3S-GE ACIS/Beams discussion, Discussion about ACIS, TVIS, VVT-i, etc. applicable to 3S-GE motors Options

[delusionz]

thats alright

how would i go about modding my ACIS?

rather than tell you how to mod it heres a way how not to mod it
http://toymods.net/forums/showthread.php?t...;highlight=ACIS

(also I recommend a new thread for 3SGE ACIS/Beams discussion)

I've been playing around with ACIS recently and I've discovered a few things about it,

The basics ... when the vacuum diaphragm pulls the throttles, the larger diameter in the corner of the inlet pipes open up (under the lid) for high rpm and when there is no vacuum to pull the throttles are free to return to the constricted low rpm position.

A few problems noted with ACIS:

1. When switching between high and low rpm modes, the vacuum diaphragm sometimes get stuck in the high rpm mode
2. The engage point is too late

First experiment was to see how the car behaved with the throttle pull lever tied up with cable ties as to lock the throttles in the high rpm position,

What I observed with the butt dyno was that under full throttle the rpm range where the car would "suddenly get up and go" was lower down, noticed in terms of road speed 65kph before, 55kph after (2nd gear) so in other words 5000-7000 was the get up and go range, without ACIS constriction in the intake the get up and go range was observed from 4000 to 7000.

No loss in acceleration was noticed from idle to 3000 under part throttle, but loss was noticed under full throttle, between 3000 and 4000 I couldn't tell either way in neither part throttle nor full throttle whether ACIS was better in low rpm or high rpm mode....

This suggests to me that 4000 is a better changeover point than 4800 for performance. 4800 is an rpm not reached by normal driving due to speed limits & gear selection thus ACIS seems to exist for the purpose of keeping intake noise down at legal road speeds rather than for improving low rpm torque as midrange torque takes a hit with this setup.

My proposed solution on how TO mod the ACIS, is to gutt the vacuum actuator system and replace it with a motorised cable pulling actuator triggered by a frequency switch relay at 4000 rpm the signal could be obtained by the ignitor right behind there.

[BonzaiCelica]

can I ask what is wrong with the Factory extractors? Because your wanting to spend about US$850 for 1.1KW? The factory extractor type manifolds fitted the 3S-GE and BEAMS 3S-GE are very good. Toyota put some effort into the design and flow of these.

I think your better off putting your money towards your BEAMS engine.

rusty is right, there isnt a lot wrong with the stock extractors, the dimensions may be quite tight but they are fine for a near stock cam, the problem is and this is typical toyota the ingredients are right, the execution not so, the welds tend to be tack welds on the outside and welded on the inside, if you reweld the manifold so the welds are on the outside of the pipe, take a dremel and grind out the garbage on the inside of the pipe, so far i've found the manifolds to be really sloppy here, the design is fundementally fine, but the execution is poor. This isnt a power adder as such but will free up the engine at high revs, we found this on the beams and its also true of the newer 2zz engines where usually a ported stock manifold is better than the aftermarket ones.

To make it complicated It is worth leaving a step though at the bottom of the manifold floor where the manifold meets the head, you dont want it exact you want the pipe to be slightly bigger at the floor so there is a step down leaving the head, this helps to break up reversion pulses and does no harm to the exhaust flow.

what do you mean by the stuff I highlighted in Red. Also what type of synthetic oil does the 3S-GE Beams Redtop use??? I just read that the 1zz-fe which has dual vvt-i uses 5W-30 and synthetic oil changes should be done every 6,000 miles??

This post has been edited by BonzaiCelica: Jan 18, 2011 - 11:14 PM