Why do 99.5+ superduty 7.3's have different hp ratings?

George4 · Feb 3, 2013

So I am talking about 99.5 through 2003 7.3L Powerstrokes. This might sound like a newbe question, but I know the ones with manual transmissions have slightly more power, but why? Besides the PMR starting in 2001 what is the reason for hp difference? Is it all just tuning to keep up with the competition of the time? The reason I started thinking about this is that I was emailing a tuner about getting some new tunes and at the bottom of the email it said. "Stock HP Ratings... 99-00 trucks are 190rwhp 2001-2002 trucks are 220 rwhp rated .....Torque stock is 525lbs" And it just got me wondering. Thanks
~George

JLDickmon · Feb 3, 2013

George4 said:
So I am talking about 99.5 through 2003 7.3L Powerstrokes. This might sound like a newbe question, but I know the ones with manual transmissions have slightly more power, but why? Besides the PMR starting in 2001 what is the reason for hp difference? Is it all just tuning to keep up with the competition of the time? The reason I started thinking about this is that I was emailing a tuner about getting some new tunes and at the bottom of the email it said. "Stock HP Ratings... 99-00 trucks are 190rwhp 2001-2002 trucks are 220 rwhp rated .....Torque stock is 525lbs" And it just got me wondering. Thanks
~George

Dunno.. wiped the tag off on mine doing GP's Saturday and it said 250 hp.

dentexpowerstroke · Feb 4, 2013

I have never heard 190 and 220. My 01 tag said 250 too

smokedout250 · Feb 4, 2013

Our 2000 f450s are 235....

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Petro · Feb 4, 2013

My 99 is 235 and my Dads 97 is 225. Honestly the 97 has more power than my 99, or at least it feels that way.

bad12jr · Feb 4, 2013

Weight difference and probably 4:10 vs 3:73 gears. My obs feels quick compared to the SD.

Sent from my x2 chillin in the middle of no where

Bobby@cp · Feb 4, 2013

Op stated rear wheel horsepower, tags on the motor state flywheel horsepower...... Just to fix any confusion.

George4 · Feb 4, 2013

Bobby@cp said:
Op stated rear wheel horsepower, tags on the motor state flywheel horsepower...... Just to fix any confusion.

Thanks for bringing this back on track. I am glad someone caught rwhp...

85_305 · Feb 4, 2013

Petro said:
My 99 is 235 and my Dads 97 is 225. Honestly the 97 has more power than my 99, or at least it feels that way.

Agreed. My 6spd 99.5 felt MUCH slower than my lifted/35's stock OBS did. Due to weight-differences namely.

Bobby@cp · Feb 4, 2013

My stock 02 feels faster than my 97 and that one had a chip on it

George4 · Feb 5, 2013

Any ideas? Is there any mechanical differences besides forged vs pmrs during those last few years of the 7.3 that would raise HP?

Petro · Feb 5, 2013

I imagine it was just to keep up with the competition.

George4 · Feb 5, 2013

Petro said:
I imagine it was just to keep up with the competition.

Do u think that ford just tweaked the tunes a bit from the factory?

Petro · Feb 5, 2013

Yep, I believe you could put an 03 pcm in a 99 and have a few extra ponies.

dietoremain · Feb 5, 2013

Aftermarket tunes will raise ya somewhere in the 300 something range in the rear wheel.

Morgan@Midwest Diesel & Auto · Feb 6, 2013

Petro said:
Yep, I believe you could put an 03 pcm in a 99 and have a few extra ponies.

Ya and I'd like to count how many codes came up after you did that. And it probably wouldn't do very much for overall performance.

Too many things changed between those years to just swap a PCM out and make more power. Truck definitely would run funky.

Arisley · Feb 6, 2013

Sledpull said:
Ya and I'd like to count how many codes came up after you did that. And it probably wouldn't do very much for overall performance.

Too many things changed between those years to just swap a PCM out and make more power. Truck definitely would run funky.

Not even sure if it would run, they changed a lot of wiring in '02.

seeyalater5.9 · Feb 6, 2013

Bobby@cp said:
My stock 02 feels faster than my 97 and that one had a chip on it

your chip must of been really weak or your 97 had something wrong with it IMO..

the 7.3 SD's are DOGGGGS. Cant get out of their own way :lame:

George4 · Feb 6, 2013

seeyalater5.9 said:
your chip must of been really weak or your 97 had something wrong with it IMO..

the 7.3 SD's are DOGGGGS. Cant get out of their own way :lame:

What is the weight differance between the OBS and the SD? You would think a better HP to weight ratio means more go unless you are compairing a OBS truck with 4.30 axle to a SD with a 3.73. And I think almost all 7.3s are kind of weak without a tuner, but we are talking about a engine that they quit making 10 years also. You also need to compair them to the other trucks that are older than 10 years before you can say they are dogs.

85_305 · Feb 6, 2013

George4 said:
Any ideas? Is there any mechanical differences besides forged vs pmrs during those last few years of the 7.3 that would raise HP?

George4 said:
What is the weight differance between the OBS and the SD? You would think a better HP to weight ratio means more go unless you are compairing a OBS truck with 4.30 axle to a SD with a 3.73. And I think almost all 7.3s are kind of weak without a tuner, but we are talking about a engine that they quit making 10 years also. You also need to compair them to the other trucks that are older than 10 years before you can say they are dogs.

Most obs trucks are between 6000-8000 lbs and typically have 4.10 gears. Most superduty's are between 8000-10000lbs and have 3.73's.

Again, keep things in perspective; go drive a stock 160hp cummins....if you think a 4.10 geared powerstroke is weak, drive a 160hp 12v inline motor w/ 3.53 gears and a defuel set to 2100 rpms.