what the difference between the 7.3's?
#1
12-20-2009, 02:52 PM
Join Date: Nov 2009
Location: Crapy southern New Jersey
Posts: 4,556
Likes: 0
Received 0 Likes
on
0 Posts
#2
12-20-2009, 03:00 PM
Hotshot
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.
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.
#4
12-20-2009, 03:06 PM
Join Date: Nov 2009
Location: Crapy southern New Jersey
Posts: 4,556
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
#5
12-20-2009, 04:31 PM
Posting Guru
#7
12-20-2009, 07:37 PM
Last edited by plowhand; 12-20-2009 at 07:37 PM. Reason: spelling
Trending Topics
#9
12-21-2009, 10:53 PM
Post Fiend
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
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
#10
12-22-2009, 01:01 AM
Join Date: Mar 2006
Location: Vacaville, Ca
Posts: 7,841
Likes: 0
Received 0 Likes
on
0 Posts
#11
12-22-2009, 09:40 AM
Hotshot
#12
12-22-2009, 12:53 PM
Post Fiend
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
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
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
#13
12-22-2009, 01:24 PM
Hotshot
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
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
#14
12-22-2009, 01:57 PM
Post Fiend
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
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
#15
12-23-2009, 09:10 AM
Hotshot
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?