Quiet HP Increase in Exhaust
 

Which is the quietest performance exhaust for a 01 Box S but increases HP among the most popular performance exhaust?

i think that the further you get the cats downstream, the better the exhaust airflow is able to setup and, presumably, add a bit of power. so, some catless headers, and relocate the post-cat o2 sensors to after the secondary cats on the midpipes.

otherwise, 987 exhaust has a better sound and will make more power. apparently it bolts right up.

I’ve read this in multiple places before. I can’t seem to recall anyone having actually used the entire 987 setup to confirm yet. I’d try myself, but it’s hard to find an entire setup in canada for a decent price just to experiment with it.

there are some guys on this board that have done it, just can't recall who. re finding a set, check planet 9 (987 board) and look for take-offs from guys putting aftermarket exhasut on - usually available cheap.

does the 987 exhaust bolt up to all versions of the 986? so a 97 2.5 can use the exhaust from a 3.2 987?

I have a question along these same lines. I have a 03 986S that now has a 3.6 Carrera M96 engine in it. I'm still stuck with the 3.2 exhaust manifolds, cats, etc, but did do the pedro modification to the muffler.

As I know there is some HP yet hiding, I would love to see more horsepower and maybe a little bit better sound but believe that the current primary bore on the exhaust headers need to be bigger than what the 3.2 offer. Does anyone have any ideas? I don't have to worry about emissions.

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Hmm. A guy with a 3.6 in his Boxster and he needs more power. Where does the madness stop!!! :cheers:

Just a little bit more...I live in the mountains and am down at least 10-15% due to altitude. Capiche? ;)

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Unless you have a turbo; unaffected by altitude

well, i've not done it but have communicated with several members who have done it. from what i understand, the only thing which may require a bit of fabrication is how the muffler attaches to the transmission (you may have to mix and match mounting brackets). note that there are several versions of 987 exhaust for the various engines in the car; for 986 applications realise that a 2.5 might want a smaller diameter pipe compared to a 3.6 so choose accordingly.

NA engines are absolutely affected by altitude. Significantly.

The formula for hp loss is "e x 0.00003 x hp", where e=elevation and hp=horsepower at sea level.
A NA car that produces 200hp at sea level will only produce about 168hp in Denver (elevation 5,280ft above sea level).

An '01S 3.2 rated at 250hp at sea level would produce about 210hp in Denver. Just a smidge more than a stock 2.5 base (201hp). ;)


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Interesting post. :cheers: I used to have a GPz 750 Turbo. Always wondered why guys at altitude would pay so much for adjustible boost. Now I know.

It WAS a lot of fun on the road that circles Lake Tahoe. Especially with a muffler that had no packing. I think you could hear it coming 3 miles away.

This from a "responsible senior" https://phoenix.craigslist.org/nph/cto/d/2000-porsche-boxster-turbo/6522725024.html Yeah, right!

This is why it is so easy to get more power out of a turbo engine. The factory tune has to satisfy all the different parameters like altitude, octane level, clean/dirty air filters, temperature range, etc. Manufacturers opt for an average tune that makes everyone happy. If you are at sea level, can get high octane gas and are in a moderate temperature zone it's easy to get 20% more hp and especially torque without any hardware mods.

I'm only 5years late in responding...
 

All,
I just stumbled on to this thread from back in 2018. I suffer from CRS these days and am a bit embarrassed to find this. I am still with original exhaust set-up and did look into 987 manifolds. Turns out I also DO need to worry about emissions. Thanks for your weigh-in!:cheers: