Engine/Transmission (1998.5 - 2002) Low end torque, still not enough

[Big Don]

Guys,



Big Don here. Been vacant for sometime as I am working on a new shop.

I still have my first gen 'Ol Blue. at 202,000 miles, I still love her. I have added a 2000 2500 to my stable. It has a Power Edge comp, DD II's, psycotty II, PDR modified HX35 and a Southbend clutch. I also put 285's on it. With the 3. 54 and 6 speed, it wants to "bog" off the line in 2nd gear. It comes on strong around 2000 rpm's. How can I increase the torque down low (1500 rpm's)??? My ol truck will really grunt down low and when it hits 1500 rpm's you better have it pointed straight!!!

Don't get me wrong, the new truck will outrun most any diesel truck I've ever run against, I am still missing the torque of the old truck. When towing I have to change gears too much and keep the rev's up to get the power out of it.



thanks

Don Peters

 

[Cummins Cowboy]

I think this is just the nature of the ISB engine. I have said this before on this forum myself, having come from a first gen myself as well. Off idle torque is way down on an ISB. My '02 comes on real strong around 2100 rpm but is kinda doggy below 2k. I think my old first gen with mildly tweaked pump could out pull my ETH if you kept the revs on both below 2k while pulling the trailer i have. but mind you my new truck prolly weighs 2000#'s more than the old truck. I theroize that the ISB has too much timing advance at low rpm's this is why they are so much louder especially when started cold. The timing advance would also explain why the newer engines run so well when the rpm's start to come up. Don't get me wrong I like the new trucks pulling ability it will pull my 6k enclosed cargo trailer pretty much like it isn't there at 85+ mph. but I do miss the grunt of the old truck.

all trucks with mechanical style pumps p7100 and the VE seem to have gobs of low end but the new trucks don't.

 

[LSMITH]

Don, long time since you have been around!! I am glad all is well with you and I am glad to hear from you.





Buy or borrow a Van Aaken, it will give you the low end you want. UNHOOK the data link (3 pin cable connection on the comp) of the comp BEFORE hooking the VA up. Leave the pump wire and the MAP connections from the comp.



The EZ part of the COMP comes in late, around 2K RPM, Fact of life with the box you chose.

 

[pkennedy]

This is an enherant problem in all the electronic diesel engines. Your mechanical pump delivers X amount of fuel to the injectors at idle whether lifting or not. The torque rise is set in the governer springs in conjuntion with the air fuel ratio control as you accelerate in the bottom end. By product of more fuel and torque is smoke and the ECM will not allow it. However the ECM is set to increase RPM if it falls below idle or RPM does not coincides with throttle position. Second reason is the camshaft profiles were changed to accomadate emissions as well therefore different toque specs at different rpm's. 24V industrial engines show higher torque ratings at lower HP than the Dodge, again the emission specs are different for off highway engines. DC made this even harder to mess with by NOT using a Cummins ECM. Cummins programming is all inclusive for cruise, high idle,PTO applications on all engines. PK

 

[Big Don]

LSMITH,



I have a Van AAKen that we used to run on our '99. You say if I unhook the data link from my comp box and then hook up the Van aaken to the pump then everyhting will be okay??? The VA box I have only hooks at the large connection on the back of the pump. It is one of the early ones before they had two hookups.





thanks

Don Peters

 

[LSMITH]

Don, that is exactly what I am relling you. Unhook the 3 pin connector (from down near the PS pump on the 99, back under the fuel filter on newer trucks) for the data link. Plug the VA into the pump just like you did on the 99.



The early VA is supposed to be the strongest of the VAs, but I have only used the old style VA and I LOVE it.



I will send you an email on the other questions you asked.

 

[Big Don]

thanks

Don

 

[boydo]

I found that adding propane to the equation gave my truck a massive attitude change. I gain great bottom end power-without lpg it was sluggish until 1800 rpm, with lpg it starts to come alive a 1400 -1500 rpm. On a hydro dyno I had a gain of 90 whp @ 2000 rpm - with NO extra heat. How it works - Diesel engines only burn 75-80% of the diesel added. When LPG is added 100 % of diesel is consumed resulting in more power better economy. After researching LPG systems I have found that vapor propane with a digital controller is the best, since it can be set up for any diesel engine from 3. 0-8. 0 litres from stock to bombed.

 

[WestTN]

low end torque

The electronically controlled engines have less torque at low RPM's, but it is not because of the 24 valves. The fuel curve is controlled at all points by the computer to eliminate smoke (over-fueling) and to limit torque at a set maximum number appropriate for your engine calibration. The 1sy gen VE and 2nd gen P7100 pumps were mechanical and could be adjusted for more bottom end even though it produced smoke. Fuelling boxes can restore the torque at lower RPM's, but the truck will then smoke. It was an EPA thing they had to do.

 

[Diesel Freak]

With my Puck and DD3's I have more low end torque than I can effectively use... .

 

[LSMITH]

Same here with my DD3's and the VA Cliff.....

 

[Diesel Freak]

hehe... I like the way things start to happen at 1500 followed by the 1700 RPM "hit" in the powerband... then she revs out to 2700 in a heartbeat!



according to my last "baseline" dyno run... March of last year.



I had over 400 FtxLbf at 1650 RPM

750@ 1800 RPM

Torque peak was 876 FtxLbf @ 2000RPM

It did not drop below 600 FtxLbf till 2900 RPM

HP was 358 @ 2500 RPM



Yes, I need a bigger turbo!

 

[John]

Come on Cliffy, ya need more than that!



My last dyno:



448. 2 BHP/1018 lb. ft. Torque







DTT rules!

 

[Diesel Freak]

Originally posted by John

Come on Cliffy, ya need more than that!



My last dyno:



448. 2 BHP/1018 lb. ft. Torque







DTT rules!

your telling me!



Got beat by Eric W last time in Monroe! But he took the easy way out... he tapped the pump wire.



Evan and I have a plan! Not going to beat you though.

 

[John]

Well Cliff, as you know, I have tapped the pump wire so-to-speak (I used the Blue Chip VP44 replacement cover... BOMBed of course... with all connections soldered and Weatherpack connectors utilized... )... and I'm darn glad that I finally did that too.



heh,heh,heh

 

[Diesel Freak]

John, you crack me up!