SANDDEMON08

I have a Ls1 that i have built up as shown in my sig. I need to re-tune the engine for the changes. I currently have a mefi 4. My cam is around a .560 lift and a 115 LSA. From what i have read and the people i have talked to everone is telling me to dump the mefi4 and go with the stock computer because it has the MAF sensor. Does anyone have any good info on this.

I will have to buy tuning software for the Mefi4 if i keep it, which will be around 600.00

Mike @ CMS

I worked in the off road industry for 2 years using the mefi 4 system and although it works good in the off road atmosphere its years behind the stock PCM. The tuning software for the mefi is complete crap compared to software such as efilive or hptuners. My advice would be to dump the mefi and upgrade to stock pcm and speartech harness.

Eurospec2

iTrader: (2)

I agree

SANDDEMON08

That seems to be the senus so far. Thanks for the info

MEFIburn

SANDDEMON08, I would have to disagree with the others who have told you to switch out your MEFI, for a number of reasons. Most people are not very familiar with the MEFI controllers and have not seriously looked at their capabilities, which far exceed most of the stock type controllers. Until recently the only software available to tune the MEFI controllers was an old GM DOS based package, that only authorized GM suppliers had, and it was pretty simple and crude. The more recent Ingenius software package sold by UMI/AZspeed/MSD is a good package, but it is expensive, and only does the latest MEFI 4B controllers. It is also tied by a security key to only 1 controller, which ultimately makes it very expensive for doing more than 1 car.

Your car's MEFI runs a speed density type calibration, most likely set up for open loop operation. The MEFI can be run in closed loop using narrow or wide band O2 sensors, boosted applications, alternate fuel applications, or any combination of them. MAF versus speed density discussions have raged on every forum there is to talk about them, but all else being equal, speed density has a slight edge. Switching to MAF would make no sense in your application, especially considering you already have a better setup on your car.

EFILive, HPtuners, Speartech are great packages and setups, but they are not low cost by any means. Your MEFI setup was chosen for good reasons: it is an extremely rugged, compact, flexible, and fairly low cost controller that can be tuned easily and perfectly for your application. These controllers run on practically every brand and type of engine you can imagine, and the only compelling reason I can think of where a stock controller would be used is for a variable cam timing setup, which would need an E38 / E67 / MEFI5 type controller.

Just my 2 cents, but from a cost and performance standpoint, you are far ahead tuning what you've got. Call me if you want someone near you with our MEFIburn package.

Bob

Schwanke Engines

iTrader: (1)

I agree with MEFI Burn, but I am biased to the UMI software as I worked there for a year. That software is by far easier to run and will be better to work with your situation.
I think the best thing to do is get the tuning software and a couple of widebands and start tuning. There are various writeups on here about tuning, so it should be pretty straight forward.
If you or anybody else has any questions regarding the InGenius software, I would be more than happy to answer them. And, if I can't I know the people that can.

Mike @ CMS

I am familiar with the Mefi Ingenius Pro software and HPTuners software and I would have to say hands down HPT is more user friendly. There is also no way in hell that the Mefi 4's capabilities exceed that of the stock computer. You do not need to run a MAF with the stock computer it just makes tuning a small cam or stock motor easier. Mefiburn everything that you've stated that can be done with the stock computer, not to mention the fact that the Mefi 4 runs on batch fire injection unlike the stock computers use of sequential fuel injection. The Mefi 4 is an outdated computer that cant keep up with the technology of today. Most likely SANDDEMON08 is running a Mefi 4A and like you said switching to a Mefi 4B would have to be done in order to used MSD's Inginous software. When I dealt with MSD to buy Mefi4B's they wanted an additional $400-$600 for one of there Mefi 4B's that can be tuned using thier software and, the software, a key and serial cable. Thats on top of the $600 for the Mefi 4B. That was my cost as a dealer. Prices may be a little different now as that was 2 years ago.

MEFIburn

Yes, it all depends on which stock computer you are comparing it to. An E38 / E67 / MEFI5 and others are one generation newer, and yes, they will have more capabilities than the 4's. That's the nice thing about the evolution of the controllers.

The point is he doesn't have to change a thing on his car, whether he has a MEFI 4, 4A or 4B, he can just plug in with the MEFIburn package and tune it. With the same package he can do any of the previous generation MEFI's, a Mercruiser 502 running a MEFI 1, an older Ramjet with a MEFI 3, etc. I'd start to worry though when he tunes a MEFI equipped Hyster forklift, getting the 0-60 times down is tough on those.

SANDDEMON08

I appreciate all the Info Guy's