My curiosity finally got the better of me, tried to read enough forums to answer my own questions, but failed badly. Would greatly appreciate some help please.
1 Why come there isn't a 98 PSD ?
2 Why doesn't 94.5-97 PSD turbochargers have a waste gate ?
3 Which mod do you do first the IDM (got my Digi-Key resistors today, little suckers) or the ICP ?

Thanks,
Darron

 

i dont know why they did it. but ford didnt make 98 f2 or 350s.
that is the only question i have a half decent answer for.

 

Never really thought about them not making a 98 PSD till I got on FTE.

 

Ford was changing the body style from OBS to NBS and had to set the assembley lines up.

Not 100% sure, but alot of turbos do not have waste gates (tractors, big rigs). Someone with more knowledge in this area should be able to help.

Flip a coin, or do them both in a weekend.

 

Thanks immastrokinnow and plowhand for your answers. Yeah I'm pretty familair with tractor and big rig turbos, generally the turbo can't pump enough air to hurt engine ,I guess because of the turbo's size. I was wandering why, because the later models have waste gates.

Thanks,
Darron

 

The old body style trucks (OBS...95-97) do not have a wastegate because of the lack of an intercooler and the fact that the turbine housing (exhaust side) of the turbocharger is rediculously huge (by huge, I mean large A/R.....flows A LOT). The lack of an intercooler overshadows the lag that would be produced with such a large turbine housing. Therefore, to keep EGTs in check, Ford used a very high-flowing turbine housing that does not lend itself to high drive pressure.......and therefore keeps boost in check without a wastegate.

The Superduty trucks used a smaller exhaust housing that allows quicker spool-up with the intercooler. Since an intercooler was used, EGTs were less of a problem with the smaller turbine housing. But the possibility exists of overboost because of high drive pressures, so a wastegate was used to bleed it off.

 

great post...reps sent

 

yup, great answer and to add to the no 98 question, there technicly was a 98 f-series. it is the 94-97 bodied trucks that were still in production and carried over to get prepped for the 99 style. then the 99 style actually came out early and is reffered to as a 98 and a half by ford fans. my 97 f250 is technicly a 98 since it has a build date of 12/97

 

ford did make a f250 in 98 but it was a light duty model still had 8 lug wheels but didn't come with a psd and the front end of the truck was ifs.

 

I thought it came with those funky 7 lug wheels...

 

hmm it might have i guess i just stopped counting after i seen five i didn't pay to much attention since it wasn't diesel

 

Good post. You don't have to worry about drive pressure's if your a stocker. However, it will become a problem if you start bumping up the fuel.

 

Thank all of you for your answers,(reps sent) saved me some reading time that I really don't have. Does anybody have idea of how much boost (ball park) the older 7.3's can stand without popping head gaskets, stretching nogging bolts and such, if you turn the fuel to it max, with no waste gate and add the intercooler mod.

Thanks,
Darron

 

The OBS can handle around 43-45 lbs before you blowout a gasket or stretch the studs. Adding an intercooler or a wastegate does not affect how much the studs can handle.

I think you'd be safe running 40 all day long.

The wastegate is there is relieve pressures between shifts, hard acceleration then backing off, etc. I'm pretty sure they don't open once you hit a certain lb. Blow off valves will though.

 

Thanks FARM69, if you are going to push it kinda to the max, do blow off valves need to be installed.

Darron