7MGE TVIS vacumn hose

[ed]

tvis changes the port sizing though doesnt it - acis just changes the plenum from spilt to single, nil volume change, and certainly nil change to the runners - doesnt really do that much on a 7mge imho

[JustCallMeOrlando]

TVIS has 12 runners, and opens 6 of them below 4200rpm, and 12 above that. From what I can gather, isn't ACIS trying to maximise pressure at the inlet valve?

[ed]

its changing the harmonic of the resonant wave in the intake, or rathr maintaining the number of the harmonic as the frequency increases with increasing revs - which would improve cyl filling, however its only going to be most noticeable at a descrete rpm, and to be honest the value of catching the the 4th vs 6th harmonis isnt going to be 'that great' to notice by the seat of your pants... unlike tvis where youve doubled the port volume and vastly improved port flow

[Alchemist]

Strange, again I know I'm talking 2J, not 7M. But I feel a definate kick when the butterfly opens....

[ed]

are you sure?
theres ofen a torque loss at approx 1/3 to 1/2 way to rpm redline with the cams toyota grinds, and they way their intakes are harmonically tuned. this is a region of significant intake reversion - demonstrated on practiclly everyones dyno sheets as a dip, followed by a surge as you exit the reversion fireld...

i bet you its this surge youre feeling. disconnect the acis vacuum butterfly and see what you think

[ed]

example of REALLY BAD intake reversion.... good for demonstration purposes - and note this engine is only going to 75%redline

but i bet youll find something similar on your graph, as will everyone

[Alchemist]

Sadly not able to correctly identify which VAC line does this I've got the diagrams just no idea which one...havn't got an answer from senor dong on this yet...

[Alchemist]

Latest dyno graph....I guess to my untrained eye only surge I could see is where 100Km/h and about 82KW intersect on the higher graph. But it happens in all gears at roughly the same point.....

[JustCallMeOrlando]

You don't have the dip, from memory, even Glen's old JZA61 had the dip when the ACIS switched...yours just goes up!

[BlackSupra]

Can't find a new one, but does the same thing




Nathan has removed the intake resonators on his intake.

There is a brown VSV under the intake plenum that you will have bugger all chance of seeing from outside the car. Thats the one you want to unplug.

[JesseCrown]

i got the engine from stitt, he said you definately used to feel when ACIS kicked in, made a big difference, and i took him for a ride in it and his convinced its not going as fast as it used to.
so can anyone tell me where that hose from the diaphram is meant to go?

[Alchemist]

Nathan has removed the intake resonators on his intake.

True.....Wayne has similar setup now though, curious to see if his graph now mirrors mine...

There is a brown VSV under the intake plenum that you will have bugger all chance of seeing from outside the car. Thats the one you want to unplug.

I don't want to take the intake plenum off.....way too much stuff to break, even if it isn't a daily anymore.