home made true cold air intake

[jacabean]

i think a larger throttle body and tee would be a better project to do.

[Topless]

Originally Posted by jacabean

i think a larger throttle body and tee would be a better project to do.

As long as you are attaching that larger TB to a shiny 3.6L motor you got a winner.

[jaykay]

Actually I think jhandy and sparker's intake arrangements are quite good and show some nice design sense.


Gentlemen some points to consider:

-Some are into design development and testing (hard to do accurately without lots of cash) and some are not. Perhaps a hobby to some? To each his own.

-To some an extra 10hp is worth looking for (track; racing...); optimization etc. Don't worry about it if you are just cruising about

-There seems to be some evidence to suggest that the 3.2L has been detuned. This would likely include intake flow area/lose restrictions. Of course you have to correct them all (and no warm air) in unisom in order to have some hope of good results.

-Of course big air box intake systems are likely the most efficient and the way to go

..... but I wouldn't be too quick to discard jhandy and sparker's intake arrangements and lump them in with crappy hot "cold" air intakes. They are actually very good conceptually; have a closer look and understand. They are sealed cold air intakes that could outflow the stock air box. One would have to test to know. Their arrangements are not unlike (perhaps better as they offer better filter protection) the set up now used on some racing Caymans.

-Have a look inside the stock airbox you will find a small snorkle in there. What is its flow area?

-Is the stock TB @ 68mm dia (less than three inches) an intake choke point?

-Is the the intake runner velocity ultimately metered at a 3.5" dia. for the left and right plenums and is this flow dia arrangement better served by a larger TB?

-What are the experiences of IPD plenum users with larger TBs?

[Ghostrider 310]

I agree with Jaykay, there are also the factors in manufacturing such as cost containment and especially German TUV noise standards. I think TUV is the reason the intake sounds are so muffled. Some 986 information seems contradictory, for example, there are numerous people saying reducing the back pressure with headers would reduce the HP as well. Theory was based on a given needed amount of BP for the flat six to run correctly. In my experience the headers made a difference, I didn't measure it but I did hear and feel it. I've also noticed when reading about modded Porsche cars in excellence, exhaust is frequently changed in diameter or configuration for more power.