rx7newbie_2001

Hi, how does a boost pill work, and how would I go about putting one in my 93rx7. I have a dp, intake, and racing beat cat back. I cant afford an ECU right now, and I really need to find an inexpensive way to lower my boost. I have the stock cat on right now, is that enough to keep the boost down without having to change the ECU? Should I add a bigger fuel pump?? Any help is greatly appreciated.

Flybye

The pills are basically restrictors. If you want less boost, you install a pill with a larger opening. Basically what is happening is more presure would be entering the wastegate allowing it to open more and vent additional exhaust from the turbo. Therefore providing less boost.

If you look at the Wastegate and the Pre-control actuator, there is a hose that runs between them and the turbo manifold. The pills are installed there. Another inexpensive way of controlling boost is by installing a valve in those lines. This would, at least, help you in fine tuning it.

Here, you can see the hose between the actuator and the turbo manifold. It is the smaller hoses on the top side of them.

http://www.geocities.com/MotorCity/S...s/preshose.gif

Here is a good shot of them. The hoses on the left of the actuators are the ones where the pills are installed.

rx7newbie_2001

So if I do this I wouldnt have to upgrade or replace the ECU? Where could I get boostpills? Thanks again

Flybye

The only thing you are preventing is overboost. Overboost meaning you will hit fuel cut with the stock ECU. Fuel cut = bad.

I use the valves and really have no clue as to what size pill you can use. What you CAN use is Carburetor jets sold by Holley. They sell an entire kit that is about $10 or so with different size jets that you can use as pills. The only thing I can recommend is use the one with the largest opening and work your way down in size until you no longer boost past 10.5psi. I'm sure someone will chime in here with the exact size of pills/jets that you should use.


You WILL have more hoses with the valves, but at least they are fully adjustable.

rx7newbie_2001

If the boost pill is the solution to overboost, what is the advantage of upgrading the ECU? Is it really worth spending a grand or more?

Flybye

You will notice a BIG differance if you buy an ECU. Also, having the ECU will mean you can safely raise the boost over 12psi. All depending on what ECU you buy and what boost you have it programmed at. Although, it is not recommened to run over 14psi with the stock IC, though.

Gir

Flyby where can I find more info on this valve and how it is installed?
Is it strong enough to hold boost pressures over long periods and not be something else to check if your having boost probs?

Flybye

Here is what I am talking about.


You are going to need a little bronze valve from Home Depot Racing part #A42 PB9106-CP which is a 1/4" valve. These can commonly be found in the plumbing section.

Open the valve about 1 turn all the way open from close. You should be seeing between 8-10psi on both turbos. The valve is VERY precise. when closing it to get your desired boost pressure, close it in 1/8th intervals. You will begin to notice that just turning it a hair will change your boost setting.

Antoher alterntaive is to install a Dawes Devices Valve. This valves goes in the same location. Further information can be found for this valve at http://www.dawesdevices.com/boost.html

rx7newbie_2001

So if I get a m2 ECU for my mods I would just send them mine and they reprogram it? After I recieve it I would just install it and thats it?

BrianK

yes