Boost on 6.9/7.3 idis

[94f350]

So on most boosted trucks the most I'll ever see is like 15 psi. What's stopping people from studding it, dropping the compression, and running higher psi numbers. I know it would be expensive but I'm just curious as to whether it's been done or not.

 

[Nero]

Money.

 

[hacked89]

So on most boosted trucks the most I'll ever see is like 15 psi. What's stopping people from studding it, dropping the compression, and running higher psi numbers. I know it would be expensive but I'm just curious as to whether it's been done or not.

There’s multiple trucks that can / are doing 35psi + without dropping compression. Mine included. Planned for 35psi @ 2800

 

[FrozenMerc]

It just comes down to money. After about 12 to 14 psi, you need to start upgrading the fuel system in order to take advantage of the extra air. With R&D, CD, and a few other vendors, there are many more options today for a high performance DB injection pump. Years ago, once you maxed out the stock pump, it required wheel barrel's full of cash to adapt a P-Pump or similar to provide the extra fuel.

 

[03wr250f]

There are tons of people doing exactly that.
Stud a 7.3 and it's good for 60psi+ with the proper turbo
Stud a 6.9 15ish psi max
Head studs are smaller on 6.9s otherwise time and money are the limits

 

[captain720]

There are tons of people doing exactly that.
Stud a 7.3 and it's good for 60psi+ with the proper turbo
Stud a 6.9 15ish psi max
Head studs are smaller on 6.9s otherwise time and money are the limits

I have heard of much higher numbers for a studded 6.9. The difference between 7/16th and 1/2 is 1/16th inch and that is substantial but it is not huge.

 

[Black dawg]

Nobody really knows what the limit is, just because it held whatever boost doesnt mean longevity hasnt been affected.......

lots of 7.3 turbo trucks out there been making 10-12psi for alot of years/miles, seems to be a safe recommendation. I personally feel comfortable 15psi long term. Have personally run one (non studded or intercooled 7.3)at 20psi and 11-1200egt for a whole tank of fuel+.......with many years around that truck afterwards and didnt see anything happen because of it. I am sure there were many more times it was worked that hard when I wasnt driving it.

I personally don't think these engines are worth getting too crazy with, for me they do a pretty good job at maxxed stock pump turboed levels.

 

[03wr250f]

I have heard of much higher numbers for a studded 6.9. The difference between 7/16th and 1/2 is 1/16th inch and that is substantial but it is not huge.

Yes I agree many have seen higher boost levels than 15 psi on 6.9s
How many have held the heads on long term for that?
As someone who has been around the forums and pages going on 12 years I have seen many people who will disagree with that, and end up lifting heads. I know of one 6.9 that is consistently hitting up to 22 psi. And he torque to yeilded his head studs. He did a whole write up on fte. Com about it. Bills crew cab. I don't recommend this to most people as he also has a engineering degree to his name.

That being said 1/16" is not much but in material thickness that is miles. As far as clamping ability of a fastener.

All this coming from someone who for a year and a half ran a non studded idi to 19 psi intercooled, WW2 and water m3th

 

[94f350]

There’s multiple trucks that can / are doing 35psi + without dropping compression. Mine included. Planned for 35psi @ 2800

Are you running studs on yours and is it a 7.3 or a 6.9?

 

[Austin86250]

I believe Justin’s stage 1 turbo is good for 35 ish psi with the right pump
Studded and intercooler of course,
A other limit is the rods somewhere in the 350-450 hp is where the n/a rods let’s go

 

[hacked89]

Are you running studs on yours and is it a 7.3 or a 6.9?

Studded and intercooled 7.3

 

[94f350]

Studded and intercooled 7.3

Is it reliable running a lot of boost? And how much was the cost of the build?

 

[hacked89]

Is it reliable running a lot of boost? And how much was the cost of the build?

Reliability unknown but soon to be known. It’s going to be going on frequent cross state trips. I have it in spreadsheets. Not sure. Not cheap. If you’re worried about cost don’t mod an IDI.

 

[u2slow]

I've spent enough years with IDI's that I'm never going to spend the money or effort to try and make a powerful one.

 

[hacked89]

I've spent enough years with IDI's that I'm never going to spend the money or effort to try and make a powerful one.

This the same reason I like spending money and effort on them.

If OP is just looking for an engine that you slap some upgrades on and it puts down good power then he should build a fummins