3S-GE ACIS/Beams discussion, Discussion about ACIS, TVIS, VVT-i, etc. applicable to 3S-GE motors |
3S-GE ACIS/Beams discussion, Discussion about ACIS, TVIS, VVT-i, etc. applicable to 3S-GE motors |
Sep 13, 2008 - 11:05 PM |
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Enthusiast Joined Feb 11, '08 From Auckland, New Zealand Currently Offline Reputation: 0 (0%) |
thats alright QUOTE 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. -------------------- Mike W
1996 Toyota Celica ST205 GT-FOUR GT2860RS turbine, TiAL mvr44, JE 86.5φ piston, Clutchmasters FX400, APEX P-FC 269awhp / 273ft-lbs |
Feb 3, 2011 - 2:18 AM |
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Moderator Joined Nov 5, '07 From New Zealand Currently Offline Reputation: 3 (100%) |
I read this awhile ago, but cant remember where I found it, thought I should add it anyway...
QUOTE In reality, Toyota didn't delete the TVIS system for the 3rd Generation 3SGE. They rather changed the way it works so that it removes the restriction that the TVIS butterflies had by being at the entry point of the intake ports (they were restrictive even when fully opened). For the 3rd generation, they used variable plenum volume. In other words, they created a secondary set of runners connected to a secondary plenum, which allowed for more air volume at lower RPM. At 5250, the valves close (much in the same way they opened with TVIS) and the air only travels through the primary plenum and runners, thus increasing air speed and creating more power. There are some pictures out there about how the system works. For what is worth, I think that both systems are just as effective for what they were created. The change in sound and pull from the 3rd Gen system is very noticeable (almost like an S2000). Opps forgot to add my info on custom 3sge manifold and ACIS plus turbo, will try add that this weekend. -------------------- |
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