The 1/4 mile track is just as effective and cheaper.

 

The intake manifold is actually below the plenum. There are 3 pieces. The upper plenum and lower, which is like a collector and then the actual intake manifold below it, which is 6 relatively straight tubes, one for each cylinder.

 

Oh, and zmann, did you contact Doug at Crawford Z and ask him what might have caused the problem? If so, what were his best guesses?

In my experience, as my previous post implies, I've found the hp gains with plenum begin to be "noticable" on the 'ol butt dyno about 4k-4500, and really "kick in" at about 5000 (haven't re-flashed my ECU to a higher rev limit yet, and redline just rushes at me from 5k; hard to keep from bouncing off the rev limiter in manual mode) ; to me, the feeling is the same as VTEC kicking in on the '02 S2000 wife and I owned.

 

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Alright, now I'm curious. I sure don't know a ton about cars, but I do know that several people who DO know cars, including several who (drag) race, without me saying the word "plenum," have pointed to my Crawford and asked where I got the "intake manifold." It may just be semantics, but how long has the word "plenum" been around? I can honestly say I've never known a single car buff outside the Japanese make modding community to know what a "plenum" was.

I'm also on a 'vette forum a lot, and I haven't seen the word plenum at all, ever, either to refer to "that part," whatever it really is, or any other part.

 

I first learned what a "plenum" was about 8 years ago when reading the installation manual for an autometer boost gauge that said something like "tap line into vacuum system or directly off plenum."

Yes its sad that I was reading the instructions and not just looking at the pictures.

 

No big surprise, Adam, Doug first told me what one was! AAAAAND I just did a little on-line research on a couple of dictionaries and encyclopedias--very intuhrestink! By FAR the most common engineering/mechanical use of the word is in the heating and A/C context, which makes sense when one considers the most general def. of the word that applies to our cars, i.e., an enclosed space which gathers air for distribution.

 

I noticed last night that my crawford V5 plenum - the nylon washers on the top two bolts in the middle of the plenum were melted to CRAP

probably was leaking air

I'm using metal ones now...

 

. . . And before the flaming begins, I just visited the 'vette forum and did a search, and while they're in the minority, a lot of guys ARE starting to call "it" a plenum.

 

Ahh yes VTEC...gotta love it. But my plenum did not feel like any kick in pants power after a certain rpm. In fact it felt more so like that after the plenum was taken off......who wouldve thought?

I did not speak to Doug..though its probably a good idea. I sold the plenum to a local who is on the boards after about 2 weeks of use....so theres no point for me to do so. I just figured I have one of the Z's that doesnt want to respond to mods like a couple of others here on the boards....