hi all just wanted to konw what you ca foke do with the vac butterflys in the inlet manifold. I have gone with a after market computer and want it gone

With my autronic I've plumbed/wired them up to open at 4500rpm.. as per the book.

If you don't connect any vaccuum to the powervalve, then the valve will stay in the open position.

pull the plates off, remove the shafts and plug the holes with bolts or weld em watea u want. i just finished doing this and port matyching everything, including the head.

kegs info is what Kev Rowley also suggested i do and have done to ours.

sweet thanks guys that is what i was thinking but just wanted to know what you all do i will put some pics up over the next few days

I still stand by the dyno testing I did with my engine :

1. always open

versus

2. keeping them closed until 4500rpm, then slowly opening them using the restrictor as the factory intended.

They should snap shut under vaccuum and under 4400rpm to clearly improve on/off throttle response.

I think I'm the only person outside of Nissan to do such testing. I too was of the 'more flow is better crowd' until I tested it.

Another pretty easy test for someone with a standard CA18 + standard ECU to test. Just stick a small g-clamp on the vaccuum hose going to the power valve. Do a couple of timed runs from a standing start, and report the difference with and without the hose clamped.

like dattodde said and i applaude him for doing it the way he did but depends what u want from the car if throttle response and driveability dont bother u that much rip em out surely there wil be a difference in power if u want crisp throttle and less lag keep em simple

I imagine you would have more lag if you ripped them out (which I think is what you meant).

I don't image it will make much difference to the peak hp, will just effect your acceleration below 4500rpm.

In mine I just pissed off all the millions of vaccy lines and canisters and just ran a line to manifold vacuum - they will still open but without the sophistication of the stock setup.

Like this:

theres nothing wrong with throttle response and drivability
how much do you gain by ripping them out?
no one seems to be able to give an accurate answer
mine are removed and welded and i'm regretting it now. should have tested first.
this from NA pulsar shop manual
starts opening at 3800 fully open at 4000
chris try changing the switch on rpm to 3800 and see what its like

mildman i noticed you said it would craete more lag, but that statement is actually incorrect as lag is craeted by the turbo trying to pressurise a larger area, when you take them out its not changing the internal area at all just changine the air velocity. lag will remain the same just possibly less n/a power down low