[60bugeye]

Will the complete turbo system off of a 7.3 IDI fit onto the 6.9? Also in a conversation with a diesel mechanic friend of mine he emphatically stated that I wont notice hardly any difference in the 6.9 after installing a turbo. According to him, and figures he showed me from international, the turbo only adds 5HP!!! So what gives? Is he right OR wrong? Is it worth the expense to install a turbo?

Leo

 

[sle2115]

From the posts I have seen here and the 6.9's I have driven with a turbo, you need to find a new diesel authority cause he couldn't be more wrong! The turbo seems to be the number one way to increase power. Several here that have them will chime in I am sure.

Also, as far as I know, everything except the internal dimensions are the same on the 6.9 and 7.3 other than a few minor issues that will not hamper installing a 7.3 IDI turbo on a 6.9. The main differences that come to mind are the glow plug controller, which was also used on the later (1987) 6.9's as mine has one and the fuel filter system which on the 7.3 has the water separator and filter all in one unit. As you will see in my signature, they can be used on the 6.9 as well as you can see in my signature.

Most here agree that you should install new head gaskets and studs before adding the turbo as the original gaskets seem to be a weak point even with non-turbo, let alone stuffing more air in there. ARP studs seem to be the way to go as they have more clamping force and cost less than new OEM headbolts. I have seen figures as high as an additional 125 HP gains, but I would say it might be a little more modest, I don't have one, so can't tell you for sure. Others on here that do have turbos will have more idea of the actual HP gains.

 

[beretzs]

I would say on the CONSERVATIVE side, you will see 50HP and 100ftlbs of TQ, these will go up even further once you get more fuel going into the new found air. Turbos's are about the only way to make alot of power with the trucks. You can do other things, but a turbo will take a slow hill climber, slow trailer puller into a monster that screams over hills and makes trailers seem light. I know it is a bold statement but you will never believe the difference, it is incredible. Scotty

 

[asavage]

[ QUOTE ]
I would say on the CONSERVATIVE side, you will see 50HP and 100ftlbs of TQ, these will go up even further once you get more fuel going into the new found air.

[/ QUOTE ]

Assuming the NA motor wasn't overfuelling before adding the turbo, how do you get more power with the same amount of fuel? Merely adding air? 50 HP??

I'd think you'd need to get more fuel in to match the added air before any significant power could be generated. But I'm not running one, what do I know?

 

[DeepRoots]

it's the turbo conspiracy....
they want all us stock truck people to spend lotsa money stuffing more air into our engines.

truly they must be stopped, err till I find the time to get a turbo and install it.

 

[Gandalf]

I have had two Fords, two diesels. /ubbthreads/images/graemlins/biggrin.gif Both are in my sigblock below.

The '86 had a turbo, the older Banks with the big square airbox on top of the 6.9 engine. The '92, 7.3 liter, has no turbo. /ubbthreads/images/graemlins/shrug.gif

All other things aside, the '86 had more power than the '92. It had more towing power and more hill-climbing power. Granted, the '92 is larger and heavier, but not by all that much. The '86, with the turbo, just had more power than the '92.

I sure do miss that power and that distinctive turbo whine. /ubbthreads/images/graemlins/wink.gif

Ken

 

[beretzs]

That is with the Banks 1/4 turn on the fuel screw. Your right, you probably would not notice much, without adding a little fuel, but the 1/4 turn would probably really Overfuel a NA truck, whereas with a turbo, you are just getting started. I have currently ran out of fuel screws to turn. Might have to swap out fuel lines for garden hoses to get what I want. Just kiddding.. Scotty

 

[60bugeye]

As I have been reading all of the information here (especially when it comes to turbo's) I tried to explain all of the comments here to my friend and all he said was "phooey". He said it was all seat of the pants claims and that the factory horsepower ratings dont back up the claims. Specifically, he claims that the 6.9 wasnt designed to take advantage of turbo charging and as such doesnt have the cylinder capacity to have more air stuffed in it. Well I am not going to argue with him and I belive the statements here more. In support, why else would Banks, ATS and others develop turbo kits for this motor if it didnt give substantial gains. That said, how much can a person expect to pay for a turbo that will fit the 7,3 IDI stup. I can buy a complete turbo mounting assembly EXCEPT for the turbo off of another person I know for $100.00. I think it's going to get a turbo installed WHICH means that I will pull the heads and put in the ARP studs. Thanks for evryones comments.

Leo

 

[asavage]

Oh, I think 50 HP is very achievable with most any turbo on a 6.9l, just that the IP has to supply more fuel to do it. Turbochargers are efficiency-enhancing devices, in that they allow an engine of displacement Y to process the fuel/air load of engine (Y x 1.5) or better, without the increased friction of larger cylinders, longer strokes, etc. And turbochargers reclaim some waste energy from the exhaust heat when they're working.

Hey, I'd snap up a turbo system (sans turbo) for that price without a second thought! But turning up the IP screw is part of the deal -- just adding boost is only going to make the EGTs run cooler and your air filter work harder, not make more power by itself.

Unless I'm missing something.

 

[ziggster40]

[ QUOTE ]
just adding boost is only going to make the EGTs run cooler and your air filter work harder, not make more power by itself.

Unless I'm missing something.



[/ QUOTE ]

Well, sorta...

The thing is that there is a lot of energy going out the exhaust in heat and expanding gasses that is all wasted on a n/a engine, and the fuel doesn't burn completely due to low oxygen in the incoming air.

So, without even adding any more fuel, you can see a fairly modest increase in power(read efficiency) just in the recovered energy from the exhaust, and of course since you're stuffing more air(oxygen) into the combustion chamber, the fuel you are putting in there can burn more efficiently.

Of course when you turn up the fuel that's when you see the real gains in power. If you turn up the fuel on a N/A engine you'll likely not get much more power, but more smoke(wasted unburned fuel) and way high exhaust temps.

This is one reason why lpg works well. Even though it is actually more fuel, it acts partially as a catalyst to more efficiently burn the diesel, and thus more power from the same amount of fuel. Downside is that it does raise exhaust temp somewhat.

Zigg /ubbthreads/images/graemlins/smile.gif

 

[Joe Mc]

There has been a lot of speculation on this site. That the HP numbers were kept so low because the were about to release the Power Stroke and wanted it to have much more impressive numbers.

 

[hesutton]

[ QUOTE ]
Will the complete turbo system off of a 7.3 IDI fit onto the 6.9? Also in a conversation with a diesel mechanic friend of mine he emphatically stated that I wont notice hardly any difference in the 6.9 after installing a turbo. According to him, and figures he showed me from international, the turbo only adds 5HP!!! So what gives? Is he right OR wrong? Is it worth the expense to install a turbo?


[/ QUOTE ]

A turbo system from a 7.3 IDI will bolt up to a 6.9. With that said, I'm afraid you friend is miss informed. Yes, the 6.9 and 7.3 IDI have high compression ratio's that limits the volume of air that can safely be stuffed into the motor. But, you can safely run 12 to 15 psi of boost. Adding more O2 via a turbo and more fuel via modifying the IP equal more power. And not just 5HP. THE BANKS system adds 80+HP and 140+lb-ft of torque. Anyone who has added a turbo will tell you it makes a huge difference and they wish they had turbo'ed the truck much sooner.

Does this guy own an IDI? Has he driven a turbo'ed IDI? My guess is NO to both. Trust me, turbo'ing make a BIG difference.

Heath

 

[beretzs]

All I can say, is you will know that you have not wasted your money. Trust all of us on this. When you put a turbo on, you will have alot more power, all the time. Most guys that dyno with just a small fuel increase and a turbo are getting about 40+HP.. Scotty

 

[agnem]

Leo, no doubt your mechanic friend is aware that the stock 94 IDI turbo is rated at only 10HP more than the NA version. This horsepower limitation is due to the poorly designed down pipe and the injection pump calibration. As was stated, it was a marketing choice, and not a technology factor that resulted in only 10HP. The 50 HP gain most speak of is simply the result of a better exhaust system, and turning the pump up, as is proper on any turbo application. Factory trucks were not equipped with an EGT gauge which is mandatory on any engine with a turned up pump, and obviously Ford didn't want to offer an IDI with near as much power as the PSD, and a warning sticker saying do not exceed 1250 degrees EGT.

 

[asavage]

[ QUOTE ]
The thing is that there is a lot of energy going out the exhaust in heat and expanding gasses that is all wasted on a n/a engine, and the fuel doesn't burn completely due to low oxygen in the incoming air. [ . . . ] This is one reason why lpg works well. Even though it is actually more fuel . . .

[/ QUOTE ]

You can't have it both ways. Supposing that a turbo improves power without adding more fuel because we had too little air before, and then thinking that adding propane (which displaces air!) somehow makes there be more air on a non-turbo engine is not consistent.

[ QUOTE ]
[LPG] acts partially as a catalyst to more efficiently burn the diesel . . .

[/ QUOTE ]

IMPCO (the most widely-known mfg of OEM and aftermarket LPG equipment for alternate fuelled vehicles) used to have a support forum, and two of their support people were adamant that there is no way for propane to be a "catalyst" for diesel combustion. Adding fuel (via LPG fumigation) is just adding fuel. Less dense fuel, too, but very easy to light off, high octane. I expect (my guessing here) that propane fumigation has a similar effect to multiple injection events in PS and newer high pressure diesel systems: the propane combusts prior to the diesel, but at a very low density not much pressure is generated, but a wave front is started, and then the diesel is fired into the middle of this event, reducing noise (peak pressure spike) and increasing burn efficiency. But not "catalyzing" anything.

[ QUOTE ]
. . . and thus more power from the same amount of fuel.

[/ QUOTE ]

But it's not the same amount of fuel: you've added propane.

 

[hesutton]

[ QUOTE ]
...[LPG]... very easy to light off, high octane.

[/ QUOTE ]

Just to make sure no misinformation is spread (this is not a flame)...Propane has three carbon atoms and eight hydrogen atoms. Octane has eight carbon atoms and 18 hydrogen atoms. Octane is a liquid at normal temperature and pressure. Propane is a gas at normal temperature and pressure. Octane resists compression ignition - that is why it is needed in high performance/high compression gasoline engines (prevents early compression ignition - detonation). It is not in propane and it doesn't light off easily. Propane itself does burn easily. Again, just to give a little info. on the chemistry of the petrolum products well all use everyday....not to flame.

Sorry, most of that information is useless huh? /ubbthreads/images/graemlins/biggrin.gif

Heath

 

[Spencnaz]

I will say this, any engine and I mean any engine can benefit from turbo charging. For the 6.9 it's recommended that you dont go above about 12psi due to the already high compression ratio.

All I know is that my turbo'd 6.9 is alot more powerful than my friends NA 6.9 with the same milage.

 

[sle2115]

As far as a turbo is concerned (have to think too much to argue about propane!) I think it all relates back to more efficiency. If you are burning 80% of the fuel entering the engine, by adding more air and burning even 1% more, you will be making the engine more efficient and gaining power, probably not noticeable, but if you can get to 90%, that is a 12.5% increase in combustion which converts to about 22 HP.
(175 X 12.5%)

My guess is that 12.5% is a low guess.

 

[asavage]

Yeah, Heath, I should have said "high octane-rating", but I figured we all know what I meant. Still, it's good to point out just what "octane" is: a chemical that is rarely used outside of testing labs. It just provides a handy reference; "100" on a scale.

Diesels burn clean, in terms of tailpipe emissions of unburned hydrocarbons (HC) and incompletely burned hydrocarbons (CO). So clean, that for years and years the EPA did not test diesels at all. Then, when passenger diesels began being popular and in poor condition, many municipalites went to opacity (smoke) testing of diesels only. It's only been recently that diesels needed more emission controls to meet escalating clean air stds, but in comparison to gasoline, diesel was a LOT cleaner in HC & CO at the tailpipe, for many years. Notice I'm leaving aside polycyclic aromatics and soot, but that's another topic altogether.

Having low HC & CO means that there is not, under normal conditions, a lot of unburned fuel in the combustion chamber to benefit from more air. Put more air in, and all you get is cooler parts, reduced thermal stress, and that's about it. Modern diesels don't have intake throttles (though older diesels did, notably the MB 200D and older, and the Nissan SDx series), so they enjoy greater efficiency WRT the pumping losses (add'l HP required to just move the air in and out of the engine) than gasoline engines, but adding a turbo recovers some waste energy from the exhaust (heat is exchanged for rotary motion) and lets the engine benefit from even lower pumping losses, so there's a bit of HP to pick up there, but we're not talking double-digits.

My point is, there isn't any add'l fuel to burn in an engine to which a turbo has been added, unless the engine was over-fuelled to begin with. Because diesels squirt the fuel into the middle of hot air, very little reaches the relatively cool cylinder wall or combustion chamber surfaces to be quenched and prevented from burning completely, which is why diesels are so much cleaner in HC & CO than gas engines that always have fuel sitting next to cooler surfaces and get swept out the exhaust without burning -- to get oxidized the catalytic converter instead.

But I agree that turbocharging should be on all engines. Why isn't it?

 

[sle2115]

Here is what MR. Sharkey has to say about it:

What it is...and why:

Simply stated, Propane (LPG) Fumigation is the introduction of gaseous propane into the air intake of a diesel engine for the purposes of attaining more power, economy, or both. The parallel is often made between fumigation and using Nitrous Oxide on gasoline vehicles to achieve a power increase. Basically, this analogy is correct, although the properly implemented use of LPG on a diesel engine will actually result in a better-running engine without the possible damaging effects that N2O has on gas motors.
Exhaust emissions are reduced as a result, with lower quantities of unburned hydrocarbons and fewer particulates (smoke). LPG fumigation will even clean up the odor of diesel fuel in the exhaust, making the smell from the tailpipe of an engine utilizing it much less objectionable.

How it works:

Introducing LPG gas into the combustion air intake of a diesel engine acts as an accelerant, promoting the even burning of the diesel fuel, and more complete combustion, resulting in more power being produced. Propane by itself will not self-ignite inside a diesel-fuel compression-ignition engine. During the compression stroke, the air/LPG mixture is compressed and the temperature is raised to about 400?C, not enough to ignite the LPG, which has an ignition temperature of about 500?C. When the diesel fuel is atomized into the cylinder under high pressure, it immediately self-ignites (diesel ignites at about 385?C.), and causes the LPG to burn as well. Since the LPG is in mixture with the air, the flame front from the diesel spreads more quickly, and more completely, including igniting the air/fuel mixture which is in contact with the cylinder walls, which are cool in comparison to the super-heated air inside the combustion chamber. Much of the cleaner burning of the fuel is attributed to this ignition against the "cooler" components of the engine, and accounts for raising the percentage of combustion from a typical 75% for a well-tuned diesel engine running on pure diesel fuel alone, to 85-90% with the addition of LPG. Obviously, this more complete combustion also gives a nice boost in power, with an accompanying increase in fuel economy and reduction of pollutants.



(text extrapolated from http://www.mrsharkey.com/lpg.htm)

For the complete article, visit the site at Propane Fumigation