The Megasquirt project has a spinoff known as Megajolt. Megajolt will be a distrubutorless ignition that will work either standalone or with the Megasquirt system.

Check the group out here:
http://autos.groups.yahoo.com/group/megajolt/

The reason I bring this up is that plans for forced induction should include a method for retarding the timing under boost to avoid detonation. A good distributorless ignition system should be able to provide this.

Megajolt is not nearly as fleshed-out as Megasquirt is. The site above doesn't give nearly the clear-cut instructions that the Megasquirt sites do, but hopefully that will change.

My two cents on throttle-body injection vs. port injection:

If you're going to spend time and money on upgrading to EFI, do it right. Port injection has a couple of advantages, compared to TBI:

1. Fuel distribution will be the same to each cylinder (if the same amount of air gets to each cylinder, too, you won't have one cylinder running lean, and another running rich).

2. When set up properly, port injectors will spray atomized fuel directly onto a nice, hot intake valve (ideally, when it is closed). TBI and carburetors both atomize fuel into the airstream long before it gets near the head. So, when the runners are cold, fuel drops out of the mixture, pools in the runners at idle conditions, and gets picked up again at unpredictable times. In order to get a good idle, you either have to heat the runners (using the too-hot exhaust manifold, or a water-heated intake like my Clifford), or you have to run your mixture overly rich.

TBI's only advantage over a carb is that the fuel delivered is measured more precisely.

I've been eyeing the Megajolt for a while, but haven't taken the plunge. Anybody who does it to a \6 should let us all know how it works out for you!

Mark W. Marasch

I am just getting back to this thread. Here are my thoughts:

While multiport is more efficient, I see that a lot of time and money is required to set it up. "New" 1bbl carbs are probably hard to get and I am not impressed by rebuilt ones that my dad has gotten in past years. If you could install a TBI for the same price or less, and you are not comfortable with all that needs to be done for multiport, why not?

A donor is certainly needed. Mustangsix has some good suggestions, and I agree that only one donor should be selected for each setup (1bbl & 2bbl). Ones with a crank sensor would definitely be out. I plan on doing this whether others are interested or not. I have my old "Slant Center" partner coming out from Florida in a few weeks and we will start scrounging the yards for a donor. It would be nice to have any data that others have dug up on donors. Something fairly prolific and easily adaptable, preferably "bolt on", is my first goal.

I am going to start out with the ECM that comes from the donor car. If I can get something from a car close to 225ci then I should be able to get it running easily and the computer with an O2 sensor should compensate for any differences. A different injector may also be an option to get the system "closer" to the 225 engine size. I would also like to have the MAP sensor.

I am not looking for a "one size fits all". My primary goal is as easy a replacement for the 1bbl and 2bbl as possible. For those wishing to go multiport, there is a lot of good data on this site.

I am trying to put together a system that will only require the installer to install a cable linkage and a "bung" in the exhaust pipe for the O2 sensor. I would like to make up the wiring harness and provide the linkage brackets and rods for the auto trans.

Stay Tuned!

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Chuck Rivers, Webmaster

Chuck,

While I rambled on about how much better multi port injection can be, I have to admit that you've got some good points. Amplifying those:

-Slant sixers are not, by and large, ready to spend a whole lot of money changing fuel systems. A less expensive approach is welcome.

-Carburetors are extremely crude instruments, and TBI would provide some nice improvements.

-A ready-to-go TBI kit would probably be quite a hit in this community!

While I'm still hell-bent on doing multi port on my car (followed by a supercharger), last thing I want to do is discourage you from doing something that the slant six community would benefit from!

Let us know how it goes!

Mark W. Marasch

Bump

Just wondering how the tbi settup is coming along?

Keep us posted!!!

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If it ain't broke, I haven't started "fixing" it yet.

I am about 1/3 of the way through building the MegaSquirt computer - it is pretty easy with their awesome directions. I'll post my results with my TBI, and later with batch MP-EFI. I expect to have it up and running with the TBI in approximately 6-8 weeks.

Lou

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Home of Slant6-powered fun machines since 1988

What would happen if you took a TBI and ecu from a donor car along with the sensors out of the donor car andslapped it on the slant engine? Would it run? Has anyone tried it?

Hmm...

I belive that the engine would run (It would be like taking a carb off of another engine, and slapping it on), but it probably would be out of tune. Unlike a carb where you can turn a screw to "tune" the engine, a tbi uses sensors instead of the screws(basically). So it would run alittle off, but might be close enough, depending on the tbi size, injector output, ect.

Has anybody thought of the tbi off a 318? I picked up my holley(carter bbd) off a 318, and haven't adjusted it too much. I belive they are the carters off the slants, just richer settings. Maybe the 318 throttle body would be a good size for the slant?

I have my eye on the projection for the jeep, I belive it would bolt right up(they came stock with the carter bbd). The engine size is only like 25ci difference. Plus it looks fairly easy. Has anybody tried this setup? With the exchange, and shipping, it is like 1300 bones. Yikes! If it comes on ebay, I will pick it up, but that is alot of money for a student!

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If it ain't broke, I haven't started "fixing" it yet.

Well as for the jeep, I think the projection setup you refer to is an aftermarket holley one right? if so yep they are mondo expensive and don't come around on ebay all that often. Also dart 270, what tbi did you use and did you need an adapter? I thought the 318 tbi units required a cam sensor, and I thin we are in search of a tbi setup that doesn't use a cam sensor. Any thoughts on that? I think the throttle body itself off of a 318 would fit but the other sensors and ecu is what I am worried about.

As I have said, I use the Holley Projection TBI from '93 or so - came with an adapter to fit a 4bbl intake.

You should not need a cam/crank sensor for any kind of TBI, as far as I know.

Lou

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Home of Slant6-powered fun machines since 1988

Mark,

Thanks. I certainly believe that multiport is the best way to go but I am looking for a "quick & dirty" (but GOOD) setup for the masses. Thanks for the encouragement.

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Chuck Rivers, Webmaster

My very close friend and former partner in my Slant Center repair business in the 80s, Dan Wagner, was helping me with the TBI "kit". He was going to be here next week and we were going junkyard hunting for TBI stuff. Unfortunately, Dan passed away very suddenly from a heart attack on 1/24. He was only 45 so this came as quite a shock. He was also the driving force for the new Dutra Duals casting project. I will now have to pick this stuff up on my own.

I saw mention a little later in this threrad about the 318 TBI. I would like any info on what cars this was installed on. It could be the donor I am looking for to do the 2bbl kit. I used to run a 318 carb (re-jetted) on my slant.

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Chuck Rivers, Webmaster

Lou,

I am really interested in what TBI you are using. If we all pool this great data I think we will have a great setup. I was thinking about the possibility of using a GM 3.8l ECU because the size is so close to a slant and it may cut costs. I haven't picked up a megasquirt yet. Dan and I were going to look into that after testing some OEM units.

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Chuck Rivers, Webmaster

I wanted to try this first, but I haven't gotten out to find a donor yet. As I mentioned in another post, my buddy Dan was going to go "donor hunting" with me this month but he passed unexpectedly.

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Chuck Rivers, Webmaster

I could use any data you have on possible donor cars.

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Chuck Rivers, Webmaster

I don't think the TBI cares about the sensors. That is done in the ECU. Maybe the 318 TBI with a GM 3.8 liter ECU?

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Chuck Rivers, Webmaster