairs of companion cylinders together. Hmmm. I wonder?
If you desire to use P&H injectors then the 749 would be optimal. From what I have read, that seems to be the main hardware difference between the 730 and 749. The 730 can be used with boost if you use the mask from the 749 and tune from there.
I realize that the se ECMs can run a vehicle with twice as many ignition events, but the slowness that I am talking about is the time the computer takes to respond to what the inputs are telling it. If nothing else, trying to tune with the slow *** 160 baud ALDL stream will provide you with vague tuning information.
I also completely understand what you are saying about the abundance and cost of the 747. They are everywhere. A 730 and a727 are still in pretty high demand so they bring a much higher price from a private party. Although, the 730 was used in quite a few vehicles, so it should be fairly readily avail\able. Forget about trying to just walk into a yard and find a 749 for $20. That ---- is not going to happen.
In conclusion, I still stand by using the 730 ECM for running a MPFI with any number of cylinders. Whatever you decide make sure that you thoroughly research the GM hardware and code. One of the best sites for research is http://www.thirdgen.org/. Look around in the classifieds section and find the DIY PROM, TPI and TBI boards. I do not claim to be an expert on this subject by any means, these are merely my suggestions based on what I have read.
Hey Bone that's a CLEAN *** TA
. Any mods, times, etc? I will get back to this project eventually and will post up the results.Thanks for the info guys.
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