What are the limits for the 545rfe?

[Evanp2005]

I am interested in undertaking an engine build project for my 04 Hemi. I want to do a cam, headers, install the K1 stroker kit get a bigger TB and a tuner. I’m worried about what the trans will handle tho. I’m sure I’ll have to get my shift schedule adjusting and increase line pressure. But how much can this trans take if im daily driving the truck to work? I wanna put the power to use on weekends for towing and maybe some not so competitive racing. Any advice from people who know these trannys well or people who have done similar builds is appreciated

 

[HemiLonestar]

Cam - good call, don't go apesh!t
Headers - good
Stroker kit - time for a trans swap lol
Bigger TB - waste of time, unless you think your new small bore 392 with less than apache heads is gonna pull more air than a factory 392 (same size TB)
Stroker + 545RFE = here for a fun time not a long time
Stock install the most the 545 ever had to deal with was the 390hp/407tq with prodigious amounts of torque management. Physically one would think it to be a stout piece but the factory programming is one of its issues, the other being the existence of 2 prime and the weak clutches. 450 flywheel hp seems to be the absolute limit and that's with no kickdowns, so either manually shifting to 2nd to romp it or only from a stop. Even a mildly built 5.7 based stroker with decent heads should be north of that. Anyone with a decently buuilt engine generally looks at trans swap, be it manual, 46RE (or even RH) or lately the 8HP70.

 

[Evanp2005]

Cam - good call, don't go apesh!t
Headers - good
Stroker kit - time for a trans swap lol
Bigger TB - waste of time, unless you think your new small bore 392 with less than apache heads is gonna pull more air than a factory 392 (same size TB)
Stroker + 545RFE = here for a fun time not a long time
Stock install the most the 545 ever had to deal with was the 390hp/407tq with prodigious amounts of torque management. Physically one would think it to be a stout piece but the factory programming is one of its issues, the other being the existence of 2 prime and the weak clutches. 450 flywheel hp seems to be the absolute limit and that's with no kickdowns, so either manually shifting to 2nd to romp it or only from a stop. Even a mildly built 5.7 based stroker with decent heads should be north of that. Anyone with a decently buuilt engine generally looks at trans swap, be it manual, 46RE (or even RH) or lately the 8HP70.

Would a manual swap be out of the question? Like an NV4500 or 5600 with a south bend clutch. Never done a manual swap before so I’m not sure about what sensors are gonna need to be disabled and what tuning will be necessary

As for the cam how much is too much. I wanted some chop to it so I thought about like a 268 from COMP. but that might be kinda overkill. And what tuners should I look into for a mild setup such as this?

 

[Lyle Longboat]

I blew up my 545rfe twice. Now, do an 8 speed swap if you have the funds and can do it yourself or have a very very very reliable shop/mechanic that knows what they’re doing (will be a total Waste of money if they don’t).
Now the option I went with (only due to me knowing nothing about swapping trans and having no shop that would touch my truck in my area) was go with ATS’s stage 5 545rfe that was rated for 900HP (don’t believe it). However, it has worked for my truck that has the stage 2 TSP cam, 4:56 gear swap and most bolt ons. She’s ruining 37s (literally live offroad).
I have a large aftermarket trans cooler, ATS DEEP (it’s deep) pan. My stall is set at 2800/3000 for my cam. I got lucky with a great Christmas deal on the trans here in Ontario Canada, including free shipping. But nonetheless… you’re going to blow the 545rfe, not a question… been there twice. 2 options listed above….. then again, you’re going stroker, 1 option…8 speed!

Forgot to add I have ATS’ copilot which I like.

 

[Lyle Longboat]

Would a manual swap be out of the question? Like an NV4500 or 5600 with a south bend clutch. Never done a manual swap before so I’m not sure about what sensors are gonna need to be disabled and what tuning will be necessary

As for the cam how much is too much. I wanted some chop to it so I thought about like a 268 from COMP. but that might be kinda overkill. And what tuners should I look into for a mild setup such as this?

HP tuners

 

[HemiLonestar]

Would a manual swap be out of the question? Like an NV4500 or 5600 with a south bend clutch. Never done a manual swap before so I’m not sure about what sensors are gonna need to be disabled and what tuning will be necessary

As for the cam how much is too much. I wanted some chop to it so I thought about like a 268 from COMP. but that might be kinda overkill. And what tuners should I look into for a mild setup such as this?

Not at all, hence why I mentioned it:

Stock install the most the 545 ever had to deal with was the 390hp/407tq with prodigious amounts of torque management. Physically one would think it to be a stout piece but the factory programming is one of its issues, the other being the existence of 2 prime and the weak clutches. 450 flywheel hp seems to be the absolute limit and that's with no kickdowns, so either manually shifting to 2nd to romp it or only from a stop. Even a mildly built 5.7 based stroker with decent heads should be north of that. Anyone with a decently buuilt engine generally looks at trans swap, be it manual, 46RE (or even RH) or lately the 8HP70.

You'll either need the PCM from or the flash from a 2500 5.7 stick shift, or you can just ground pin #4 in the trans connector (make sit think it's in neutral) then adjust rpm limits.
Just so you know, there is currently a 2004 quad cab with a 6.1 based 392 hooked to an 8HP70 running around. He got tired of futzing with the OEM software so he installed a Holley Terminator standalone that somehow talks to the factory gauges. Very viable solution for early 3rd gens (even with the significant upfront cost) that is so much more reliable than worrying about when your RFE is gonna blow the OD clutches out on you.
Pick a cam you can live with, keeping in mind you have a big heavy truck with a relatively small displacement V8 and not a lighter car. The wilder the cam, the higher the power curve is in the rpm range (requiring more gear and more stall speed) and the stock hemi torque peak is already fairly high as compared to the wedge style engines that preceded it.

 

[Evanp2005]

Not at all, hence why I mentioned it:

You'll either need the PCM from or the flash from a 2500 5.7 stick shift, or you can just ground pin #4 in the trans connector (make sit think it's in neutral) then adjust rpm limits.
Just so you know, there is currently a 2004 quad cab with a 6.1 based 392 hooked to an 8HP70 running around. He got tired of futzing with the OEM software so he installed a Holley Terminator standalone that somehow talks to the factory gauges. Very viable solution for early 3rd gens (even with the significant upfront cost) that is so much more reliable than worrying about when your RFE is gonna blow the OD clutches out on you.
Pick a cam you can live with, keeping in mind you have a big heavy truck with a relatively small displacement V8 and not a lighter car. The wilder the cam, the higher the power curve is in the rpm range (requiring more gear and more stall speed) and the stock hemi torque peak is already fairly high as compared to the wedge style engines that preceded it.

Are there any other trans sensors that the truck will run like **** without I should know about? And as for adjusting rpm limits am I gonna need to find someone with expensive software or can I do it with a simple obd2 tuner?