Hey everyone, I'm thinking of doing a turbo and aftercooler on my 92 7.3 idi this summer. It's already got an ats turbo on it but it only puts out about 7 psi absolute tops. First, is there any way to get it to put out more and second, if I aftercool it and turn the pump up some will I need to to studs? I may also find a turbo off an IDI that was turbo'd stock. Any idea's? Suggestions? Not looking to make a powerhouse, just get a little more out of the old girl. I'm hoping the aftercooling will give me a little better mileage? Open to suggestions and idea's, the help is appreciated.

 

I believe the word your looking for is intercool and depends on the psi numbers you are going for but my thing is if your going to do that much work to it why not stud it? Just to be safe a stock ats turbo probably won't be any better than what is on the truck a good down pipe will improve your outflow and power, and if you have a wastegated turbo and its set at 7 it won't build any more psi than that... If you don't have a pyro I wouldn't turn it up any higher without it! I am personally about to start working on my truck and adding an old stock turbo

 

I believe the actual technically correct phrase is aftercool but as long as it gets the point across. I would stud it, but i wont say that you must. Seeing as its a 7.3 i would say youre "safe" running up to 20psi with a 10% over torque. If you have the 093 turbo (its wastegated) then yes, you pull the rod off cut some more thread on the rod and thread it in tighter and that will raise the opening point. Dont forget a pyro. Need some more specifics on the turbo, a picture wouldnt hurt. More or less an IDI turbo is an IDI turbo unless you want to step up to an S200. If everything remains how it is and add an intercooler, then yes your MPG should go up some.

 

studs require engine removal or fighting with heavy heads in the truck and they cost hundreds.so unless it's something you would benefit from,there is no point in adding them.

a typical turbo kit doesn't boost high enough (in it's efficiency range) to require head studs.so unless you plan on a turbo upgrade beyond the typical ats/banks/ h-max kit,which simply generates more heat than the extra power would be worth your best off keeping the $ and the hassle of pulling the engine to install studs.the 7.3l head bolts haven't failed for turbo kits (non upgraded turbo's) over countless combined turbocharged miles on these engines since the 80's.

if you plan to upgrade or change out to larger turbo's to boost past 10-14 psi then things change of course.

 

Thanks. I know studs are a big job so I'd rather not if I don't have to. It's non waste gated turbo. I'm not looking for boost over 12 psi really, like I said i don't want a real powerhouse, just a little more than what I got. Maybe I'll check out getting a turbo off an IDI that was turbo'd stock. The ats kit came with a threaded port for the pyro probe, my current pyro probe is burned out so I will be getting that fixed. So then My next question is, to do with aftercooling. How much would I be able to turn up the pump after I aftercool it? I'm not looking to "roll coal," Just to get more power. Also, I've heard the 7.3 PSD aftercooler is a good one to use for this purpose. Any suggestions?

 

You want the 7.3 superduty all aluminum one. Do you know if your turbo is the 085 or the 088 kit? Max the pump out and im sure you will be fine, ive maxed both my pumps on the 92 and egts were still safe non-IC. Boost will come with fuel, if its a healthy pump the 088 will run 20psi maxxed out. Mine doesnt because i have an up pipe leak and weak pump. As long as it clears up the fuel and doesnt run hot, boost is just a number.

 

Alrighty! Thanks. The IP was just replaced this past spring so it's good. The injectors I'm gonna do first thing this summer, they're getting pretty bad. As to the turbo model, I don't know. It came on the truck. But I will go look when I have a chance.

 

I dont know anything about the 085, but the 088 is the same turbo as the 093 with different housings as i understand it. They are decent up to 20psi, my 088 has pretty nice response, even with the drive leak.

088


085

 

Aftercooling and intercooling are different, or thats what I have gathered, the old 466 JD motors were aftercooled with a water cooled intake plenum, but that doesn't really change the point because we all know what each other mean. I think you can never go wrong with studs. Especially if you have to have the heads off anyways. And besides, you should have to pull am engine to install them. You don't have to pull an engine to do head bolts. The studs just add that extra safety that nothing is going to pop around 20 psi

 

Yeah I have the 88. So you're saying if I up the fuel, it'll start pushing more boost? It won't just get more smokey? Pretty sure I will aftercool it though. Gives me a good project to work on. One last question. Will aftercooling it improve my mileage? I got 4.10's and so I'm hoping to either find a bolt on OD or put taller tires on to get it to rev a little lower.

 

You should be able to turn the fuel up, and yes, it will help spool the turbo and get more boost. I would ~highly suggest that you get rid of the air intake box and put together a good cold air intake and free flowing filter. That will help with spooling as well, and keep smoke to a minimum... and that box kills the turbo whistle. I would also ~highly suggest that you get a working pyrometer before you mess with the fuel screw. The intercooler is a worthwhile mod, but expensive and labor intensive to fabricate it. It will help with EGT's and get you a bit more power, but it won't do wonders for mpg. If you want fuel efficiency, gearing is by far the biggest game changer, along with fresh IP and injectors. Bigger tires increase your effective gear ratio and lower your rpm's but slinging the additional weight around will hurt your mpg's more than you gain from the ratio change. Stick to stock tires for best mileage, and look at taller axle gears and an overdrive transmission or overdrive unit for mpg gains.

 

Alright, thank you all. I shall do a good cold air intake. The IP was new last sping and has about 8000 km on it so it'll be fine. It's an OD tranny, the ZF5. Thanks again for the help and suggestions.

 

You might consider running 285/75/16s, not much, but a little taller than 235s, will drop gearing some. Im getting 16 with mine right now same setup, ZF 4.10s 235s i pretty well drive the hell out of it. I think i would expect .5-1mpg adding an intercooler depending on usage. And yes, the "stock" airbox sucks, brand new filter will pull the vac. meter to 10" at WOT, then again, its only like a 125cfm (nom.)

 

This is generally correct, but the disagreement Id have is that the efficiency point is really no issue. People have said that the 093 doesn't make anymore power after 15 or so PSI, but Id raise that to the low 20's or so and only there because nobody has run more fuel on the 093 than a cranked stocker IP. Yes, the air is hot, but we have the advantage of being able to spin the hell out of this turbo, and generally the H3 trim makes more power than we make with stockish pumps, on other platforms. After many turbos on IDI's, Id say that the 093 is more limited on the turbine wheel than anywhere, its choked. If I get a chance, ill post a pic of the P-trim wheel vs. the stg-3 (093 wheel). I am willing to bet that a turbine wheel upgrade (as opposed to a compressor upgrade) would increase the output of this engine.

Either way, an intercooler pretty much negates the compressor efficiency problem, in a round-about sense.

Studs are always a great idea in every sense, however, might as well push it beforehand, when you blow your gaskets, youll be pulling the heads anyway, so do studs then. Im willing to bet that a steady eye on EGT's, and you will have nothing to worry about with a cranked pump, whatever boost you can get from that.

 

What's with the 20psi on stock headbolts? I know I haven't been around much lately, but when I first got my IDI, everyone said 15psi would put the heads through the hood. I'm familiar with the nothing but hot air past 12psi argument(on the regular turbo arrangements), but the inability to handle the pressure always seemed to go hand in hand. Has something changed? Not intending to step on any toes here, just curious if the IDI world has learned a new trick.