i got a 91 f-250 4x4 super cab and i want to know if any one here has put any custom turbos on there 7.3 or 6.9 im not talking no bolt on kit i mean complete fab and custom job i got 2 garrett tp-38's off 94.5 power stroke want to twin my 7.3 i mounted the turbos under the floor pans and im pluming oil from the oil pressure sender im wondering if the exaust from 4 cylinders is enugh to spool up that tp-38 and people are telling me that it going to be to much pipe from the turbo to the intake but i think it shouldent mater how much pipe there is it all sealed and the pressure should be the same everywere if anyone has tryed any thing like this i woul like your input im in the middle of this project and i want to make it work

 

Vintage super duty,
Welcome to FTE and the IDI forum.

I have seen a couple guys that did a single Power Stroke turbo install on an IDI motor. They did fab up the required piping to make it work.
I know one of them blew the head gaskets out of his engine, the other did even more damage if I remember right.

The more pipe you have, the more area you have to build pressure in before it makes boost. (turbo lag)
This also applies to both pipes, intake and exhaust.

How are you getting the oil back into the oil pan?

You are only going to have 1/2 the exhaust flow the turbo needs to spool up correctly, so the boost produced will be low.
This will probably be good though, the heads may stay on it longer.

A Power Stroke motor has 18 to 1 compression ratio.
The 7.3 IDI has 21.5 to 1.
A 6.9 has 22.5 to 1.

The low compression ratio is how the Power Stroke can run 30 PSI boost.
On a 7.3 IDI your head gaskets are in danger at anything over 15 PSI with stock head bolts.

I built my 6.9 last summer with the intention of running more boost.
I milled the pistons down and dropped the stock 22.5 to 1 compression ratio of my 6.9 down to 20.25 to 1.
Milling the pistons down does create a cold start issue, the more you mill them down the harder it starts at low temps.

Then I used ARP head studs to keep the head gaskets in place.

Everything was working great, till I was racing up a hill on morning and blew the intake manifold gasket out. Tear the motor top off again, replace the valley pan which i sprayed with copper gasket maker several times on each side. Then I replace the intake manifold bolts with grade 8 bolts and doubled the torque on them.
I also noticed I had blown an exhaust manifold gasket, so I replaced them and gave them the same treatment I gave the valley pan.

Now I am reliably running boost numbers in the 20's.

All that with an ATS single turbo for an IDI motor.

There is more to turbocharging a diesel than just bolting on a turbo or two or three.

For what it is worth, I am running an effective compression ratio after figuring in the boost and base compression ratio that is higher than a Power Stroke motor is running 30 PSI of boost.

Not bad for 21 year old diesel technology with a few tweeks.
And it has bitten a few Power Strokes and Cummins diesels.

 

hey dave any dyno numbers?

 

I've also been collecting parts to build a remote mount single turbo. I am planing on using a single turbo from a 2000 powerstroke. For the oil I am going to run its own oil pump/reservoir off the front of the motor using a power steering pump with a pressure relief valve to keep the oil pressure below 40psi. Too much will blow the seals. I will use synthetic oil due to the small reservoir to keep good lubricating properties. I am told that the lag from remote turbos are minimal because of the large volume of air a turbo moves. (The volume of the pressure tubing between the turbo and the intake is usually less than the volume of air used by 1 or 2 revelutions of the engine)
The most important thing to remember when experimenting with turbo setups is use gauges. Make sure you have a pyrometer to keep an eye on the exhaust temp. Too high and your engine is ruined. And a boost gauge. Too much boost and you'll loose head gaskets, intake gaskets or worse. You should be able to turn down the boost with the use of the waste gate actuator.
It takes a lot of parts, patience, research and fabricating to do a project like this and it can end up only being educating and expensive when all is said and done.
Good luck.

 

No dyno numbers yet, the last time I could have done a dyno run it had under 500 miles on the engine.
There was no way I was going to run it that hard till I had it at least partly broken in.

I would like to know what it is able to do, but I can say it is enough for me right now.

 

you wont have much luck keeping that engine together once you get it done. those engines are not made for turbos and they do not stand up to much boost at all. but good luck

 

Jonboy,
I just re read your post and one thing did jump out at me.

You are going to be running very hot oil through the turbo after a very short distance.

 

Mr Dave Spougle could you send me a email or pm telling me about how you were able to put around 20lbs of post. I have been wanting to put more than 10-12 lbs of boost on my truck. I have a 6.9L 1984 F-250 4x4 w/ a C6. I love to drive it and couldn't be prouder of it but i was wondering what i could do to get some more power. The only thing i could think about was the ats turbo kit and propane injection. My dad thinks that would be too much. So if you could help me out that would be great. It seems as if i could model my engine somewhat similair to yours. PS i live in arizona and we do not have many cold days so i wouldn't think it would be to hard to start most of the time and if it does would a block heater do the trick.

 

I have to second what second what Dave said about the hot oil. I don't have the reputation or experience dave has but I've got some and read alot.
I hope your plans include a good oil cooler (probably a water to oil would be best, but maby a big tranny cooler?) The engine obviously has very large oil capacity to dilute hot oil comming out of the turbo and the colant works to disapate the oil's heat as well as the combustion heat. On my turbo diesel volvo there is a water to oil cooler even with the turbo sharing the engine oil.
Dave McGuire

 

I've thought about that myself. I will definitely run something for an oil cooler, but i'm not sure it is going to be quite as bad as you may think. For one thing, with the turbo mounted farther away from the exhaust, it stays cooler and spins somewhat slower than a typical setup. (that is why I chose a model that normally would make more boost than I would want since it won't make its full potential where I will mount it)Also the oil is going to have to travel through about ten feet of tubing from the pump to the turbo and then ten feet back. Using 3/8" steel "brake" tubing, I can easily ad coils to add lenghth. The distance of travel must add some amount of heat displacement. It also ads to the volume of oil. Another thing to think about is the lubricating properties of synthetic oil. Let me share an example with you. I have some experience with commercial zero turn mowers. They have hydraulics that run all the movement of the machines, plus various other "things". On an older machine I had, the hydraulic resevoir held 12 quarts of 10w-40 traditional motor oil. The reason for the volume is to cool things down and maintain viscosity. On a newer version that I have now I can only run 15w-40 synthetic oil. The resivoir holds 2 quarts! And with 3200hrs on this machine and zero hydraulic problems, I am a believer.
Sorry for the long post. Let me know what you think though.

 

howdy, i am new to this turbo world, please let me know if I'm wrong here. A turbo has pressure in both the exhaust turbine side and the compressor side. The seals on those are reverse to prevent blow by into the shaft/oil cavity. As engin rpm increases, thus oil pressure increases, as does boost and exhaust pressure(in the housing itself). I thought that is why the turbos are mounted on top of the motor, or at least above oil pan level, so that oil can be pumped up to it, then with relative low pressure, fall back to the pan. I also beleive in synthetics. love this site. Great info and seems to have very knowledgable and helpfull users.

 

jonboy where are you mounting yours i changed my mind im only going with one now puting it under the passenger floor pan so im looking at about 6 to 7 feet of pipe to the intake

 

turboman24,
Read post #10 in this thread.
https://www.ford-trucks.com/forums/5...ur-engine.html

The 84 block was discussed several posts below my first post in that thread.

Jonboy,
I still think you better plan for an oil cooler, the turbo will still be seeing exhaust gas temps well above what even synthetic oil can handle.
I used header wrap to keep as much heat as possible in my exhaust between the exhaust manifolds and turbo to increase the boost level a bit higher.
After installing several layers of wrap, the exhaust temp at the turbo is almost the same as it is in the exhaust manifold.
The oil does absorb a good amount of heat from the turbo.
And thermal breakdown of the oil is still a factor in synthetic oil.

I do use synthetic oil in my engine, worth every penny it costs in my opinion.

 

I'll have to check to see if there are provisions on my radiator for a auto trans. oil cooler. Since I have a manual they would be unused if they are there. Those would make a pretty nice and rather easy oil cooler.
Dave, I read that post. Your motor is inspiring to say the least. And trust me, if my experiment works, I'll be keeping my boost rather low. I know 83 wasn't the greatest year for the 6.9
And vintage super duty, I decided under the driver side floor board is the best place. Originally I was going to use the pass. side, but it is pretty tight there. I don't have my front fuel tank any more, and since the driveshaft is offset to the pass side, the divers side looked too tempting to pass up.