I was reading another post regarding (mostly) fuel economy on our cars, and a lot of folks suggested upgrading the carburetor to fuel injection. We all know how well the LS-1's and LT-1's run and what great economy they offer for the power. Most of that is because of fuel management. Now unless you can get Lars or one of the other carb gurus to tune your Quadra-bog or Holley, it's probably not running as well as it should.
I've got a friend at work who is building a 2006 Grassroots Challenge car and is using a product called MegaSquirt. This allows you to use pretty much any type of OEM fuel injection unit and sensors and using a laptop, adjust all the fuel curves, and in some systems ignition curves as well.
Has anyone here used this on a Vette? The small blocks would be pretty easy what with any number of TPI units available, but I'm more interested in something for my 427. I'm not familiar with TPI offerings for big blocks, So I was thinking of a 750 cfm or better TBI probably out of a truck.
The Megasquirt project is 'open source' meaning that the software, maps and other intangible pieces are free, and you can modify them in anyway necessary. You can also buy 'black boxes' and have a mostly complete system that just requires you to add sensors and tune.
Anyone got any experience with doing this?

 

I have accel gen 7 dfi and it is great. The only complaint I have with it is that there is nobody out there that can give assistance with it. I asked questions on a couple of the boards and never get any responses. The system is real nice though. Well built, nice looking, makes amazing torque.


-Justin

 

I like the GM/Delco computers. There is a ton of info out there for tuning, and the boxes are cheap at the boneyard. Plus, if something goes wrong, it's easy to find a replacement. Check out www.diy-efi.org/gmecm for more info.

 

I had always wondered what kind of things you would have to do to a stock computer to get it to work in a different car with different sensors and outputs. I know some can take EEPROMS so that you can make changes, but they can't be adjusted 'on the fly'. Are either of you running big blocks?

 

Breathial had a Megasquirt on his EFI Supercharged BB, I'm not sure if he got it running right in the end though, maybe he will chime in.

Megasquirt looks like a good system, and fairly cheap, but I have no experience with it.


76custompaint

 

On the fly adjustments would be nice with a stock comp. I kno that some people have come up with clever testing solutions like chips that can hold more than one program and a switching system to change programs. That way several different things can be tried in one run.

 

I have been collecting the pieces to go to Megasquirt for a while, and am now in the process of doing the install. I am also going to use distributorless ignition. The DI adds a fair amount of complication, but I think it's worth it to be able to control the spark. For me, one of the hardest parts is the tooth wheel that is needed with the DI. I have a friend that made the wheel for me, now I am working on mounting the wheel and making a bracket to hold the sensor.

As for the intake, I am using an Air Sensors throttle body that has four large injectors in it. It's not like the GM or Holley TBI, the injectors do not sit above the throttle blades. You can find this piece, and a lot of other good parts and service at www.auto-nomics.com. I eventually want to make a port injection manifold, but the throttle body will serve to get the car running.

I am hoping to have the car running by my next open track day in July. It will be a lot of work, but I think I can do it. I'll try to post some updates as I go.

Ken

 

I have had a TPI on the original engine and a open tube/mani/plenum TPI on this roller engine, in my '72 vette....

and I have had all sorts of problems of long standing nature, due to my time and money sequence...money but no time, time but no money...freaking stupid,....anyway....I finally got another chip for that MAP 1227730 computer and so arenow finally getting some of the parameters sorted out with help from a guy down the coast...I will tell of him when it's finally right....

not happy with the chip I have now....another story....

wish I had my original chip/cal-pak from up north again, it ran fine...

GENE

 

Interesting stuff. I put a 350 crate engine in my car a few years ago. Have thought about how nice it would be to have EFI for driveability and fuel mileage. Saw a write up in Corvette Fever I think on TBI conversion. TBI would be OK with me. Of course hood clearance can always be one of the many issues with the early cars.

Thanks for the links.

 

I've heard very good things about megasquirt for a budget fuel injection setup. i plan on doing it at some point or another.

 

The budget part about MS can be a little misleading. The nice thing is that you can buy it in pieces, and save money by using off the shelf, even used, parts. However, I am going to have over $1000 in my system when it's done. Here's the way it breaks down for me:

Throttle body: free from my dad
Machining throttle body to add TPS and idle air solenoid: $200
Wiring harness from Auto-nomics: $125
High pressure fuel pump: $90
Fuse block: $25
MS kit and associated parts: $300
Ignition coils and EDIS8 ignition module: $100 (ebay)
MSD distributor plug: $150
Other sensors and various items: $200

Of course this doesn't include any labor. The computer will slightly more expensive if you buy an assembled one. The reason I went with MS was the ability to buy in pieces; the fact that a kit for a BB Chevy is extremely expensive and won't clear the hood; and most importantly the flexibility. MS has grown to become more than just a cheap fuel injection computer. The group of people that are always working on it is what makes it great. If you can think of it, somebody else probably has as well, and is probably working on it in MS. For instance, there are multiple traction control upgrades, multiple ways to do rev limiters, there is an upgrade for multiple wibeband O2 sensors in the works, you name it somebody is working on it. You basically have a Corvetteforum type atmosphere focused just on fuel and spark control.

Ken

 

I remember talking with Bruce Bowling of M Squirt fame some years ago in the DIY-EFI groups.....back about 10-12 years ago, even got him on the phone once or twice...doubtful he'd remember me though...

all I can say is, I am sorry I didn't just change the trany to a 2004r and have done with all the engine upgrades....

as it was I put a roller engine, 355, 4 bolt mains, 89 truck block and 700 in the car, and lost fuel economy...car only gets....12 mpg now....really really really lousey, it used to get 24 on freeway with the original (rebuilt-prev owner, mild cam) L48, and muncie...and of course the TPI, as a carbed car it got 12 mpg...14 on freeway...so go figger...

I went from about 250 hp to about 375-400 hp with o/drive and am now having long standing problems with tuning, and of course the lousey mileage....can't win...

GENE

 

I'm working on a megasquirt setup as well. I'm going to use the distributor but eh ms will get the signal from the distributor and tell the msd6 what to do.

As for intake choices for a big block, you are pretty limited. Accel has a multiport intake, but the pieces are expensive (~$500 for the top, ~$500 for the bottom), the gm ramjet manifold is about the same price for the pieces and you still need a throttle body that works with it. Another other option was to convert a single plane manifold. Then there's the mercruiser big block manifold, nice cross ram type setup, comes in oval and retangle port, and goes on ebay for $300 for the lower manifold. Sometimes you can catch the entire manifold including the throttle body for $500 to $900. Some people even sell them complete with the electronics. Arizona speed and marine also sells these intakes with modifications like extrude honeing and porting and runner length reduction. And well there's always the option of cutting out the center of a single plane manifold and making custom carbon fiber intake runners and a custom plenum and make it all yourself. Right now that's my plan B if the boat manifold won't fit under the hood. I'll know on monday when DHL drops it off at my door.

I'm also going to use the Inovative Motosports LC-1 Wideband O2 to get a more refined tune once I have all the pieces put togther.

There are a lot of nice ecu's out there, Megasquirt, Accel, Holley, FAST,...all of them have their good points and bad points. Its a matter of how deep your pockets are and what the system offers you as far as how you want your install to look and how comfortable you are with the interface that tunes the ecu.

 

Has anyone tried a new system out called "Mass-Flo"? It uses Ford components and is supposed to be a true "plug and play" system.

edit to add link http://www.mass-floefi.com/

 

I have an TPI accel dfi gen 7 on a 383 stroker motor with a 3200 stall converter on a worked 700r4 trany. I'm putting out 696 hp to the rear wheels. The system is great imho! I get about 21 mpg in od when just crusing on 93 octane. For the track I push a button on my laptop so it changes the settings to run on 101 octane (I have a saved file to change it to).

The only problem I found is that you have to tune these setups on a dyno to get the full potential. I had mine running good, well I thought great. Then I took it to a friends shop and dyno tuned it. We got an extra 112 hp to the rear wheels. It was unreal! There are just too many factors to tune on the street for a system like that imho.

 

The only way I could see this system being "tune free" is by it adjusting auto maticly for 14.7:1 air fuel ratio or some other preset number. Accel DFI's system can do that too. However, every motor is different and can not great on a preset number imo.

For example:

My 383 with a DFI system is set to run at 13.8:1 air fuel ratio for crussing. Anything higher and the engine runs a bit rough and hot (even with adjusting the timming).

In my oppinion, to claim that a fuel injected system is plug and play is hard for me to beleive.

Now, I do not have any experience with this perticular system, I am just speaking from my experience on other injection systems I have worked with. Maybe this company has some alien technology I have not worked with yet.

 

Hey guys, I am a C4 owner but having been doing alot with megasquirt. I've done half a dozen cars so far; from my 84 vette to a 97 stang to a 72 delta 88 with a 455 in it.

It works great once you get past the learning curve. There is alot more work involved than an off the shelf ECU, but the experience and knowledge make up for it.

If anyone in the new england area wants to stop by and see the vette or whatever let me know. I will try to help with as much as I can.

Good luck!