So I got the x51 in my 04 Porsche. I was thinking about upgrading to a IPD plenum. I do have K&N CAI. What are your guys thoughts? Is it worth the money?

 

I have one and it is a nice mod. I would only do it if you are going to do a chip upgrade and also a free flowing exhaust.

 

What kind of upgrades you have? How is the performance difference?

 

Revo Chip
Plenum
EVOMS Intake
FVD Exhaust (Headers, X-Pipe 200 cell Cat's, Exhaust)


Here's an old dyno sheet after the mods (this was with my previous Maxspeed full exhaust)




Recently installed the RSS Underdrive pulley (and bypassed the A/C Compressor). This is a real nice mod.

 

Sometimes I forget what bolt on's I have. I have it too along with EVOM Intake, GIAC and GHL exhaust. I know from several fun runs that I'm quicker than stock 996's and a little quicker than 996"S" with exhaust mods. I did dyno too years ago. I'd have to find the numbers but I think I recall 300whp using a dynojet machine.

 

What does the RSS underdrive pulley do? is it something you can "feel" by the seat of your pants?

 

It's a smaller diameter crank pulley and smaller belt. Therefore you slow the use of the other accessories (alternator, power steering, water pump and a/c compressor). The slowing of those accessories frees up WHP. I had a problem with my a/c compressor, so for now I bypassed that as well (therefore using an even smaller belt). I can definitely feel seat-of-the-pants gains. The power feels more much more contiguous...

 

good to know..

did you get the shortened belt from RSS as well? is it a complex install do you need any additional bolts when doing this...?

 

Which K&N intake are you running, and what's your normal type of driving (city/highway/track)? You need to use a cold air intake that doesn't draw in air from the very hot engine bay, especially if you're not typically driving at high speeds. The location of the filter in car with most cone filter setups means you're getting a whole lot of hot air into the engine and probably hurting your performance.

 

RSS does not supply the belt but it's a common Gates belt that can be had locally. The install is pretty straight forward. The only "tricky process" is shaving down the Timing Boss which is a small metal part that sticks out of the block. For that you will need a powered grinder. Here's a picture of the boss after being removed (see clear silver area) and the pulley installed. Notice I was changing out my water pump as well...It's easier to do the water pump with the crank pulley removed.

 

I have the Regular K&N, I think they only make one for our cars? I do have a 997 GT2 wing with the air scoops that feed directly into the bay.