Hey all,
I've been researching how to convert over to an N/A intake manifold set up and leveraging the ACIS technology on my 7mgte motor. Some people may think why the hell are you doing this in first place? What's wrong with the stock turbo manifold? Why not just go FFIM? Well, my main reason is i dont have the funds to go FFIM and I want to do something different. Personally, I like the looks of the n/a y-pipe set up and it seems that ACIS does have some good hp benefits.
Anyway, back to my question. I have all the n/a manifold parts for the conversion: upper and lower intake manifolds, n/a throttle body, n/a breather tube assembly and soon I'llbe getting the n/a vacuum control canister. This is where the valve in the intake manifold is controlled by vacuum. My main question is how is this valve going to be activated properly or even at all? The 7mgte harness and ecu do not have the VSV1 (intake air control valve) signal. I looked this up in my TEWDs. The 7mgte does have a vsv for egr and vsv2 for fuel pressure up. So I foresee the ACIS system not working properly. From my research the actuator is controlled by the ECU and opens based on the position of the TPS and engine speed. If there is no signal that will tell the valve to open then I'm not sure how this is going to work. I may have answered my own question. I could use VSV2 for fuel pressure up. I am upgrading to an AFR set up so wont need that. But I'm not sure this signal will fire at the right time to mimic the behavior of the VSV1 air control valve.
I am wondering if anyone has done this setup and if they were able to get a signal to control the vsv or if you don't need it all?
Here are some threads i researched:
http://www.supraforums.com/forum/showthread.php?224175-How-to-increase-low-rpm-power-from-7mgte&p=2283118&viewfull=1#post2283118
From this post http://www.supramania.com/forums/threads/40185-7mge-ACIS-system-questions
First of all, it does not ever "kick in". The default position of the valve is springloaded open, which is high rpm use. Vacuum pulling on the diapragm closes it to boost low RPM torque. The manifold with longer runners aids low end torque, but starve the engine at higher engine speeds. The shorter ones lose velocity, but can fill a cylinder at high RPM.
So the system is set up for high rpm, and closes the valve for low speed torque. If you really feel it kick in, your probably does not work, and the vacuum solenoid is froze. Take a good look at that stock torque curve, and how flat it is.
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.
I've been researching how to convert over to an N/A intake manifold set up and leveraging the ACIS technology on my 7mgte motor. Some people may think why the hell are you doing this in first place? What's wrong with the stock turbo manifold? Why not just go FFIM? Well, my main reason is i dont have the funds to go FFIM and I want to do something different. Personally, I like the looks of the n/a y-pipe set up and it seems that ACIS does have some good hp benefits.
Anyway, back to my question. I have all the n/a manifold parts for the conversion: upper and lower intake manifolds, n/a throttle body, n/a breather tube assembly and soon I'llbe getting the n/a vacuum control canister. This is where the valve in the intake manifold is controlled by vacuum. My main question is how is this valve going to be activated properly or even at all? The 7mgte harness and ecu do not have the VSV1 (intake air control valve) signal. I looked this up in my TEWDs. The 7mgte does have a vsv for egr and vsv2 for fuel pressure up. So I foresee the ACIS system not working properly. From my research the actuator is controlled by the ECU and opens based on the position of the TPS and engine speed. If there is no signal that will tell the valve to open then I'm not sure how this is going to work. I may have answered my own question. I could use VSV2 for fuel pressure up. I am upgrading to an AFR set up so wont need that. But I'm not sure this signal will fire at the right time to mimic the behavior of the VSV1 air control valve.
I am wondering if anyone has done this setup and if they were able to get a signal to control the vsv or if you don't need it all?
Here are some threads i researched:
http://www.supraforums.com/forum/showthread.php?224175-How-to-increase-low-rpm-power-from-7mgte&p=2283118&viewfull=1#post2283118
From this post http://www.supramania.com/forums/threads/40185-7mge-ACIS-system-questions
First of all, it does not ever "kick in". The default position of the valve is springloaded open, which is high rpm use. Vacuum pulling on the diapragm closes it to boost low RPM torque. The manifold with longer runners aids low end torque, but starve the engine at higher engine speeds. The shorter ones lose velocity, but can fill a cylinder at high RPM.
So the system is set up for high rpm, and closes the valve for low speed torque. If you really feel it kick in, your probably does not work, and the vacuum solenoid is froze. Take a good look at that stock torque curve, and how flat it is.
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.