Forum Discussion

bucky's avatar
bucky
Explorer II
Feb 15, 2014

Want towing comparison between OBS 7.3 and SD 7.3

I have a shot at a primo 97 7.3 and was wondering how it would pull without the intercooler that came with the newer 99-03 Super Duty 7.3s. I could always add one, but how does the actual towing power compare stock to stock? I previously owned a early 99 Super Duty, but this truck is many miles away. I would not be able to test pull with it before buying it. Any input would be appreciated, thanks.
  • My 97 Pulls my 12,500lbs 5th no issues, I have full set of gauges and run 4:10 gears. I run TS chip and run it on the 50 HP setting all the time. I have looked at adding an intercooler, but what I have found A Snow Methanol injection system would cost less and add more power while keeping EGT in check.
  • Mild tow tune, gauges (especially EGT), intake, 4" exhaust and you should be sitting pretty, that is if everything is functioning properly. You should have no problem with close to 500lb. torque.

    I would have no problem driving a P.S. 7.3 OBS if well maintained, running properly and the above mods. They are sweet looking with an awesome engine, just too doggy for me bone stock.
  • I have a 1997 F250 Powerstroke with 250,000 miles on her and pull a 37' fifth wheel. All I have done to the truck is a tuner, intake and exhaust. I pulled about 10,000 miles last year and it does a great job. You will not be the first one to the top of a 10,000 ft pass but you will get there. The only problem I have is keeping the EGT down on long hills, I have an intercooler ordered to address that issue. The best part about the 7.3 is they are pretty much bulletproof without all of the problems associated with the newer, more complicated diesels.
    Can't comment on the newer 7.3 but hope this helps.
  • OBS 7.3's have 90 CC injectors, no intercooler, and a smaller high pressure oil pump. The early 99's were a step up and the late 99's to 03's better yet, I think 120 or 130 cc injectors, intercooler, 17* high pressure oil pump and better air flow into and out of the engine.

    You can really wake up an obs 7.3 with aftermarket (bigger) injectors, slightly bigger high pressure oil pump and some custom tunes to match the engine mods. Do not buy out of the box programmer for the 7.3 engine!!

    Tranny may need mods after engine mods, but if driven responsibly will last a while before needing strengthening.

    Hope that helps.
  • Yeah, it's pretty slow in comparison to the SuperDuty (which is still pretty slow stock compared to the 6.0 PSD or the V10).

    Add an intercooler, open up the exhaust, add a programmer, and then you'll have a truck that's competitive with something newer.
  • My mom's '97 is a turd. Slightly better after they threw a bunch of money at Banks to help it get out of its own way.
  • I surprised myself by finding some info. Look at this article in Wiki for the power ratings year by year:

    Wikipedia

    It started out at 185 HP/350 Ft-Lb and at the end of it's model life was at 275 HP/525 ft-lb. That doesn't directly tell you what it could tow but it will give you an idea. Hard to believe that the intercooler made that much difference.

    I'm not sure if Trailer Life's ratings go back that far but you should check those.