I’ve got a 90 d-150 with a 5.2 magnum and 46re Id like to turbo want to end up at around 400whp. I know I will haft to do head gaskets arp bolts or studs and fix the plenum gasket issue or get a different intake. I have a big fuel system that should support 600hp what injectors should I run? I’m still on the stock jtec computer. Can I use a srt4 map sensor if I got a different pigtail? How much can the trans hold? How much can the bottom end hold?

 

How are you going to manage fuel? Your stock computer won't understand a 2 or 3 bar map sensor, and you can't reprogram it.

 

It’s a obd2 harness from a 2002 van and hp tuners mvpi2 will tune it. from how I understand a map sensor it’s only a 0-5v switch just because the cells say it’s in vacuum doesn’t mean it is half the chart would be in vacuum and half would be in boost if I used a 2 bar map from how I understand it idk I’m only 17 tho😂

 

MAP sensor gets a reference voltage from the PCM, generally 5 volts. The sensor modifies that voltage according to manifold vacuum/pressure that it sees. It's a scale, not a switch.

OBDII harness and PCM will certainly be programmable, however, a lot changed from 96 when OBDII was first implemented, to the 02 version. In around 98, dodge changed the way things work, and EVERYTHING runs thru the PCM. Including the friggin gas gauge.... 96-97 are just OBDII, and all they care about is running the motor and trans. I think that would make the conversion a LOT easier. (still gonna have to do some re-pinning on the connectors though, or, get the interior harness as well, I *think* that would be a direct swap.) I suspect you will want the PCM/Harness from a truck though, as wire lengths on the vans is rather different. Getting it from a truck would assure it would fit, and everything would be in the stock location. (OBDII PCM might mount differently as well, something to pay attention to.)

Keep in mind, how the trans worked ALSO changed with the advent of OBDII. 95 and older are pretty much hydraulically controlled, 96 and up are electronically controlled, so, your existing trans won't be compatible with the OBDII stuff, and the PCM won't know what to do with it. (not to mention the 3 pin vs 8 pin connector change..... ) So, need a trans from a 96 or newer as well. The internal electronics changed in 2000 though, and the P/N switch changed in 02, it think... so,96 to 99 trans would be best. And you WILL need to beef that up to live behind a turbo motor. Good news is, 47 or 48RE hard parts fit inside the 46RE case. (the bell housing bolt patterns are different though, so, you can't use the 47 or 48 case behind a V-8.)

This is NOT going to be an inexpensive undertaking. But, if you are successful, you are going to learn a LOT about how computer controlled vehicles work. Or don't....

Start with a pretty mild tune, and boost levels, figure out the tuning, and go from there. (or, are you going to pay someone else to do the tune?) Build the motor with boost in mind as well, so, no really lumpy cam, etc.

 

right now I want to stay with the stock motor it’s wore out so it’s got plenty of ring gap😂 I will probably tune it I’ve tuned motorcycles off o2s and reading the plug but I’ve never used hp tuners so it will be a learning curve. I have another 318 on the stand right now I’m goin to do heads cam rods and pistons and a older 340 steel crank but by then I will probably go to a Holley ecu and if I can find a controller and flex plate I’d like to do an newer 8 speed swap. For now I want to get everything mocked up and see how it performs I’m curious to find the limits of sock parts. But I do want to go to a older harness because I got the truck with the magnum swap already done and the wiring was not done right what so ever there was so many unused wires and no relays I’ve got everything cleaned up and relayed and fused now.

 

Yeah, the learning curve is initially QUITE steep. Controllers for the 8 speed trans are not cheap though. In the neighborhood of several thousand dollars..... I don't think any of the aftermarket engine controllers would have a clue what to do with 'em.

 

Alright I’ll stick with the 46re then and build it. Is there a good place to find wiring diagrams and pin outs. I have an old Haynes manual but it doesn’t have all the diagrams I need.

 

In the 2nd gen Ram DIY/FAQ section, there is a thread with links to service manuals of various years. (find it here.) Wiring diagrams are in section 8W.

 

Thank you for the help. You know where I can get a diagram for a 90 d150 50 pin cab plug?

 

Probably need the service manual for an accurate one. They are generally available as PDF downloads from various places. Just make sure ya get it from a legit source. Check on EBay... they have some rather odd and strange stuff for sale there.