ACIS

Edophus · 05-05-2007, 07:38 PM

Hi guys, this is just an "out of interest" thread, but i keep reading about our engine and occasionally ACIS is mentioned, and it crops up in wiring diagrams aswell, so i did some looking around, and older 3s engines seem to have lage chambers with valves that open and close to increase the plenum volume, the beams does not have that exactly, but there is something odd that sits underneath the throttle body, check the diagrams on the redtop site, could this be some form of ACIS? and what benefits does it bring?

Ben · 05-05-2007, 08:59 PM

This is basically what I had to learn from my Toyota tests:

Acoustically Controlled Induction System (ACIS) varies the length of the intake plenum. ACIS helps improve low end torque by having air travel a longer distance, then at higher RPM a valve closes that makes air travel a shorter distance.

As you said above, Toyota Variable Induction System (T-VIS) has a set of butterfly valves that vary the volume of air entering the combustion chamber. The valves are closed at low RPM to allow for more low end torque, and open at higher RPM for more higher end torque.

I don't think that Toyota started using ACIS in the US until 2005 with the 1GR-FE motor? I thought it was new technology, but I guess not....

Roman · 05-05-2007, 11:14 PM

ACIS was available on the gen 2 and 3 3SGEs, and then dropped for the 4th gen engines.

The Altezza engines have 'acis', but it's a different system, as it works *before* the throttle body, in the airbox I think.

The stuff on the throttle body of the FWD beams engine is the idle control mechanism, throttle position sensor, and water lines to heat the throttle body.

05-05-2007, 07:38 PM	#1 (permalink)
Edophus Beams Owners Group Join Date: Oct 2006 Posts: 370 Thanks: 8 Thanked 17 Times in 15 Posts iTrader Rating: (0/0% )	ACIS Hi guys, this is just an "out of interest" thread, but i keep reading about our engine and occasionally ACIS is mentioned, and it crops up in wiring diagrams aswell, so i did some looking around, and older 3s engines seem to have lage chambers with valves that open and close to increase the plenum volume, the beams does not have that exactly, but there is something odd that sits underneath the throttle body, check the diagrams on the redtop site, could this be some form of ACIS? and what benefits does it bring?

05-05-2007, 08:59 PM	#2 (permalink)
Ben Same In The End Join Date: Aug 2006 Location: Oceanside, CA / Reno, NV Posts: 4,274 Thanks: 20 Thanked 309 Times in 284 Posts My Google Map iTrader Rating: (16/100% )	This is basically what I had to learn from my Toyota tests: Acoustically Controlled Induction System (ACIS) varies the length of the intake plenum. ACIS helps improve low end torque by having air travel a longer distance, then at higher RPM a valve closes that makes air travel a shorter distance. As you said above, Toyota Variable Induction System (T-VIS) has a set of butterfly valves that vary the volume of air entering the combustion chamber. The valves are closed at low RPM to allow for more low end torque, and open at higher RPM for more higher end torque. I don't think that Toyota started using ACIS in the US until 2005 with the 1GR-FE motor? I thought it was new technology, but I guess not.... Last edited by Ben; 05-05-2007 at 09:21 PM..

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05-05-2007, 11:14 PM	#3 (permalink)
Roman Beams OCD Support Group Join Date: Feb 2006 Location: Auckland, NZ Posts: 946 Thanks: 23 Thanked 56 Times in 36 Posts My Google Map iTrader Rating: (2/100% )	ACIS was available on the gen 2 and 3 3SGEs, and then dropped for the 4th gen engines. The Altezza engines have 'acis', but it's a different system, as it works before the throttle body, in the airbox I think. The stuff on the throttle body of the FWD beams engine is the idle control mechanism, throttle position sensor, and water lines to heat the throttle body.