LQ9CHEVELLE

iTrader: (2)

I am changing a LS1 engine in a friend's sandrail, and replacing it with a heads / cam 6.0. So....obviously its going to need a retune. It has a MEFI controller, and it looks to be running open loop speed density, as it has no O2 sensors, or MAF meter. This type of tune could be accomplished with a recalibrated factory PCM also. What is the benifit to the MEFI computer setup? It seems most sandrails and Marine applications with GM engines almost all run some version of the MEFI stand alone controller. Is it a durability issue with the factory PCM? It seems to me that they are pretty durable, and wouldn't have a problem, unless actually submerged in water, or subjected to insane vibration or contact with debris / etc. Is there a benifit to running MEFI software? With people running 8 second quarter miles and making 850+RWHP on the factory computer, and street driving the car, it would seem that it could easily adapt and live in a sandrail or boat, giving the proper mounting for the PCM and a good tough wiring harness, with the factory weatherpack connectors. If anybody has any info on this, please chime in. It's hard to find people to tune MEFI, and if they're isn't any benifit to running it, then why do TURNKEY engine supply and all these other companies continue to use and push this product over just using a recalibrated factory PCM and a stand alone harness? Lord knows the cost difference between the MEFI and a factory setup is immense. ? ? ? ? ? ? ? ? ? ? ? ? ?

jimmyblue

iTrader: (11)

Because boat and buggies don't have to pass smog,
and far from shore / road there is more of a value
put on simplicity / less stuff to fail?

hellbents10

iTrader: (10)

I really like tuning the GM controllers much more then the MEFI stuff. Every time I go tune a buggy/boat it reminds me tuning a OBD1 car.

The MEFI setups are nice because of their simplicity and compact design though. Not to mention you can get a MEFI 4 with harness for about $600 new!

LQ9CHEVELLE

iTrader: (2)

Yea, but a nice stand alone harness and gm PCM can be had for $600 also! MEFI just seems very dated, and it uses all the same sensors as a speed-density tuned factory setup, so it has the same amount of crap really. Just the computer is 1/2 the size. I guess it saves 6".......

poconojoe

iTrader: (43)

A new factory harness and PCM can not be had for $600, only an aftermarket harness and used PCM. With MEFI, you're getting new factory stuff.

Frost

iTrader: (45)

That's true but I have to say, in the last 45- years working with PCMs, I may have seen 2 that actually had problems. They were both 98s.

At LEAST once a week, I get a box with a PCM sent in for mail order tuning which will nearly have enough room in it for two PCMs. Instead, it will have 1 PCM and NO PACKING AT ALL. Seriously... just a PCM by itself banging around in the box and beating up the box. I used to expect that sooner or later I'd find one dead from banging around the whole way here. Hundreds and hundreds later and they all are good though... They can be had for about $75, so why would you need a NEW one?

TooLateVTEC

iTrader: (2)

What program gets used to tune that type of computer?

slow

iTrader: (7)

You don't want a hot wire maf setup in a enclosed boat engine compartment, which is why these are speed density systems.

mefiburn is one program that I have heard of for those controllers.

Ryan

Schwanke Engines

iTrader: (1)

I used to work at UMI Racing and I think there are 2 reasons they are running these.
A. because using the MEFI, they, being engine and car builders, could lock out the computers so they couldn't be tampered with.
B. I think when they started doing all these sand cars, the only thing available at that time was either MEFi or Motec, and you know which one of those is cheaper and easier to tune.
I know for the direct customers I had at UMI Racing, they liked the MEFi because it was easy to tune and get running. We had plenty of good starter cals so they weren't having to start from scratch to get running.

Frost

iTrader: (45)

You can lock a car's controller too if you wanted though...

Schwanke Engines

iTrader: (1)

10 years ago you couldn't.