DODGE RAM FORUM banner

1 - 19 of 19 Posts

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #1
Hello, new to this forum! I recently bought a 2018 RAM 2500 SLT Crew Cab short box with the 5.7l Hemi...got a good deal and it still had warranty, so this was my choice. I did make the mistake of buying the truck before I bought my RV so i am now feeling the consequences of that choice. I have a 2014 Keystone Outback 310TB travel trailer toy hauler that weights about 7500lb unloaded and has a max of 9000lb fully loaded. It is a toy hauler and has a garage on the FRONT of the trailer for putting the motorcycle in. I will put my big Harley touring bike (Ultra Classic) in the garage occasionally (most of the time I ride, not trailer...but on occasion). I will also have all the other typical stuff in the trailer like a bicycles, grill, food, clothing, rec gear, etc.. So, I suspect my weight will hit the max of 9000lb pretty easily. I will probably end up putting the grill and some other heavier items in the bed of the truck.

I took it out this weekend for the maiden voyage. No motorcycle and no water in the tanks. I had a reasonable amount of gear inside (food and clothing and the like) so I'd say maybe 500lb or so. I'm estimating the trailer weighted between 8000-8500lb. This 2500 Hemi seemed to pull it ok on the straight away, but as soon as I hit hills she really bogged down. At one point I was going up a pretty good grade and had it floored and was barely keeping at 50MPH and the motor was at pretty high RPM. I read the max towing is about 12,000lb with this configuration of truck, but I really don't know if this is realistic. I'm now considering trading the truck for a 2500/3500 with the Cummins, but I really would hate to do so because I'd lose so much in the trade, plus the state taxes.

I live in Colorado and plan to do quite a bit of pulling in the mountains, state parks, national parks and then over to the Midwest and maybe south during the winter months.

My question. Any recommendations on how to improve towing performance? Has anyone done breather, exhaust, and tuning and seen a vast improvement? Or should I just suck it up and trade it in? I'd appreciate constructive feedback, not really looking for hyperbole or "get the Cummins, it's just a better blah blah..." type feedback.

I've searched the forum, but mostly come up with results for the 6.4l Hemi and the Cummins motors, so I appreciate any feedback.

Thanks,
Randy
 

·
Super Moderator
Joined
·
34,698 Posts
I think you are still well within your limits; I actually thought the 5.7 was dropped earlier than 2018 in the HD trucks but maybe not.

I think a lot of people get uncomfortable with their gas truck engine spinning 3500-4000RPM when heavily loaded and going up hills, especially if they've towed with a turbodiesel which pulls grades at lower RPMs and makes more power at elevation; but gas truck engines are designed to do it. You gotta burn more fuel to make more power, and you need air to burn fuel. Diesels are high compression and forced induction so they can just force more air into the combustion chamber to burn more fuel in the same space and maintain that low RPM; naturally aspirated gas engines have to rev to make power because they are essentially limited to atmospheric pressure in the manifold. They have to rev to get more air to burn more fuel to make more power, especially at elevation where the air is thinner.

Engines like the 5.7 Hemi and 6.0L Vortec that were designed as truck engines have cast iron blocks which are more stable at high RPM under load than aluminum blocks. The Hemi was tested at 500+ hours of wide open throttle when it was designed, and the Vortec has a reputation for being revved to the moon and living forever with a load behind it. People these days get all bent out of shape about volumetric efficiency and how there are 2 liter engines making 500 horsepower while these truck engines only make 360 horsepower with 3 times the displacement. They don't understand that they were designed for longevity and a broad flat torque curve at the expense of peak numbers.

You can get a diesel if it would make you more comfortable, but remember that diesels weigh a lot more and that a similarly optioned 2500 diesel will have significantly less payload than your gas truck.
 
  • Like
Reactions: HEMIMANN

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #3
@Thunderhorse thanks for the very informative reply! A lot of great points to consider. I guess I would like to have a bit more power to get up those mountain passes. I'm wondering if a good cold air intake, freer flowing performance exhaust and a tune would produce a few more HP and Ft. L.B. to make things a bit better. I don't mind the higher RPM's so much, it's just not having the pedal responsiveness to get up to about 65MPH on an incline. I'm kinda worried I'll be one of those guys in the right lane with his 4-ways on doing 40MPH...want to avoid that if possible. I live in the south Denver suburbs and plan to go up into the mountains a few times each season and just don't want the drive up to be a buzzkill.

On the other side, if I do upgrade I'd probably be looking at a 3500 long bed (probably a SRW, unless the right deal came along for a DRW), which would help with the payload. I know the 3500 would be overkill for what I'm going to use, but I would hate to regret it later if I decided to upgrade RV's too...then I'm possibly back looking for a prime mover again.
 

·
Registered
Joined
·
756 Posts
WE have been looking at toy haulers for a couple years now. I looked at the style you have but crossed it off the list for 2 reasons. Once I got bike in front it put all that weight say 900-1100 lbs on the tongue. And while loading the bike might not be bad, unloading down that ramp with the heighth it has would be scary. I have a Victory Cross Country so not a small bike or light. My 5.7 could use some more ponys too, but dont we always think we need more power RRR. You could turbo or super charge it. I dont mean like 500 hp type but mild. No idea what the cost would be, but might be less than the hit on a trade. The 2018 might be about where FCA started "locking" or whatever they did to the ECM so you cant just plug a tuner in. But a tuner would allow you to change things up to get a bit more power.
 

·
Super Moderator
Joined
·
34,698 Posts
They started locking PCMs in 2015 IIRC
 
  • Like
Reactions: HEMIMANN

·
Registered
Joined
·
238 Posts
There's actually more upgrades available for the 5.7L than the 6.4L, because it came out first and is in more vehicles.

As Banks would say, the best bangs for the bucks are (1) opening up airflow, (2) tuning (3) engine internals

Cheapest airflow improvements are CAI and Throttle Body porting (venturi profile). Don't buy an intake spacer - they aren't high enough to increase flow velocity much.
Next is exhaust - start with long headers, if you can afford them. They pulse-tune the engine by improving scavenging of exhaust gas and reducing intake restriction.
A number of tuners are available, visit sponsor PowerTeq. I went with bolt-on, pre-canned, in-line tuner "chip" Edge Pulsar. Very satisfied with Fuel Economy and Towing pre-canned tunes. You can also swap your locked ECM for a custom-tuned ECM, but costs at least double the add-on route.
Then the usual internal engine suspects, where available - add-on turbos, blowers, cam-swaps, piston-swaps, crank-swaps, etc. etc.
 

·
Registered
Joined
·
238 Posts
P.S. - diesels make torque, sparkers make power. Gasoline engines gotta rev to get to their torque peaks because their cylinder pressures are limited to that which doesn't detonate. So, to get power, you need to rev it so you get more combustion events per unit time than a diesel. This is well known by gas engine makers, as Thunderhorse says. Nascar engines rev to 10,000 rpm to run @ 200 mph. They don't last that long - the more you rev, the more cylinder wear, but that's the tradeoff from the vastly more expensive diesel engine & transmission.

Diesel cylinder pressure is only limited to how much iron and bolts you can throw at it.
 

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #9
Hello @HEMIMANN, Thanks for the replies. I'm thinking I'm going to keep the truck and do some mods. I guess I'll do some research and select a CAI, throttle body, exhaust and some sort of tuner selection. I've done this process for my Harley's a few times, but never for a truck...so hopefully I get it right! :)
 

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #10
WE have been looking at toy haulers for a couple years now. I looked at the style you have but crossed it off the list for 2 reasons. Once I got bike in front it put all that weight say 900-1100 lbs on the tongue. And while loading the bike might not be bad, unloading down that ramp with the heighth it has would be scary. I have a Victory Cross Country so not a small bike or light. My 5.7 could use some more ponys too, but dont we always think we need more power RRR. You could turbo or super charge it. I dont mean like 500 hp type but mild. No idea what the cost would be, but might be less than the hit on a trade. The 2018 might be about where FCA started "locking" or whatever they did to the ECM so you cant just plug a tuner in. But a tuner would allow you to change things up to get a bit more power.
I have a Harley Ultra Classic, so same size bike. I hear ya on the challenges, but others have done it so I'm going to give it a shot (have the RV now, so kinda locked in!). As far as the ramp, there are some mods out there to lengthen the ramp and change the angle, so I have some pretty good plans for that. Can't change the tongue weight except to maybe load some other heavy items in the rear bedroom to balance it out a bit more. At this point I'm not looking to do turbo or super charge, but I'll look into that just to see what it would cost. Yeah, I'm not trading...I've looked at the numbers, I'd end up taking about a $5-7K hit by the time you factor in taxes and getting hosed on the trade deal...so not worth it, I think I will do some mods to see if I can overcome this. Not sure what to do about the tuner, but it appears they have some solutions out there (see link below)...I'll have to do some reading.


Thanks for the reply.

Randy
 

·
Registered
Joined
·
54 Posts
What gear ratio do you have? 10,000 lbs. with a 3.92 gear in towing mode doesn't equal 50MPH at 5000 RPM on a 13% grade. Put some gear in it (find out what you have for a start) then see what happens. By the RAM towing guide, with a 3.92 axle on a 2500, you should be good for 16,000 lbs. of towing, assuming a 2WD truck, Mega Cab and all possible options. Sounds like you have the 3.21 axle. You'd be nearly maxed out with it at 9,000 lbs. BTW, changing rear axle ratios should cost less than $500, maybe not from the dealership, but any honest shop. BTW, I've driven a 1983 Chebbie 350 (low compression 280 HP MAYBE) class C motorhome on a 3500 chassis in Colorado at 9000 lbs. and a three-speed turbo-hydramatic (350) with a 4.11 axle without a problem up Rabbit Ear Pass. Yeah I was in second gear pulling about 4500 RPM at 55 MPH and getting 3 MPG. Give me 390 HP and I'd not have gone to 2nd gear and could have run 65 MPH. Something doesn't add up.
 

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #12
What gear ratio do you have? 10,000 lbs. with a 3.92 gear in towing mode doesn't equal 50MPH at 5000 RPM on a 13% grade. Put some gear in it (find out what you have for a start) then see what happens. By the RAM towing guide, with a 3.92 axle on a 2500, you should be good for 16,000 lbs. of towing, assuming a 2WD truck, Mega Cab and all possible options. Sounds like you have the 3.21 axle. You'd be nearly maxed out with it at 9,000 lbs. BTW, changing rear axle ratios should cost less than $500, maybe not from the dealership, but any honest shop. BTW, I've driven a 1983 Chebbie 350 (low compression 280 HP MAYBE) class C motorhome on a 3500 chassis in Colorado at 9000 lbs. and a three-speed turbo-hydramatic (350) with a 4.11 axle without a problem up Rabbit Ear Pass. Yeah I was in second gear pulling about 4500 RPM at 55 MPH and getting 3 MPG. Give me 390 HP and I'd not have gone to 2nd gear and could have run 65 MPH. Something doesn't add up.
Thanks for the reply. So, my truck is a Crew Cab, Shortbox 4x4 with the 3.73 axle ratio. According to the Ram towing chart I should be able to tow 11,180lbs and have a payload of 2,350lb (see attached). I'm not sure which towing guide you're looking at, but this one came right off the Ram site and there is no 2.92 ratio, but none-the-less. The "seat of the pants' meter says this truck feels under powered, not saying it WON'T do it, I'm just saying it seems to struggle up hills and it's not comfortable. I am at about 6000ft too, so that has to be effecting it too (I'm near Denver).

I kind of think that maybe some basic mods such as CAI, exhaust and a tune will help...maybe the ported throttle body as well. My problem is this is my first modding of a vehicle other than my Harleys...I've always done work to my bikes but never car/truck. I am sure the theory is the same...more air, less restriction in the exhaust, get it tuned right and it should pump out a bit more power. I'm not sure what to buy to be honest. I mean, I can go pick a good K&N CAI and find an exhaust, ported T-body and tuner...but I'm not sure if I'm chosing the right combos and so forth. I need to do some research I guess. Also, I'm new to this area, so I don't really know many people or good shops locally that I can trust. I'm willing to throw about $3,000 into it to find out. Oh, I'd like to do air bags too, since I'll be nearly maxing out the total GCWR by the time I load the trailer down to 9000lb and dump a bunch more in the bed of the truck for my trips out.

I'm sure I'll get something figured out... :)

133329
 

·
Super Moderator
Joined
·
34,698 Posts
Its a 2500,axle options are 3.73 and 4.10. There is no 3.21 or 3.92
 
  • Like
Reactions: rdjram2500

·
Registered
2017 2500 CTD Laramie CC SB
Joined
·
65 Posts
My 2017 2500 CTD CC SB has the same #’s as the bottom line in the chart you posted. Look at the #’s and compare, make an informed decision. Peace.
 

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #15
My 2017 2500 CTD CC SB has the same #’s as the bottom line in the chart you posted. Look at the #’s and compare, make an informed decision. Peace.
Hi Jim, Thanks for your input. So you're saying that you think it would be more cost effective and I'd benifit more by offloading the 5.7 Hemi and migrating to the Cummins rather than pouring $ into the Hemi and trying to improve the power? I would probably agree with you and think that I'd be happier with the Cummins, however the problem is I estimate that I'd probably lose $6000 on the trade (Trade in value is about $27K and I owe close to $33) plus I'd have to pay sales tax which would be another roughly $2000. So, that's $8000 that I'd have to tack on to the negotiated price of the new (used, similar year/config) truck. Now, I might be able to sell it private and save some of that money if I can get close to Clean Retail (Nada) of about $30K. Then I'd only be into it for $5000 plus the new truck. That's just a large loss to suck up in my opinion. Yes, I'd surely be happier with the Cummins, but pissing away $5000-8000 is tough. Honestly, I do regret buying the Hemi, but at the time I thought it would suffice for what I had planned. Oh well, live and learn.
 

·
Registered
2017 2500 CTD Laramie CC SB
Joined
·
65 Posts
Hi Jim, Thanks for your input. So you're saying that you think it would be more cost effective and I'd benifit more by offloading the 5.7 Hemi and migrating to the Cummins rather than pouring $ into the Hemi and trying to improve the power? I would probably agree with you and think that I'd be happier with the Cummins, however the problem is I estimate that I'd probably lose $6000 on the trade (Trade in value is about $27K and I owe close to $33) plus I'd have to pay sales tax which would be another roughly $2000. So, that's $8000 that I'd have to tack on to the negotiated price of the new (used, similar year/config) truck. Now, I might be able to sell it private and save some of that money if I can get close to Clean Retail (Nada) of about $30K. Then I'd only be into it for $5000 plus the new truck. That's just a large loss to suck up in my opinion. Yes, I'd surely be happier with the Cummins, but pissing away $5000-8000 is tough. Honestly, I do regret buying the Hemi, but at the time I thought it would suffice for what I had planned. Oh well, live and learn.
I believe we've all done the live and learn thing myself included and more than once, ha ha. I bought this truck when my sister worked at an FCA subsidiary and got FCA employee pricing. bought in November 2017, even with employee pricing and all the discounts was still 60k out the door, Laramie BTW. My plan was to do some full time RVing with a TT Toy Hauler taking along my 2014 Ultra Limited for a few years and see more of this great country of ours, but life happens and that plan is on hold. I just turned 16k on the odometer a couple of weeks ago. So my big bad truck is still getting groceries.
I have no idea about how much more power that would be good for towing can be gotten out of the 5.7 or what the $ would be. I do know at the end of the day it would still be a 5.7.
Best wishes to you in this endeavor.

PS My HD; Screaming Eagle intake, free flow exhaust, "small cam" and progressive suspension. I love her. LOL
 

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #17
I believe we've all done the live and learn thing myself included and more than once, ha ha. I bought this truck when my sister worked at an FCA subsidiary and got FCA employee pricing. bought in November 2017, even with employee pricing and all the discounts was still 60k out the door, Laramie BTW. My plan was to do some full time RVing with a TT Toy Hauler taking along my 2014 Ultra Limited for a few years and see more of this great country of ours, but life happens and that plan is on hold. I just turned 16k on the odometer a couple of weeks ago. So my big bad truck is still getting groceries.
I have no idea about how much more power that would be good for towing can be gotten out of the 5.7 or what the $ would be. I do know at the end of the day it would still be a 5.7.
Best wishes to you in this endeavor.

PS My HD; Screaming Eagle intake, free flow exhaust, "small cam" and progressive suspension. I love her. LOL
Well, since you don't need a diesel and I do we can just swap! Mine's still got about 12,000 miles warranty left! :) Sorry your plans changed, hopefully it gets back on track one day. I'd love to do full time, but it's not in the cards for us right now, so we'll do vacation and weekend warrior stuff.

You're right, it will always be a 5.7 Hemi...gotta accept that for sure.

My HD is a 2010 CVO (bought new way back then!) with the 110 that's pretty stock except for breather, pipes and supertuner. I had a 2003 Ultra (also bought new) that I did all kinds of motor work to (big bore, stroker 103, etc.), but I decided to leave this one alone...she pulls great as is.

Randy
 

·
Registered
2018 RAM 2500 SLT, Crew Cab, Shortbox, 4x4, 3.73 Axel Ratio
Joined
·
8 Posts
Discussion Starter #18
Well, I said "F" it...I found a nice 2018 3500 Laramie with 24K miles on it and traded! Not looking back... :) First tow coming up! Thanks for the help all.

Randy
 
1 - 19 of 19 Posts
Top