Chipped P28's And Stock B18c1 Intake Manifold?

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ASpec818

Junior Member
i've heard that by using a chipped p28 in a b18c1, u won't be able to activate the second stage vtec from the b18c1 because the p28 is only for single stage? they said to get the skunk2 manifold so it'll be single stage. other ppl say that the p28 does activate it and sticking with the stock intake manifold is a good idea???
 

pills_PMD

New Member
a p28 will not open the secondaries, but it will also not throw a code. only the prelude / gsr ECUs will open the secondaries.
get a skunk2 manifold and use a p28 w/ hondata and then get girls.
 

ASpec818

Junior Member
the guy that worked on my car said the p28 does open the secondaries and ading a skunk2 intake manifold to my stock motor won't yield much power.

will getting the skunk2 intake manifold yield more power since my p28 an gsr intake manifold don't work that well together?
 

GSRCRXsi

Super Moderator
VIP
what would happen if you got a skunk2 manifold and kept the p72 ecu? would i get decreased power?
 
Now I know the secondaries on a GSR are opened by the loss of vacuum on the diaphragm. If you disconnect and plug the vacuum line the secondaries are open all the time. I have done this on my GSR when it was stock and it definitely cost some low end power but by about 5500 it works fine since it normally opens at 5750. Would this be a solution for GSR owners to run a p28? It's at least better than being on the primaries at 8000. :p What do you think pills you seem to be the most knowledgable on this subject?
 

pills_PMD

New Member
you can just ground the pink/blue wire coming off the IAB and have it open all the time.

i would just get a skunk and not worry about it

a skunk2 w/ a p72 is fine as well.
 

GSRCRXsi

Super Moderator
VIP
will i throw a code because of it? since the secondaries dont exist with a skunk2 mani
 

chet

Senior Member
stay with a p72...you'll get the best midrange.

unless you're going with hondata...then go with a p28...etc.

i'm not a huge fan of a chipped p28...i've run one...and didn't have great results with it.
 

posol

RETIRED
Originally posted by ASpec818@Mar 11 2003, 04:46 PM
the guy that worked on my car said the p28 does open the secondaries and ading a skunk2 intake manifold to my stock motor won't yield much power.

never go back to this retard again. he doesn't know anything about honda, obviously.
 

ASpec818

Junior Member
also, the secondaries is different from vtec right? i feel the vtec kick in at 5700 rpm. this isn't the secondaries activating right?
 

posol

RETIRED
right. IAB's are in the intake manifold. They open and close by a solenoid and are a butterfly valve, kinda similar to how a throttle body works. The optimize mid range torque.
 
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