Forum Discussion
4x4ord wrote:
^^^^And he said he’s already installed a dual disc clutch ..... so I’m kind of curious what steps would a person need to take to build a reliable, deleted, non smoking, tow unit? Say to get the truck to a USEABLE 400 RWHP. Cummins increases boost and lowers the compression ratio to add power.... Are those mods unnecessary if only adding 120 HP? (But again wanting to be able to use the power while towing) Is a new air to air and radiator necessary? I guess if all you have to do is swap out the exhaust and add a tuner it’s not terrible expensive.
400 rwhp is already usable on the Cummins. In fact, that is exactly the power level that most tuners call their "heavy tow tune" on the Cummins. I know my hot shot buddies generally leave theirs on 425 hp, but they have aftermarket turbos. The exhaust side of the HE351 VG turbo on the Cummins is your bottleneck. It is small and very restrictive so you would have a hard time sustaining higher power levels while keeping EGT's in check.
It is not about adding boost to increase power. It is also about injection timing, injection duration, and injection pressure. Just as it does on a gas engine, increasing these will increase power, but will also increase emissions specifically NOx and PM. Boost is just an after thought on a diesel. Remember, a diesel is regulated by fuel, not air, so the amount of air it is using is determined by how much fuel is injected. It is the opposite for gas engines where the amount of fuel being injected is determined by how much boost(air).
As stated before, the Cummins HE351 exhaust housing is small and restrictive. This is good at quick spool up and keeping power even at higher altitudes, but it is not good if your goal is to achieve the highest power levels possible. It is not just about boost either. Flow also has a lot to do with it. At 15 psi, my turbo is flowing a lot more air than the HE351 turbo is at the same psi. If I recall correctly, the HE351 has a flow of around 60 lbs/min while my turbo is 82 lb/min.
Also, Cummins did not lower compression ratio to increase power so to speak. They lowered it to meet NOx emission while increasing power. They could have kept the same compression ratio and easily increased power, but NOx levels would have been high. So in order to increase power and to keep NOx within regulations, they had to lower compression ratio which in turn also lowers the efficiency of an engine. Hence the reason why the lower output "efficiency" Cummins with 68rfe has a much higher compression ratio of 19:1 versus the high output engine.
You will notice this with all of the big three diesels. As power output increases, compression ratio decreases. The Duramax used to have a compression ratio as high as 17.5:1, but overtime as they increased power, it decreased to 16:1 with the 445 hp L5P. The 6.7L Powerstroke used to be 16.2:1 and now it is 15.8:1 with the added power of the 475 hp 2020 PSD. The 6.7L Cummins used to be 17.3:1 and now it split to 16.2:1 for the 400 hp high output and 19:1 for the 370 hp standard output or "efficiency" engine. Notice one big thing about these compression ratios compared to the HP outputs of each engine?
So those who say that they wish the engine makes would focus on efficiency rather than power do have a point. The more power they add, the less max efficiency potential the engine has due to lowering the compression ratio in order to stay NOx compliant at that power level. This loss in engine efficiency can be made up in other ways like gearing and so on, however, you are still losing max potential efficiency by wanting more power on a stock truck that has to be emissions compliant.- ^^^^And he said he’s already installed a dual disc clutch ..... so I’m kind of curious what steps would a person need to take to build a reliable, deleted, non smoking, tow unit? Say to get the truck to a USEABLE 400 RWHP. Cummins increases boost and lowers the compression ratio to add power.... Are those mods unnecessary if only adding 120 HP? (But again wanting to be able to use the power while towing) Is a new air to air and radiator necessary? I guess if all you have to do is swap out the exhaust and add a tuner it’s not terrible expensive.
4x4ord wrote:
A clutch can’t take the kind of torque that can fed into the new automatics ..... Back in 93 with my 6.5 turbo diesel and manual transmission I got stuck in a snow drift with a heavy trailer on behind . I ended slipping the clutch with only 400 lbft of torque .... I didn’t realize it until the cab startled filling with smoke. I think a tuner could cause you more grief than it would alleviate.
Stock clutch, no. However, there are aftermarket clutches available that can. One of my hot shot friends has a South Bend dual disc rated at 650 rwhp that did not cost that much more than the OE clutch replacement. If I am not mistaken, he has had it in the truck for at least four years now and is still going strong. I know he is pushing at least 100 rwhp over stock. South Bend makes them up to 950 rwhp for the G56, but they are pricey when you start getting that high of power levels.blofgren wrote:
Grit dog wrote:
blofgren wrote:
4x4ord wrote:
How many km?
Still has under 50k because it's primarily a trailer tower. 75-80% of that mileage has been towing.
Even if it had 150k I wouldn't be worried about it's reliability. I am high on maintenance to keep my vehicles in tip top shape.
Wow man! Super garage queen! At that rate it will still be like new with only 100k (miles) when it’s over 20 years old!
Dude, I’d keep an eye on if Canada clamps down on deletes and if they do, get a delete tuner and at the very least stash it away for a rainy day. But since you’re out of warranty it would actually be money well spent to delete it now.
Good for the engines health and reliability. Plus it would be free, takeoff emissions parts fetch good money, here at least.
Yep, she's never seen winter, either. :)
I have been thinking of buying a Bullydog delete tuner. I have been thinking of deleting it, but it is nice to not have the stink when starting it in the garage and so far so good for all of the emissions equipment. I think it will happen at some point, though. The emissions equipment does fetch good $ here too.
It has a Southbend dual disc clutch in it now; the stock one was starting to slip a bit while towing hard on steep pulls. Funny thing is the stock one looked brand new when it was pulled out; just not enough clamping force I guess.
A clutch can’t take the kind of torque that can fed into the new automatics ..... Back in 93 with my 6.5 turbo diesel and manual transmission I got stuck in a snow drift with a heavy trailer on behind . I ended slipping the clutch with only 400 lbft of torque .... I didn’t realize it until the cab startled filling with smoke. I think a tuner could cause you more grief than it would alleviate.- ^Yup I’ve learned how to keep the EB working most of the time I want it to with the new auto truck, but takes more buttons and fiddling with it then just pulling the switch on the old truck.
Grit dog wrote:
ShinerBock wrote:
blofgren wrote:
4x4ord wrote:
How many km?
Still has under 50k because it's primarily a trailer tower. 75-80% of that mileage has been towing.
Plus you have a "Holy Grail" G56 manual transmission that they ae not putting in HD's anymore. I wish mine was a manual, but the wife put a kibosh on that. She has to drive my truck sometimes and tow the horse trailer. Or drive me home from the farm when I have had too many Shiner's. At least my JK is a manual.
Which is a shame btw. Ram could have kept that option easily with little capital cost IMO. It pained me to sell our 07 G56 truck. But hard to pass up getting 27 grand for a 14 year old truck with 180k (miles, lol) on it! FWIW, paid $30,800 for it in 2008 with10k miles on it. Not a bad ROI for a depreciating asset.
The downside is I’ll now likely never have another manual trans tow rig, which is soooo nice when towing. Although I always wished it was a G57!
That's awfully good resale value on that truck, bud. Those trucks seem to go for a pile of money around here too. Back in 2014 I looked at a 2007 Ram 3500 Laramie DRW 5.9L G56 with 100k on it. The guy (dealership) wanted $40k for it and would not drop below $39,500 even with no trade. I thought it was too much and moved on. A week later it was gone so obviously someone thought it was a good buy!
I definitely love the manual trans while towing; a real bonus on the Cummins 6.7L is that the exhaust brake works down to 800 RPM with the G56. No using the service brakes even when creeping around a steep campsite with the 16k fiver in tow! :CGrit dog wrote:
blofgren wrote:
4x4ord wrote:
How many km?
Still has under 50k because it's primarily a trailer tower. 75-80% of that mileage has been towing.
Even if it had 150k I wouldn't be worried about it's reliability. I am high on maintenance to keep my vehicles in tip top shape.
Wow man! Super garage queen! At that rate it will still be like new with only 100k (miles) when it’s over 20 years old!
Dude, I’d keep an eye on if Canada clamps down on deletes and if they do, get a delete tuner and at the very least stash it away for a rainy day. But since you’re out of warranty it would actually be money well spent to delete it now.
Good for the engines health and reliability. Plus it would be free, takeoff emissions parts fetch good money, here at least.
Yep, she's never seen winter, either. :)
I have been thinking of buying a Bullydog delete tuner. I have been thinking of deleting it, but it is nice to not have the stink when starting it in the garage and so far so good for all of the emissions equipment. I think it will happen at some point, though. The emissions equipment does fetch good $ here too.
It has a Southbend dual disc clutch in it now; the stock one was starting to slip a bit while towing hard on steep pulls. Funny thing is the stock one looked brand new when it was pulled out; just not enough clamping force I guess.ShinerBock wrote:
blofgren wrote:
4x4ord wrote:
How many km?
Still has under 50k because it's primarily a trailer tower. 75-80% of that mileage has been towing.
Plus you have a "Holy Grail" G56 manual transmission that they ae not putting in HD's anymore. I wish mine was a manual, but the wife put a kibosh on that. She has to drive my truck sometimes and tow the horse trailer. Or drive me home from the farm when I have had too many Shiner's. At least my JK is a manual.
Yep, I was looking for an automatic when I spotted this one at the back of the lot; a new leftover 2013 in the spring of 2014. Exactly what we were looking for and the manual transmission was a bonus! They wrote me a deal that I couldn't refuse and the rest is history.
My wife has only driven it a couple of times and it wasn't pretty. Even the Cummins stalls when trying to take off in 4th..... :S
But I do have her convinced to keep trying to drive it and I'm sure she'll get better on it with time. Now that we have a boat, usually the Yukon is with us camping so she has something to drive.ShinerBock wrote:
My truck or my brand, same thing. I grouped them because I own a Cummins. If I owned a Dmax then I would have said CTD/PSD. You are injecting your own thoughts in my words and I assure you that they are not the same.
Stop quoting him please. I'm tired of reading the same drivel from him over and over again. He is a one-trick pony that hasn't had anything intelligent to say in a very long time...FishOnOne wrote:
I never said and will never say "my truck is the best" and it's interesting that you group the PSD/Dmax owners from the Cummins owners in your above response. There must be a reason!
My truck or my brand, same thing. I grouped them because I own a Cummins. If I owned a Dmax then I would have said CTD/PSD. You are injecting your own thoughts in my words and I assure you that they are not the same.
