Johnny_N_TX
Junior Member
- Joined
- Dec 15, 2020
- Posts
- 7
- Reaction score
- 5
- Location
- Houston, TX
- Ram Year
- 2002
- Engine
- 4.7 liter V8 with 545RFE (6spd jeep computer)
Just wanted to share my experience thus far with owning and upgrading my Ram:
I inherited a 2002 Ram from my Dad last year. It came with a 4.7, 45RFE (it was originally a 4 spd) and 3.55:1.00 gear with an open diff. The truck was a real pig. It was slow to get up to 65, got horrible fuel economy (16 mpg at 65), and drove like a boat. I decided to take advantage of some time off and upgrade the drivetrain, suspensions and brakes...
I started with the engine. There is basically nothing you can do to the 4.7 without dropping some major coin. I wasn't about to drop $5k-$10k into a truck that was only worth $1500... so I went with a K&N drop in filter (no performance gains, but this eliminates the garbage paper filters) and a diablo programmer. The diablo programmer was actually a nice surprise. The truck had quite a bit more "zing" to it and I dropped about 2 seconds off of my zero to sixty times (although going from 12 seconds to 10 seconds is not all that impressive...LOL). I was running on 265/70R17s at the time (31.5" diameter).
I noticed my tires were cupping really bad so I started looking for cheap tires. I went back and forth with type, brand and size for several days but then ran across some factory, chrome 20"s with brand new 275/60R20s for $600 (cheaper than just buying 4 new tires for the 17" rims). These tires were about 1/2 an inch wider, but they were 33" tall, so I lost my 0-60 times went up again. However, I was getting closer to 18-19 MPG on the highway (dropped from 1700 rpms to 1500 rpms on the highway). This was not good for me because I don't need a truck for low rpm cruising. I need to be able to tow a 7500lbs RV and a 6000lbs boat. Time for some new gears...
I installed a trutrac soft locker along with some 4.56:1.00 gears. This made a HUGE difference in acceleration and RPMs on the highway. My 0-60 went down to 7-8 seconds. It's not fast, but not bad for a 7000 lbs, basically stock 225 hp 4.7 with a slush box transmission). My highway RPMs were up around 2300. Oddly, my fuel economy at 65 was actually not affected. I was getting 20mpg. The engine was operating a more optimal rev range so I didn't need to give it any throttle to stay at that speed. The main thing I didn't like was the transmission started to feel slushier than it did before. I did some research and discovered that this model transmission has a constantly variable feedback loop which controls the torque converter lockup and is actually an variable transmission controlled by the programming of the TCM.
I started looking into options to fix up the transmission performance and discovered you can drop in a factory jeep TCM that will convert a 45RFE to a 545RFE. I now have a "6 spd" transmission in this truck. It has 3 forward gears plus a "prime gear" for low speed passing, and 2 overdrives (25% and 33%). It was a 5 minute swap and made a huge difference in highway RPMs (dropped from 2300 to 2000). I decided to try one more trick with the transmission and installed the sonnax line pressure kit. I was changing the fluid and filter anyway, so when I dropped the pan I installed the spring and then once it was all buttoned back up I installed the harness. I did a full tranny flush (went with lucas full synthetic) and with these upgrades the transmission now has a much crisper feel when making shifts and no longer tries to run the RPMs up to 4k-5k before shifting. The trip computer started reporting 23-24mpg at 65. (WHAT!?!?!?) This has to be from the RPMs dropping to 2000 at 65 with the new 33% overdrive.
I went under the truck and swapped on some hellwig 3500lbs overloads, hellwig HD sway bars, and Bilstein 4600s at all 4 corners. Combined with the new tires, the truck now handles and drives amazing. I did a flush and fill on the the power steering which got rid of the supercharger whine coming from under the hood.
While I had the wheels off I also installed EBC brake pads, did a full fluid flush and changed over to high performance fluid (the old stuff was nasty). This is a huge improvement in stopping power from a very simple upgrade.
When I hook up to my RV, I can feel a major difference in the way the truck feels (no sway, and the back end doesn't squat to the frame rails anymore). The way it pulls the load is even better now because the 4.56s make it feel more like a 2000 lbs load than an 8000 lbs load. I do flash the ECM with the diablo towing tune whenever I hook up to the boat or the RV, and it seems to make a bit of difference in the fuel mix... feels like it is running intentionally rich, but that is probably better for keeping the engine cool under a constant load.
Overall, I am really happy with these upgrades. It pulls as well as my buddies F150 twin turbo does. It's not as fast, but it pulls just as easy. It actually handles better than his new truck and doesn't sway as much (thank you hellwig). I also get the same fuel economy as he does (22 avg empty and 16 avg towing).
I did one other simple upgrade, but it is purely for personal joy... I installed a flowmaster 3", catted Y-pipe (high flow cat) and a 2 chamber (40 series) with a single 3"in and a dual 2.5". The 4.7 sounds really good with a two chamber exhaust. I have been looking at the shorty headers but i haven't gone that far yet. They advertise 20 hp at the rear wheels... but I doubt I'd see any real performance increase from headers. That said, t's a cheap upgrade ($350 for BBK chrome equal length shortys) and I might do it just for the "cool factor".
Cost of upgrades thus far:
Diablo Tuner - $200
K&N - $40
Sonnax trans kit - $60
Tranny flush and fill - $200
TruTrac - $500
Ring and Pinion - $300
Diff Rebuild Kit - $200
Hellwig HD Sway Bar Kit - $400
Hellwig (softride) 3500 lbs overloads - $250
EBC Brake Pads - $200
Brake Flush - $100
Steering Flush - $50
Catted Y-Pipe- $300
Cat Back single to dual - $200
Parts total so far - $3k
Not yet purchased:
BBK Shorty Headers - $350
Header studs and gaskets - $100
I'm also going to gut the interior next week so I can install a new dash assembly. I need to do the AC duct-door upgrades, rewire the doors to fix the broken wires, install a new keyless entry/remote start (the old one doesn't work anymore), install a gauge pod so I can keep a close eye on temps and pressures when towing, a 360 degree driving camera system (records what happens around the vehicle so you have a video record of accidents, road ragers, etc.) as well as back up and entry cameras that will be wired into the new head unit that has a 5" display with a DVD/Bluray player. I'll probably go ahead and install some amps and speakers since the interior will be apart anyway.
This may be the last truck I ever buy. I only drive it when I'm towing and again once a week to keep the seals from shrinking. I am really happy with all my upgrades, and just wanted to put a list out there for anyone else who is wondering what they will get from certain budget friendly mods.
I am going to investigate another transmission mod that will allow me to select which OD is engaged via a dash mounted button. That way I can tow in 1:1, 0.75:1 or 0.67:1 final gear. I still have the factory unit, so I am going to contact a company that flashes these and ask them if there are any unused pins on the plug where I can route a simple ground signal that will let me choose which OD I want to be the final drive ratio. I'll update the thread if/when I am able to make any forward progress on this.
Happy Motoring!
-Johnny
I inherited a 2002 Ram from my Dad last year. It came with a 4.7, 45RFE (it was originally a 4 spd) and 3.55:1.00 gear with an open diff. The truck was a real pig. It was slow to get up to 65, got horrible fuel economy (16 mpg at 65), and drove like a boat. I decided to take advantage of some time off and upgrade the drivetrain, suspensions and brakes...
I started with the engine. There is basically nothing you can do to the 4.7 without dropping some major coin. I wasn't about to drop $5k-$10k into a truck that was only worth $1500... so I went with a K&N drop in filter (no performance gains, but this eliminates the garbage paper filters) and a diablo programmer. The diablo programmer was actually a nice surprise. The truck had quite a bit more "zing" to it and I dropped about 2 seconds off of my zero to sixty times (although going from 12 seconds to 10 seconds is not all that impressive...LOL). I was running on 265/70R17s at the time (31.5" diameter).
I noticed my tires were cupping really bad so I started looking for cheap tires. I went back and forth with type, brand and size for several days but then ran across some factory, chrome 20"s with brand new 275/60R20s for $600 (cheaper than just buying 4 new tires for the 17" rims). These tires were about 1/2 an inch wider, but they were 33" tall, so I lost my 0-60 times went up again. However, I was getting closer to 18-19 MPG on the highway (dropped from 1700 rpms to 1500 rpms on the highway). This was not good for me because I don't need a truck for low rpm cruising. I need to be able to tow a 7500lbs RV and a 6000lbs boat. Time for some new gears...
I installed a trutrac soft locker along with some 4.56:1.00 gears. This made a HUGE difference in acceleration and RPMs on the highway. My 0-60 went down to 7-8 seconds. It's not fast, but not bad for a 7000 lbs, basically stock 225 hp 4.7 with a slush box transmission). My highway RPMs were up around 2300. Oddly, my fuel economy at 65 was actually not affected. I was getting 20mpg. The engine was operating a more optimal rev range so I didn't need to give it any throttle to stay at that speed. The main thing I didn't like was the transmission started to feel slushier than it did before. I did some research and discovered that this model transmission has a constantly variable feedback loop which controls the torque converter lockup and is actually an variable transmission controlled by the programming of the TCM.
I started looking into options to fix up the transmission performance and discovered you can drop in a factory jeep TCM that will convert a 45RFE to a 545RFE. I now have a "6 spd" transmission in this truck. It has 3 forward gears plus a "prime gear" for low speed passing, and 2 overdrives (25% and 33%). It was a 5 minute swap and made a huge difference in highway RPMs (dropped from 2300 to 2000). I decided to try one more trick with the transmission and installed the sonnax line pressure kit. I was changing the fluid and filter anyway, so when I dropped the pan I installed the spring and then once it was all buttoned back up I installed the harness. I did a full tranny flush (went with lucas full synthetic) and with these upgrades the transmission now has a much crisper feel when making shifts and no longer tries to run the RPMs up to 4k-5k before shifting. The trip computer started reporting 23-24mpg at 65. (WHAT!?!?!?) This has to be from the RPMs dropping to 2000 at 65 with the new 33% overdrive.
I went under the truck and swapped on some hellwig 3500lbs overloads, hellwig HD sway bars, and Bilstein 4600s at all 4 corners. Combined with the new tires, the truck now handles and drives amazing. I did a flush and fill on the the power steering which got rid of the supercharger whine coming from under the hood.
While I had the wheels off I also installed EBC brake pads, did a full fluid flush and changed over to high performance fluid (the old stuff was nasty). This is a huge improvement in stopping power from a very simple upgrade.
When I hook up to my RV, I can feel a major difference in the way the truck feels (no sway, and the back end doesn't squat to the frame rails anymore). The way it pulls the load is even better now because the 4.56s make it feel more like a 2000 lbs load than an 8000 lbs load. I do flash the ECM with the diablo towing tune whenever I hook up to the boat or the RV, and it seems to make a bit of difference in the fuel mix... feels like it is running intentionally rich, but that is probably better for keeping the engine cool under a constant load.
Overall, I am really happy with these upgrades. It pulls as well as my buddies F150 twin turbo does. It's not as fast, but it pulls just as easy. It actually handles better than his new truck and doesn't sway as much (thank you hellwig). I also get the same fuel economy as he does (22 avg empty and 16 avg towing).
I did one other simple upgrade, but it is purely for personal joy... I installed a flowmaster 3", catted Y-pipe (high flow cat) and a 2 chamber (40 series) with a single 3"in and a dual 2.5". The 4.7 sounds really good with a two chamber exhaust. I have been looking at the shorty headers but i haven't gone that far yet. They advertise 20 hp at the rear wheels... but I doubt I'd see any real performance increase from headers. That said, t's a cheap upgrade ($350 for BBK chrome equal length shortys) and I might do it just for the "cool factor".
Cost of upgrades thus far:
Diablo Tuner - $200
K&N - $40
Sonnax trans kit - $60
Tranny flush and fill - $200
TruTrac - $500
Ring and Pinion - $300
Diff Rebuild Kit - $200
Hellwig HD Sway Bar Kit - $400
Hellwig (softride) 3500 lbs overloads - $250
EBC Brake Pads - $200
Brake Flush - $100
Steering Flush - $50
Catted Y-Pipe- $300
Cat Back single to dual - $200
Parts total so far - $3k
Not yet purchased:
BBK Shorty Headers - $350
Header studs and gaskets - $100
I'm also going to gut the interior next week so I can install a new dash assembly. I need to do the AC duct-door upgrades, rewire the doors to fix the broken wires, install a new keyless entry/remote start (the old one doesn't work anymore), install a gauge pod so I can keep a close eye on temps and pressures when towing, a 360 degree driving camera system (records what happens around the vehicle so you have a video record of accidents, road ragers, etc.) as well as back up and entry cameras that will be wired into the new head unit that has a 5" display with a DVD/Bluray player. I'll probably go ahead and install some amps and speakers since the interior will be apart anyway.
This may be the last truck I ever buy. I only drive it when I'm towing and again once a week to keep the seals from shrinking. I am really happy with all my upgrades, and just wanted to put a list out there for anyone else who is wondering what they will get from certain budget friendly mods.
I am going to investigate another transmission mod that will allow me to select which OD is engaged via a dash mounted button. That way I can tow in 1:1, 0.75:1 or 0.67:1 final gear. I still have the factory unit, so I am going to contact a company that flashes these and ask them if there are any unused pins on the plug where I can route a simple ground signal that will let me choose which OD I want to be the final drive ratio. I'll update the thread if/when I am able to make any forward progress on this.
Happy Motoring!
-Johnny
