More C8 HP

When they advertise 490 engine HP it may not be what you think you get.

Just for information

When they say it is 490 HP certified to SAE J1349/J1995 then they ran a number of engines per the SAE J2723 procedure( GM follows SAE). Then there are issues of Green engines( not run in) and the engine dyno(which must be calibrated to a set standard. The SAE Standard conditions corrects for a number of items such as air pressure, humidity, temperature, etc. There are also ISO and DIN Standards.
Most shops use a chassis dyno, which are much less accurate as it has to be corrected/estimated for many other factors to get back to engine HP. Then there is the issue many shops use STD(4% higher) not SAE for corrections. So it is very difficult to compare chassis dyno numbers to engine dyno numbers.

So After all is said and done in your real life application on the street at the air temp of that day and humidity, fuel quality used and barometric pressure, your engine as it is will make between 450 to 520Hp.
So basically, you can say your engine makes over 500HP on a good day.
HP ratings on engines have always been a contentious issue. As even when run back to back on a good dyno in a controlled room they can vary by 1%(4.9HP in your case)
Hope this helps.

A good site

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Excerpt:

Since very few engines are actually run in these conditions we apply these correction factors so that it is possible to compare the results taken on different days. First lets just look at the weather correction, we will see the second section dealing with mechanical efficiency later. Consider if you take a baseline run of a normally aspirated four stroke V-8 engine on a sultry day in late August, say 85°F and 85% humidity and 28.85 in-Hg and the engine produced 400 Hp. Then after you finished making all your modifications you retest the engine in late September when it is 55°F and 35% humidity and 30.10 in-Hg, the engine now makes 442 Hp. That’s almost an 11 percent increase in Hp, however the engine is actually producing the exact same amount of horsepower according to the J607 correction values of 400 Hp * 1.1005 ≈ 440 Hp and 442 * 0.994 ≈ 440 Hp. If you had retested the engine in the same weather conditions it would have made 400 Hp again.

Just for info.

C8Dave said:

How can I add 5 plus HP to my Z51 2022 C8 without super/turbo charging or expensive aftermarket exhaust system?
Is there any inexpensive chip/tune/cold air modifications available to do this?

Click to expand...

Dave, I own a C-7, so I'm not versed on how your C-8 will react to some small but effective changes that I found made my car really respond well. Not to give them a shameless endorsement, but I found removing the paper filter element and going with a K&N Filter in place of the stock filter improved things noticeably- probably a very realistic 12 to 15 horsepower to the rear wheels. I also found out that the stock Delco ignition wire had deteriorated quite a bit. I bought my C-7 with 12,000 miles on it and tested the Ohms of resistance in the @ 10 inches of each wire. Turns out there was about 5000 to 7000 ohms in each individual wire. I replaced it with MSD Super Conductor 8.5 mm wire. There was @ 40 to 50 ohms in each new MSD wire and that lower resistance fired the spark plugs very effectively. The wire change did not necessarily make more horsepower, but it did restore the ignition systems ability to fire the plugs at any rpm level just as it did when it was a new car. As I said earlier, I'm not sure if your LT2 uses ignition wire or has coil on plug ignition. Obviously if it is coil on plug, the voltage to the plugs is substantial, and that is good. However, the K&N filter will definitely bump your horsepower enough that you should notice n improvement in acceleration.