Ford Truck Enthusiasts Forums - what the difference between the 7.3's?

Ford Truck Enthusiasts Forums (https://www.ford-trucks.com/forums/index.php)

- 1994.5 - 1997 7.3L Power Stroke Diesel (https://www.ford-trucks.com/forums/forum170/)

- - what the difference between the 7.3's? (https://www.ford-trucks.com/forums/912945-what-the-difference-between-the-7-3s.html)

what the difference between the 7.3's?

What is the difference between the 94.5 - 97 7.3 turbo diesl and the 99 - 03 7.3 turbo?

The engines themselves are basically the same. The 94.5 to 97 has a manual/mechanical fuel pump, smaller turbo, different type of injectors, (single shots), and different IDM' and PCM's to control them. The early 99's are a little different from both of them, but I don't know the specifics. All the engines up to sometime in the year 2000 have forged rods. The later ones have PMR's which don't hold up as good under higher horsepower.

Also, there is about 25hp difference between the older ones and the newer ones. the California models are a little stronger. Manual tranny trucks have 25 more hp than their automatic counterparts.

Quote:

Originally Posted by CampSpringsJohn (Post 8262868)

Ok thank you but not sure what mean by IDM and PCM. Also are the 94.5 - 97 IdI or derect injection?

Direct injection

Injector driver module ?
Powertrain control module

Thanks guys for the info. Now 1 more question, Can I put a chip into the 94.5 -97 engine?

Quote:

Originally Posted by dougbrown (Post 8263704)

Thanks guys for the info. Now 1 more question, Can I put a chip into the 94.5 -97 engine?

Yes. Here are two of the ones most liked by folks here http://www.totaldieselperformance.com/ DP-Tuner

The later ones also have a intercooler.

you are backwards on teh turbo statement, the 94-97's have a larger turbo. thus why we dont have wastegates on them.

but to make it simple,
mecanical vs electric fuel pump.
angle of attack in hpop is different,
intake manifold are larger on sd's
turbo is wastegated on sd
intercoolers on sd's
single shot vs split shot injectors

X2 what Joe said.
The cool thing is we can add all of the 2000-2003 parts to our trucks. Just need to modify our firewall and make sure to get all of the related parts when we upgrade.

The reason the 97 Cali models are a little stronger than the other OBS trucks is that they got the larger AB code injectors, 120cc split shots that the early 99's have. The other OBS trucks have AA 90cc single shot injectors.

Quote:

Originally Posted by c00nhunterjoe (Post 8268211)

you are backwards on teh turbo statement, the 94-97's have a larger turbo. thus why we dont have wastegates on them.

but to make it simple,

mecanical vs electric fuel pump.

angle of attack in hpop is different,

intake manifold are larger on sd's(on late '99-'03, Early '99 had same intakes as the OBS)

turbo is wastegated on sd(with diff. compressor wheel and housings and prone to compressor surge)

intercoolers on sd's

single shot vs split shot injectors(single shots were 90cc and splits were 120cc)

pistons- SD had lower intermediate ring groove with bigger ring

crankshaft

SD cam doesn't have the mechanical fuel pump mojig

OBS- 100V IDM..... SD- 120V IDM

OBS pcm reads the MAP by frequency instead of voltage like the SD

i added a few to Joe's list. the SD's had quite a few more changes to them than ppl recognize b/c they are essentially the same engine. the SD pistons will go in these trucks, but SD rings won't work on our pistons. we cant use the SD crank i don't think, but i gotta look at the difference between the 2 b/c the SD's were weighted differently. there may be more differences. i will look.

we can do anything to the OBS that can be done to the SD's. chips, injectors, turbos, regrind cams(gotta use an SD cam), pistons, rods, girdles, etc. hahahaha

tatsch your list isn't all correct. Only early 99's have 120cc splits, late models have 140cc splits.
Early birds have a 110v IDM, late models have the 120v.
Early 99 compressor wheel, aka wicked wheel, same as OBS
Early 99 has a w/g turbo, but it is physically smaller than the late turbo even though the A/R is the same

Quote:

Originally Posted by superduty4x4 (Post 8269973)

tatsch your list isn't all correct. Only early 99's have 120cc splits, late models have 140cc splits.

Early birds have a 110v IDM, late models have the 120v.

Early 99 compressor wheel, aka wicked wheel, same as OBS

Early 99 has a w/g turbo, but it is physically smaller than the late turbo even though the A/R is the same

this is true. got in a hurry since i'm at work. thanks for the correction. not many people know that the crank, pistons(ring grooves), and rings are different though. haha.

Quote:

Originally Posted by strokin'_tatsch (Post 8270053)

this is true. got in a hurry since i'm at work. thanks for the correction. not many people know that the crank, pistons(ring grooves), and rings are different though. haha.

Very true, I wasn't aware of that stuff either. I wonder if the change to the crank came with PMR's? Any chance you have access to an SD forged rod block to compare an OBS, SD forged, and SD PMR crank?