Mid 20s boost IDI !
- Thread starter 77f250diesel
- Start date
Dave Sponaugle
Registered User
That depends on how I run it.
Normally I am towing or hauling something, my yearly MPG average is around 11.5.
But a couple days plowing snow with MPG numbers around 3 or 4 sure do drag the yearly averages down fast.
Towing in the 20,000 pound range I usually see around 8 MPG.
Normal average MPG per fill up is usually close to 12 MPG, but I carry 66 gallons of fuel.
Truck full of fuel without me in it weighs 8000 pounds.
Rather large frontal area since I am running 33" tires, have a 2" body lift, have west coast mirrors and a flatbed dump.
All of those are dropping my MPG, but they are tools I use every day except the body lift.
That was to make room for the 3" down pipe.
As far as turbo boost, the other day I was driving up a long grade at low RPM in high gear.
Traffic in front of me cleared so I just mashed the throttle at 1000 RPM.
By a bit over 1100 RPM the boost was passing 6 PSI rather fast.
By 1500 it was going past 12 PSI rather fast.
AT 2000 RPM just under 19 as near as I could tell.
70 MPH is 2500 RPM for me, so a drive on the interstate sees boost numbers between 5 PSI going downhill to 22 going uphill.
What we consider flat ground here sees boost numbers around 15 PSI at 70 MPH.
In 2006 when I built that engine, my operating expense that year was 68.3 cents per mile.
Not bad considering there was 4000 dollars worth of engine work in that number.
Granted it would have been a lot higher if I had not done most of the work myself.
I am very pleased with the results, I had not built an engine since 1986 and that was a 396 for one of my oldest friends at home.
Right now I am around 40,000 total miles on the rebuild, so I have more miles on this one running 3 times as much boost as I saw out of all of the 7.3 re mans.
I will say the way it runs on these very cold mornings we are having now is making me look at an inter cooler harder.
I may have to loose the AC so I can mount it high on the radiator is the best I can see right now though.
The best part about doing an old engine, I am very happy that I can take a 22 year old engine, the one that started diesels in pickups and run right with any of the new stuff.
I will be the first to admit that there are faster trucks out there.
There are trucks that will pull more.
But I also realize they have a lot more money it what they are running and break downs cost a lot more for them to fix.
One of my friends just paid 8000 dollars for a new set of injectors installed in his Duramax.
I can build two motors for that much money.
I will never run a sleeved motor in my truck again.
The only thing wrong with the 6.9 motor that was produced in late 85, all of 86 and all of 87 was the head bolts.
That can be corrected with a set of head studs.
It is a dependable motor, if I am not at home I am in my truck.
It runs every day, sometimes all day every day.
I would not think twice about driving it to Alaska if I had to go there, change the oil and let's go.
I do run synthetic oil, and it does get changed every 3000 miles, religiously.
Normally I am towing or hauling something, my yearly MPG average is around 11.5.
But a couple days plowing snow with MPG numbers around 3 or 4 sure do drag the yearly averages down fast.
Towing in the 20,000 pound range I usually see around 8 MPG.
Normal average MPG per fill up is usually close to 12 MPG, but I carry 66 gallons of fuel.
Truck full of fuel without me in it weighs 8000 pounds.
Rather large frontal area since I am running 33" tires, have a 2" body lift, have west coast mirrors and a flatbed dump.
All of those are dropping my MPG, but they are tools I use every day except the body lift.
That was to make room for the 3" down pipe.
As far as turbo boost, the other day I was driving up a long grade at low RPM in high gear.
Traffic in front of me cleared so I just mashed the throttle at 1000 RPM.
By a bit over 1100 RPM the boost was passing 6 PSI rather fast.
By 1500 it was going past 12 PSI rather fast.
AT 2000 RPM just under 19 as near as I could tell.
70 MPH is 2500 RPM for me, so a drive on the interstate sees boost numbers between 5 PSI going downhill to 22 going uphill.
What we consider flat ground here sees boost numbers around 15 PSI at 70 MPH.
In 2006 when I built that engine, my operating expense that year was 68.3 cents per mile.
Not bad considering there was 4000 dollars worth of engine work in that number.
Granted it would have been a lot higher if I had not done most of the work myself.
I am very pleased with the results, I had not built an engine since 1986 and that was a 396 for one of my oldest friends at home.
Right now I am around 40,000 total miles on the rebuild, so I have more miles on this one running 3 times as much boost as I saw out of all of the 7.3 re mans.
I will say the way it runs on these very cold mornings we are having now is making me look at an inter cooler harder.
I may have to loose the AC so I can mount it high on the radiator is the best I can see right now though.
The best part about doing an old engine, I am very happy that I can take a 22 year old engine, the one that started diesels in pickups and run right with any of the new stuff.
I will be the first to admit that there are faster trucks out there.
There are trucks that will pull more.
But I also realize they have a lot more money it what they are running and break downs cost a lot more for them to fix.
One of my friends just paid 8000 dollars for a new set of injectors installed in his Duramax.
I can build two motors for that much money.
I will never run a sleeved motor in my truck again.
The only thing wrong with the 6.9 motor that was produced in late 85, all of 86 and all of 87 was the head bolts.
That can be corrected with a set of head studs.
It is a dependable motor, if I am not at home I am in my truck.
It runs every day, sometimes all day every day.
I would not think twice about driving it to Alaska if I had to go there, change the oil and let's go.
I do run synthetic oil, and it does get changed every 3000 miles, religiously.
dave-
I have a ATS "half height" kit on my '92 and still have my AC. I do need to put in aux fans for the condenser since the airflow has impaired the R134 system to the point where I popped my safeties on the compressor in 110 deg Brastow, Ca heat. I am working on moving the condenser in front of a full height IC off a 7.3 PSD, so if you're willing to wait, I can be the lab rat for the project
I have a ATS "half height" kit on my '92 and still have my AC. I do need to put in aux fans for the condenser since the airflow has impaired the R134 system to the point where I popped my safeties on the compressor in 110 deg Brastow, Ca heat. I am working on moving the condenser in front of a full height IC off a 7.3 PSD, so if you're willing to wait, I can be the lab rat for the project
Dave Sponaugle
Registered User
OK look at this for what I have on my 86.
I am running a Snoway plow.
There is a 1/2" thick steel plate that wraps around the ends of my frame horns and goes down about 8" below the bottom of the bumper.
That plate also runs from side to side to the outside of the frame on both ends
The lower mount bracket than bolts to that steel plate.
No direct air flow to anything from the bumper top to the bottom of the radiator.
If I ever T bone someone, I pitty them.
I am running a Snoway plow.
There is a 1/2" thick steel plate that wraps around the ends of my frame horns and goes down about 8" below the bottom of the bumper.
That plate also runs from side to side to the outside of the frame on both ends
The lower mount bracket than bolts to that steel plate.
No direct air flow to anything from the bumper top to the bottom of the radiator.
If I ever T bone someone, I pitty them.
jimraelee
Full Access Member
Ordinarly Id think your added and extra ZERO on that figure, but I was talking to a neighboor,shortly after I got my truck. He said that his work truck Cummins just got back from teh dealer... it was hard to start and keep runing... neighbours boss told the dealer to keep it under $10k for repairs... well they passed up that number and was approaching $22k when the finally got it to run good... the shop and the stealership did come to a commong price, but it was still outragious.
Dave Sponaugle
Registered User
I have to say that repair was a warranty covered item.
But that was the number on the bottom of the bill in round numbers.
I have no idea what it takes to install a Duramax injector or how much they are.
But even at today's shop rates....1000 dollars an injector...that is ridiculous.
But as soon as I say that, I also realize that a lot of the new trucks have to have the cab lifted up to even see the engine and all the injectors or where they are installed.
I can't imagine anyone trying to do an engine swap in a 99 or later Stroke in a home shop.
I am sure there are people that do, but I don't think I want any part of it.
But that was the number on the bottom of the bill in round numbers.
I have no idea what it takes to install a Duramax injector or how much they are.
But even at today's shop rates....1000 dollars an injector...that is ridiculous.
But as soon as I say that, I also realize that a lot of the new trucks have to have the cab lifted up to even see the engine and all the injectors or where they are installed.
I can't imagine anyone trying to do an engine swap in a 99 or later Stroke in a home shop.
I am sure there are people that do, but I don't think I want any part of it.
Diesel JD
Full Access Member
The thing is that if you want a diesel you better have deep pockets, have something you can work on yourself, or get a new one as soon as its out of factory warranty. Most diesel shops around here are charging $80-90 an hour, at that rate, it real easy to run up a $500 bill in labor alone. I can do most work on my IDI myself, and 90% of what I can't do, my mechanic friend will do in sidework at a much lower price. I wouldn't know what to do aside from oil changes and filter maintenance on one of these really new trucks. I could figure out hardware and software on a 94-97 PSD and might sometime, but there is the learning curve...
gamudslinger88
Full Access Member
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I have a friend who had a psd with 1 bad injector, sent it to the stealership shop and they said 1300 to replace one injector, He traded his in for a new cummins at the dodge dealership across the street. I like the price of our idi's more and more each time I look at buying stuff for mine.
redneckaggie
rebel w/o a cause
I had a friend who just took his 97 psd to the shop(he used to be a top notch mechanic but swore off of touchin "that computerized bulshitt" in his words) the mechanic replaced all of the injector wiring, cranked it up and still knockin, checked the camshaft sensor said it was shorted out and fried the computer. all in all the summary of the bill goes somethin like this
new cam shaft sensor
new injector wiring
new computer
new mech fuel pump
total bill-$4500 or $5000
and we are good friends with the mechanic that did it and he gave us really good rates
my moms 94 psd started doing the same thing and we just went and bought another ford idi for $2500
ain't had a single problem out of it
new cam shaft sensor
new injector wiring
new computer
new mech fuel pump
total bill-$4500 or $5000
and we are good friends with the mechanic that did it and he gave us really good rates
my moms 94 psd started doing the same thing and we just went and bought another ford idi for $2500
ain't had a single problem out of it
sootman73
Registered User
dave its great to see someone embrace these idi's. it makes me even prouder to show all my gm counterpart buddies that the ford idi's can hold their own even next to their electronic 6.5l's love it! it would be really nice if you could get some videos to see how she moves and sounds! either way great truck!
Greenbeast6.9
grease monkey
You guys are crazy! First off i have not seen any IDI that will take a OBS PSD in a drag, ever. Second I have less than $1000 in the motor of my OBS, I have put a chip in it and injectors that i did myself. Its not that hard to work on the new stuff if you do a little reading. I bought my 97 for $9000, and i love it! Now I'm not saying that modding the old IDI will get you no where, but it will take lots of R&D and motors to get a reliable one. Good luck to you! 
P.S i just want to say that i love my IDI, Its just not a platform to start with if pure power is in mind.
gamudslinger88
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I never said I didnt like them just that they are expenssive to work on, nice but expensive.
Uh ya, now I am considering a 6.9 with 9/16" studs......for the next engine.......
Dave Sponaugle
Registered User
If I want to drag race I have a 1973 Kawasaki Z1 punched out to 1127cc and built as a drag bike.
It weighs 485 pounds and has 150 HP, much better drag racer than my 8000 pound truck would be unless it was up in the 2600 HP range which is even far outside what any of the new engines are capable of in a streetable version.
However, if I have 3 or 4 tons of stone or dirt to move a few miles, my truck is my vehicle of choice, it is much better at that job.
I don't do burn outs, I don't speed shift because I already stress or break enough parts in the driveline.
I use it to haul weight, get me off road and plow snow, that is what it was built to do.
My mods over the years have increased those capabilities.
With 3.55 gears and 33" tires with a four speed tranny, 70 MPH is about as fast as I want to run, faster starts to get expensive fast with todays fuel prices.
Back in the 70's and early 80's I was an over the road meat hauler.
I have already spent more time in a truck running insane speeds than a person should and live to tell about it.
1984 on the Indiana Toll Road running close to 100 MPH with a load of swinging meat on what turned out to be Black Ice was the end of that career for me.
Missed ramming the rear of a freight hauler trailer running 35 MPH by less than 6".
I finished that round from Denver to NYC and back, when I got out of the truck I never got back in one again.
That was as close to dying as I ever want to get because of stupid stuff like delivery schedules made by someone sitting behind a nice safe desk talking on a phone all day while I was out there driving trying to keep up with their phone calls.
The only good things I can say about those days were I saw the USA, all of it from the interstate at 80 or 90 or 100 MPH.
I also learned a few things about making diesels go fast, make good power and be dependable.
Many of the tricks I used in my engine were adapted from what we did in those days on the big ones.
Air is the key, you need lots of air in, lots of air out.
There is no way you can ever get to much air though a diesel engine.
Air does two things, it makes the fuel burn and it carries heat out of the engine.
The first increases the power, the second makes the engine live longer.
After you have all the air you can get, start increasing the fuel.
Injection timing is another place to get power.
What is mine set at, I don't know, but it sounds right and it runs right.
That is just another place that numbers don't mean much to me.
How did I set it, adjust it and drive it.
Listen to the sound, watch the water and oil temp, watch the pyrometer, watch the boost gauge and how does it feel in the seat of your pants.
But also I have been running and listening to diesels since I started driving one of the family diesel tractors back in 1964, a Massey Ferguson 50 with a Perkins diesel.
Black smoke has been in my blood for 44 years and since fuel was 9 cents per gallon.
It weighs 485 pounds and has 150 HP, much better drag racer than my 8000 pound truck would be unless it was up in the 2600 HP range which is even far outside what any of the new engines are capable of in a streetable version.
However, if I have 3 or 4 tons of stone or dirt to move a few miles, my truck is my vehicle of choice, it is much better at that job.
I don't do burn outs, I don't speed shift because I already stress or break enough parts in the driveline.
I use it to haul weight, get me off road and plow snow, that is what it was built to do.
My mods over the years have increased those capabilities.
With 3.55 gears and 33" tires with a four speed tranny, 70 MPH is about as fast as I want to run, faster starts to get expensive fast with todays fuel prices.
Back in the 70's and early 80's I was an over the road meat hauler.
I have already spent more time in a truck running insane speeds than a person should and live to tell about it.
1984 on the Indiana Toll Road running close to 100 MPH with a load of swinging meat on what turned out to be Black Ice was the end of that career for me.
Missed ramming the rear of a freight hauler trailer running 35 MPH by less than 6".
I finished that round from Denver to NYC and back, when I got out of the truck I never got back in one again.
That was as close to dying as I ever want to get because of stupid stuff like delivery schedules made by someone sitting behind a nice safe desk talking on a phone all day while I was out there driving trying to keep up with their phone calls.
The only good things I can say about those days were I saw the USA, all of it from the interstate at 80 or 90 or 100 MPH.
I also learned a few things about making diesels go fast, make good power and be dependable.
Many of the tricks I used in my engine were adapted from what we did in those days on the big ones.
Air is the key, you need lots of air in, lots of air out.
There is no way you can ever get to much air though a diesel engine.
Air does two things, it makes the fuel burn and it carries heat out of the engine.
The first increases the power, the second makes the engine live longer.
After you have all the air you can get, start increasing the fuel.
Injection timing is another place to get power.
What is mine set at, I don't know, but it sounds right and it runs right.
That is just another place that numbers don't mean much to me.
How did I set it, adjust it and drive it.
Listen to the sound, watch the water and oil temp, watch the pyrometer, watch the boost gauge and how does it feel in the seat of your pants.
But also I have been running and listening to diesels since I started driving one of the family diesel tractors back in 1964, a Massey Ferguson 50 with a Perkins diesel.
Black smoke has been in my blood for 44 years and since fuel was 9 cents per gallon.
sootman73
Registered User
wow thats a great story! i love hearing about what it was like before my time. 
course im not sayin ur old, im just young. i have great respect for those who have worked hard for what they have. they have made it possible for me to be where i am today.
100 mph in a semi? thats amazing. didn't know you guys ran that fast that long ago! that def takes some balls!
course im not sayin ur old, im just young. i have great respect for those who have worked hard for what they have. they have made it possible for me to be where i am today. 100 mph in a semi? thats amazing. didn't know you guys ran that fast that long ago! that def takes some balls!
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