EFI on an SD4? (Page 1/4)
Raydar FEB 05, 12:12 PM
I realize that they're kind of few and far between, but has anyone successfully run EFI (preferably GM EFI) on an SD4?
What did it take to do it?
(Search came up with nothing.)

Thanks!

------------------
Raydar
88 Formula IMSA Fastback. 4.9, NVG T550

Praise the Lowered!

dobey FEB 05, 12:31 PM
I thought they were EFI already, using either TBI or an ITB setup?
Raydar FEB 05, 12:34 PM
The ones I have seen online and in magazines, and the one I have seen in person, are all carbed.
Blacktree FEB 05, 01:07 PM
I'm sure you could run it with a MegaSquirt. And with the MegaSquirt, you could run DIS and MPFI (assuming you can find a compatible crank trigger wheel, and can mount injectors on the intake manifold).
dobey FEB 05, 02:06 PM
This one sure looks like it's set up for EFI:




Maybe it's just always been easier for the people installing them in Fieros or anything, to use carbs? There's no reason you couldn't use a GM TBI on the 4bbl intake, or something like the Holley 4bbl EFI setups, or an MPFI setup on the ITB intakes.
fierosound FEB 05, 04:00 PM
GM developed the Pace Car's SD4 engine using a 4-bbl carb, then tuned an ECM to run a Throttle Body on the engine due to Indy Rule requirements.
You can see a TB mounted on the Edelbrock 4-bbl intake in the Pace car's engine pics.

Unfortunately, there's no data on exactly what they did (none that I could find anyway).

------------------
Calgary time/temp

3.4L Supercharged 87 GT Click me
Super Duty 4 Indy #163 Click me

[This message has been edited by fierosound (edited 04-26-2020).]

lateFormula FEB 05, 07:22 PM
I know a member of the Michigan Fiero Club who has a 3.0 liter 2 valve Super Duty engine in his car and he has had port injection on it for at least the past 20 years (as long as I've known him). His engine had a carb intake that was cast with bosses for port injection which he had to have machined so that he could install injectors. Where the carb would mount there was a 90° elbow that was made for the intake and that elbow had a mounting flange for a twin butterfly TPI style throttle body. The throttle body was in a horizontal position. Ten or so years ago he designed and had a one-off intake manifold made that has a large plenum and equal length runners to the intake ports. Still has port injection on the "new" intake.

I don't know what kind of ECU he is using to control the engine, but I wouldn't be surprised if it were a Bosch Motronic, as this guy has spared no expense on his engine.
Raydar FEB 05, 08:43 PM
Thanks for the info. I see no reason that it couldn't work. I just wondered if anyone who had done it could share any info.
But what's postred here gives me some food for thought.
And yeah.... that Cosworth looks like it's FI'd. Just never saw (or at least never noticed) that one, before. But then, I wasn't looking.

What is the point of all this? A few weeks ago, a friend bought the Automoda / SD4 that I posted about. It runs like kwrap. (Actually, at this moment, it doesn't run at all. Blowing fuel pump fuses. )
I'm about to go through it and see if I can make it run. And make it run well.




Gall757 FEB 05, 09:06 PM


This should be fun.
foxgapfiero FEB 06, 07:41 AM
When Stickman still had his IMSA there was a SD4 in it with a Bosch Jetronic setup on the engine. He had the car at my house one day and were looking it over trying to figure out how it worked, I think it was a really strange looking manifold with port injection.

Mark

------------------
Mark Hoagland
86 1/2 GT 3.4 5-speed 355 nose and tailights REAL bright yellow

84 SE Convertible