Burn Prom or MS

Fuelie74

Well-known member
Joined
May 7, 2008
Messages
770
Location
Monroe, WI
I have a stock 92 350 TPI in my Vette that I am getting ready to start modifying. I plan to switch to vortex heads and change the cam this winter. With that I am going to need to do some tuning with the computer. I am debating at whether to get everything to burn my own proms or possibly switch to megasquirt. I know very little about either and am more familiar with the plug and play stuff. I am on a very tight budget so no high dollar stuff like FAST. I want it to be rock solid reliable, sequential port would be nice but not necessary, and best bang for the small buck. How much total would I be looking at for either system and what would the down sides be?
 
I am not aware of ANY, let alone affordable DPFI intakes for the Vortec heads, I understand the induction is totally different and older SBC stuff will not fit....

I have never played with any Vortec stuff though...

as far as computers go, I would just do a LT1 top setup like I did last winter...but you need do some work on it to fit what you have now....
which is essentially the same as your engine....a ZZ4 if you will.....

the work entails mucho cutting and machineing to be done with hand drills, drill press, and then you have to TIG up the manifold for water and dizzy mounts....
just takes time and thought, I can help if you take that route.....

the Mega Squirt is something I played with over the winter some 1.5 years ago, and I found the unit AT THAT TIME had a serial D port connector for .commm with the laptop...well I had a HUGE problem with that because none of the laptops could talk to IT, as well as send files over the net or even transferr to any PC I had....I finally gave it the hell UP already....hopefully they updated the thing by now and have a USB .commm port and if not, you going to have a problem....

I think it's mucho cheeper to just do a larger induction, step up the cam, and get that chip/calpak to a tuner for a update, and let it go at that...

I get 22.2222 mpg at 90 mph....so not so really awful evil and I have a 1227730 speed density computer out of a '91 F body....

:smash:
 
As far as the heads go. I go them for free and they are way better than the ones that came on my 92 Fbody 350. I am going to use the dirt trackers trick and have them redrilled to take a standard (old style) intake.

On the LT1 intake. Do you have any picture of this. I seen it on a couple websights and it kind of looked like a cluster, but mayber that what just in how they did it. I have everything in my garage to do the modifications so that wouldn't be a problem.

I thought about just ordering a chip but, I would really like to be able to tune and play myself.
 
I will give you my 2 cents.
IMHO it is a waste of money to try to buy all the support hardware, (emulators, programmers etc. etc. to upgrade the older GM stuff. After all is said and done, you will have spent almost as much $$ and still not have the capability you need much less want.
Ease of tuning is a must. So, Wideband O2 should definitely be in your plans. Otherwise you are shooting from the hip. Real time operational calibration also fits in the must have category. The hit and miss tunning cycles requiring burning proms will drive you to drink. :suicide:

There are other nice to haves that I have now come to believe are also necessary, like dual fan control, Sequential injection, Dual fuel maps for economy and performance, future NOS capability to name a few.


If I were in your shoes, I would consider going with something like the Accel Thruster ECU, (Which is upgradeable to Gen VII btw) and a LC-1 wideband O2 system. I would rewire your existing wire harness to adapt it to the Thruster ECU to save money on a new aftermarket harness. This is where you may have to spend the money if you don't feel comfortable doing cable rewiring. Accel gives you a detailed system schematic for guidance.
your probably looking at ~ $1k - $1.3k after all is said and done.

I know there are a lot of people who swear by MS, but for my money, its not worth the investment. It is, however, a great EFI learning approach it you want to invest the time.

Bullshark
 
I would love to go that route but it is out of my price range. After doing some more reading on megasquirt it seems like a fairly good option I am conserned about its durability though and would like to hear from people who have them.
 
I would love to go that route but it is out of my price range. After doing some more reading on megasquirt it seems like a fairly good option I am conserned about its durability though and would like to hear from people who have them.

I have one. It is definitely not packaged for extreme environments. You could probably get away with installing it under the hood in a benign location but, I would recommend putting it inside under the dash. It is not packaged for high vibration, heat or moisture. Accel and other aftermarket ECU companies sell a ruggedized version that they fill with potting. This is not something I would opt for, for obvious reasons......it fails, you throw it away. GM's MEFI 4 is the best ECU I have seen for severe environments. The only one I would consider mounting under the hood. The RamJet mounts it on the engine intake.:thumbs:
The MS system's reliability has a lot to do with how good an electronics tech/assembler you are. If you haven't done something like this before, there is a learning curve. :smash:

I know $1K sounds expensive, but what's that old Fram filter saying....Pay me now or pay me later" A few bucks up front will save a lot of headache down ther road.

Bullshark

BTW, I still have Gene's (mrvette) MS sitting in a drawer, with no plans for it. If your interested, let me know. I will sell it for what he charged me. cheap!:noworry:
 
I have my current ecm under the dash on the passanger side so that isn't a problem. I also don't plan on going off road in my Vette so if I mount it with some rubber isolaters like an MSD box uses I shouldn't have a problem that way either. I think I will give MS a try. I am always up for a challenge. I PMed you.

Thanks.
 
If you go with MS, let us know how it works out. I hear a lot about it but don't see much info posted about actual installations.

Of course, pictures are good!:idea:
 
The system itself is fine, and rugged enough for car INSIDE use, but I would never consider mounting electronics under the hood anyway, be damned what GM does....heat and moisture WILL take it's toll, period....

your challenge is the programming, it's preloaded with a program what would run my car fine at warmup, but die when reaching operating temp at ~160 or so....it IS fixable if you can get the software correct.....

:nuts:
 
I have desided that I will be going with MS. This will happen over the winter when I have time to work on it more. I will post some pitctures and my thoughts of the install at that time.
 
I went with MS (have got an assembled unit, but sorry no info on the way it works....will get back to that later).

Anyway, it looks pretty good to me. However I do intend to install it under the dash.
 
Top