The Official N/A Upgrade FAQ

[Ma70.Ent]

Thanks for posting that. Anyways, this is what he was talking about:

Maybe this will help. I don't have one on my car but this is what the tech manuals say:

The ACIS is designed to shift the torque band higher along the rpm range. It does this by responding to changes in the throttle opening angle (VTA signal of the TPS) and engine rpm (NE signal in the CPS). The air control valve is then opened or closed by the ECU via a VSV and vacuum actuator.

The valve is located in the center of the manifold and when closed divides it into two sections - a front chamber for cylinders 1 to 3 and a rear chamber for cylinders 4 to 6. A closed ACIS valve has the same effect as lengthening the intake manifold while an open valve has the same effect as shortening the intake manifold. In other words flow efficiency what's being controlled.

When the ECU turns on the VSV vacuum is applied to the actuator and closes the valve. When the VSV is turned off atmospheric pressure is applied to the actuator and opens the valve. There are four combinations of speed and throttle angle the ECU uses to decide when to open or close the ACIS:

1) Above 60% throttle angle and above 4,200 rpm: VSV off, ACIS open.

2) Above 60% throttle angle and below 4,200 rpm: VSV on, ACIS closed.

3) Below 60% throttle angle and above 4,200 rpm: VSV on, ACIS closed.

4) Below 60% throttle angle and below 4,200 rpm: VSV off, ACIS open.

 

[Smeg!]

I've heard you can use the throttle body from the 1UZ with some minor mods, it this true? anyone done it with actual results? Anyone know what size throttle body is used on the 1UZ?

 

[tonystarks]

so can turbo pistons be used in our NA's? I have been trying to search for this for 45 minutes and got fed up!! So any answers would be appreciated. I priced a set of JE's for around 800 dollars. IDK if any suggestions pm them to me so I dont jack this thread.......:1zhelp:

 

[JesseH]

so can turbo pistons be used in our NA's? I have been trying to search for this for 45 minutes and got fed up!! So any answers would be appreciated. I priced a set of JE's for around 800 dollars. IDK if any suggestions pm them to me so I dont jack this thread.......:1zhelp:

yes you can.

 

[bluedragon17]

yes you can use turbo pistons the only difference is they are lower compression than NA pistons so you will notice a loss in power

 

[JesseH]

yes you can use turbo pistons the only difference is they are lower compression than NA pistons so you will notice a loss in power

a lot of people will do this if they are going NA-T

 

[tonystarks]

I was planning on just going turbo but instead am just going to go all forged and spray a little bit. I just want something reliable and occasionally take it to the track :naughty:

 

[7Mboost]

Just an idea on a possible addition which I have no idea about, pullies...?