I wanna go fast, but I've got a 5 speed.

[rduchateau2954]

A 5 speed and 97k miles.

I've always drove old gm trucks (94 or older), and switched to Ram years ago. I did about two minutes of research when I first bought this truck and immediately learned the 5 speed trucks can't handle power, so I stopped looking.

Now she's pushing 100k and with no plans on selling her I'm starting to get itchy again.

First thought that comes to mind is the trans, build kit? Whole new trans from somebody?

What's out there that can handle power?

What corresponding engine mods could be done with that trans?

Should I forget all of this and go buy turbo side by side? Used RCSB 8speed and leave my current truck alone?

I'd buy a Corvette or something but I'm not a car guy.

 

[Burla]

Gears

 

[rduchateau2954]

What kinda gears

 

[tidefan1967]

What kinda gears

4:10's if you have stock size tires. If you have oversized tires and a lift I would go with 4:56's

 

[Fast69Mopar]

It always amazes me how the 545RFE gets a bad rap. I started drag racing a truck with a 45RFE in 2002 in a 4.7 regular cab Dakota and to this day I have owned 7 vehicles that had an RFE unit and I have never had a failure.

I work for Chrysler so I know there have been plenty of RFE failures. Back in 2008-2009 it seemed the only vehicles coming in the door that needed an overhaul or complete replacement were ones with an RFE. I got so tired of working on them.

If you want to go fast with a 545RFE my biggest suggestions are to spend your money on a quality torque converter along with the Sharondon valve vody, a big trans cooler and a lower gear out back.

The larger cooler will help keep the temps down. The Sharadon valve body has lightning quick shifts which extends clutch life. Choosing a torque converter to suit your needs and driving habits will make a huge difference in how your truck performs.

With all of this, going with a 4.56 gear out back will make the truck so much more fun to drive. A 4.56 gear will help get your heavy Ram moving.

Another thing that can hurt the 545RFE is WOT downshifts. If you can avoid doing this you will be able to extend the service life of the trans. WOT downshifts like a 5-3 or 5-2 downshift are super hard on these units and they don't like it. WOT upshifts are fine but downshifts are a no-no.

Do some research and find what fits your needs and your wallet. Don't hesitate to ask questions.

 

[rduchateau2954]

Thanks Fast, exactly what I'm looking for.

I'm surprised to see gears go 2/2 so far. I just assumed having a rcsb with 3.92's it's something I wouldn't have to worry about.

Doing everything you mentioned, what would you then do to the motor?

Also, going to 4.56 what should I expect when towing 5-6k at 70/75 mph? I'm not looking for a gas sipping setup here, but do a lot of driving in the summer and would like to about single digit mpgs.

Thanks

 

[crackerjack1957]

^^^
Tire height also determines rpm.......you tow in 4th or 5th?

 

[Burla]

If you would have said you were worried about gas mileage and you wanted to go fast, I would have passed on the thread. Towing and 75 mph is just stupid as well.

have a good day

 

[rduchateau2954]

^^^
Tire height also determines rpm.......you tow in 4th or 5th?

5th - Tow/haul mode

 

[Fast69Mopar]

Is your truck 2WD or 4WD?

Doing a little math along with some assumptions, here is what I come up with for engine RPM with a few different gear ratios out back.

The formula to calculate engine RPM based on gear ratio is as follows:

Axle Ratio x Vehicle Speed x Trans Ratio x 336 / Tire Diameter

Now, let's say you have a 3.55 out back, 275/60/20's along with the 545RFE's 5th gear ratio of .67:1
This is what the formula would look like with your current axle ratio...

3.55 x 70mph x .67 x 336 / 33"

We come up with 1695RPM at 70mph in 5th gear with a 275/60/20 tire

Now let's toss in a 4.56 gear...

4.56 x 70mph x .67:1 x 336 / 33

We get 2177RPM at 70mph in 5th gear with a 275/60/20 tire.

Wanna tow in 4th gear with a 0.75:1 ratio and 4.56 gears and a 275/60/20 tire?

4.56 x 70mph x .75 x 336 / 33

We get 2437RPM at 70mph in 4th gear with 4.56 gears and a 275/60/20 tire. Not terrible in my opinion.

 

[rduchateau2954]

If you would have said you were worried about gas mileage and you wanted to go fast, I would have passed on the thread. Towing and 75 mph is just stupid as well.

have a good day

You gotta read better. Those were two seperate questions.

1.) What's towing going to be like with 4.56's?
2.) What can I expect to happen to mileage?

I already average around 9mpg towing, that's life. What I don't want is 9mpg empty.

Thanks for stopping by though.

 

[rduchateau2954]

Is your truck 2WD or 4WD?

Doing a little math along with some assumptions, here is what I come up with for engine RPM with a few different gear ratios out back.

The formula to calculate engine RPM based on gear ratio is as follows:

Axle Ratio x Vehicle Speed x Trans Ratio x 336 / Tire Diameter

2011
4wd
305/70/17
3.92

You are the man Fast69. I'll run through that formula a few times when I'm not at work.

 

[Fast69Mopar]

2011
4wd
305/70/17
3.92

You are the man Fast69. I'll run through that formula a few times when I'm not at work.

No problem man. If you have any questions about building the engine or the trans or whatever don't hesitate to ask.

 

[rduchateau2954]

What motor mods would you do after gears and trans upgrades?

Standard cam/lifters/headers/tb/tune?

At what point do we get out of the realm of reality for a daily driver?

 

[Wild one]

What motor mods would you do after gears and trans upgrades?

Standard cam/lifters/headers/tb/tune?

At what point do we get out of the realm of reality for a daily driver?

I don't see anything in your list about re-doing the engine first.You throw those parts on a 100,000 mile engine and start driving it aggressively ,it's probably not going to be happy for very long.Before you start throwing high performance parts and tune at it,i'd seriously look into rebuilding it first,or buying a reman long block assembly and throw those parts into it instead.

 

[rduchateau2954]

I don't see anything in your list about re-doing the engine first.You throw those parts on a 100,000 mile engine and start driving it aggressively ,it's probably not going to be happy for very long.Before you start throwing high performance parts and tune at it,i'd seriously look into rebuilding it first,or buying a reman long block assembly and throw those parts into it instead.

That is exactly why I'm asking you guys because that was my 2nd train of thought. Buy a block and maybe even a trans, take my time and put it together during the summer.

That option though would more than likely mean I would wait until I buy a new truck in a year or so and get a little crazier.

 

[rduchateau2954]

Alright, let me throw out some of the things that have been bouncing around my head between the last few months and today.

Let me know what you think. Hopefully in the next few days/weeks I some kind of game plan.

1.)Gears and trans mods fast 69 suggested, leave everything else alone. Sounds like a solid plan but, if I have lifter issues in the future, what would be the way to go?

2.) Build a seperate engine and trans. Buy a new truck this time next year. Put built engine/trans/gears in current truck when I'm not depending on it to get to work and have lots of time.

That sounds like a blast but it's also the biggest unknown to me by a long shot. Might be a really good way to end up with a pile of money and time into a half completed job while my truck sits stock.

3.) Leave my truck alone. Next fall pick up a used 5.7/8speed/3.92 truck. Do the usual cam/lifter/headers/tb/tune.

4.) Forget all this, buy a Polaris rs1 1000, make it faster, and scratch the itch in something with a 5pt harness and a roll cage.

Am I thinking in the right direction or way off?

 

[Wild one]

Alright, let me throw out some of the things that have been bouncing around my head between the last few months and today.

Let me know what you think. Hopefully in the next few days/weeks I some kind of game plan.

1.)Gears and trans mods fast 69 suggested, leave everything else alone. Sounds like a solid plan but, if I have lifter issues in the future, what would be the way to go?

2.) Build a seperate engine and trans. Buy a new truck this time next year. Put built engine/trans/gears in current truck when I'm not depending on it to get to work and have lots of time.

That sounds like a blast but it's also the biggest unknown to me by a long shot. Might be a really good way to end up with a pile of money and time into a half completed job while my truck sits stock.

3.) Leave my truck alone. Next fall pick up a used 5.7/8speed/3.92 truck. Do the usual cam/lifter/headers/tb/tune.

4.) Forget all this, buy a Polaris rs1 1000, make it faster, and scratch the itch in something with a 5pt harness and a roll cage.

Am I thinking in the right direction or way off?

Either rs1 or pick up a newer truck with the 8 speed would be the way i'd go,lol. The rs1 will probably be more entertaining though,lol.Mod for mod with bolt-on trucks the 8 speed is generally about a 1/2 sec quicker at the track then the 5 or 6 speed trucks are. The downside to anything newer then 14 is having to buy an unlocked PCM to tune it. Don't be hung up on finding an 8 speed truck with 3.92's though,the 3.21 geared 8 speed trucks are definitely holding their own at the track these days

 

[rduchateau2954]

Either rs1 or pick up a newer truck with the 8 speed would be the way i'd go,lol. The rs1 will probably be more entertaining though,lol.Mod for mod with bolt-on trucks the 8 speed is generally about a 1/2 sec quicker at the track then the 5 or 6 speed trucks are. The downside to anything newer then 14 is having to buy an unlocked PCM to tune it. Don't be hung up on finding an 8 speed truck with 3.92's though,the 3.21 geared 8 speed trucks are definitely holding their own at the track these days

I get ya, I keep on eye on truck prices just because and have seen several very nice sports, Laramies, and Longhorns with the 3.92.

Sounds like I've got a year or so to do some research. Lurk around the 5th gen forum and see how their performance mods go.

So far I'm torn between an 18 sport rcsb, and 18 Laramie, or a 19+ Laramie longhorn. I'll have to see when the time comes if I want to go full because racetruck or luxury cruiser with more powah. I'd love for my current truck to last forever but unfortunately in Wisconsin that isn't reality.

Thank you guys for all the information.

 

[rduchateau2954]

Alright one more question since I've got y'all here.

Superchargers, where can I learn more about adding them to a 4th or maybe a 5th gen? What's involved and what are the supporting mods?