I have a 05 ram 1500 with the 4.7. I built a single turbo for. I recently purchased the same truck year and everything with the Hemi. I'm switching the Hemi into my truck and will build a new single turbo kit using a Gt45. My question is the torque converter. Both the 4.7 and 5.7 have the same transmission (545rfe). The converters appear to have different part #s. My guess is the 4.7 converter would stall higher which I want for a little more fun on the street. I've searched the net for weeks but can find zero info on this. Does anyone no the difference between the 2 converters? Any info? Im planning to due the swap soon. Thanks.

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Got some time today so the Hemis almost out then onto the complete harness, gas pedal etc. I got to make a decision on which converter to use here soon.

 

So you think the 5.7 would be better suited to hold more power down the road? I was hoping to have a little higher stall.

 

Big tires (without a gear swap), and more torque equals slippage. I'm with Ken, i'd stick with the 5.7 converter. You'll probably get more stall from the 4.7, but it will be loose anytime its unlocked. I have a Cummins with 35's, a billet converter, and 3.54's.... until it locks up, it puts no hp to the ground, and is no fun to drive. This is why good turbo converters are so expensive...lol.

 

I did put 4:56 gears in front and rear with a posi. Guess I should have mentioned that. The OEM tires are actually 33" tall so going to 35's and 4:56 gears is actually geared lower than stock. Does this change you guys input? Thanks guys.

 

A little known fact was the first Jeep SRT8 used the converter from the 3.7 behind the 6.1. That's part of the reason those things would rip your head off from a start. This was using the nag transmission but in 2002 Jeep put the 545rfe in the liberty with the 3.7 as well. I've been eyeballing it for my 4.7, but my experience is that a turbo engine favor a tighter converter. I think the 4.7 behind a hemi would probably be pretty good though. I ran a chevy trailblazer converter (L6) behind my LS1 in my t/a and it was a small bump over stock.

 

Hmm id use the 4.7 converter for a little more stall if I knew it would hold a gt45 at 6psi...I can't imagine it would be more than a couple hundred rpms...

 

A gt45 on a 5.7 should be making boost pretty early on giving you a bunch of tq which is what will make the converter feel loose. But the worst that happens is that you have to swap it back.

 

I'll keep an eye out for the results on this one. I've got a 5.7 Hemi for my Dakota. I was planning a GT45 single build for as well. I'll be running an NV-3500 though, so I can use a dual friction clutch and have no issues. Everything else will be very similar though.

 

Hemi is in and running perfect. I did use the 4.7 converter because I know my transmission and didn't want to use a converter that may or may not be contaminated. Needless to say the converter stalls on the brake until 2000rpms. Which is just like the hemi converter. Maybe they're the same.. Don't know. I'm going to start collecting parts here fairly soon and put a gt45 on it))

 

How do you tune the Hemi with a turbo. I'm almost done with the piping but I have no idea how I'm going to run this thing. Mine is an 03 with the 5.7 Hemi.


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