Engine/Transmission (1998.5 - 2002) Is it just me or did my 95 have more bottom end?

[MxerChris]

Seems to me that my 95 auto, 3:54, had more bottom end torque than my 99 has now, granted the 24ver pulls harder past 2300rpm and the 12ver defueled about there, the 99 does a much better job pulling the camper, pulled it to Bristol last weekend for the race for the first time, I had made the same trip with the 95 about 3 times so I had something to compare the 99 to and there was no comparison! I just have a hard time getting used to turning this one up so much higher for the power and with the 4:10's it seems to be screaming compared to the old one. The 99 is great but it just seems it doesnt have the gobs of torque around 1700-2000 rpm range that the old truck had, is this normal? I'm thinking of getting a set of 275 injectors first, after reading some post this seems to be a cheap, safe and effective means of more power for pulling.

 

[fox]

That is the difference between the inline pump-12 valve and 24 valve electronic pumps.

You need injectors 275's or DD2's and at least an E-Z box. Or the comp box. Get rid of the muffler or go to the 4" exhaust.

If you don't have gauges it should be first so you can keep an eye on things.

If I was doing it over I'd keep the 12 valve for the trailers.

The old trucks were a lot easier to trouble shoot, if you ever had too!! They will go many miles, and we don't yet know how far the electric trucks will go.

 

[LSMITH]

A Van Aaken will put the torque in a LOT lower than what you have now. It still will not have the driveability of the 95 but will be close. Definately more pleasurable to drive.

 

[BV]

It's not just you

I also noticed that the low end grunt of my 92 was better than my 99. The 275hp RV injectors and PS boost module helped a lot.

 

[Gary - K7GLD]

PERSONALLY, having "been there, done that", I think it's mostly an illusion!



The primary problem is NOT a "reduction" in low-end grunt - but more likely the RUSH of additional power beginning at around 1800 RPM that creates the ILLUSION of reduced power down lower! If you look at a torque/HP graph comparing the differences between the 2 engines you are discussing, I think you would be surprised at what you would see at various RPM points... Any real differences between your old engine and the newer one in power/torque down below 1800 RPM are likely to be considerably LESS that you might think!



PLUS, it's especially deceiving to try to compare an automatic drive truck - with it's built-in slippage in the torque converter - with a manual transmission that is directly LOCKED to the engine thru the RPM range.



My old '91 - with an automatic transmission ALSO seemed to provide more power over a wider speed range - but that was mostly due to a VERY loose torque converter that allowed the engine to wind up well into it's maximum power range regardless of road speed - at the cost of overall efficiency and fuel consumption. It had NOTHING to do with "better low end grunt" or "superiority" of a 12 valve over a 24 valve engine - regardless of how much some in these groups like to continue to drive a wedge between the 2 engine types...



In actual operation, and after about $3000 spent on various performance mods on the '91 (Banks, propane injection, US Gear OD, pump tweaks, etc... , my new '02 would match it in power right outta the box - and has GREAT added potential with the mere addition of a $600 Edge Comp power box.



BUT, if more power, and a broader power range IS what you want, seriously consider a power box for your truck - I prefer and recommend the Edge Comp for it's flexibility and adjustability from the driver;s position, and while in motion - you will be absolutely amazed at the improved performance and broader usable power range!



And *NO*, you DON'T need "2 trucks", one for towing, and another for driving around empty!

 

[Cummins Cowboy]

Both of my CTD's have been manuals so my view point is from that vantage. My '02 doesn't seem to have nearly the low end balls that my first gen had. Even off idle torque doesn't feel as much. The old engine made no mistake about what was under the hood. It was a torque monster and was the heart of the truck. The torque would come on fast and brutal till about 2100 rpm then fall off quickly. Giveing the sensation of unreal amounts of torque. I do agree partly with what gary said above. You have to remember the difference between torque and horsepower. above about 2300 rpm on a 24 valver your torque is being delivered at alot higher horsepower so you are moving the same load faster. Where as down lower the 12 valve is at its prime. I think the 24 valve engine is alot easier on the drivetrain because most of us tend to rev um up a little more, That may be why you don't hear about so many 5 gear nut failures on 24 valve trucks. pulling my trailer at 70 + mph is where the new truck really shines it is like it comes to life or something and will not break a sweet up till as high as 90mph. And the best part about the higher rpm is if you have to down shift you can still easliy still go 70mph instead of having to slow to 60 on the old truck. I think an edge box would cure all inferior feelings about the new truck and torque

 

[Jeff Knight]

I think my 95 5sp 4. 10 had more off idle torque than my 02 HO with 4. 10 Jeff

 

[Gary - K7GLD]

I'd like to see a dyno graph of HP/torque comparison between engines as we're discussing here - if I get time, I'll look around for some - I suspect that our memories and "seat-of-the-pants" dynos sort of lie to us... Much like the fellas who wash and wax their cars - then swear they have more power and snap off the line...



Then too, is it possible we're comparing the two vehicles, and "forgetting" those power enhancements we had installled on the old rig - and are then making comparisons between an older modded truck and a new stock one... I, for one, KNOW my old truck, when stock, was NO match for my new one - after mods, yeah - but NOT stock-for-stock!



*I* can tell ya for SURE, one thing I *don't* miss on my '91, was it falling on it's face at 2500 RPM, and a power band that was at BEST only 1500 RPM wide... NOT a good thing when all ya have is a 3 speed transmission with a loose converter...



"I don't lie - I just "remember" big... "

 

[andrewkoperdak]

racingfan,

This is my first dodge diesel. To keep it short here... my truck makes maximum torque at 2279 RPM and max hp at 2689 RPM. I still have loads of pull down low in the RPMs. By that I mean around 1400 and above. I have stage 3 injectors and that changed how my truck pull in the lower end. Anyway according to some stats I saw you engine made max at less RPM than mine. The 24Vs need RPM to breath and to make power.

andy

 

[DDahl]

When I got my 96 215hp 5 speed, it was pretty dead on the low end. It would pull my trailer up hills better at 70 mph than 60. Also there was quite a bit of vibration at lower rpms under load. I added a TST torque plate. It helped high end power, but mostly generated smoke at the low end. 5th gear nut backed off at 80k and the injection pump governor died at 90+ k.



I went off the deep end and put in the expensive Cummins 1553 up-rate (pump and injectors). The low end torque really improved! 650 ft lbs to the ground at 1500 rpm. Boost builds up to 18 psi at 1300 rpm, and torque dies after 2300 rpm (250 hp to the ground). I checked with Cummins and the injection pump has a faster lift cam to improve low end torque. Also, high torque at low rpms produces very little vibration --- the 5th gear fix is still holding at 200k.



It certainly isn't the higher rpm hotrod I bought. BUT it really pulls my trailer up the hills (seldom do I ever need to shift down to 4th!). In my opinion there is no substitute for low end grunt!



The 3rd gen common rail injection system gets the fuel in faster at lower rpm too (to improve low rpm torque via better combustion). Hopefully the stock 3rd gens will have good low end grunt too.

 

[Gary - K7GLD]

Cummins can easily design these engines to provide a power band most anywhere they choose - it's no great engineering feat!



So WHY do you suppose they are currently apparently focusing on generating their power rise at and above 1500 rpm - instead of down lower in the RPM range?



Can you spell d-r-i-v-e-t-r-a-i-n?



Most of manual and AT failures so common to DC are directly related to low RPM torque, and the characteristic jackhammer-like combustion impulses the Cummins 6-cylinder provides as RPM is lowered. We all know what the difference is between an impact wrench, and an ordinary lug wrench - the principle is the same in the destructive tendencies when low RPM impulses are applied to a drivetrain instead of smoother, closer spaced one - that's ONE curse of a high-torque, 6 cylinder low RPM engine compared to a V8 - fewer combustion impulses per revolution at low speed = potential damage...



So how does a manufacturer reduce the damaging tendencies obviously causing early failures in their drivetrains, while still providing competing power for the work these trucks are intended for? Easy, simply tailor the power to come on a bit further up the RPM scale, where the load has already been put in motion, and less stress is applied from a dead stop upon the drivetrain...



Dunno about you other guys, but I spent too much for this truck to be replacing busted drivetrain parts often - it STILL has plenty of guts off the line - and once moving, is unstoppable up a grade - JUST the way *I* like it!