This would be for a truck application,low RPM engine.My sig truck is a 1969 L-600 cabover with an LA 318 and an added edelbrock 4bbl.I've recently parted out a couple of vans with Magnum V8 engines,one a 1994 5.9,OBD1.The other is a 1998 5.2 OBD2.I'm thinking of swapping in the >94 5.9 for the easebof the stand-alone aspect of the OBD 1 setup. But then thinking this big truck with a turbo would be cool,and different as well. Not sure how much tuning would be needed for a low pressure turbo setup but wondering if the OBD1 is up to adapting or if the OBD 2 is better suited for the turbo.Has anyone ever added a turbo to either system be it in a stock or swapped vehicle?
Thanks for any and all input! RT

The OBD1 will not adapt very much at all, forget putting a turbo on with that system. It will need to be tuned and for that you will need the OBD 2.

What intake? That beer keg might be a problem with the bolt on bottom plate under pressure (known problem of blown gaskets with vacuum). Standard intakes are limited, 340-360 intakes can be used after re-drilling the heads, so something to think about before going with the Magnum. Other than that I think it's a good platform to turbo. I to would like to hear if there's a hand held to re-program the stock obc

Thanks guys,I was thinking OBD 2 would be the choice for it but the OBD 1 is nice being a simple harness to fit in the truck.
As far as the intake I'd keep the kegger with the Hughes plate or weld a solid plate on the bottom. I've used the Hughes plate on prior Magnums,it's a thick chunk! Thanks again,RT.

I have a thread on here in the truck section where I detailed splicing the OBD2 PCM to the OBD1 harness. That's what I'll be using in my 74 W200. It's about 40 wires depending on what accessories you'll be using like cruise, a/c, autotrans, etc. I'll see if I can find it later, it's not hard.

You can make either work, especially since you are going low boost/ low rpm. There are ways to fool the engine with early ecus. Not that it is easy, but it can be accomplished since your not going crazy with grabbing the max power capability.
Fuel multipliers and coolant enrichment trickery would be fine with what you are describing (as I understand)

U
Have you done this? This is a speed density system, no mass air flow sensor. These were never intended for positive plenum pressure, only a vacuum. I don't know of any way to overcome that.

A single bar map sensor cant read boost. The Ecu wont know there’s boost. A fuel multiplier just increases fuel pressure in a non-linear curve to match the extra air.
If the multiplier doesn’t do enough, you just need to momentarily “alter” the cts value to enrich to mixture with pulsewidth from the coolant temp table.
These tricks don’t work with high rpm/ high boost.
This is ancient tech, but would work with this application.

Interesting,this sounds like the EFI piggy-back tuners did for Harley early injection systems.I do have the complete OBD 2 harness as well.Not sure on the trans but I would like to keep the NP435 4-speed for nostalgia but.I do have either the 46RH or the RE trans for each respective engine as well. How does a fuel multiplier get implemented into a system like this?
RT

Are you going to tow or haul with that truck or is it a driver only empty show type vechicle?
If your going to tow or haul some serious weight put a real truck motor in it, like a Cummins 5.9 12 valve or bigger
I'm surprised it has a 4 speed in it, I'm assuming it has a two speed rear end in it also, does it?

Here is the link to my OBD I to OBD II thread. I'm still using my NP435 at this point as well but will be swapping in the NV 4500 soon.
OBD I to OBD II

Because you will always want more boost I would go standalone. A Megasquirt 2 system is cheap and can control the fuel and ignition.

https://www.diyautotune.com/product/megasquirt-ii-ems-system-smd-pcb3-57-assembled-ecu/

I had a problem where I ran around with lots of fox body mustang guys years ago. The things people do to trick the computer was funny. One of the weirdest ones I saw was a dry nitrous kit that applied nitrous pressure to the fuel regulator to close it off and boost the fuel pressure when the nitrous was on. Things like that and the "Boost a pump" that cranked more voltage to the fuel pump. All in the name of not letting the computer know what was going on.

That is why I used to be scared of EFI lol.

Thats sort of what the fuel multiplier does. It is basically a fuel pressure regulator that raises fuel pressure at a rate that is higher than 1:1.
Vortech makes them. They are part of some of their low boost kits.

Cab,Yes it has a 2-speed axle with 5.83/8.11 ratios,well I have an original to swap back in anyway.It has what appears to be a non original single speed in it now. I'm not opposed to a Cummins swap but with the NP435 trans and it's small block bellhosing that has the rear motor mounts the Magnum is an easy install. Plus I just got a '98 Cummins Ram 2500 as a driver,so that will be the tow rig.This cabover would just be a local fun/cool driver. However if I find a Cummins V903 I may slate that for a later swap,I just think that would be very different and cool

TRENDZ,Thanks for posting the fuel multiplier,I was trying to search for one.

Bad340fish,The MS2 looks like a good option.I may install it with the OBD1 to get things operating first,then if the turbo is added that could be a great system. Thanks for the link.
RT