Considering a 5.9 EFI swap into 68 Val -833 O/D car

Hey All,

So I've always wanted to build a big block A body. I've had my 68 Val 273, 904, 7.25 axle, factory A/C for some time now and just enjoyed tooling around with it. Recently I got my 8.75 axle, 833 O/D trans and all the parts needed for the swap (save for sb bellhousing which I am working on right now). I have also got just about everything for my 73-76 disc brake upgrade, sway bar, .995 torsion bars, etc. So I am going to get the rear, trans and front end squared away with the existing 273 engine and drive it until I can get together everything needed for the engine swap.

So then I start reading about Magnum EFI swaps.............................

I have driven a Magnum truck for 15 years now. I bought my 2000 Ram brand new and now it has 240K on it! While the stock trans leaves something to be desired, I have liked the engine (a 5.2) very much. A bit anemic as I had the "death flash" done to it, but reliable and drivable.

Add the fact that I have a spare 5.9 Magnum (99 vintage I think) sitting on a stand in the carport. I was going to put it in the Ram but the poor ol' ram is rusting out pretty bad and I am just thinking to buy a new-ish truck in the future.

This car will be street driven 95% or more of the time. I do want to do some auto-x with it and maybe a track day once in a while at our local road race course (Summit Point WV)

With that in mind I am thinking torque, torque, torque. And I'd really like to be SOLIDLY in the 375 to 400 HP range. I am keeping the A/C too.

Questions are these:

-Can a stock, reflashed PCM handle the duties of controlling a 375-400 horse motor effectively and efficiently? (thinking to go the "Hotwire" harness route)

-What would I have to do to my stock 5.9 motor to get it there? Would cam, headers, injectors and throttle body get it there? Or would I have to get into the mill and raise compression via pistons/stroker/decking, etc.?

Thanks for any thoughts from those of you who have done it!

CE

I'm running a reflashed 1998 factory Dodge Ram 2500, 5 speed ECU in my 68 Barracuda convertible. The same ECU was reflashed to run my previous otherwise stock 5.9 with a bigger Hughes roller cam, headers and bigger injectors.

Recently I reflashed it for a fresh 408" motor with ported Eddie headed, match-ported Airgap intake, Hughes Big Gulp throttle body, 10.25 to 1 compression, with even a bigger cam and injectors.

Same ECU made both motors run excellent using a Hotwire Hotrod harness. I went with a guy named Sean aka Hemifever for the handheld programmer and tunes. He's good at what he does! Fresh tunes are emailed to me, I download them into the handheld tuner and upload them into my ECU. I send him a video clip of the wideband readings and the car driving on the road from cruise to full throttle and he tweaks the tunes to optimize them.

It's as plug and play as it gets. If I went aftermarket, I would use the Holley ECU's.

JCB, I have read many of your other posts and I was hoping you'd chime in.

My idea is to just get the stock 5.9 in the car (maybe with the headers) via the Hotwire harness, and get everything shook down and working. Then save the $'s for the engine upgrade. The hitch was whether or not the stock PCM would do both the stock motor and subsequent upgraded motor. Sounds like the answer is YES! Cool.

This makes for a few more questions too.

Do you know how much HP/Torque you were making with your 5.9 that just had the cam, headers and injectors? How did it drive? Pull good, etc?

Do you know how much HP/Torque your 408 is making? At 10.25 to 1 can you run pump gas in it? I always heard you had to stay below the 10 to 1 ratio to run pump fuel.

Do you have contact info for Sean (Hemifever)? Or can you tell me what the programmer and tunes cost? And how many tunes can you hold on your programmer? It would be nice to have a highway mileage cruise tune and a makin' power gettin' nasty tune.

What is wideband? I assume it has to do with O2 sensor? What are the benefits and what mods are necessary to use/install it?

Thanks again,

CE

jbc426 said:

I'm running a reflashed 1998 factory Dodge Ram 2500, 5 speed ECU in my 68 Barracuda convertible. The same ECU was reflashed to run my previous otherwise stock 5.9 with a bigger Hughes roller cam, headers and bigger injectors.

Recently I reflashed it for a fresh 408" motor with ported Eddie headed, match-ported Airgap intake, Hughes Big Gulp throttle body, 10.25 to 1 compression, with even a bigger cam and injectors.

Same ECU made both motors run excellent using a Hotwire Hotrod harness. I went with a guy named Sean aka Hemifever for the handheld programmer and tunes. He's good at what he does! Fresh tunes are emailed to me, I download them into the handheld tuner and upload them into my ECU. I send him a video clip of the wideband readings and the car driving on the road from cruise to full throttle and he tweaks the tunes to optimize them.

It's as plug and play as it gets. If I went aftermarket, I would use the Holley ECU's.

Click to expand...

Honestly, I would personally go stand alone, like a Megasquirt 3 or Megasquirt 3 pro. That way you can do sequential injection, program everything yourself to fix things you don't like, have a self-learning feature, etc, etc. Change/upgrade as you go.

goldduster318 said:

Honestly, I would personally go stand alone, like a Megasquirt 3 or Megasquirt 3 pro. That way you can do sequential injection, program everything yourself to fix things you don't like, have a self-learning feature, etc, etc. Change/upgrade as you go.

Click to expand...

This is where I start to get very confused. Megasquirt, Holley ECU, SCT. I don't understand what all of these are or what they do.

Does a Megasquirt replace the factory ECU or is it a programmer for an ECU. Do they come with wiring for the engine or do you still use a "Hotwire" type system with them?

Is there a huge learning curve to program your own "tunes?"

Are these systems geared toward those who want to eek out every last 10th of a second on their ET's, or do they make a considerable difference with the same engine as compared to a factory ECU?

Thanks!

CE

goldduster318 said:

Honestly, I would personally go stand alone, like a Megasquirt 3 or Megasquirt 3 pro. That way you can do sequential injection, program everything yourself to fix things you don't like, have a self-learning feature, etc, etc. Change/upgrade as you go.

Click to expand...

Oh also, are they as reliable as factory ECU's are? I want to DRIVE this car and not have to worry about something aftermarket kicking the bucket when I am 3 states from home. In 15 years I have never had to think once about the ECU in my 2000 Dodge Ram. It just works. That is what I am looking for in my Valiant build.

Thanks!

CE

Megasquirt is a "stand alone" system so you wouldn't need the factory PCM. Just really the engine harness for some connectors. Obviously you have to connect all the wires from their harness yourself so that's a bit time consuming. The ones from DIYAutoTune have their own markings for what they go to so it's not that terrible.

I've talked to a lot of people that have Megasquirt systems and so long as they did a decent job tuning and they either bought a pro-assembled one or did a good job soldering their DIY kit together, I really haven't seen any problems.

There is a bit of a learning curve but now they've gotten to the point that you basically program your parameters and you can use VE Analyze live to get the tune worked in pretty good in the driveability section automatically. There are also people that can look at your file online and the logs and help you make changes.

Any one else have any input on either of these questions? Please tell me about what you have been able to achieve or what you would do differently. I'd really like to hear about it. Thanks

ValiantOne said:

-Can a stock, reflashed PCM handle the duties of controlling a 375-400 horse motor effectively and efficiently? (thinking to go the "Hotwire" harness route)

-What would I have to do to my stock 5.9 motor to get it there? Would cam, headers, injectors and throttle body get it there? Or would I have to get into the mill and raise compression via pistons/stroker/decking, etc.?

Thanks for any thoughts from those of you who have done it!

CE

Click to expand...

I resealed a junkyard 5.9 washed it, painted it threw in a Hughes cam and their 1100 springs(cam now sitting on my bench) and did the intake modification. Unfortunately, one of the cylinders ended up only pumping 90 psi, but it still ran great. I had a 727 with 3.23's in it. It was probably in the 14's like that.

from what I have read, there are a lot of guys with stock ecms and sct tuners running heavily modified 5.9 mag engines. you can find a lot of good info at dakotart.com. hope this helps.

I did not go hotwire or anything like that on the harness. I have a '97 harness modded for a '96 computer and a mix of '96 and I think a '98 or '95 sensor or two.

Having everything from the PCM, fusebox, and the harness. Everything you can get will make your life easier later, anything unnecessary can be removed. I didn't hook up the CEL yet.

In the future, for a 904/727 swap- I'd get a whole 3spd 5.2 or 5.9 van.

goldduster318 said:

Megasquirt is a "stand alone" system so you wouldn't need the factory PCM. Just really the engine harness for some connectors. Obviously you have to connect all the wires from their harness yourself so that's a bit time consuming. The ones from DIYAutoTune have their own markings for what they go to so it's not that terrible.

I've talked to a lot of people that have Megasquirt systems and so long as they did a decent job tuning and they either bought a pro-assembled one or did a good job soldering their DIY kit together, I really haven't seen any problems.

There is a bit of a learning curve but now they've gotten to the point that you basically program your parameters and you can use VE Analyze live to get the tune worked in pretty good in the driveability section automatically. There are also people that can look at your file online and the logs and help you make changes.

Click to expand...

This...diyautotune.com... Or Spectre performance sells one assembled,ready to play. About 6-8 bills,IIRC.

dusterMike said:

from what I have read, there are a lot of guys with stock ecms and sct tuners running heavily modified 5.9 mag engines. you can find a lot of good info at dakotart.com. hope this helps.

Click to expand...

The SCT Tuner works great. It is what I am using with great ease and success, but the key to them working great is having an experienced tuner map out and load the tunes for you. Sean at Hemifever provides great customer service and excellent tunes.

Infecteddog said:

I did not go hotwire or anything like that on the harness. I have a '97 harness modded for a '96 computer and a mix of '96 and I think a '98 or '95 sensor or two.

Having everything from the PCM, fusebox, and the harness. Everything you can get will make your life easier later, anything unnecessary can be removed. I didn't hook up the CEL yet.

In the future, for a 904/727 swap- I'd get a whole 3spd 5.2 or 5.9 van.

Click to expand...

What is CEL? Thx.

CEL= "check engine light"