the RMM looks like it's only a filter with an adapter braket an heat shield. that is why i got the k&N it's a complete sytem and it's CARB, so if you are in cali you will pass smog. the K&N sounds mean. i can hear it over exhaust on high rpms.

 

I bought the K & N FIPK about 2 years ago and absolutely love it! I purchased the 3.5" intake piping (1 90 degree and 1 straight) and simply extended the K & N intake (no altering was involved). The only thing that I had to do unfortunately was to cut a 4" hole through the metal plate behind the headlight in order to have the piping run into the wheel well. Performance... I noticed a definite increase in power especially at higher RPM's. At lower RPM's it almost feels like it has slightly more lag but when it hits it throws your head back!!! (like a very small turbo feel) I think this lag is due to the 90 degree bend that I used. I am in the process of purchasing a 45 degree intake pipe to angle in there a little better and make air flow not as abrupt as it is in the 90. I believe this will *help* with the lag issues (eventhough it is not much more than when I just had the K & N FIPK intake in place). I also have done some research with regard to a tapered design on the intake piping. I might buy a straight and a 45 degree in only a 3" or 2.5". I read that the larger the piping will take longer for air to swirl into the throttle body than a smaller pipe. However, go too small and your hurting performance. Now, if the natural vacuum from the engine is pulling a certain CFM and you have a smaller intake pipe in the beginning of the intake then it might be able to ram more air faster into the rest of the intake (larger diameter) thus pushing more and faster into the throttle body. After ALL the reading I have done on the internet I have concluded that not only it's the temp. of the air, and air velocity (CFM) but it's also the swirling effect of the air before it enters the throttle body ...there are different designs in intake systems that can take advantage of ALL of these items if customized properly (very simply DYI). As far as my lower air dam... I installed a sliding mechanism. When it rains heavily I close the slide (last pic)...when it's dry out I open it up (second to last pic). I noticed another gain on this especially of speeds above 30MPH...pulls even harder than just the CAI extension. The only downside is that the filter gets dirtier faster. Every little bit of power helps...especially if you wind up doing internal motor work the mods will have more of a performance effect with a better intake setup. Thanks for all the comments.
-Nick

 

Would you mind telling me where you purchase the pipe at?

 

I purchased the piping at a local speed shop. However, sfxperformance.com sells intake parts such as piping, filters, adapters etc.

 

does anyone know where the intake air temperature sensor is on the 98' gs400? need help, thanks

 

what do you do with the second rectangular intake that goes to the engine cover? Its where the maf sensor is now, it would originally go to the engine cover.

 

The MAF and ALL stock vacuum hoses hook up to the K & N FIPK intake perfectly...nothing is left out or bypassed!

 

I am in the process of having a local fabricator put together a cold air setup for me and that is definitely good to hear that you feel a difference. I figured that would be the case though because on the dyno there really isn't enough airlfow to give you real world results. Once you get on the road and that cold air is moving through the front is when you see that extra power.

 

Exactly!!!

 

how hard is it to take the filter on and off do u have to take the whole bumper off or what?

 

you dont have to remove the bumper at all. its a piece of cake to remove. just a few bolts and clamps.

 

i got the K&N and you guys are all right. there is a lag until you get to about 2500 RPM. then it takes off. Does anyone know if putting a full exhaust including headers will help with the low end torque that the K&N takes away??

 

Yes, and if you want to completely burn your tires up from a stand still, buy a 3000 stall PI TC. About $800 bucks and another $500 for the install.

 

sorry im a bit dense , so once i get everything installed and done. and a few months later, the filter is dirty and i want to clean it, how would i go about taking the filter out of the bumper once i get it off the intake tubing? if that makes any sense

 

you are talking about if you had rock-a-lex's setup?? if you are you would have to remove the bumper im sure. but the K&N filters can be washed once they are dirty.