now ive tried many variations of the intake and exhaust set ups on the HC 929 with the stock N/A motor. i suggest cold air and a straight pipe from cat convertor to a chambered muffler and out.
doing the intake is the cheapest HP for the $$$ especially if you do a cold air set up which is slightly harder but not by much.
this is what youll need:
MAF adapter plate (~$25) goes in place of the stock air box. bolts to the MAF sensor & has an adapter for a 3" pipe/filter on the other end.
clamps about 2 or 4 for cold air.
rubber sleeve for pipe if u use one.
a good cone filter, get a K&N (~$25-35) they are good & reusable, lots others even $$$ ones but not necessary. i used a huge k&n filter, 3" and about 10" long. sounds real nice.
3" piping (optional) you can go without it but if you decide to go wid it, youd wanna clamp it right on to the adapter plate. its gonna be better than the stock set up but it will be around warm air especially in those hot Georgia summers. thats why i think its better to get a 3" pipe about a foot or more in length but with a 90 degree (i think) bend, bascially enough bend to reach into the lower fender after youve drilled a 3" hole. i borrowed my piping form a Accord short ram intake. look at my pic and look under the area where the stock air box sits, you will see where intercooler piping would have run if this car where in Japan with the 2L turbo option, and thats where i drilled my hole for the intake pipe. basically you are putting the cone filter in the area where the intercooler was ment to be if our car was in Japan with the turbo engine.
see how i have the stock ducting and how i drilled a small hole for the vacuum line to run into the pipe. you will have to attach the metal bracket with the other vacuum lines and wiring like i have did to the stock support of the air box
u can see where the intake pipe bolts to the MAF or watever and its connected with a sleeve, i borrowed a AEM one from a friend. u can also see the small vacuum line run into the red pipe, and the it disappears into the fender. i later ripped out my intake duct.
going with a custom set up is the next best bang for the buck, its easy on the 929. I suggest spend the extra $50 on piping a get it straight through from the cat, deleting the stock resonator and RV sized muffler. thats what i have but i finish mine off with a N1 style muffler. a Dynomax with a nice tip will work fine.
use no bigger than 2.5" piping, see how mine goes way back to the cat. its straight through and using a chamber styled muffler (Dynomax) will be alot quieter than my straight through muffler
at the time 2 years ago, this is the style i liked, the muffler also sits angled and slanted upwards/outwards. i would like to change it if i could afford too wid something more classy and VIP stlye.
im never doin this again it will be archived for ever now !!!