plenum spacer or plenum replacement?

[chad1200]

the cost to space my g35 sedan's plenum is about $290-$325 Motordyne). a new plenum (Kinetix) costs $300! which way should i go on this? I also see that there's a 1/2" spacer and a 5/16". looks like most of you guys go with the 5/16". why not the 1/2"? i have an 04 sedan, fyi.
Modified by chad1200 at 4:08 PM 4/8/2007

[macspeed704]

I am going to purchase the 5/16 spacer because I can use my engine cover. I believe if you use the 1/2 your engine cover will hit the bottom of your hood.

[gjohnson66]

The first thing I would ask is do you want to retain your engine cover? If yes, then both the 1/2" Motordyne spacer and the Kinetix unit are out.

According to what I've come up with, the Kinetix unit should give you the best bang-for-the-buck.

Beyond that, I'd say it's pretty much up to you and what you want to do with the car. Also keep in mind that there are other manufacturers of plenum spacers as well -- Motordyne just the best, IMO.

[joe603]

Read the info on the motordyne website. There is a reason not to use the 1/2" spacer besides retaining the engine cover. The larger spacer will decrease HP in non-boost apps due to fluid dynamics...

[chad1200]

i see. that's why the 5/16" is the more common one. thanks guys!!!!