M939A1 NHC Turbo

[Steve92307]

You may have to swap the fuel button. Those are easy as well. Just order your button.before hand

I was reading about the fuel line mod. Should I do that as well. Also where should I plumb the guage into? Which line is the supply line? I can post pics if you need me too

 

[simp5782]

I was reading about the fuel line mod. Should I do that as well. Also where should I plumb the guage into? Which line is the supply line? I can post pics if you need me too

There is a pipe fitting on the side of the fuel shut off valve on top of the pump


Dual line would be useful

 

[Steve92307]

There is a pipe fitting on the side of the fuel shut off valve on top of the pump


Dual line would be useful

Ok, I'm gonna have to snap a pic of my pump for you. Last night I was looking at it and noticed that the primer isn't hooked up. So I'm thinking something might not be right on it. I'll get you some good pics when I put my little down later

 

[simp5782]

Ok, I'm gonna have to snap a pic of my pump for you. Last night I was looking at it and noticed that the primer isn't hooked up. So I'm thinking something might not be right on it. I'll get you some good pics when I put my little down later

Primer isn't needed. It just fails and sucks air

Solenoid has a plug like shown below. Remove it and use hydraulic fittings. And hose and a liquid filled gauge

 

[Steve92307]

Primer isn't needed. It just fails and sucks air

Solenoid has a plug like shown below. Remove it and use hydraulic fittings. And hose and a liquid filled gauge

Awesome, thank you

 

[Crf450x]

I added an ht3b turbo to mine and noticed no difference in power, though I’m sure there was a reduction in egt. I didn’t have a gauge before I put the turbo on. With stock fuel I made about 9 psi and egt would not go over 800. My stock rail pressure was about 150. I swapped the fuel button (#35) for a #17 and it made a huge difference. Egt still won’t go past 800, boost is about 12, and rail pressure is 180. And that’s with no intercooler at all.

For what it’s worth, I saw absolutely 0 difference with the dual fuel line deal, neither subjectively nor objectively. To be honest I don’t even see the logic behind it without more injector flow. But everyone speaks highly of it so I did it.

Im curious what turbo you have? Your egt should be low and you should certainly make more than 1 psi unless it’s some monster turbo or you have a large boost leak.

Edit: I just noticed the air filter. That is waaaay small. I’d pull that off and go for a test drive.

 

[Steve92307]

I added an ht3b turbo to mine and noticed no difference in power, though I’m sure there was a reduction in egt. I didn’t have a gauge before I put the turbo on. With stock fuel I made about 9 psi and egt would not go over 800. My stock rail pressure was about 150. I swapped the fuel button (#35) for a #17 and it made a huge difference. Egt still won’t go past 800, boost is about 12, and rail pressure is 180. And that’s with no intercooler at all.

For what it’s worth, I saw absolutely 0 difference with the dual fuel line deal, neither subjectively nor objectively. To be honest I don’t even see the logic behind it without more injector flow. But everyone speaks highly of it so I did it.

Im curious what turbo you have? Your egt should be low and you should certainly make more than 1 psi unless it’s some monster turbo or you have a large boost leak.

Edit: I just noticed the air filter. That is waaaay small. I’d pull that off and go for a test drive.

I will pull the air filter and take her for a ride. I'm not sure what size the turbo is but the guy told me it was over 100mm. Like we were talking about in the previous posts. It seems like I'm not getting enough fuel therefore the turbo may not be boosting. I dont get any smoke at all coming out of the stack and its literally attached to the turbo and comes thru the hood. Also my Egts go high very quickly. I'm gonna put a scoop or louvers on the hood and try and direct the air thru the intercooler better. Thanks for the advice.

 

[Lonnie]

You said the temps go high... but never quantified that. What reading are you seeing?

Also, mine would not make over 3-4psi boost with stock fueling. It is up to 12psi now with 200psi rail pressure & still only emits a light trail of smoke.

 

[Steve92307]

You said the temps go high... but never quantified that. What reading are you seeing?

I've never pushed it but it can easily hit 1100 degrees. I try not to let it go above 1000 degrees.

 

[Lonnie]

Sounds like the turbo is not spooling. You obviously have no exhaust restriction, but the inlet air is in question.
I test drove mine with a K&N cone filter on the turbo & it worked OK before I got the factory canister piping built.

 

[Steve92307]

Sounds like the turbo is not spooling. You obviously have no exhaust restriction, but the inlet air is in question.
I test drove mine with a K&N cone filter on the turbo & it worked OK before I got the factory canister piping built.

Yea I dont think its spooling either and with nm nothing coming out of the exhaust, even if you floor it. Def could be a fuel issue with the Air intake issue. I'm gonna have to Fab something because I dont have the stock components.

 

[simp5782]

Where in California are you located?

 

[Steve92307]

Where in California are you located?

Apple valley, right next to victorville. 3hrs south of Vegas off the I15.

 

[Lonnie]

The boost curve is pretty lazy & will not make much boost until the revs are up in the 1800 range, below that it falls off fast.
1100 is not bad for an exhaust temp, but I could not make any heat with the turbo before I increased the fuel... under 800 was it.

The intercooler you have will be pretty restrictive, as it provides a lot of surface area for cooling, but these types are usually designed for high boost applications where losing 5# boost across the intercooler is not an issue.

 

[Steve92307]

The boost curve is pretty lazy & will not make much boost until the revs are up in the 1800 range, below that it falls off fast.
1100 is not bad for an exhaust temp, but I could not make any heat with the turbo before I increased the fuel... under 800 was it.

The intercooler you have will be pretty restrictive, as it provides a lot of surface area for cooling, but these types are usually designed for high boost applications where losing 5# boost across the intercooler is not an issue.

So maybe I should just do away with the intercooler then.

 

[Lonnie]

If you up the boost & relocate it in front of the radiator it will help. There it is likely heating the air from the engine/radiator heat.

 

[Crf450x]

The turbo is far too big if it really is 100mm. The intercooler isn’t hurting anything. Probably not helping but it’s not hurting. More fuel will likely just make it run hotter. There is a problem that should be fixed. First I’d try it without the air filter. If that doesn’t help I’d figure out what turbo it is. If there is no data plate on it you can pull the compressor housing off and measure the small diameter of the wheel (inducer). And if it really is that big, I don’t think you’ll ever get it to run right. That’s just my $.02.....

 

[Steve92307]

The turbo is far too big if it really is 100mm. The intercooler isn’t hurting anything. Probably not helping but it’s not hurting. More fuel will likely just make it run hotter. There is a problem that should be fixed. First I’d try it without the air filter. If that doesn’t help I’d figure out what turbo it is. If there is no data plate on it you can pull the compressor housing off and measure the small diameter of the wheel (inducer). And if it really is that big, I don’t think you’ll ever get it to run right. That’s just my $.02.....

Just talked to the guy I bought the truck from. He confirmed that it's a 101mm ball bearing turbo. Its was one of 2 turbos he had on his dodge Cummins race motor, so I dont think its gonna work for me. I'll pull the air cleaner off and see how it does but will probably just remove the turbo all together.

 

[simp5782]

Just talked to the guy I bought the truck from. He confirmed that it's a 101mm ball bearing turbo. Its was one of 2 turbos he had on his dodge Cummins race motor, so I dont think its gonna work for me. I'll pull the air cleaner off and see how it does but will probably just remove the turbo all together.

There has to be a model number. If he didn't know that then he is talking crap. Or he was an idiot that thought any turbo would work. Cause um it has to be a reverse rotation turbo or it won't work on thr 855. Like a T46. T50. HT3B HT4B. 4LHR733

 

[Steve92307]

Lol, I'm not sure man. He told me he had it custom built by a turbo company in San Dimas. Said he just threw it on there because he had it laying around. Anyway. Ill just do what we discussed and take it off if I have to. No big deal to me either way.

There has to be a model number. If he didn't know that then he is talking crap. Or he was an idiot that thought any turbo would work. Cause um it has to be a reverse rotation turbo or it won't work on thr 855. Like a T46. T50. HT3B HT4B. 4LHR733