Turbo boost hits 15 psi plus

[cranetruck]

During a 10-mile test drive today, the turbo boost gauge pegged out at 15 psi. Before FDC bypass, the max reading had been 12 psi or so.
The turbo was really wipping the boost gauge needle around, never saw it respond so quickly.

The FDC was bypassed the other day and the unit itself replaced with one from a parts engine. The stop block is frozen in the "gasoline/start" position, all the way down.

It was the first time in a long while I have driven the deuce empty (16,500 lb). Lots of Fun! Would feel even better if the engine knock was taken care of.

Image shows deuce with bypassed FDC.

 

[ken]

Was the turbo surging? or was it able to produce 15PSI constantly?

 

[cranetruck]

Was the turbo surging? or was it able to produce 15PSI constantly?

No surging, it responded to my right foot.

 

[willysmd]

How do you boost the stock turbo sounds good, any drawings ?????

 

[bottleworks]

What were the pyro reading @ that much boost? Still good?

 

[cranetruck]

About 1,100 °F, I didn't stay long enough at the high boost to give the EGT a chance.
Shows how important the pyro and boost gauges are, easy to do damage with more fuel available.

 

[OpieNoTool]

On my duece with the "C" turbo and the pump turned up, nothing else, i run 10 psi at 2500 rpm @ 900 degrees but if your pullin a load or a hill the boost gauge will hit 16 and pyrometer gets up to 1100. No problems yet with 1200 miles on it since the turbo install. Knock on wood

 

[Djfreema]

I get 14-15 psi and dont go over 1200 without a load but as soon as I hit a decent hill with a load (10k on my last run), I keep the boost at 10 ps or under, otherwise the egt's start to go over 1200. I think the stock pump setting keeps everything right in the safe zone no matter what the load. A key to keeping the egt's down is not lugging the motor(like 1800 rpm or under), the higher the rpm the better.

 

[houdel]

I feel cheated. The best my "C" turbo will do is 8 PSI on a long uphill climb at about 1100-1200F on the pyro, fuel turned up 2 flats (1/6th turn). Any more fuel and the pyro gets up to 1250F.

 

[OPCOM]

Very nice boost figures Bjorn, do you get any black smoke when you do that?

 

[cranetruck]

I got a lot of blue smoke when I first hit the road after months of standing at idle and crane use. That would be unburned fuel, I guess. No black smoke and the amount of smoke tapered off during the drive. Really need a longer trip to "clean the pipes".

 

[FSBruva]

Bjorn-
Thank you for the caption about your truck. I thought something looked different, but I couldn't quite figure out what.... now I know it looks different with the FDC bypassed!!!

I was just looking back at an older thread in which ken pointed out that the seals in the turbo will let oil past them when run with low EGTs:

They have lybrinth seals in them (old tech). There is a small channel on the comperssor side that brings charge air to the lybrinth seal. This pressure counter acts the thrust and pressuizes the outer parts of the bearing housing. When you idle for long periods there is too low boost pressure and the oil can excape. After running it hard the oil that got out will be burned. This also restores the pressure and seals off the bearing housing

I get the same symptom (puffs of blue smoke, decreasing dramatically as I drive) if I have done even 5 minutes of idling.

Matt

 

[OPCOM]

looks like all fixed up for mothers day!

 

[alphadeltaromeo]

When I was driving with the semi on the back of the dolly for recovery, water temp reached 195 degrees right...surely wish I had installed a pyro and boost gauge so I could have seen how "chick" was performing. Purchasing those gauges will be on my hit list quite soon.

 

[yorkgulch2]

Pyrometer and boost gauges are next on my list too.

 

[builder77]

When I picked up my Deuce from Chambersburg it was was making some serious smoke and felt a little weak. It all went away after stretching her out a bit though. My parents were a little concerned following me though.

I noticed the same thing as OPCOM. With your truck parked in front of that bush it looks all dressed up. At first glance I thought you had wrapped a wreath around your crane like you had won a horse race or something.

 

[jimk]

I added the D turbo to the LD .Finally took it for test drive(s) last night. More power with almost no smoke (it used to have a long black tail). The gage shows 15psi+ at redline (15psi gage, FDC on line).Pyro ~900(postT) though needs more study. I turned the fuel down a bit, late, and will check it again today. The plan is to set the max. manifold pressure at 12psi.

New power steering, coolant filter, gages, intake elbow, battery box, low air buzz bypass, and stack muffler work very well.

Thanks [all] for the inspiration, and pioneering work. JimK

 

[houdel]

The plan is to set the max. manifold pressure at 12psi. JimK

Just how do you "set" the max manifold pressure? Isn't that determined by whatever the turbo decides to put out for pressure?

 

[jwaller]

The plan is to set the max. manifold pressure at 12psi. JimK

Just how do you "set" the max manifold pressure? Isn't that determined by whatever the turbo decides to put out for pressure?

yup and thats controlled on a diesel without wastegate (ie deuces) with the fuel delivery rate.

 

[houdel]

The plan is to set the max. manifold pressure at 12psi. JimK

Just how do you "set" the max manifold pressure? Isn't that determined by whatever the turbo decides to put out for pressure?

yup and thats controlled on a diesel without wastegate (ie deuces) with the fuel delivery rate.

My Deuce was pretty doggy, so I cranked up my fuel 1/2 turn (3 flats of the adjusting nut, one flat at a time, with pyro in place to make sure I didn't run too hot). Performance and starting improved, but the best I ever get out of my "C" turbo is about 8.5 PSI with EGTs in the 1150F-1200F range and a mild amount of black smoke on acceleration (smoke goes away as rpms build up). I since backed off 1/6 turn (one flat) on the fuel. Should I keep cranking up the fuel to get more boost?

I know EGTs go up with fuel delivery, but what about boost? It seems that increased boost should lower EGTs.