I'll defer to Dave and other folks but I'm thinking there's no such thing as too much free flowing air on the intake. I read some in the supercharger/turbo forum where folks were spitballing adding a blower to a non-turbo or a turbo diesel. Some diesel guys weighed in with their thoughts... its worthwhile reading.
As far as sequence goes with my project (when I make up my mind) turbo first followed by opening up the exhaust. I'm already into it at that point so might as well keep going. Then when I see what room I have to work with I'll try something like Dave did for intake.
I'm trying to remember some basic pneumatic principles from 20 years ago and coming up short but it seems logical that max boost stayed constant but was achieved faster - lower rpm.
I too am curious about the fuel mix. Dave did you tweak fuel at all after opening up the breather pipe?

 

I do not think the backpressure is exactly the problem you will have, I would be concerned about the EGT's though.
Here in the wonderful WV mountains with stock fuel settings on the 7.3 turbo I could easily run the exhaust temps way to high running up a mountain empty at 75 MPH on the interstate. I would have to back out of the throttle after about 4 miles of a 5% grade or the pyrometer would be over 1150 and still going up, fast. My thermocouple is in the exhaust manifold 2" from the cylinder 8 exhaust valve. And this is with the 3" downpipe and dual 3" stacks. I have about 5' of single 3" pipe till it splits to duals.

I did the 3" dual stacks when I had a NA 6.9 stock engine. It did make a difference you could feel pulling a big load in the higher RPM range.

Then I installed a reman 7.3 turbo. I hooked all the air ducting back up on it so I was getting cool air from in front of the radiator. By 2000 miles the air filter indicator was showing the filter needed changing, but it always looked new. So I unhooked the air duct to the air box. Filter indicator showed OK after 5000 miles of the same kind of driving as before. So I started looking at the stock air intake, man that thing was tiny.
One day I got brave and figured it was time to do the intake right.
So I started looking for pre made parts. The only thing I did buy that worked was the 4" single wall adjustable elbow and a 6" round x 4" round reducer. Nothing else was close to fitting what I wanted to do. So since I have done duct work before and had the tools, I made all the rest of the pieces myself.

The fuel is still at stock settings from the factory and will stay that way for 8 more months till the engine warranty is out. I noticed the EGT's dropped about 200 degrees with the extra air. I would worry about high EGT's if I did the intake before the exhaust. You have to let the heat out of the engine or it will melt. The larger exhaust also dropped the EGT's over the stock exhaust even with a NA motor. I do not remember how much it was any more, but I was happy that I could turn the fuel up more without melting the pistons.

Before the intake mod, the 7.3 engine did leave a slight black smoke trail at wide open, but now it does not smoke at all unless I lug the engine down.

If I had to do it all over from scratch again, I would do the exhaust, the intake, the fuel and then propane.
It runs like a scalded dog now, and as soon as the warranty is out on December 15th the fuel is going up and the propane will follow right behind that.

 

THe ATS turbo is wastegated. The wastegate will open at the preset level of boost. So once it gets to that level it will not go any higher.
Atmospheric pressure is 14 PSI at sea level in round numbers.
So if you have 14 PSI of boost you are introducing almost twice as much air as a natural aspirated motor will take in.
A turbo will give you all the air you need, 15 PSI is about max if you want to keep head gaskets in the proper places.

 

Dave, thanks for sharing your info for the air intake, it looks like an excelent mod. One worry I would have is the potential of water entering the turbo when driving in heavy rain. I know a little water will not hurt the motor, but the turbo might not like it. Any thoughts? Any recomendations or advice regarding boost and pyro gauges?

thanks

josh

 

Josh I was wondering about moisture also. But I think Dave's design has some inherent protection built in unless he drives through a flood. (Especially with the plow on - I glanced at Dave's bio to see what the heck he does with this truck).
Dave, interesting info on the fuel and EGT etc.
Now with your 7.3 the intake mod dropped your EGT 200 and you lost the little bit of smoke you had and noticed some improvement at lower RPM. Sounds like your exhaust system is doing a great job and fuel efficiency improved.
On the 6.9 you put on the 3" downpipe and stacks and noted that the EGT went down. So you turned the fuel up so it was running where you liked your EGT? With that kind of thinking I can see why your counting the days on that 8 month warranty! <Grin> and propane too?
At the risk of getting totally sidetracked here... How long have you ran the airbags on the front end? Did it help wear and tear wise? Are you running them with a constant pressure over say 5 lbs or do you air 'em up for the plow? Ever have to replace the bags?
Thanks Dave!

 

I did see a TSB or something recently that insisted that the OEM air filter or equivlent be used as it is designed specifically to lessen the amount of water that could be potentially ingested by the turbo. I do not off road and do not expect to drive through any rivers, however we do get some serious rain storms. Still, I think I should look into doing this mod along with the 3" downpipe/outlet housing.

 

I run a Purolator air filter for the stock 93 turbo motor. It has a nice foam prefilter on the bottom that should stop any water that goes in the filter box.
I had a K&N in my 6.9 and did not like the amount of servicing it required since I am in very dusty conditions during the summer. When the oil on the filter gets dry, the fine dust goes right through the filter.

The 6.9 was a natural aspirated motor, but I have a neighbor that has an exhaust shop. We left the downtubes from the manifolds but welded a 3" pipe up that they both dropped into. Made a noticable difference at high RPM responsiveness.

I am running Isspro pyrometer and boost guages, that was what I always had in the big rigs. If they worked good in a 600 Cummins that was putting over 800 HP to the ground. it is good enough for my Ford. Never have had one fail in many years of over the road driving. An I was a meat hauler so our trucks would run. Some of the tricks I know now are from those days in the big rigs, we tricked them out with a lot of the same tricks that work on the IDI motors. Wish my IDI had pistons the size of gallon paint cans though like the 600 did.

Rain has never bothered me with the intake, but snow is another story. When you are running in a snow storm you have to unhook the plastic hose from the air box or it will cake on the filter and the engine will die from lack of air. I found that out at 3 AM one morning under conditions I do not like to think about, thank god I was the only one out there at that time under those conditions is all I can say. Also if I was in water that was close to bumper deep I would unhook the hose as well. It even has "Remove for Fording" molded right in the plastic.

As far as the air bags go, I installed them in 96 when I installed the plow. My 250 has an IFS front axle. Changing the air pressure in the bags changes the front end alignment. So when I had it on an alignment rack we played with the air pressure to see what was best and set the alignment for that pressure. So I normally run 15 pounds in them when the plow is off the truck so the alignment is right. When the plow is on the truck I run 100 pounds in them and it is like the plow is not even there.
That was the best 300 I spent after I installed the plow. After 9 years of running them one has developed a very small leak that loses 5 pounds of air in two weeks. That is not a big deal as far as I am concerned after all the use I have gotten so far.

 

Dave, I had a similar problem with one of my 'bags'. 1/4 turn of the shrader valve stopped the leak. More than likely, your leak is in the plumbing, not the bag.

 

I was thinking that it was, but since I am changing springs and front axles in the very near future I have not been messing with it. I am going to have to take it all apart when I do the swap anyway.

Mine uses a 1/4" nylon air line that just pushs into the fittings on the schrader valves and the air bags, I think that is where the problem may be at.
The leak is so slow that I just include the air bags in the weekly tire pressure check and adjust proceedure.
Man that limited slip Dana 60 is going to be nice under the front, I just hope it drives as nice as the IFS I have now does.

Southpaw, I am in the excavation business. I have an 8' x 9' dump flatbed on my truck that I haul lots of dirt, stone and broken concrete on.
When I am just running around I have a 100 gallon off road fuel tank and about 1000 pounds of tools on the truck.
I also tow our Cat mini excavator and skid steer loader around the mountains here. Also I haul lots of ductile iron pipe and PVC pipe to jobsites all around the state. In the winter I plow snow and have a salt spreader on the truck.

Everone tells me I need to get a new truck, but after 19 years we are like old friends. Besides my operating expenses for the year would not even make the payments on a new truck. Then the insurance payments and operating expenses for the new truck would have to come out of my pocket. Over it's life with me, the truck has paid for it's self and it's upkeep plus put money in my pocket every week. It has done everything I ever asked it to do without a single complaint. I will be the first to admit that I ask a lot more of my truck than most people would ask of theirs. But if you looked at my gallery I guess you know that already.

 

Dave, I was betting landscaping and then plowing in the off season. I tend to agree with your logic on buying a new truck. I had a 95 psd that I used much the same way when I landscaped my yard. (Not your typical suburban yard - couple of ponds, some waterfalls, etc.). Traded it because I also hauled a slide in camper for fun. Kids got too big for the backseat of the supercab. The complaining became louder than the diesel. Should of kept it though. Very minor problems considering.
This '93 drives good... but its not a turbo.
Turns out the coolant is probably not a problem. I sent my brother a test strip kit and he checked the fluid I'd left in the machine shed. Tested good. Turns out the coolant he used is SCA precharged - forget the brand. I do have to say I did not know there were test strips til I read it on this web site. I just put in additive every fall or on changing out the coolant every other year.
Learned something else. Happened to be near a small town that has a diesel shop I'd heard good things about so I stopped in. Explained what I was thinking of doing.
1) He told me if they dyno'd the motor he'd expect to see 115-125 hp with 115k miles. He thought this to be normal but not a candidate for a turbo as it would accelerate wear on the injectors and I'd be looking at new injectors and a pump sooner rather than later. Since neither of us were busy we dyno'd the truck ($70) and on two runs hit 90 hp at about 1400 rpm (40-41 mph) and soon peaked at 117+ out to 3100 rpm (70+ mph). He reiterated that they wouldn't want to add a turbo without doing the injectors and pump first.
2) He recommended a Banks turbo. I grilled him a bit on this and he told me that they didn't 'like' Banks but their experience showed that Banks turbos worked out best for that motor.
Is there a good reason to change out the injectors, pump and lines before you start noticing a problem? Other than you're doing it on your time table other than the trucks.
I have to consider this fella's looking at this from a business perspective with shop warranties, etc. Then again a day later I realized I never paid him the $70 for the dyno and their phone number isn't on the paperwork he gave me.
3) On the '93 the air intake sits right above the driver side battery. Its small. With a warm engine I opened the throttle and you can actually see the hose contract from the vacuum. So I cut another hole in the bottom of the plastic nozzle. Definitely getting more air and I think I notice a difference but could be just wishful thinking! Only did it yesterday.

 

I had 300 thousand on my 6.9 with the original pump and injectors.
Lots of people like the Banks system.
I have had no experience with them, but I have heard they are kinda cheaply made as far as some parts fitting well.
I do know that I like my ATS and it fits very well. Also with the ATS and Ford research during development of the stock Ford 7.3 turbo I think they have a foot up on Banks.
With the driveline loss those numbers are not to bad.
And if it was my truck I would install the turbo without changing the injectors and IP.
Sure if you change them it may run a little bit better with the turbo, but it is going to run a lot better just adding the turbo than it does now without the turbo.
Before I changed injectors I would pull them out and have them bench tested, you could do that to the IP also. I would not waste the money unless the engine was not running right though.
I think that intake snorkel Ford used on the early 90 models was even worse than the one on the mid 80's models.
If you can get the air from outside the engine compartment it will be cooler and help the engine run better.
There are a few tricks to the ATS that will blow the Banks away. One of the first is guages and intake mods so you know what the engine is doing and it is getting all the air it can take.

 

Thanks. Did you buy your turbo direct from ATS?
Also I just spent a few minutes trying to find a replacement hoodliner and came up short online here. Could use a suggestion where to look. This one's disintegrating. Fast.
And Happy Easter!

 

My turbo came installed on the reman engine I bought. One of the main reasons I got the one I did.
But since I had a few problems with it, that might not have been good thinking.
Few problems means I have the third engine in the truck right now since I did the original swap a year ago in December.
Most of the rebuilders would have cancelled the warranty if I installed a turbo on their engine before the warranty ran out though.
They even gave me grief over running Mobil 1 synthetic oil in the second engine.
So now I have to be real good till December 15 this year in case this one lets go also.
Cracked block on first one at 2700 miles and 2 months.
Broken crank on the second one at 9700 miles and 4 months.
With my fingers crossed I am over 13,000 miles and 9 months with this one, so far so good.
All I can say is thank god for two year unlimited mileage warranties.