Lucio Cesaro

Hello everyone. I joined the forum as I saw discussions about the 981 engines. I just wanted to know how it was possible that the base model with the PSE, 2.7, was louder than the 3.4. Shouldn't it be the other way around? How can you explain this to me? I just ask for information, thank you very much.

cjrhoades

Link to the discussion you're speaking of? Assuming the exhaust systems are identical (headers, cats, mufflers, piping length/diameter, etc), the exhaust valves are the same diameter, and the exhaust ports on the heads are the same length, shape, and diameter, then theoretically the 3.4L engine should be louder as it has a longer stroke which would make the piston speed higher causing the exhaust gasses to be expelled from the cylinder at a higher velocity. That's a lot of assumptions though and I doubt the engines actually share that many parts. There's too many variables to say for sure which "should" be louder.

RGS

Did the 3.4 also have PSE?

hsattley

My understanding is: comparing a 2.7 and 3.4 without PSE, the 2.7 has a freer flowing exhaust. Porsche had to find some way to up horsepower despite downsizing from the 987.2’s 2.9 unit. See: https://www.caranddriver.com/reviews...-drive-review/

The 3.4 is also essentially a slightly reworked version of the one in the 987 S, so assuming they kept the exhaust similar for the 3.4 in the 981, it wouldn’t be impossible that the 2.7 is louder. I have driven a base and S 981, both w/o PSE, back to back, and I also found that the 3.4 was quieter. If the 2.7 with PSE is louder than 3.4 with PSE, then it’s likely something to do with the engine itself because I assumed that the PSE is the same for both cars.