Go with what you know and get that rascal to BTS. Worry about the rest later. Good thing it's not your daily driver now but still gotta get it there to cash in on that sweet deal.

On a side note, how long was that other turbo on there, miles, months?

 

Man, sorry to hear about the turbo issue, Jeremy. Good thing you've got a spare already, but still... sucks. Hope you get it swapped or tightened or whichever you decide without too much trouble.


Haha, I did a bit more today... after pulling out of a station after refueling, I got on it pretty hard up to 55 and OH MY LORD it pulls hard. This was in the 80 setting... really blew the old SCMT 1700 away, big time. The shifting is great still... really looking forward to the valve body.

/multitopic-hijack-discussion

 

I may try to swap the turbo tonight. I've got to sit through another continuing ed class today, and I don't know how long it will last. If I can get home early enough, I'll start on it tonight.

That turbo has only been on there for about two weeks. I made one long trip with it last weekend, but that's about it. Probably not more than 600 miles on the turbo, but I know for sure it's less than 1000.

 

how many lbs. of fuel pressure do you think the OEM (plastic) fuel filter cover will hold?

 

I would be hesitant to push it past 70-75 psi with the stock fuel bowl still in place.

Different note, but still part of this thread, the truck turbo is back in. Running well. There was a bit of damage, but not much. I'll start a new thread about it.

 

what are you using instead of the stock fuel bowl then????

 

It's an aluminum Y-fuel block. There are some pics of it at the bottom of my fuel system gallery. Also, see this thread for all the info about it: https://www.ford-trucks.com/forums/s...d.php?t=490094

 

Did a little more driving over the last couple of days. Maybe it's in my head, but it feels like the truck sure is funning better with the increase in fuel pressure at boost. It seems to pull a little harder, and it almost feels like the turbo is spooling just a tick faster. I'll be able to tell a lot more on the 4 hour drive down to BTS tomorrow. There's some pretty good hills on the way down there, and a lot of highway cruise time where I can play around.

 

OK. Below is word-for-word what Dennis at ITP had to say about using the port. I think you really need to put an emergency fuel pump shutoff switch right on the dash if you're going to keep the setup.

"It is a boost reference port for use on gassers, increases fuel pressure 1psi for every 1psi of boost. Problem is that it will increase the fuel pressure on a PSD too much. If the starting pressure is 65 and you make 25psi of boost, that's 90psi of fuel pressure. For one, that way too much and totally unnecessary...the truck won't make any more power and it's hard on the fuel pump.
The other side is that if the diaphragm in the regulator ever fails, it will dump diesel fuel into the MAP hose, which will dump into the intake...and you could have a runaway (extremely dangerous).

I STRONGLY RECOMMEND NOT DOING THIS!"

 

Reasonable. It's better to err on the side of caution.

I think that is a situation that could be easily avoided by a simple mechanical check valve. Possibly something like THIS.

As far as "too much and totally unnecessary" and "the truck won't make any more power"....I think that is arguable at this point. At least two of our members have reported at least a percieved gain, if not actually measured.

 

Wouldn't this stop the boost pressure from returning to the intake and cause your fuel pressure to stay high?

 

Simply turning off the ignition would stop the fuel pump from running.
There would still be plenty of diesel fuel running into the runaway engine.
I've never seen one, but have read about devices that cut off the air intake somehow to stop a runaway diesel engine. They are required on oil field trucks and possibly tanker trucks as well. Probably something like a throttle body that closes in an emergency.

 

I believe that was the purpose of the "experiment". Nobody has offered any hard numbers on this so therefore it remains theory. I know too low of a pressure results in poor performance and somewhere in there is an optimum number. If big oil and injectors is the answer for more HP, then why wouldn't pumping up the volume on the stockers net results? A few dyno runs can settle something like this.

As you stuff more air (boost) into the cylinders, how can one expect the same injector cycle and PSI level to keep up for an optimum mixture? While the reg may be designed for gassers, that is what that reference port is for, to compensate.

As for the increased load on the pump, it's not a continuous one as we don't drive around at 20+ PSI for very long as something else is likely to fail before the pump would in my opinion.

I think this is an excellent experiment and look forward to more results from JT. As for concerns over failure of the reference port diaghram, I think Aeromotive would be the folks to take that up with. I've dealt with Dennis before and he is a great guy, but has he offered any evidence of this failure theory?

 

I just wanted JT to know about the potential for disaster. Maybe he hadn't considered what would happen during a regulator failure. I've found it is much better to go through disaster scenarios in your mind before you are forced to think them through in a fraction of a second!

 

Thanks for letting me know. I had actually thought about that, but I'm not too concerned with the regulator failing. Has anyone actually heard of a regulator failing? Worse case scenerio, I turn the key off. Upon further driving, I feel like it's helping the performance of the truck. On the trip down to BTS, where I could evaluate it before some major changes, the truck felt strong when the boost came on.

I also noticed something else on the way home from BTS. The fuel pressure would not go above 80 psi. I'm going to check for a boost leak around the hose, and possibly get a smaller, tighter fitting hose to be sure there are no boost leaks. But, I'm thinking that the stock fuel pump just can't deliver any more fuel. Not that it's not capable of higher pressure, but at high RPM the injectors are using enough fuel that the pressure doesn't go any higher. It confuses me though, because I've seen higher on the first drive after I put the line on.

Also, I talked to Cale about it while at BTS. He mentioned several other guys are doing it, and he's seen it before. Remember that Jody also didn't see a problem with it. I would think that if there were a huge problem with doing this, one of the two, Jody or BTS, would have stopped me in my tracks.