So who has bumped the power on a 6CTA cummins

[ClarkeF]

Spook - yes dead on. I used Young Gun's PDF and the pictures of his modification tool, along with the posts from neverenuf.

http://www.steelsoldiers.com/showthread.php?74925-So-who-has-bumped-the-power-on-a-6CTA-cummins&p=1438636&viewfull=1#post1438636

Here is the link to the tool pics that Young Gun posted - the link to the drawings is below. VERY helpful.

One last thing that may prove helpful to those of you considering these pump mods: this link from post #59 (thank you Young Gun!)

http://www.steelsoldiers.com/attachment.php?attachmentid=453641&d=1380133189

This PDF was EXTREMELY illustrative and helpful in my understanding of the mods at the rear of the MW pump, but I had read through the ENTIRE THREAD at least six times before I found it and opened it. I'm referencing it here again for those of you jumping in here late that may be reading past that link the same way I did.

Hopefully, I have addressed all the issues questioned in the PMs I received. Thanks again to all of you for a great thread!

 

[nevrenufhp]

Okay, a did the Low Buck mod on the full fuel screw, I turned it out 3 full turns and tightened the jamb nut back down, went for a ride and really don't see a big difference. So I will take the next step, the star wheel, one full turn for starters. I take it, these are subtle adjustments/tweaks - not like adding a programmer on today's diesel pickup to jump 100hp. It's more like 30 or so?? And with the mass of the huge trucks, 30hp is a grain of sand on the beach.

Do a few more turns on that screw. Some pumps need like 10 turns to make a difference in power. On a big engine, 30hp is also around 75 pounds more torque. You will feel that much diference. Jumping up by 100hp is a whole other can of money worms....but still possible.

Thanks for the detail and pictures. A broken EGT probe (thermocouple) located pre-turbo would not go through your compressor, but rather through the turbine housing.

I'm also interested in the next step for increased airflow in regards to lowering EGT, such as the BatMo wheel on our stock HX40 turbo, or does one move up from the HX40 to an HX50 or even HX55? Isolate the after-cooler onto it's own dedicated coolant circuit with electric pump? Swap to a true front-mount intercooler like the more modern big rigs?

I would think the BatMOwheel would be just right for what you got. Upping to a '50 or '55 would need bigger injectors(350-450hp rated) and the front mount intercooler for the high flow.

 

[spook]

Sorry, 74M, I meant turbine instead of compressor.

Neverenuf, is this the wheel you think is the best upgrade for our turbos?
http://baeturbosystems.com/hx45turbocharger.aspx

I'm willing to give it a run "for the team" but I'm hoping for some guidance/addl input from "the team" before I order. I have to pull the turbo anyway to drill my exhaust manifold for my secondary TC install (to make sure I get the cuttings cleaned out completely) so I might as well swap the wheel while it's out, right? (This is where you all become "enablers"!).

 

[nevrenufhp]

That is a good upgrade. It just seems a tad too much. The stock compressor inlet is 60mm, and this one is 67. That's quite a lot. I was thinking in the 62mm range. You may find that you need marine injectors with that upgrade.....now that would be a shame to be forced in to the 400hp range.
This is the one I was thinking for a mild upgrade and EGT control: http://baeturbosystems.com/upgradekits-4.aspx
Just to note, you will have to take apart the turbo, and have it machined to fit the bigger wheel.

 

[Tornadogt]

So I had to jump in an join the group... We started with a M923a2 Turd (by the term "Turd" as we got it from Auction the idle was set around 400rpms in gear and was very slow at accelerating from a dead stop and idle) The truck is completely as it came from DRMO stock exhaust/air inlet/air cleaner.

Did the Full fuel adjustment on back of the injection pump, put the 10mm nut flush with the stud. Next did the low fuel adjustment on top of the injection pump 3 full turns. Next was the Governor springs (they seemed to have almost no preload on them to begin with) We did 3 click on each..

Started the truck and instantly the idle was 700rpm's in neutral and 600rpm's in gear without any adjustment of the linkage... Very happy with this..

With a hard free rev medium to heavy black smoke before the turbo spools then lightens up.. For my taste I like a little show off smoke

Under driving conditions, light throttle and in first gear, STANDING on the accelerator, Heavy Smoke for 3-5sec. for the turbo to spool then lighter to very minimal as the truck accelerates through the gears. There is a little medium smoke between gear shifts.. Cruse is clean with only light haze coming from the stack.

VERY Happy..
Much more pleasant truck to drive, by no means a race car but it can get out of it's own way if needed now.
We can tweak the top Low fuel screw, and the no air adjustment to reduce the Heavy smoke conditions but I believe that is personal preferences, I Say Let it SMOKE

Thanks everyone...

 

[racing4funn]

Tornadogt, I hope you covered all the basic stuff first. Fuel tanks, lines, even crud at the injector is all thing mentioned here related to poor proformance. Since you don't know the history of the truck and all...

 

[Tornadogt]

Tornadogt, I hope you covered all the basic stuff first. Fuel tanks, lines, even crud at the injector is all thing mentioned here related to poor proformance. Since you don't know the history of the truck and all...

I did say it was fresh from DRMO (GL) as far as condition, but we did service it and have over 600 miles (half of that were towing another M923) and 2 plus full tanks of fuel run through it before these modification. The truck is mechanical sound it just had the typical sluggish nature of the trucks in stock form... Again very happy with the improvement..

 

[HETvet]

Thoughts and opinions on using an HX80 turbo off of a cummins powered generator?

 

[Suprman]

After turning up the power a bit I changed both fuel filters I did seem to make a difference with the new filters. The old filters looked ok when I took them out. As much as I would love to put big injector and a larger turbo on a 5-ton I think it would significantly decrease longevity.

 

[nevrenufhp]

Thoughts and opinions on using an HX80 turbo off of a cummins powered generator?

Going to an '80 by itself is too many steps up. You could use the 80 in a compound setup, along with the stock HX40. Even still, an HX60 would pair better with the 40.

 

[Jeepsinker]

What about an HX 50? That should be a bolt on with some tuning I would think. I don't know, I'm not a diesel performance guru.

 

[nevrenufhp]

A 50 would be great. Just needs the fuel to spool it.

 

[Jeepsinker]

But then again, more air and more fuel make for higher EGTs, so at some point an intercooler will become a must, especially in my case (wrecker) so that I don't melt a motor down. I need to be able to harness the extra power gained without having to take my foot out of it halfway up every hill.

 

[Jeepsinker]

So I guess what I'm asking here is: is it even worth going to the HX50 and bumping up the fuel, maybe stepping up to larger injectors if I don't go intercooled? I need sustained usable power.

 

[nevrenufhp]

A 50 would work at max fueling, but still may need slightly bigger injectors. You will probably need intercooler one way or the other. The better you can keep it cool, the less stressful it is driving it.

 

[hklvette]

Something else to consider is making sure that the throttle lever on the pump is being run all the way forward by the throttle pedal. On mine, the small spring on the pump lever was fighting the spring on the throttle rod preventing full-throttle operation. I removed the small spring and put a slightly stronger spring in place of the throttle-rod return spring to ensure that it would return to idle. Works much better now. I'll get around to loading pictures at some point...

 

[PWM]

When I did my truck I had to adjust all the linkages and the bolt under the throttle pedal, it took a while but was well worth the time.

 

[ronnycordova]

Installed a boost & EGT probe today and went ahead and adjusted the rear screw on my pump. Went from barely 22PSI at 2100 to about 31 at 2100. I still have the governor springs to do but just doing the rear was definitely worth it so far. I actually have to watch the speedo now to keep it under speed haha.

 

[cumminsbandit]

So this weekend my cousin got a m923a2, so i met up with him to check it out. it was idleing a bit low so i turned that up for him and i went to turn up the top screw like i did to mine and got no results... i turned the screw on my truck about 2 3/4 turns and is a coal blowing monster and i did the same to his and got nothan... I then kept futzing with the screw for a bit and cracking the throttle and all of a sudden i got it to spit out one BIG puff of smoke and then touched nothing and with the next crack of the throttle i got nothing again. What is going on? something maybe sticky in the pump? I had the screw out about 4 turns at the most and it seemed like it was getting ready to run out of thread.(and didn't want to risk dropping in pump) Filters are good and its not the linkage... Any ideas???

 

[ronnycordova]

Did you try adjusting the star screw at all? That should increase the fuel rate at no-boost so I would think that would help with throwing coal. Just a guess though.