• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

 

So who has bumped the power on a 6CTA cummins

YOUNG GUN

New member
155
10
0
Location
Sherwood, Oregon
Maybe he was just being extra cautious...
What do you think would be safe continuous boost, and how about EGT's?
I'm just learning as I go:)
 
Last edited:

nevrenufhp

New member
200
16
0
Location
Sacramento
Before the turbo, 1350* sustained, or 1300 for conservative side. Upping just the fuel on these pumps should NOT make it run that high, unless there's a problem(air restriction).
He was telling you safe and cautious, at 30 pounds. It can take 30 pounds at 100% duty cycle. I would put the actual limits the same as a 5.9(6BT), with 45 pounds of boost on the stock head bolts.
 
Last edited:

YOUNG GUN

New member
155
10
0
Location
Sherwood, Oregon
Does a 200-300F drop pre turbo to post turbo sound about right?
I've got my probe installed about 1.5" after the turbo where they recommended.

Also, to do the real fuel adjustment you've gotta have a special socket inside a socket tool, I can post a couple pics of what I made if that's helpful.
 
Last edited:

nevrenufhp

New member
200
16
0
Location
Sacramento
Yes, that's about right.
I remember seeing the nuts up inside the AFC. Thought of trying to make my own tool also. Yes, what does your home brew tool look like? I may just buy the real one, and rent it out.
 

YOUNG GUN

New member
155
10
0
Location
Sherwood, Oregon
I've heard the tool costs about $200, but I could be wrong.
I just took a 14mm & a 10mm deep socket and turned down the OD on the 10mm and bored out the ID on the 14mm; I'll either use vise grips for the 14mm or tack weld a tee handle on it, and use a regular 3/8" drive short extension with a ratchet on the 10mm.
It only took me about 10 minutes on the lathe and $14.00 in the 2 Armstrong sockets.
 

Attachments

nevrenufhp

New member
200
16
0
Location
Sacramento
A dog off the line, back out the screw on top a few (about 5)turns, plus the full fuel that Young Gun described a few posts back.
 
Last edited:

nevrenufhp

New member
200
16
0
Location
Sacramento
One note on the full fuel nuts; It wasn't mentioned yet, but both nuts will need to be backed out, once you break them loose. They are on a stud, and are basically jammed together to make the rack stop, and limiting the fuel. I'm 99.8% sure that if you back them all the way to the last threads, it still wont get hot enuf to hurt it.
 

insas

New member
32
0
0
Location
PDX/OR
So I tightened the gov springs 4 clicks and backed out the top fuel screw 3.5 revs.... my truck now idles at 1070 rpm instead of 500... is that about what the rest of you are getting?

Thanks!
 
Last edited:

Bolkbich

Member
306
7
18
Location
MAHWAH, NJ
Its fine to run the truck like that. I didnt like the high idle so i only went 2 click on the gov springs.... idles around 725 or so. When the idle is too high it slams into gear then it tries to hold the high idle and pushes the truck too much. Slamming into reverse on a m939 makes me worry about the T-case.
 

nevrenufhp

New member
200
16
0
Location
Sacramento
It's normal for it to raise the idle rpm after tightening the gov springs. Adjusting the idle is as simple as a bolt with a jamb nut. Cycle the lever with the engine off, and you will see it. Idling at 500 is not good either, it should be at 650 in gear. Go for the 4 clicks, and back off the idle adjustment.
Each click is a quarter turn. You would be at 360* on each nut.
 
Last edited:

YOUNG GUN

New member
155
10
0
Location
Sherwood, Oregon
222.jpg333.jpg444.jpg555.jpg

UPDATE:
Finally did the "real" fuel adjustment... Holy crap!
I backed it out about 2.5 turns and adjusted the "no air" screw, and this thing screams!
I'm taking it easy on her and watching all the important gauges, but it's quite impressive compared to stock.
Hills that I used to get passed on constantly by semi trucks are no longer, they're left in my dust/smoke:driver:

Definitely need to get more air into her though, anyone have any good air intake mods?

Also, the inner socket must be modified to fit the "special" outer jamb nut on the fuel adjustment... see attached pics.
 

Sambor

New member
39
0
0
Location
Weatherford, Texas
How about you or neverenuf posting some pics of each adjustment on the 8.3 so us dummies can follow along. With all the tubes/pipes/linkages it might be useful. I turned up my fuel under the plug on top of the pump and it made a BIG difference. Haven't done the gov yet. According to the tach, it is set at about 2-2100. What would be a good safe max for it? I don't have a pyro or boost gage installed yet.

John R Dunn
Weatherford, Texas M931A2
 

Suprman

Well-known member
Supporting Vendor
6,835
646
113
Location
Stratford/Connecticut
The governor is set stock at 2100 rpms. It is my understanding that the 8.3 motor can safely spin well into the 3k's but the drivetrain wont like it. I went one click on my gov springs it gave me another 100 or so rpms without any idle issues.
Will
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks