Hybrid Boost Controller [Archive] - SaabCentral Forums

: Hybrid Boost Controller


Silver 9-3 Arc
17th February 2004, 09:56 PM
Does anyone know if this device will work on the 2003 Saab 9-3 Arc's turbo without any problems?

http://www.dawesdevices.com/hybrid.JPG

http://www.dawesdevices.com/boost.html

joshd2012
18th February 2004, 01:34 AM
I don't think anyone has done it sucessfully yet.

I know that it works great for the T5, but with the T7, they had to do it in series (?) to get it to work with the ECU. I haven't heard of anyone getting one to work with the T8 (the engine in the SS).

Silver 9-3 Arc
18th February 2004, 02:55 AM
I don't think anyone has done it sucessfully yet.

I know that it works great for the T5, but with the T7, they had to do it in series (?) to get it to work with the ECU. I haven't heard of anyone getting one to work with the T8 (the engine in the SS).

So, I pressume the ecu somehow compensates for it and reduces the extra boost?

I may test it out with a bleeder valve first to see how the ecu responds.

saabie
18th February 2004, 03:42 AM
The ECU should adjust and maintain the air/fuel ratio. 14.7kg of air : 1 kg of fuel
However at WOT our ECU will follow a fixed algorithm. Generally this algorithm will make the mixture richer(more fuel) and thus keeping combustion temp down. Adding a booster controller and dialling in extra boost will make this mixture leaner.

Make sure you get a good boost gauge and more importantly a good air/fuel ratio gauge before trying anything

Good luck :)

Silver 9-3 Arc
18th February 2004, 05:29 PM
The ECU should adjust and maintain the air/fuel ratio. 14.7kg of air : 1 kg of fuel
However at WOT our ECU will follow a fixed algorithm. Generally this algorithm will make the mixture richer(more fuel) and thus keeping combustion temp down. Adding a booster controller and dialling in extra boost will make this mixture leaner.

Make sure you get a good boost gauge and more importantly a good air/fuel ratio gauge before trying anything

Good luck :)

Well, what I would do is get the car on a dyno with a wideband 02 sensor. I would run it and see what it makes without it and monitor the A/F ratio. Then I would install the boost controller and see if it increases HP and verify that the A/F ratio is safe.

pjku79
18th February 2004, 06:18 PM
sounds like a plan to me. be sure and keep us up to date

Javier
18th February 2004, 10:00 PM
I think it is not wise to install the external Boost Controller, as the T8 shall control the boost. Dr Boost mentioned before that it will upset the balance between the Turbo and Throttle control. Pls find his post replies in the following link:

http://www.saabcentral.com/forums/viewtopic.php?p=193147&highlight=#193147

Silver 9-3 Arc
18th February 2004, 10:14 PM
I think it is not wise to install the external Boost Controller, as the T8 shall control the boost. Dr Boost mentioned before that it will upset the balance between the Turbo and Throttle control. Pls find his post replies in the following link:

http://www.saabcentral.com/forums/viewtopic.php?p=193147&highlight=#193147

Hmmm... I dunno. Has anyone tried it?

I am not so sure that the balance between turbo and throttle control would be affected. I need to do more research.

saabie
18th February 2004, 11:03 PM
In theory there should not be a problem. The T8 controls the solenoid valve by opening it when a certain pressure is reached between the solenoid and the turbo.(This is the little 5cm pipe U see near the heat shield for the turbo. The pressure in the turbo should equal the pressure at the solenoid valve.

Most boost controllers will be installed along this little pipe to create a gradient of pressure between the turbo and the solenoid valve. Therefore the turbo creates a higher boost pressure while the solenoid valve still thinks it is at the lower original pressure.

I don't see any connection between the throttle and the turbo. :wink:

That being said I would still go to a professional for a second opinion before trying anything.

Javier
19th February 2004, 12:01 AM
Putting a resrictor or bleed/ball spring valve Boost controller or external solenloid valve on the hose between the compressor and the WG Actuator will cause the T8 to lose proper controlling function of the WG, thus not being able to control boost. This device might increase base boost too high which will result into engine damage :cry: from denotation if your car is running on bad fuel or extensive WOT at high ambient temp. I think the T8 gets the Torque request signal from the gas pedal position, and adjust the throttle opening electronically and the turbo boost to achieve the desired air mass, so if the turbo is boosting higher, more than it is required, the T8 will reduce the opening of the throttle, so no increase in torque but increase in backpressure.

Just my 2 cents.

:roll:

saabie
19th February 2004, 11:31 AM
Did a little more research and found that the T8 monitors what something called the pressure ratio (A ratio of the charge air pressure against the atmospheric pressure ). If the ratio is too high, the T8 tries to protect the turbo by reducing torque. This is done by reducing the trottle opening. Perhaps even advancing the ignition timing

So even though you can trick the solenoid valve and the WGA by installing a bleeder valve etc, you cannot trick the charge air pressure sensor.

The take home message is Do Not install a boost controller valve :(