I am currently building that new Motown LS block 427, which is a nice looking piece of iron. I think it was money well spent. My question is do you think my factory 730 ECM is good for this build or do you think I should go with EFI connection and their LS1 ECM swap?

 

You will need a distributor or EDIS with the 730 ECM. Did you plan on that or going with 8 coil packs?

 

No, this is what I'm building: http://www.worldcastings.com/product...ecipe-dvd.html

The new motor is based off of 1st gen bottom end with LS top end. So I will not need 8 coils just the standard dizzy.

 

That's pretty cool.

 

Should not be a problem, its more a function of horsepower. The 7730 will cap off somewhere near 550 HP or so, then you will need to do the patch to your bin to allow more. I ran into the problem where my inj pulse width was being capped off at 7.34 ms.. After the patch my pulsewidth is around 8.2 with 42lb injectors. Current flywheel hp is right at 600 and will increase soon with new intake.

 

I've never understood how the ECM can be limited to a certain amount of horsepower. All it does is take in signals, process that information and spits out injector on signals and timing advance signals to put it simply. It can only use the information that it receives and processes how it is programmed to respond to those conditions.

Power limiting factors are more along the lines of injector size, and ability for the engine to breath.

On my test bench I have had injector PWs into the double digits (according to the ALDL output, still trying to figure out what O-scope to buy), but that doesn't mean much, when at the "RPM" that would be at, the long PW is pointless and would need more injector to actually flow the fuel into the cylinder.

 

What happens during the STOCK $8D code is an over/underflow during the fuel algorithm. Suppose I said pick two numbers between 1 and 10, then multiply them...........but the result must be less than 50. Now suppose you picked 10 and 10, so 10*10 = 100 which is an overflow because the result must be less than fifty. Same thing happens in the ECM.

Once the cubic inch and injector constant increases, then this overflow occurs in the ECM. GM never designed the math to handle this because it was going on a 350ci with 22#/hr injectors. The SAUJP changes the fuel equation to handle larger cubic inch and injectors. I recommend he start with the latest SAUJP revision and all will be fine.

OP,
Since you chose to go with a dizzy then the 730 ECM with the SAUJP would work fine. Going with the LSx PCM offers 8 coil packs and sequential injection but costs a lot more in hardware and software.

 

On fast spooling turbo engines with a fair amount of boost at low RPM the double digit PWs are normal. Lots of fuel is needed for peak torque/high VE and the RPM is low so the cycle time is long.

 

Is that 8.2ms pulsewidth with or without the open and close time? The $8D only reports the actual PW without the open/close time. What was the RPM for the 8.2ms PW?
From memory my PWs are in the 8.xx ms range with the 42#/hr injectors, but I don't think I have near 600 FWHP. Was the FWHP done on an engine dyno, chassis dyno, 1/4 mile ET & MPH calc?

 

His car traps 130 on motor (10.6's ET) and before the bin patch put down 468whp I do believe with a mid 13's to 1 air fuel. With the patch its got to be near 480-490whp with more room for improvement as the air cools down. Its a stout motor and runs very strong. My 383 dyno'd 392whp HOT and trapped 128 with a 150 shot.

 

That is a good engine. His BSFC is probably down around .45 to .50, where as mine is a lame .58.

 

Its being held back some by the miniram intake. Its unported and the heads flow near 320cfm I think, so lots more to be gained. That motor always impressed me.

 

Thanks justin! heads are only 309 though, but I think I still have more, I hope to hit 132 with the intake..

Junk, my FP is at 50psi.. So my 42lbs may be a little misleading.. My PW range from 8.24-8.33 through the RPM Range, makes peak power at 6100ish now, should raise to 6500-6600 with intake change. Thanks for Disecting my PW vs fuel vs output, I think its doing ok..

 

I've been 11.3x @ 121 mph on motor and 10.3x @132 on a 150 shot using a 730 ecm with no problem with my current set up. My question was pertaining to cubic inches wheather or not the 730 ecm can handle it. But you guys seem to have answered my question. Thanks, it's going to be pretty mean.

 

Just letting you know you are still going to have an issue, so you have to use the Pacth or Super AUJP.. You ran 10.3 on spray, your getting your fuel from that not the ecm. If you plan to make over 550 you will need to patch or run massive fuel pressure.

 

Does super AUJP have that patch in it already?

 

Let me start over, I've been using Super AUJP for years to include the lasted version. I also have 42lbs injectors with FP set at 43 psi. I had to add more fuel to my PE mode to keep my AFR in check while on the spray, so the extra fuel was not coming from the nitrous kit. Again thanks for your feed back.

 

The super AUJP has the patch from what I understand, so you are good to go.. My point was, not knowing you were using the super aujp.. Unless running a dry kit, your 500+ hp was not all comming from ecm Fueling. Just trying to save you a step and not run into a problem like I did.
Good luck! should be a nice build