what is this? 3sge owners

[vr4boy]

there is a part bolted on to the inlet manifold that has 4 butterflies inside, what is this? and do i need it??

[Dell'Orto]

Sounds like the TVIS plate. You dont reeeeeeally need it, but you'll need to tweak a few things if you ditch the butterflies.

[vr4boy]

what does it do? and what do you mean by twecking things?

[RomanV]

No, its the ACIS system.

It increases the volume of air in the intake runners once you get to a certain RPM. (5xxx rpm IIRC)

[vr4boy]

ohh yea so ishould keep it there then?

[RomanV]

Yep.

Your car would lose top end power if you removed it.

[Caveman]

If hes talking about gen1 3sge or st162 then its TVIS, if its MR2 then its ACIS

Theres a discussion on tvis in the FAQ section

[vr4boy]

its an mr2

[Malcolm]

yes it's ACIS (acoustically controlled intake system). Keep it, those butterflies open at high RPM to alter the reasonant frequency of the intake system to suit the higher RPM range. I guess you could enlarge it to improve things further if you were running crazy RPMs, but other than that I'd think leaving it alone would be the best idea

[CozmoNz]

Yep.

Your car would lose top end power if you removed it.

youd loose low end....

high end if anything youd gain something being less restriction.

[RomanV]

The butterflys open at top end....
If you removed the ACIS system (and blanked it off) you'd lose top end.

If you just took out the butterflies, then you'd lose bottom end... but that's not what he said.

And they arent a restriction anyway.

[Malcolm]

Yep.

Your car would lose top end power if you removed it.

youd loose low end....

high end if anything youd gain something being less restriction.

have you ever seen a 3SGE ACIS manifold? there's pics on my website under the 3sge generations section.

The second plenum is off to the side of the inlet runners, so I imagine air doesn't even flow through the butterflies, it simply changes the acoustics of the inlet. It is different from the 5e-fhe ACIS, which from what I can tell, has 2 different lengths of runners and it switches between the two with butterflies

[Adamal]

Helmh*ltz!!!!

sw20 n/a mr2 -JSTTRY- 15.24@142.37kmh 1/4 mile

Ahhh, I've seen this one around the shore. Was behind you the other day when you pulled into Repco. The plate is fairly recent, isn't it?

[vr4boy]

yeap would have been me, i live on the shore, car has no motor no, time to build something with some decent power, and im not to sure what you mean by the plate being recent.

[Adamal]

I'm pretty sure I've seen you round before, but not with that number plate.

[vr4boy]

ohh the plates been on it scince ive owned it (dec '04) and car was fully stock then, so just looked like any sw20.