I`ve just been reading the answers on boost controller topic and i`m getting worried now,
because i`ve just ordered an in car boost control (the simple one where you just turn the **** to turn it up or down)and a lot of people are saying not to fit bosst controllers or the engine might go bang.
The reason for getting one of these is because my engine is running at 1.6bar and i want to turn it down, because a lot of people have told me this is too high for the quality of our fuel.
My Impreza is a 1998 STI4 Type R (import).
Help i need some advise.

 

As I understand it, the theory is to keep the pipework as short as possible to prevent overboost.

Using a regular bleed valve would allow the boost to be turned down - see Lee's site for detailed instructions:

 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by gaudy:
<B>I`ve just been reading the answers on boost controller topic and i`m getting worried now,
because i`ve just ordered an in car boost control (the simple one where you just turn the **** to turn it up or down)and a lot of people are saying not to fit bosst controllers or the engine might go bang.
The reason for getting one of these is because my engine is running at 1.6bar and i want to turn it down, because a lot of people have told me this is too high for the quality of our fuel.
My Impreza is a 1998 STI4 Type R (import).
Help i need some advise.[/quote]

Hi Gaudy,

A boost controller by itself is a very useful tool and doesn't blow up engines. Improper use of it (going into ballistic figures) does. :-)

Most electronic boost controllers go by the bleeding principle. They bleed off air going to the wastegate actuator and thus enables a higher level of boost to be built. But if you're thinking of LOWERING your boost using one of these, it can't be done. EBCs can certainly restrict the air flowing toward the actuator with a solenoid or stepping motor, but there's not a single one that can help draw in even more air! The lowest you can go is the stock boost, which in your case is 1.6bar and way too high.

For your problem, try to find out if the solenoid is faulty (unlikely) or if there are leaks along the hose from the solenoid to the wastegate. If there's nothing out of the ordinary, maybe you'd want to consider changing the actuator spring to one with a lower spring rate.

[This message has been edited by jack (edited 21 October 2000).]

 

Sorry Jack but you can reduce the boost level using a bleed valve - I did it when I fitted one..... 9 psi (12psi standard on my car)

I deliberately fitted it with the valve almost open to allow me to fine tune the settings without starting off high.

If you take a look at Lee's site and in the section about his car, you will see detailed instructions.

The way that Subaru control the boost, you can reduce it down to approx. 7 psi.

Thanks

Gavin

 

Remember guys,

The scooby has a boost solenoid as standard (in the left hand corner of engine bay behind airbox) to increase the boost over stock, it's just not a very good one. Stock boost (boost that would be produced if the car had no boost solenoid) is approx 0.45bar, not to be confused with the boost a standard car runs which is around 1bar. So effectively an EBC/EVC can reduce boost down to 0.45bar.

Gaudy you would have no problem reducing the boost. 1.6bar is way over what the car should be boosting at so the car must have been fettled in some way!

Nito

 

I'm running 10PSI (Lower than std boost) and 18 / 19 PSI high boost on a UK 94 with no problems.

APEXi Boost controller and Fuel controller.
Toggling between the two couldn;t be simpler.

Mark.

 

I just played with it and I understand now. :-) The minimum boost if we're only dependent on the actuator is 0.45-0.5 bar. The ECU controls the solenoid to do the bleeding to bring it up to what we call the "stock" boost of 0.8-0.9 bar right? Thanks guys!

[This message has been edited by jack (edited 22 October 2000).]