desmotesta

Simply put, more volume of Air IN and Out will have positive gains BUT.. The Stock Cat and Exhaust is already a choke point due to Emissions. Adding more intake volume isnt going to result is any gains unless that Choke point is rectified.
If someone wanted a Single Bolt-ON Mod on an N/A engine that is sure to provide noticeable and usable gains, its Sport Cats..Period.. Most conservative estimate on the 3.8L is at least 18-20 RWTQ/HP
If someone wanted to do things right, add IPD, TB, Sport Cats and Tune.. Now you are talking a ton more money, and the most conservative gains may be in the 25-27 RWTQ and HP

Your choice is pretty clear..

AdamSanta85

I just got off the phone with Dundon Motorsport, discussing their intake runners for our car. They suggest pairing it with a stock plenum and stock throttle body.

I was under the impression the Cayman GT4 CS intake manifold would fit our car but we were recently informed, no, it has clearance issues in some areas.

Would really love to find a set of these used...

https://www.dundonmotorsports.com/pr...rs-981991-3-8l

IXLR8

Spot on, especially the last part. Best money I ever spent.

George from MD

Thank you. I really believe that. One day at a DE event will take far more off your lap times and make you a much better (e.g.... faster) driver than any app will. I've seen it happen often.

IXLR8

This coming from an ex-flight instructor with thousands of hours teaching students. Both the instructor and student learns. And after you get your private or commercial, learning never stops.

AdamSanta85

Nice, that’s a sweet system. I have the Fabspeed catted headers and Cargraphic cat back. I had similar observations of increased mid range and torque.

The intake runners supposedly add another 30whp to the high rpm range. Similar to what the dyno of the X51/GTS cars look like.

George from MD

I'm too old to get my pilots license now but always wanted a Cirrus SR22. I spent 20 years plus teaching DE and was amazed that students (as well as myself) could take tens of second off their lap times by just learning in a day or two. Mods (IMO) are mostly for street poseuers- but if you really track the car and have already taken it to its limits (and of course your own) good on you,

I never made one mod to the engines in my cars. But the brakes and suspension were a whole nother matter. And I had about 80 hours in a Piper before the wife said no.

Engine mods (IMO) are a way to void your warranty, reduce reliability and make wanna be tuners rich. Especially that stupid plenum.

IXLR8

Same here and if I wanted or needed to do anything, it would be to my brakes or suspension (tires as well) as I often recommend. But they are fine x 1000 on my GTS for street use. In my motorcycle world of almost 50 years, you'd see all these riders modding and when there is nothing left to buy, they sell it and start all over again with another new motorcycle. LOL

malahhaor

Unlike most people in this thread, I had one on my 997.1 and i currently have one on my 991.1 3.4L. Granted different designs but effect is similar. I can tell with most certainty that there is a difference. i don't know how having it and not being able to tell a difference is possible...
Granted i already had xpipe when ipd was installed. But there is a clear and good difference after about 3k rpm in the mid range. Dont know if there is much power at high end but very noticeable in mid.
Its almost as if there is a rush coming on accompanied by a light whistling noise form the extra air intake takes in. Imagine a turbo spooling but a very small fraction of power. It made the car very enjoyable to drive if you're in mid range allot. For me its a DD so im in it all the time.
Not a singe person will be able to convince me otherwise, and please don't bother. I don't need to prove it to you with dyno charts. It makes a difference and makes the car more enjoyable in daily driving even if total power output is same.
OP, real question is; are you willing to spend that money? Is it worth it to you? I got mine used and dealer charged me allot less because they were in there already doing heatshield recall.