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View Full Version : LS1 PCM puts the MEFI4 to shame



S10Wildside
June 18th, 2009, 09:41 PM
A recent customer received a 1998 K1500 pickup with a RamJet 350 crate engine and MEFI4 controller. Here are the before/after (MEFI4/24x) results of the (SuperFlow) dyno runs.

Now to be fair, the MEFI4 could have been recalibrated. But this is what GM gives you (in blue) with the RamJet 350 crate engine.

http://www.eficonnection.com/eficonnection/images/PowerLabsRamJet04.jpg

http://www.eficonnection.com/eficonnection/images/PowerLabsRamJet01.jpg

http://www.eficonnection.com/eficonnection/images/PowerLabsRamJet02.jpg

GAMEOVER
June 19th, 2009, 03:05 AM
I'm helping a good friend of mine that bought and installed a Mefi4 controller & harness on his turbocharged 6.0 LQ4 Jeep Wrangler project. I tried to convince him to go with his stock Lsx Pcm & I would tune it with EFI Live but he didnt listen. The Mefi4 controller, harness & software is really expensive!!! The scanner always crashes when trying to data log...:bad:
The stock PCM & harness(which he has) would've been the smart choice...:D

L31Sleeper
June 19th, 2009, 07:44 PM
GAME that is along the lines of "Friends don't let friends drive Fords" :rockon:

GMPX
June 20th, 2009, 06:18 PM
I have to say that you can't blame a controller for not making power, if the controller can get the engine to run at optimum timing and AFR then the engine will make the same power. Of course the whole point of this is the money you spend on a MEFI v's LS1 PCM and the tools you have to get to those optimum running conditions.
I have not seen what the MEFI is capable of, but let's face it, there is millions of dollars on R&D sunk in to that LS1 PCM, no wonder it's so good!

S10Wildside
June 20th, 2009, 11:18 PM
Many of the Vortec truck guys I talk with have a 4L60E or 4L80E transmission. That makes the LS1 PCM even more desirable for the 90s Vortec truck.

It's just amazing to me to see how well the LS1 PCM ranks to all of the other options out there. If not for EFILive and Moates, there would not be so much to get excited about.

Not to downplay HP Tuners, CATS, or JET for their efforts; I just haven't had hands-on experience with all of their products. But anyone who sees potential in a $50 junkyard PCM is alright with me. :good:

Kleptow
June 23rd, 2009, 05:12 AM
A recent customer received a 1998 K1500 pickup with a RamJet 350 crate engine and MEFI4 controller. Here are the before/after (MEFI4/24x) results of the (SuperFlow) dyno runs.

Now to be fair, the MEFI4 could have been recalibrated. But this is what GM gives you (in blue) with the RamJet 350 crate engine.

http://www.eficonnection.com/eficonnection/images/PowerLabsRamJet04.jpg

http://www.eficonnection.com/eficonnection/images/PowerLabsRamJet01.jpg

http://www.eficonnection.com/eficonnection/images/PowerLabsRamJet02.jpg

Did you check the A/F readings? I'm willing to bet if it was a stock tune, it was so rich it would just about be able to get out of it's own way.

I've check 4 MEFI controlled engines, 2 had the Mefi3 the other 2 had the mefi4 controller and all 4 were so rich, they would not even register on my gauge's, until after I flashed them with a properly tuned bin file.

I know Mercury does this so they want have pay for rebuilds, on these so called racing motors.

GAMEOVER
June 23rd, 2009, 06:07 AM
Thats the problem I ran into! When I hooked up my wideband idle was at 12.1 AFR, part throttle & cruise were around 10-11 AFR and WOT would dip into the 9's:confused: My friend's Jeep looked like a Diesel going down the street, black smoke everywhere :shock: It ran so rich you could literally touch the turbo downpipe within minutes of shutting it off....But like Kleptow said, after a good tune or basically leaning it out in my case :) it's running pretty good now. But I still think the best choice is the LS1 PCM and a standalone harness and of course "EFI LIVE"

Kleptow
June 23rd, 2009, 11:13 AM
Thats the problem I ran into! When I hooked up my wideband idle was at 12.1 AFR, part throttle & cruise were around 10-11 AFR and WOT would dip into the 9's:confused: My friend's Jeep looked like a Diesel going down the street, black smoke everywhere :shock: It ran so rich you could literally touch the turbo downpipe within minutes of shutting it off....But like Kleptow said, after a good tune or basically leaning it out in my case :) it's running pretty good now. But I still think the best choice is the LS1 PCM and a standalone harness and of course "EFI LIVE"

I'm hoping that time any money will give me the opportunity to find out if your right, I'm planning a build of whippled N* motor for my boat.

Thanks for your reply.

-Brian

S10Wildside
June 23rd, 2009, 12:46 PM
Did you check the A/F readings? I'm willing to bet if it was a stock tune, it was so rich it would just about be able to get out of it's own way.

Remember this was not our project, but a customer's project (for his customer). He did mention a low 10 AFR during the pull. I can hardly believe that GM sells the RamJet 350 crate engine this way. :shock:

Highlander
June 23rd, 2009, 04:22 PM
Many of the Vortec truck guys I talk with have a 4L60E or 4L80E transmission. That makes the LS1 PCM even more desirable for the 90s Vortec truck.

It's just amazing to me to see how well the LS1 PCM ranks to all of the other options out there. If not for EFILive and Moates, there would not be so much to get excited about.

Not to downplay HP Tuners, CATS, or JET for their efforts; I just haven't had hands-on experience with all of their products. But anyone who sees potential in a $50 junkyard PCM is alright with me. :good:

Mike... send me a couple of those $50 junkyard pcms ;)

Highlander
June 23rd, 2009, 04:22 PM
I have to say that you can't blame a controller for not making power, if the controller can get the engine to run at optimum timing and AFR then the engine will make the same power. Of course the whole point of this is the money you spend on a MEFI v's LS1 PCM and the tools you have to get to those optimum running conditions.
I have not seen what the MEFI is capable of, but let's face it, there is millions of dollars on R&D sunk in to that LS1 PCM, no wonder it's so good!

Totally true... but... if i have more resolution for timing I can get more power out of it :D

S10Wildside
June 23rd, 2009, 10:15 PM
:grin:
Mike... send me a couple of those $50 junkyard pcms ;)

Hey Chris...location, location, location...

Used LS1 PCMs aren't abundant in PR as sunshine is not abundant in PA from December thru April.

Kleptow
June 24th, 2009, 02:34 AM
Remember this was not our project, but a customer's project (for his customer). He did mention a low 10 AFR during the pull. I can hardly believe that GM sells the RamJet 350 crate engine this way. :shock:

My buddy works in the local Chevy dealer parts dept, he said they get calls back all the time. I thought it was a fluke also but then after getting the bungs welded in to my CMI exhaust. I fired it up and the gauge flickered once and nothing else, pulled a plug and yep it was about as black as it could get with out fouling, I'm sure that would have been next if I hadn't caught it. I flashed my MEFI3 ECM re-fired it started bouncing between 11 and 14 big difference. Once it burned all of the carbon out of the cylinder it stabilized @ 12 - 14.

I'm looking forward to playing with the 2 platforms after I get my shade tree mechanic engine dyno going.

Highlander
June 24th, 2009, 02:45 AM
With efilive it will be a finer PCM...

You will like it more and the car will run better... GM Knows ;).