Big Chrysler, BBC, FI Specifics

[Mean 69]

Okay, here goes. I know a lot about suspension, but not enough about fuel injection as applied to early motors to make a good decision. I like to be informed, thank you very much. Two different motors, but I'd guess that the basic requirements aren't terribly different.

First case is my own car, a street driven, nasty a$$ 500" Chrysler motor. Solid roller cam, big heads, Victor intake manifold that will be converted to accept fuel injectors. Now, the Vic manifolds don't allow a 4500 type base, so the biggest airflow throttle body I have seen to adapt to a 4150 base is about 1600 cfm. I can buy a throttle body online, no sweat, that's not the issue. It's the rest of the story that I don't know. I understand about O2 sensors, water temp, MAF, all the other crap associated with an FI unit as applied to a late model car, for instance, and am technical enough to understand the other stuff. I just don't have time, nor interest, to figure out how to apply to an older motor.

Basic questions, i.e. the most important ones revolve around air intake monitoring, crank triggering ingnition, etc. For arguments sake, assume that the throttle body has a throttle position sensor, and, er.... Well, that's about it.

A bit more specific, I have been looking at the Autronics setup, I have been told (by an Aussie, go figure), that it is a really smart system, and have also read the same here on Lateral G. I have also looked at the BS3 setup. I am not particularly loyal or biased towards any supplier, but I am not really fond of the "try it you'll like it" type of endorsement either.

Even more specific, the car this is going into is my own shop car, which is intended as being a very capable, reliable, fun to drive, cruise, "Pro Touring" car. It's a 68 Satellite/GTX clone, big everything (body, motor, weight, stereo, tires, A/C, anything else too). I do not want to fuss with the car, I don't have an issue with initial tuning, but once it's done, this car will be driven, hard, fast, slow, and long. I'd like to tour big time in her.

Crank trigger options? Needed? Ignition system capabilities (i.e MSD Digital 6 box, distributor, etc)? I have a laptop, that's not an issue, by the way....

Second motor, well, much the same but with forced induction, more cubes, and similar intents. 572 Pro Charged Rat motor..... Customer car.

Mark

[Elusive R]

Hey Mark! Howdy from AZ.

Read the following understanding that I have very little Mopar knowledge and haven't dealt with anything over about 500hp.

For air management, I'd say TPS, MAP and IAC will be all you'll need. I don't know if the companies mentioned have MAF systems available, but speed density is certainly capable of running both of those engines.

Are you looking to run a sequential injection? That will have a big effect on what type of ignition you'll need. I personally don't think there's anything wrong with batch-fire setups, they're just not 'new'. Sequential injection can certainly help smooth out idle and transitions, but the WOT horsepower gap would be small if anything at all. Sequential will also mean you'll have to put that much more effort into tuning (more buttons to push) and spend more money. I think you could run that engine just fine with a Holley Commander or Accel DFI 7+, but obviously there are more complex systems available. Just make sure you spring for a wideband O2, it will save you so much time and maybe even the engine.

So here's my lack of Mopar knowledge - can you run an HEI type ignition (something common and simple)? If yes, then I would with your street driving intentions. I would keep it as simple as possible, so skip the crank trigger if you can. Yes, the spark won't be as accurate, but you'll be tuning with the laptop so you can keep the tune safe for the conditions you'll come across. It won't be a dedicated race car so there is no reason to set the motor on kill anyway. For what it's worth, putting a Mallory (or MSD, etc. etc.) box on my car (hopped up ZZ4 with TPI) made a world of difference on cold starts and made the idle just a tad smoother.

As for the 572, you'll have to be more careful with that one since it will be forced induction. Things change very quickly with boost, so you might want to spring for one of the systems you mentioned to have that much more adjustability. Dyno time and patience will get you a tune that can be very street friendly.

Are you doing the tuning or having a shop do it? I know you've probably already heard/read this, but if someone is familiar with a system, their tune can and should be spot on no matter what computer is doing the job.

Anyway, if I've been of no help, all I can offer is that I'm a big fan of keeping things simple. Fancy stuff is great, but what happens when you're on your way to the Power Tour and you break down 100 miles from anywhere? It's nice to get stuff from NAPA in that case.

Ryan

[Hammered]

I'm only smart enough about MOPARs to know that you've got one he!! of an engine there. I converted my 550 HP Pontiac 462 ci to EFI with little prior knowledge of EFI. Most all of the systems use mid-1990s GM sensors and switches. Most also require a spark box. You need a crank trigger if you go SFI, but there is no more programming or tuning involved with SFI versus batch fire. Sequential will help you get your idle tamed better, especially with a motor that requires big injectors.

I would get a system for which you've got some local expertise available - even if it's a fellow motorhead. I have the Gen7 with wideband and am running sequential.

The majority of my effort went into the layout and physical assembly, especially of the fuel system. I have a bunch of info posted here:

http://www.my67.net/john/efi.htm

and here:

http://www.my67.net/john/Engine%20Progress.htm

I would do your NA motor first, get it right and then worry about the procharged motor. You should be able to run the same basic system, except that you'll need a 3 bar map sensor instead of the single bar. The tune will be very different and less forgiving of errors though.

John