I was planning on using the MeagaSquirt EFI computer.

After shopping around and seeing what is available, this looks like a pretty sweet setup.

I have not gotten to the stage in my buildup where I am ready to do this, so I need to put it off for a while.

I thought it might be a good idea to start a thread discussing the Megasquirt computer with the /6. If anyone is using or has thoughts about using the Megasquirt EFI, please post your comments here.

Lou, maybe you could kick off the discussion with your background thought that lead to your purchase.

John Killin

Fellow Slanters,

I've been watching the development of aftermarket EFI/ignition controllers for the past several years. These systems are still evolving, in terms of features, price, convenience... So far, nobody has marketed a complete, universal, and programmable EFI computer for less than about $8-900, and most kits are in the $1100-1600 range with a sensors (O2, MAP, temp) but no injectors, fuel pump, rails, etc...

The companies I have checked out are:
- Haltech
- FAST
- Accel DFI
- SDS-EFI
- Electromotive
- Holley (especially the new Commander 950 series)

Some DIY info:
- Bob DiBase's EFI article (here)
- www.diy-efi.com
- www.bgsoflex.com/megasquirt.html

Some of these now allow sequential MP-EFI, and some are still working on it, or don't care to go there. From all I've read, I don't believe there will be a big gain in using sequential unless you are after really good low-end characteristics and best emissions. I would eventually like to try seq, but right now it seems too expensive for me. The Holley 950 and SDS unist are the cheapest system controllers right now, and the Electromotive and Accel DFI seem to be have the most features, like sequential, and highest prices (maybe FAST too?).

I plan to initially replace the stone-age analog computer driving my Holley 670 CFM ProJection system (on '64 Dart - running this way for 4 years) with a programmable controller, and then upgrade to multi-point with the same controller once I have the time and $$. I plan to eventually get into turbos, but not before I get a dry manifold system going (MP-EFI).

The Megasquirt site has tons of good info and well written assembly instructions and programs to get the controller running smoothly. Clearly the designers are competent engineers and have organized their information well. In addition to getting the satisfaction of putting it together myself (although the hard work has been done by Bowling and Grippo), I can order a full kit (with power relays/board) for $172 shipped to my door. The kit has all parts (resistors, CPU, relays, diodes, etc...) and a printed circuit board to mount everything. The site has assembly instructions, schematics, FAQs, and a link to a message group on Yahoo, where the designers answer questions, like this site. This seems like a very versatile system, is laptop programmable, and has as good or better time/RPM resolution than most of the canned kits out there. Somewhere around 100 vehicles are successfully running this system so far and I've heard positive reports, notably from one Mopar racer at Richmond with 2 BB cars running the MS, about easy assembly and good performance. Another cool thing is that the MAP sensor is built into the MS board, AND it has a 2.5 bar range (OK for turbos/blowers up to 22psi boost! ).

On the $$ end, I am taking a small gamble that I will get this thing to work seamlessly, but I am fed up with the computer I have now and don't have the bread to buy a $1200 kit to replace it. With the MS kit, I will understand how it works in detail and should have a fully tunable and upgradable EFI system.

That said, I'll let you guys know how things work out, at least with my TBI, probably in the next 2-3 months. These guys also just put up a partial site for a similar kit to drive a distributorless ignition with programmable timing (http://www.bgsoflex.com/mjl/mjl_edis.html). I'll be watching this carefully too.

Cheers,

Lou

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Home of Slant6-powered fun machines since 1988

The megasquirt is very interesting, and has the right price. I think they need to work on the user interface a little bit more. Using a notebook to change lookup table values and then reassembling the control program is not the best user interface. No matter how pretty the notebook side is. But, maybe this is SOP for micro-controllers. I don't know, I have never worked in the embedded market.

I have been looking at the MegaSquirt also. I saw that there was a group buy program in the Yahoo newsgroup but it is over now. I have not seen the price or ordering info on their website. I figure it must be burried there somewhere, so I would like to know where you found it.

I would also like to know what TBI you are using. I am interested in putting together two TBI kits, one to replace the ever-troublesome 1bbl carb and another for the Super Six manifold. I figure the MegaSquirt would be perfect for this. Different programs could be developed for the different TBI units and then downloaded to the MS for use with the correct TBI.

I am willing to help out. Just let me know what you need and perhaps point me to some TBI units that I can scrounge for testing. We should also watch the Yahoo site for the next group buy. The price quoted there was about $119 if memory serves.

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Chuck Rivers, Webmaster

Chuck,

I lurked on the site until they were about to sell the leftover kits from the 2nd group buy, then ordered just as they put the "order form" site back up. Only took 1/2 hour to sell the remaining 30 kits... They will be organizing another group buy in Feb/March. The MS kit is $110, and I ordered the power relay kit for $55 as well. If I order another one, I will probably do the relay kit myself, but I figured it'd be cool to see their kit since they have obviously put a lot of time and thought into it.

I think you have a good idea there for retrofit 1bbl kits. Many cars from the late 80s/90s would have suitable TBs. I think the 2.8L Chevy has a 1bbl Holley TB similar in design to (but smaller than) the aftermarket one I have ("ProJection" 670 CFM 2bbl with, 2" bores, circa 1993). SB Chryslers pre-93 also have essentially this same TB, as do many Chevys of that era. You can even get replacement aftermarket TBs in 1bbl, 2bbl, or 4bbl with various sizes from Holley 400, 500, 670, 700 CFM or larger (through Summit as well). I am fan of new (not rebuilt if possible) parts for best reliability and longevity. I think a 400 CFM 1bbl would be just the ticket for a stock or mild slant.

Cheers,

Lou

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Home of Slant6-powered fun machines since 1988

Lou,

I would like to find a unit from another vehicle that could be rebuilt. I think the cost of the new TBI unit could be a deciding factor. This would also allow a user to buy a kit without the TBI and get the TBI himself. I would like to make the kit "turnkey", providing everything the user needs except for the cable linkage.

I was not aware that Chrysler ever used a TBI. Does it use the same Carter BBS base as the Super Six manifold? If so, what cars could I look for to get the donor parts?

If you wish, you can contact me at sl6@omnipages.com.

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Chuck Rivers, Webmaster

Chuck,

I prefer to keep the discussion here for now, but I will feel free to email you if we need to coordinate something.

Chrysler (and most other makes) used TBI on LOTS of cars. Many K-cars (2.2L and 2.5L) had 1bbl TBIs in the late 80s (my wifes Aries LE is one), and trucks and vans used them (mostly 2bbls) on V8s and V6s up until 92/93 when they went to multi-point. My '92 360 van has a big 2bbl TBI and was the last year for it. I don't know if any of these would bolt up to a BBD or BBS manifold, but I doubt it. An adapter would work fine though.

OK, I can see that a DIY kit would be better to sell so that someone could use a cheap junkyard TBI.

Cheers,

Lou

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Home of Slant6-powered fun machines since 1988

The salvage yard EFI is sophisticated enough for me, I expect that these have more than enough flexibility if we have enough technical information to understand how they work, w/o having to reverse engineer them. Many of the engine management computers once used relatively simple 8-bit Motorola 6800 series, but now that the transmission shift points and even drive-by-wire throttle are integrated into the system they've become more complicated.

There is a sufficient functionality in the OEM junk yard parts, millions of dollars were spent to engineer the systems, it would be hard for an aftermarket supplier to match the features that are in late model junk yard systems.

Is projection fuelinjection with only one Fuel Injector?

Right I see nevermind I figured out my own answer. Projection is Holley's TBI or thottle body injection system. so no multipoint fuel injection.
Now the earlier supra strsight six's used TBI so assuming I made up an adapter for the throttle body I could use its throttle body and ecu on my slant right? Do TBI's have mass air flow sensors? What other stuff would I need off of it to get it running on a slant? Are there any pages on doing a tbi junkyard conversion on a slant? Maybe I'll go TBI instead of Multipoint FI, sounds much easier. My plan would to be to still eventually run a turbo, so I think I would have to look for a Junkyard TBI that had a flow of around 400 CFM. Sounds like a vb TBI system? anyone know any good donors?

Anybody ever ran across this site before?
http://www.affordable-efi.com/throttle_ ... ection.htm

If they can customize it to your engine, that's not a bad deal for all new parts and a full feedback system. The only disadvantage of TBI, especially with a turbo as I understand, is that it is a "wet manifold" system and may have distribution problems with a turbo as a carb might.

Lou

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Home of Slant6-powered fun machines since 1988

In the book on turbos that I have. There is only 1 car listed as having tbi with a turbo and only 2 with carbed turbos(trans am and pre GN 3., the rest have port fuel injection. The one with tbi is a dodge. Got a guess yet? Well its almost a dodge,its a dodge colt gts turbo, putting out a whooping 102 hp although from only 97.5 cu in. If I could get the HP per cu in out of my slant after the upgrades I'll be right on with what I am after. 225+ HP. I would really like to see 250 though.

Anyone here have a tbi they used on a slant or know a good tbi donor car? I'll have to look for a fuel injection book to see if I can find a listing of what cars have tbi.

I considered that for the conversion I have coming, up, but it doesn't solve fuel delivery issues the way multi port does. Throttle body injection, from what I've seen on several Jeeps, is no better than a well tuned carb.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

True you still have the same problem with 1 and 6. But I think it does solve a number of things, cold starts, better emmisions, better mileage, better low rpm driveability. Also for me it will solve a major problem with running a turbo on a carb. I think I will be shifting gears once again and going for a tbi turbo setup. Although If I did hae loads of money and time, I'de probably still go with a multiport batch FI system.