What RPM

So now that everyone is telling me that the h22 prelude are a dual stage vtec like the GS'R, can anyone tell me at what RPM does the first stage vtec engage i know that second stage is about 5,200. Thanks

yess sum one give us sum facts about this ... im at a loss for the whole 2 stage thingy :)

GSR's and H22's have only one VTEC crossover point. They both have dual stage intake manifolds.

GSR's and H22's have only one VTEC crossover point. They both have dual stage intake manifolds.

ohhhh now i get it :eek7:

Dual butterflies.

dual stage intake manifolds?????. :confused:

on VTEC's like the ones on preludes, there are a total of FOUR lobes between the cams for each cylinder head, 2 are your 1st stage lobes (under 5200rpm), the 2nd set or 2 are taller and more aggressive, these are engaged at 5200. when they engage is when you hear the change in sound obviously coz you're letting more air in and out of the engine hence more power. imagine a 3 stage VTEC. haha.

Dual stage intake manifolds have two sets of runners. One set is open for low rpms and both sets open for higher rpms. I can hear/feel the second set open when I'm driving. I think it opens around 3800rpm on an h22 - the intake noise gets a little louder and the car accelerates a little faster. Then at 5200 vtec kicks in hard.

H22 camshafts have 3 lobes per cyl. Two lobes for low rpm (on the outside) and one taller lobe for higher rpm (between the two low rpm lobes).

http://files.automotiveforums.com/gallery/watermark.php?file=/503/250018camshaft-h22.jpg

There is a 3 stage VTEC-E (I think it's a d15b), except it's for economy rather than power. It's still pretty damn clever...

http://www.leecao.com/honda/vtec/3stagevtec.html

Yeah, I knew I had heard of a 3-stage VTEC. Good find.