The Diesel Garage banner
1 - 14 of 14 Posts

69 Posts
Discussion Starter · #1 ·
What is out there to make the 6.9 idi have a few more hp?

132 Posts
there are turbo systems such as ones from and ats. the motors really aren't worth much without a turbo but the turbo sure perks em' right up!

349 Posts
Turbo's bigger IP pump and injectors. Bigger exhaust and better flowing intake.

Super Moderator
4,247 Posts
There is no bigger intake.

You need to get more air thru that engine or all you will accomplish is making smoke and heat, neither get you down the road any better or cheaper.

4 Posts
For people that install a turbo on a N/A engine, do you have to worry about the connecting rods? The turbo engines come with a beefier connecting rod to support the extra pressure. I've put a hole in the block from having a rod let go and it didn't have a turbo. Seems like adding a turbo is a recipe for disaster as far as the rods are concerned. Plenty of people have done it though...

Paul B

Senior Member
393 Posts
Hmm, yea i have hurd of some people blasting their internals from the extra pression...We run 14 psi top with our 7.3. That maybe pushing it with most peoples standards too...Headstuds should play a role with an idi over 15 psi, or atleast i would perfer headstuds if i was running that much boost. Most will say studs over 12 for so you won't get stranded tho.

53 Posts
to prevent complet disaster, when installing a tubocharger on a high compression you should think about the compression ratio, the 6.9l comes stock with a 20.7:1 compression ratio, which is extreamly high for a turboed diesel. Therefore putting larger thickness head gaskets, along with head studs and maybe fire ringend you should be good up to 30psi thats of course with twin turbo's and alot of $ but in your case head studs would be fine, but hurry up with getting a turbo cause banks wont be making them much longer and i dont know about good luck!!!!!!!!:93C_peelo

132 Posts
IMO hypermax has a better turbo kit than banks and its cheaper. a lot of guys like the pulse setup way more than the banks factory style setup. heres a guy that has a hipo 6.9l!

Dave Sponaugle said:
OK I am back, now a little about me, I grew up on a farm, my grandfather owned the local Ford dealership back in my home town.
My life has been spent trucking, building stuff or operating heavy machinery.

When the fouth engine was not up to my expectations I had contacted Ken at DPS with the intention of buying an engine from him.
But time was against me by the time I had money in my hands from the buyout, I have snow customers that I had to make arrangements to take care of, hence the salvage yard motor which took to much cash to still buy a DPS engine.

So after I disassembled the engine, first I took the block and heads over to the machine shop to be hot tanked and checked out.
I wanted every thing well withing service limits, everything magnafluxed that could be done.
Everything was lloking good except the cylinders, they needed 30 thou to get them back in shape.
I felt comfortable with that, still left me 80 thou more cylinder wall than a 7.3 has.
Also the coolant passages we looked inside all of them as much as we could see with a bore scope, nothing raised any red flags.
So 30 over it was.
Time to check out the rods and crank, they were perfect.
As I say this, there was evidence this engine had been rebuilt not to long ago and a lot of parts had been replaced.
So the crank was polished and it was good to go.
We ordered Sealed Power hypereutectic pistons and rings, stock height 30 over.
Sealed Power cam and lifters.
New valve springs, 7.3 rockers, push rods and 7.3 turbo valves.
Bearings came from Sealed Power I believe....been to long now.
Gaskets were Fel Pro.
While we were waiting for parts, Joe the machinist did clean up the head passage castings just a little, the ports were matched on the intake and exhaust side, nothing major though.
When the pistons, rings and bearings came in, I had him cut 40 thou off the piston tops.
I had the rotating assembly balanced to 5000 RPM.
Joe went ahead and installed the crank and pistons while we waited on the head parts.
He installed the valves in the heads and gave me a call when the rest of the parts came in.
I picked everything up and took it home to finish the assembly process.
ARP head studs, ATS upgrade turbo .85 AR if I remember right and a Melling oil pump.
Everything wiped down with acetone to remove any traces of oil that may contaminate the sealing surfaces right before assembly, this was repeated for every part.
ARP studs, torqued to 105 Ft Lbs in four steps, also installed to torque and removed four times with moly assembly lube on the studs before the final install.
Everything inside the engine was stock torque settings, a dab of Locktite to make sure it stayed there.
Everything was painted blood red with Ceramic high heat paint on the engine exterior, but I thought it needed a bit of contrast, so I got some Silver high heat ceramic paint to do some of the stuff like the turbo, exhaust manifolds, brackets and such.
I also wrapped all of the cross over pipe, turbo up pipe and top of the down pipe with a double layer of header wrap soaked with ceramic paint to keep as much heat as I possibly could in the exhaust before the turbo.
More exhaust heat = more exhaust volume = more turbo boost

I put it together, used the stock 6.9 fuel system and left the boost set at 10 PSI for 5000 miles.
What a long way 5000 miles is when you are dying to play with a new toy.
Ran it very easy, varied speeds all the time and all that good breakin stuff like you should do.
EGT never went over 800 degrees, thermocouple in the number 8 exhaust port.
At 5000 miles I cranked up the fuel to max and raised the boost to all it would do.
Almost no smoke at all and 19 PSI.

My exhaust is 3" from the turbo, and three feet after the turbo it splits to two 3" stacks.
No muffler, and no bends sharper than 30 degrees untill after it splits.
On the intake side, I am running a 40 sq in intake scoop beside the radiator, reduces to 6" round, then 4" round to enter the stock ATS filter box.
If I run a Purolator filter the turbo is seeing 2.5 PSI pressure on the intake side at 70 MPH.
With K&N it is seeing 5 PSI at 70 MPH.

OK time for smoke, Ken built me a set of Stage 1 injectors.
I ordered a stock DB2-5070 IP from Ford.
Internal fuel screw bottomed out, then backed off 1/2 flat.
RPM set to over 3800 RPM ;
DPS injectors and the IP went on at the same time.

We have smoke, but nothing extreme and the turbo boost was hitting 23 PSI.
Max EGT went up to 1000 and it ran good.
Timing advance, Power Stroke rattle big time while the cold start timing advance is on, almost there after it kicks off.
Now it is starting to wake up.
OK time for external fuel screw....SMOKE at last.
So now it has been about 6 months and I am starting to stand on it harder and harder.
One morning I was headed north in the early morning hours of December, nice and cold outside, truck is running great.
Cummins wants to play with the old Ford, blow smoke in the face and all that.
So lets see what we have, smoke on boost going over 25 and suddenly smoke gets blacker and the boost drops a couple pounds.
Great, blew head gasket I think.
Get to where I am going, sure enough, pressure in the radaitor, more than normal.
So I run it easy going home, no pressure in the radiator.
Next morning pulling that same hill about 24 pounds, the boost drops a couple pounds again, pressure in the radiator again.
Not loosing coolant, run it easy and everything is OK.
So that weekend, the engine comes out.
Valley pan has funny marks by the number 7 port.
Heads off to be sure though, heads gaskets look perfect.
All kinds of soot around the 5 and 7 exhaust port and both of the cross over pipe connections.
New head gaskets, new valley pan, new exhaust manifold gaskets and go through the NAPA exhaust gasket bin till I find a gasket that will work for the manifold to Y connection as well as the cross over pipe connections.
Also a can of spray copper high heat gasket maker.
Also grade 8 bolts that are to long for the intake and exhaust manifold bolt holes.
Reinstall the heads after sanitizing the surfaces again, torque to 110 ft pounds this time.
Custom cut each bolt to where it is bottoming out as it starts to tighten against the manifolds with no gasket in there.
Remove them in order, spray all the mating surfaces with three coats of copper gasket maker and let it all dry.
Assemble with gaskets and double washers under each bolt head, torque to double the stock torque value for each.
Install the exhaust gaskets from NAPA with tripple layer copper gasket maker on each surface there as well.
Engine back in truck.
That was 13 months and 35,000 miles ago.
Since all the exhaust is going into the turbo now, smoke is rather light again if the turbo is spooled.
Max boost is over 26 pounds.
Max EGT is right at 1200 degrees, if the hill is long enoughand steep enough I can hit 1250 if I really try.

How much power?
More than the U joints, drive shaft and transfer case can handle.
I get about 3 months out of a set of rear drive shaft U joints, but that is not to bad, I can remove the U joint with my fingers aftewr the clips are removed.
I just hope the driveshaft makes it to warmer weather.
I replaced the U joints last weekend, used a 9/16 wrench and a pair of needle nose pliers.
Never had to get out from under the truck.
Drop the U joint loose from the yoke, remove the clips, swap joints, bolt it back up.
10 minutes to do both joints.
I have also split one transfer case in half pulling a hill grossing about 24,000 pounds.

Dyno means nothing to me, put a load on it and go find a hill.
Fortunately I live in WV, I don't have to look very hard to find a hill.
The street beside my house is a 32% grade.

As a final parting thought.
You can take a Stroke or a Cummins or a Duramax and drop that 500 dollar chip in it and increase the power.
You also paid close to 50,000 dollars for the truck it is going into.
That 50,000 dollars operated my truck for the last 10 years.
It put tires, insurance, licenses, fuel, repairs and upgrades in it.
My 4000 dollars worth of engine parts and machine work is in that figure.

Now tell me how dollars per horsepower figure again.

730 Posts
John_G said:
There is no bigger intake.

You need to get more air thru that engine or all you will accomplish is making smoke and heat, neither get you down the road any better or cheaper.

What can be done to get more air thru the engine?

4,320 Posts
if you have a turbo then there must be a way to fab up a custom air intake, the 12 dodge boys just use a big napa filter and a home made torque tube!

Junior Member
26 Posts
ramalott said:
What can be done to get more air thru the engine?
A ram air setup or a Hypermax cowl induction will get more air in. Larger exhaust, flow thru muffler or straight pipe will get it out. :evil:

TDG Mafia Member #56
2,050 Posts
On a stock type air filter housing you would have to fab up something but it can be done. Another weak link in these engines when turboing them is the wrist pins. Beware run too much boost and knock out a wrist pin. Been there done that. I have even seen low boost 6.9's and 7.3's do it, but then I have seen some guys never have a problem so you really have to watch it.

12 Posts
I've seen numerous IDI's turbo engines go over 300 K miles without a prob. Peeps that run into probs, usually have turned the fuel, or wastegate up waaaay to much.
1 - 14 of 14 Posts