are you talking about the throttle-plate look a like? if yes you're suppose to remove that after going NA-T

 

I wouldn't remove it. Just take the diaphragm of the outside of the intake manifold and bolt the butterfly in the vertical position. This will cause it to act as if it has long intake runners all the time rather than just at full throttle. I don't really think it has much, if any, performance increase but it saves about 4oz of weight. Here is how mine looks.

 

As I understood it was supposed to help lowend torque on the na, someone said this is also used on some motorcycle engines aswell for a similar reason. Personally ditch it, I have noticed no difference when I was na. And since you got a turbine pumping air in there anything in the way is well, in the way

 

I've got it enabled. Principle is the same whether it's turbocharged or n/a. Keeping the runners in the "longer" configuration will restrict top end power. In stock form, the valve only closes (longer runners) when below 4500rpm and greater than ~30%tps. This is how I have it set up with the AEM.

 

Kurt did you notice any performance difference by setting the valve to open/close at your above settings after you turbo'd your NA? Mine is enabled in AEM, but it appears to keep the valve in one position the entire time.

 

If you're still on the same map, it looks like you have this output active all the time. The valve is normally open, so you have it always closed.

You will want to add some fuel above 4500rpm if you decide to have the valve open in that range.

Haven't done any comparisons between the two due to the need for retuning. Not such a simple change. Timing and fuel will be optomized for one but not for the other.

 

I welded mine open...

Jonny

 

I did a couple of pulls tonight with and without ACIS and used the math function that FWombat made on AEM fourums. The difference is around 30f/lbs between 3500 and 4000. I think I'll keep it on!

 

Wow, interesting find Kurt. I personally removed the entire thing long ago and just JB welded the holes shut in the manifold.

 

I think this might be my roblem with my car. ever since i put the turbo on, and i try to boost past 4500 rpm it like its a wall... its hard to explain it spits and sputters. many peope have thought it was fuel and timing issues but its not. i have had my car tuned by three diffrent people and they were all very respected tuners in colorado, and they have no idea what is causeing this. i removed the valve that was on it, but i left the butter fly just in there. i cant remember if its open or closed, but it jsut chill in there not moving. what do you guys think?

 

Unlikely. Aren't you using AEM? If you look at the output LS5, you can see if ACIS is active or not. I'd bet it isn't unless you specifically asked your tuner about using it. I don't believe the ACIS valve would cause any problem like that.

 

Interesting discovery guys!

 

i was running the 4runner dizzy cap with msd 6al.....i still had the problem. so i bought some ls1 coils, wired them up, same problems, then i blew the coils up..leterally. so now im in the process of wiring up TT coils, and having to customize my throttle body for clearner of the coils.

 

Hi guys, what sort of horse power levels are you running into ignition troubles at? I havent read anywhere that the factory NA dizzy and coil arent up to the task of moderately boosted na-ts. Although I would imagine once you start winding up the wick then more spark would be required

 

can the removal of this valve and buttfly have a small affect on a aem tuned car now driving slightly just slightly richer then originally tuned for example i used to cruise 14.5 to 15.1 since removal it now wants to cruis around 13.8 to 14.5

 

Take the Butterfly Plate out!
Mine once sheared off the studs at 25psi on t3/t4 setup

 

Pic?

I was planning to run 26psi with a PT67 p-trim while using the ACIS, so now I'm worried after reading your post...ohnoes:

 

I took mine out and jb welded the hole and now my powerband feels much different. there's definitely a slight decrease on the lower end followed by a huge spike at about 4500

 

Started running e85 and pushed the boost to 10psi. When I get bigger injectors I can go higher. Just a little more data to show that the ACIS functions the same with boost as it does n/a. This is a series of six pulls where I was tuning ignition, a total of 6 degrees was added from the 1st to 6th pull. For those of you not using the ACIS system, you're giving up a lot of torque early in the rev range for no reason!

 

~360 ft/lb of Torque, nice job Kurt that is awesome! How does it feel at 10psi compared to before?

 

It definitely feels a lot stronger. She likes the e85, for sure. Torque is 360 at the HP peak, it's closer to 390 ft/lb at 3800 and 5000rpm.

 

so basically there's no point of taking the butterfly out?

 

keep it in and keep the butterfly vacuum source connected to the vacuum tank on the driver's side block.

 

Take the butterfly out

 

How much boost were you running when it broke?

 

Wow, I thought it was the same material as the throttle plate. Have you heard of anyone else experience this?

 

looks like it was just hammered out or something.

 

If these ACIS valve failures are happening only on high boosted setups 20+ psi, then it won't affect Kurt's setup me thinks.