Hidden HP

[Shier32]

How much HP is hidden in the 5.3?

 

- Chevy rates the 5.3 at 355 hp, and 383 tq, 16/23 mpg.

 

- Ford rates the 5.0 at 360 hp and 380 tq, 14/19 mpg.

 

- Ram rates the 5.7 at 395 hp and 410 tq, 13/19 mpg.

 

Are these numbers purely a tuning issue so GM can claim highest MPG? It seems we should be getting a little more hp.

[fondupot]

I'm sure there is a good 30-50 hp detuned from the motor. Thats just a wild ass guess tho. Heck just using E85 raises the HP rating to 380. Im sure the motor is capable of that figure with regular unleaded when properly tuned.

[RyanbabZ71]

Adding decals opens up HP also

 

 

Ryan

[Northside]

How much HP is hidden in the 5.3?

 

- Chevy rates the 5.3 at 355 hp, and 383 tq, 16/23 mpg.

 

- Ford rates the 5.0 at 360 hp and 380 tq, 14/19 mpg.

 

- Ram rates the 5.7 at 395 hp and 410 tq, 13/19 mpg.

 

Are these numbers purely a tuning issue so GM can claim highest MPG? It seems we should be getting a little more hp.

Of course there is more HP there. These numbers are pretty much irrelevant as they are crankshaft HP and TQ numbers. That makes it hard to compare to them after mods of any kind. Now if we get rear wheel numbers from a chassis dyno then we can compare real world gains from exhaust, intake, and tuning mods. Of course the numbers would be substantially lower and not as impressive at the rear wheels due to power loss through the drive train. I wouldn't worry about numbers any way. Performance increases aren't necessarily gained by peak numbers. What matters is the entire power curve. Increasing low end torque, and mid range power will make a truck perform best, not peak horsepower. Many a drag race has been won by the vehicle with lower peak h,p. numbers but better overall power curves. Ever notice how diesels never have high horsepower numbers but sure perform well in a truck.

[thewhitestallion]

Adding decals opens up HP also Ryan

 

true statement. mine has the z71 sticker on the side of the bed and according to my but dyno I gained about 15hp. the more stickers on the vehicle the better! all I need now is a vtec sticker and a "NOS" or naaaaawwwwwzzzz sticker and i'd be set.

[scooby5121]

 

true statement. mine has the z71 sticker on the side of the bed and according to my but dyno I gained about 15hp. the more stickers on the vehicle the better! all I need now is a vtec sticker and a "NOS" or naaaaawwwwwzzzz sticker and i'd be set.

I put a camo sticker on,,, Now I am Invisible ...

I did not need to do a dyno because I cannot find my truck now. Should of put a tracking unit sticker on to so I can find it.

Scooby

 

Oh, answer to the original question... they do the numbers so the automakers can pump out more bigger gas drinkers if they show they are making lots of fuel economy in their other engines.

[Chris]

 

How much HP is hidden in the 5.3?

 

- Chevy rates the 5.3 at 355 hp, and 383 tq, 16/23 mpg.

 

- Ford rates the 5.0 at 360 hp and 380 tq, 14/19 mpg.

 

- Ram rates the 5.7 at 395 hp and 410 tq, 13/19 mpg.

 

Are these numbers purely a tuning issue so GM can claim highest MPG? It seems we should be getting a little more hp.

 

 

Of course there is more HP there. These numbers are pretty much irrelevant as they are crankshaft HP and TQ numbers. That makes it hard to compare to them after mods of any kind. Now if we get rear wheel numbers from a chassis dyno then we can compare real world gains from exhaust, intake, and tuning mods. Of course the numbers would be substantially lower and not as impressive at the rear wheels due to power loss through the drive train. I wouldn't worry about numbers any way. Performance increases aren't necessarily gained by peak numbers. What matters is the entire power curve. Increasing low end torque, and mid range power will make a truck perform best, not peak horsepower. Many a drag race has been won by the vehicle with lower peak h,p. numbers but better overall power curves. Ever notice how diesels never have high horsepower numbers but sure perform well in a truck.

 

Also these numbers are without the parasitic accessories like power steering and air conditioning.

[iCryWheniGoPoop]

Also these numbers are without the parasitic accessories like power steering and air conditioning.

In this forum section... Power steering is not parasitic.

[Chris]

There is still ac and alternator. I forgot about the move to eps. Even though the f150 in my backyard has it. But point is the numbers given in specs are of a stripped down engine with the best possible controlled conditions with their stock tuning.

[MikeNH]

Actually the numbers manufacturers supply are supposed to be a fully dressed engine.

[Chris]

Guess I spent too much time doing ag engines. Our runs were basically bare engines

[MikeNH]

It used to be that way. All the muscle cars from way back were measured on stripped engines, open exhaust, high octane fuel and so on which was how they got such huge numbers for their day.

[jcastyo]

Just a question but if there is hidden power in the GM engines wouldn't it be true with the Ford and Dodge engines as well. I mean with a tune on the Ford's and Dodge's there will be an increase in power as well.

[iCryWheniGoPoop]

Just a question but if there is hidden power in the GM engines wouldn't it be true with the Ford and Dodge engines as well. I mean with a tune on the Ford's and Dodge's there will be an increase in power as well.

Correct

[KARNUT]

The ford ecoboost V6 goes wild with a tune, I would say how much but people would say Im hitting the bottle already. I thought about it but, got to have that V8 GM sound.