• 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.

My m925a1 build "Brutus"

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
Decided to go in a different direction. Decided that I want to run an intercooler. I was given the crossover pipe and aftercooler. I didnt want to buy a new core for the aftercooler. I Was concerned if I have a failure down the road, the coolant could dump into the engine causing a failure.

Did some research and decided to go with a n14 intake. It bolts right up and flows better than the 250 intake. I'm planning on running a small intercooler. The truck is only going to make 15lbs boost. No need for a massive intercooler. I spoke with mishimoto and i'll go with one of their universal options. It will handle the cfm, and psi easily. I also have methanol so if I need extra cooling I can hit that to help drop intake temps on a large hill.

I don't know if anyone that's turboed a 900 series truck has used the n14 intake or not. Thought it would look cool. It's got a ton of pipe plugs to run boost, IATs, methanol, etc.

Got a great deal on it. The gentleman that sold me the intake has the Peterbuilt truck from Duel he's restoring.

I just need the boots, cooler, clamps and pipe. I'm going to modify my C channel bracket that I currently have for the mrap radiator. I have 14 inches from the top of the rad to the top of the inside hood so plenty of options for a nice intercooler.

Too large of an intercooler and I'd have lag. This should help if I'm towing my m1061a1 and shelter setup on long hills to help keep temps down.
 

Attachments

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
Put plugs in the intake where the original sensors went and used red rtv. Primed and used a self-etching primer.

Followed up with using a high temp flat black paint. I also bought a pressure gauge to monitor fuel pressure with a needle valve. In case I decided to increase the fuel down the road I'll be able to compare and monitor closely. Im going to mount to side of the shifter. Needle valve will also be nice to have in case I have a leak or failure on the road, I'll be able to shut the valve and stop any fuel leaks. I'm going to use ptfe line -4an line. More photos end of the week.
 

Attachments

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
I did the fuel pressure gauge install today. Bought a 2 5/8" autometer gauge to match my other gauges. Gauge went to 400 psi. To match my other auotmeter gauges I had to pick 200 or 400. Decided if I do turn the fuel up and I was to get over 200 I wouldn't be able to monitor it with the smaller gauge.

I used a 1/8"mpt to -4an 45 degree fitting that fit right in the fuel solenoid plug. Used 4an ptfe black braided stainless line and drilled a hole right above the 2 air line connections above the gas pedal.

Decided to put the needle valve right before the gauge. Reason being it's easier to adjust if I need to make changes to keep the gauge from fluctuating. I also used it to burp the air out of the line and made no mess in the cab.
It also lets me cut the fuel off if I have a leak. I'll bring the plug with me so if the line were to fail I can always plug it back up and keep driving.

The gauge works great. I saw almost 50psi when revved to 1700 rpms. Won't see a real number until I drive it. Used a 24v green led bulb to match the others. Pleased with install. Now I have a way to monitor pressure if I increase fuel down the road.

I forgot a photo of what it looked like at the pump. I'll grab one next time I'm in the shop.
 

Attachments

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
How does a needle valve on the gauge affect the pressure that the pump puts out?
The needle valve is a micro valve. It's not like a standard ball valve and lets only a tiny bit through. There could be some changes but it's designed to be very accurate. It also increases efficiency and safety. The valve can suppport 1500psi.

It wont change the pumps pressure, the pump will push out the pressure it's set at.
 
Last edited:

US6x4

Well-known member
1,256
2,308
113
Location
Wenatchee, WA
I see, I see. I've read a few opinions on what max pressure a small cam can handle and they very between 200-230 psi. What pressure would be your max and have you come across any official number from Cummins?
 

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
I see, I see. I've read a few opinions on what max pressure a small cam can handle and they very between 200-230 psi. What pressure would be your max and have you come across any official number from Cummins?
I haven't called cummins directly. Alot on here say 200 to 210 is max. I haven't driven the truck since the pressure gauge installed yesterday due to the cold and crap on the roads. Im running a #27 fuel button. Pump rebuilt by premco. 10% over injectors arent installed yet. Even with the new injectors my fuel will be so conserative, I'll never be close. I bet I'll be at 150 to 160psi when fully in it pulling a hill, which is exactly for what I'm looking for. I want the safety and reliability.. l'll be pleased with 12-15psi of boost with the intercooler as well. And down the road if I decide I want to turn the fuel up, I'll have options.
 

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
Installed the n14 intake with new hardware. Much lighter and easier to manuever, hooked the boost gauge back up. I also decided to hook the air compressor back up to the intake. Instead of pipe thread, Cummins changed it to -14ORB and then I got a 3/4" npt adapter to 1" barbed fitting. Ran a new silicone hose to air compressor.

Ordered a mishimoto J Line intercooler. It's 29" long and 7.5" tall, 4" wide. It can handle 40psi and or 500hp. Plenty for what im looking to do.

The C channel that holds the intercooler wasn't tall enough to hold the intercooler so I cut a relief in the top of the C-channel. Then used a 2" hole saw and then a Sawzall to cut the front panel out. Painted it up. Put 1/8" rubber pads under the intercooler for padding so it doesn't rub and then a gasket around the top where the intercooler drops in so it doesn't rub on the edges.

The intercooler has 2.5" inlet and outlet. So I got 2.5"-3.5" silicone adapters for either side of intercooler. I got red for hot side, blue for cold side.

I got a 3.5" 90 degree intercooler pipe for passenger side, a 3.5" 6" long cac silicone adapter and connected to 1-18" long intercooler straight pipe to the 90 coming off turbo. Cold side has a tight 90 degree meeting to a cac adapter. Then cut down a 18" intercooler pipe to a 45" silicone hose. The remainder of the 2nd-18" pipe connects to the n14 intake.

Just need some more clamps to finish it all up. Should be ready to fire up Monday.
 

Attachments

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
Ordered 7 new 395s. All balanced with beadlocks. Going to be adding to the truck tomorrow. Should make a big difference with power, egts, less weight, and less wear and tear.

Once project is done I'll post some videos of truck running and see what the performance gains are.
 

Attachments

Last edited:

hethead

Active member
153
227
43
Location
Seattle, WA.
I like that intercooler. I plan to put one on mine and that's a good size (for about 300 hp and 15 psi of boost). I look forward to hearing how it works for you. I have stock injectors with a turbo and a little over 200 psi out of the pump and set it to go up to about 23-2400 rpm to help with the 3-4 shift pulling a load on my 809. I also run the 395s and love them. They ride great and do pretty good off road.
 

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
I like that intercooler. I plan to put one on mine and that's a good size (for about 300 hp and 15 psi of boost). I look forward to hearing how it works for you. I have stock injectors with a turbo and a little over 200 psi out of the pump and set it to go up to about 23-2400 rpm to help with the 3-4 shift pulling a load on my 809. I also run the 395s and love them. They ride great and do pretty good off road.
Nice build hethead! I know the intercooler can't hurt anything, only help. I took a more conservative approach on fuel but the larger injectors will help some, that's on the list soon.
 

hethead

Active member
153
227
43
Location
Seattle, WA.
Well, higher flow injectors are the smart way to go. (as opposed to just a pressure increase). It's "squirting more fuel through a small nozzle" that strains the cam/lifters. I'll probably only put 200k on this truck so I'm not too worried, like an over the road driver would be. I imagine you have a pyro. I try to keep it under 1000 degrees pre turbo, which is pretty conservative. Some guys run em up to 1200. I plan to add meth injection for the long pulls eventually too. I don't want to be pulling liners! I only want to keep it around 300 hp and I like the high compression pistons for cold weather starting. I think I'll be good with out piston cooling at that hp.
 

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
Well, higher flow injectors are the smart way to go. (as opposed to just a pressure increase). It's "squirting more fuel through a small nozzle" that strains the cam/lifters. I'll probably only put 200k on this truck so I'm not too worried, like an over the road driver would be. I imagine you have a pyro. I try to keep it under 1000 degrees pre turbo, which is pretty conservative. Some guys run em up to 1200. I plan to add meth injection for the long pulls eventually too. I don't want to be pulling liners! I only want to keep it around 300 hp and I like the high compression pistons for cold weather starting. I think I'll be good with out piston cooling at that hp.
I'm running a #27 button built by premco and the injectors to match at 10% overs. Warren from Premco said with my goals that this will keep the engine well within the safe zone. Im running 750 to 800 degrees egt in #6 cylinder. Going to smaller tires and the intercooler will drop temps even more from the 16r20s. In guessing I'll drop another 100 degrees or so on exhaust temps with 395s. I have methanol injection on the truck as well. Snow performance kit. I went with the turbo mostly for cooler temps; the sound and a little more power are just added benefits. If I decide to turn up in the future I'll have the room to do so.

I'm impressed with how much quieter the truck is with no muffler. Granted the exhaust is 15" above the cab now but that made a big difference. I get more noise from the tires than the engine now.
 

hethead

Active member
153
227
43
Location
Seattle, WA.
I'm running a #27 button built by premco and the injectors to match at 10% overs. Warren from Premco said with my goals that this will keep the engine well within the safe zone. Im running 750 to 800 degrees egt in #6 cylinder. Going to smaller tires and the intercooler will drop temps even more from the 16r20s. In guessing I'll drop another 100 degrees or so on exhaust temps with 395s. I have methanol injection on the truck as well. Snow performance kit. I went with the turbo mostly for cooler temps; the sound and a little more power are just added benefits. If I decide to turn up in the future I'll have the room to do so.

I'm impressed with how much quieter the truck is with no muffler. Granted the exhaust is 15" above the cab now but that made a big difference. I get more noise from the tires than the engine now.
You sound like you have a pretty reliable set up and Warren has a great reputation for knowing how to tune 855's. I ran mine with no turbo and a straight pipe stack for a short while (muffler had rusted out), and damn that was loud. The turbo is a great muffler. I look forward to hearing about that intercooler's performance. I looked up their site and that might be what I end up using.
 

muthkw25

Well-known member
Steel Soldiers Supporter
510
668
93
Location
Sayre, PA
I took the truck out today for first test drive. Lots of data collected.

1) Truck feels so much lighter. The steering, the ride quality and tire noise dropped dramatically. The brand new tires was a huge bonus. Highly recommend anyone with these trucks to get new tires. Having them balanced is also a bonus. Huge thank you to MVpartsstore for helping me out with the tires and rims.

2) Truck lost road speed. This was a given going to a smaller tire. Truck now at 1900rpms is doing 60mph. With 53" I was doing 68 to 70.

3) Truck feels like I just added 100hp. I gained alot of torque going back to a smaller tire which was expected just didn't expect that large of an increase.

4) Boost went down. Before I could hit 12lbs of boost. Now I'm hitting a max of 10lbs when in 5 th gear pulling a hill. The boost went down overall. However, I'm able to fly up hills now and maintain speed easily. Once in 5th gear climbing hills and boost kicks in it feels like I'm being pushed up the hills. This is still before the injectors being done. Hopefully with the 10% overs I'll gain a little more power.

5) Fuel pressure numbers. When the trucks really working, highest I saw was 170 to 175psi. Not huge but more than I expected it to be at. Larger injectors will drop this a little bit according to Warren at Premco.

6) Intercooler is working well. No issues with the intercooler. I'm sure the 22F the truck loved it. Gotta love boost weather.

7) EGTs saw a dramatic decrease. Trucks temps dropped more now going to the smaller tire. At 55mph I'm at 600F in #6 cylinder. On hills with foot in the throttle highest I saw was 750F to 800F. If I'm on the flats the temps drop even more. Trucks temps have dropped 400F+!!! That's massive. Anyone looking for lower temps, turbo the truck you won't regret it.

8) Braking has significantly improved. Very obvious from 16r20s to 395s.

Overall this is a huge win. The truck is running incredible. The gains from turboing the truck are worth every penny. The cab is significantly quieter now with the smaller tires as well. I could listen to music with a soundbar and be comfortable.

Anyone looking to turbo just start working on parts. You'll never go back.
 

Attachments

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