So who has bumped the power on a 6CTA cummins

[Ford Mechanic]

Ummmmm, really?

Dirty old man, get you mind out of the gutter!

Yeah, I probably should have worded that better.

 

[Tornadogt]

as requested this is my "Package" including the my "Special Tool"
all sockets are craftsman and can be purchased individually if you want build yourself a kit..
Start from left to right:

14mm 6-point 1/4 drive with the drive end drilled out just large enough for a 1/4 drive extension to slide through it.


Next is a 10mm 6-point 1/4 drive socket, and
9mm 6-point 1/4 drive socket that was cut down on the end to work as a spanner socket (used on the pump with the alternative locking nut)
and 3 inch 1/4 drive extension ( you will also need a 1/4 drive ratchet)

ALSO the modified 9mm works great for turning the governor spring tensioner nuts. (I turn them 3 Clicks on each to start with)

I have a pretty good right up on doing the pump adjustments:
(this is a compilation of photos and info from 44 pages for post/photos)
but it is easy to print off and have with you while you work on the truck..

 

[JohnnyBM931A2]

View attachment 599051 as requested this is my "Package" including the my "Special Tool"
all sockets are craftsman and can be purchased individually if you want build yourself a kit..
Start from left to right:

14mm 6-point 1/4 drive with the drive end drilled out just large enough for a 1/4 drive extension to slide through it.
View attachment 599052View attachment 599053

Next is a 10mm 6-point 1/4 drive socket, and
9mm 6-point 1/4 drive socket that was cut down on the end to work as a spanner socket (used on the pump with the alternative locking nut)
and 3 inch 1/4 drive extension ( you will also need a 1/4 drive ratchet)
View attachment 599062View attachment 599071View attachment 599072
ALSO the modified 9mm works great for turning the governor spring tensioner nuts. (I turn them 3 Clicks on each to start with)

I have a pretty good right up on doing the pump adjustments:
(this is a compilation of photos and info from 44 pages for post/photos)
but it is easy to print off and have with you while you work on the truck..

Sweet Thanks for posting the pics.

 

[DinoShepherd]

Thank you all for doing the hard work here. I am building my kit now. Read all 45 pages three times now. So I know just enough to be dangerous.

Question, I haven't seen answered. I understand (basically) how the governor springs work. What I am not understanding is the functional difference between adding preload to the stock spring and going with an aftermarket 3k spring such as the pacbrake.

Any input, experience or guidance?

 

[adamsoffroadperformance]

From what I understand is the stock springs cranked won't give enough fuel at load like the aftermarket springs will.

 

[Ddmk18]

I run the pacbrake 4k springs works great.

 

[74M35A2]

I run the pacbrake 4k springs works great.

I bought the same and have not yet installed. Please tell more. Are you manually shifting it then, or does it just shift harder when left in 1-5? How far have you pushed the top speed so far? Did you swap out all the springs they supplied, or less?

 

[Ddmk18]

I usually don't have to push it to hard so I just normally let it in 1-5 unless pulling grades. You can manually shift it if you want, the highest I ran RPMs so far was 2700. Top speed isn't what I was going for but it will move. I used all the springs supplied in the kit when I put it in. The only draw back is setting high idle for pto operation. Anything 1400 rpm and below is fine but try to go any higher and she takes off. If the pto is engaged that slightly loads the engine and it will stay around 1500 but if your in the cab you can fine tune it with your foot without using the throttle cable. I used all the springs so it has full fueling to whatever RPM I decide to run it to, so it doesn't start pulling fuel around 1800-2000 like stock.

 

[Tornadogt]

Thank you all for doing the hard work here. I am building my kit now. Read all 45 pages three times now. So I know just enough to be dangerous.

Question, I haven't seen answered. I understand (basically) how the governor springs work. What I am not understanding is the functional difference between adding preload to the stock spring and going with an aftermarket 3k spring such as the pacbrake.

Any input, experience or guidance?

Simple way to understand governor springs is that the more tension is on the springs (whether it is from adjusting the stock springs or installing aftermarket springs) the higher rpm the engine will rev to before it begins to remove fuel in order to control the max rpm of the engine. Governor springs limit the rpms of the engine by removing a portion of the fuel going into the engine at the higher rpms.

 

[MtnSnow]

I bought the same and have not yet installed. Please tell more. Are you manually shifting it then, or does it just shift harder when left in 1-5? How far have you pushed the top speed so far? Did you swap out all the springs they supplied, or less?

The Pacbrake 4k GSK (gov spring kit) comes with multiple springs of different lengths and tension and I installed all of mine except for the very last one (the 4k spring) and as shown in the vid I posted earlier in this thread will limit my truck at 2800 rpm which I am happy with As for the shifting question it will still upshift like normal but when I get into the hills I manually shift into 1-4 or even 1-3 (depending on the grade) and hold the RPMs up which keeps my road speed good (I can quite often pass the commercial semi on the hills)

 

[74M35A2]

Thank you all for doing the hard work here. I am building my kit now. Read all 45 pages three times now. So I know just enough to be dangerous.Question, I haven't seen answered. I understand (basically) how the governor springs work. What I am not understanding is the functional difference between adding preload to the stock spring and going with an aftermarket 3k spring such as the pacbrake.Any input, experience or guidance?

The answer to your question:The difference between the two is a matter of spring rate (k). The stockers can only be cranked down 2-3 "clicks" before they become unstable in operation. Example, the engine may not be able to maintain idle control response time. Engine may then die when trans put into gear. If 2 "clicks" of the stock springs is not enough to do what you want, one should then shift to the aftermarket springs to increase top RPM yet still keep the governor operation somewhat content. But, as posted above, when using the aftermarket springs, the throttle hold cable can't really be used for any RPM over 1400rpm. But, if this is for a hydro PTO pump, the manual doesn't want you running it over 1800r's anyway.

 

[dangood]

We had the IP sent in to have the adjustments done to the fuel plate, timing was adjusted and installed a bigger turbo and 3000 springs on a customers truck. It's a 375-400 hp modification according to spec, and the motor is awake and alert now. (No, there is still no tire burnout or anything close, but the truck flat out gets up and goes now.) Mpg went from 8 mpg to 7, and she blows some coal at takeoff. EGT is normal still but have not pulled anything yet. But driving around town is fun now, no lag and power when you punch it...along with some black smoke if you lay it hard before the turbo spools.

 

[MtnSnow]

Who did you have do the work Dan?

 

[dangood]

Here is some pics of the 5 ton Crewcab project (the "General") with Cummins 8.3 Hp increase. We should be done in about 60 days (feb 2016) and have full test results. Started out as a 2010 rebuilt super clean 91 M931a2 tractor with Cummins 8.3 (239 Hp), and built it into a 375-400Hp crew cab flare side 6x6 pickup with sunroof, air ride seats, and 53" tires. The bed will get low profile wood stake sides and the body will be finished in the new Jeep Wrangler Green rescue paint color. It runs a LOT more peppy now but until I pull 15k lbs up a grade, I can't tell you the EGT results yet. Around town it stays right at 600-650.

 

[dangood]

Had Outlaw diesel do the IP, we did the rest.

 

[74M35A2]

More info please. What turbo and what is boost level now? There is no fuel plate in the Bosh MW pump, that popular mod is done to the Bosch P7100 pump, so that part doesn't make sense. What is the highest EGT, RPM, and top speed attained so far? Measurables help to quantify better than the opinion dyno. Also what place changed the pump timing and the cost to do so if you would be willing to say? The 5.9 GSK's supposedly have a lower result in 8.3's. If it is a 3000k spring kit, then it will produce like 2400rpm on an 8.3, or something like that. Not sure if that is actually true yet or not.

Thanks for the post, we look forward to your detailed reply.

 

[dangood]

Sorry, pics didn't post. I'll try less than 10 as per requirements when I get back to my desktop. My phone version of SS is a bit clunky.

 

[JohnnyBM931A2]

More info please. What turbo and what is boost level now? There is no fuel plate in the Bosh MW pump, that popular mod is done to the Bosch P7100 pump, so that part doesn't make sense. What is the highest EGT, RPM, and top speed attained so far? Measurables help to quantify better than the opinion dyno. Also what place changed the pump timing and the cost to do so if you would be willing to say? The 5.9 GSK's supposedly have a lower result in 8.3's. If it is a 3000k spring kit, then it will produce like 2400rpm on an 8.3, or something like that. Not sure if that is actually true yet or not.

Thanks for the post, we look forward to your detailed reply.

I'm curious about the turbo too. I was always worried that a larger turbo would mean more turbo lag. As a reference point, what is the max boost produced on a stock 8.3?

 

[adamsoffroadperformance]

I usually don't have to push it to hard so I just normally let it in 1-5 unless pulling grades. You can manually shift it if you want, the highest I ran RPMs so far was 2700. Top speed isn't what I was going for but it will move. I used all the springs supplied in the kit when I put it in. The only draw back is setting high idle for pto operation. Anything 1400 rpm and below is fine but try to go any higher and she takes off. If the pto is engaged that slightly loads the engine and it will stay around 1500 but if your in the cab you can fine tune it with your foot without using the throttle cable. I used all the springs so it has full fueling to whatever RPM I decide to run it to, so it doesn't start pulling fuel around 1800-2000 like stock.

I got to ride in this beast today. definitely no slouch and ups the fun factor forsure. Mine will be getting the same mods soon.

 

[adamsoffroadperformance]

Well Ddmk18 came out today and installed my 4k springs and turned the screws and adjusted the rack travel. wow big difference. I am very pleased. all for about $80. Thanks For the help Dillon.