You probably have to be 40 or older to really understand my curiosity here, but stock engines have gained so much power over the last 20 years it gets me wondering where it is all coming from (talking NA not turbo). Yes we have the new technology such as variable valve timing, excellent fuel injection systems, etc., but it still doesn't seem to add up:

My 2012 Super Duty 6.2L - 385 SAE Net HP
1970 454 Corvette (7.4L) - 390 BHP

1970 Corvette: Road Test of the 1970 Chevrolet 454 Corvette - Full Authoritative Test of the 1970 Chevrolet 454 Corvette

Now, the BHP rating used in 1970 produces a higher number than the SAE Net HP used since about the mid-1970's. BHP is measured without any of the belt-driven accessories, and with no restrictions for the intake or exhaust, while SAE Net HP requires all the accessories AND even the entire exhaust with the catalytic converter!

Wikipedia article on horsepower: https://en.wikipedia.org/wiki/Horsep...ower_.28bhp.29

It takes some work hopping up an engine in the traditional way, a big Holley 750 four-barrel, Edelbrock intake and exhaust headers, a hot cam, spark advanced right up to the edge of spark knock, maybe a balanced and blueprinted crank...

Also, in the 6.2L forum for example, I don't seem to see much discussion of hopping them up other than chipping the PCM. I haven't seen many ads promising significant power gains from better exhaust components, and certainly not anything like intake manifolds.

So is fuel injection and variable cams, and constant engine "tuning" by the PCM, giving most of this huge power increase? Has computer modeling provided manifolds that are so good that there is no point swapping them out?

What are your thoughts regarding the huge power increases of factory stock engines?

 

Computers are responsible but not the ones controlling the engine in these vehicles it's the computer designing them. The Big advances have been in increasing airflow through the motor, simple enough since an internal combustion motor is just a big air pump right. But the trick has been to do that while meeting ever stricter emissions standards and that is where computer design has proven it's value. It's safe to say modern engine designers know more about making power efficiently than they ever did, so much so when you turn them lose to have some fun they can easily come up with a 700hp N/A V8 if they want to, but can also design a 350hp motor that will pass Cali emissions tests.