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Old 07-29-2012, 01:53 PM   #25
Scooby Newbie
Member#: 220799
Join Date: Aug 2009
Chapter/Region: International
Location: Taiwan
2006 Impreza WRX
WRC Blue


To come back on the Syvecs topic of ALS.....

As Jura mentioned running proper ALS loses the Servo completely.....
I have been running proper ALS for larfs on my DBW car but when you lift off the turbo is still whilstling like it is when spooling No brakes so electric pump or very proper brakes are a must.

Needless to say EGTs go to 1000*C VERY quickly. When you don't spend too much time off the throttle it is OK but not long term.

TBH. ALS is merely a way to keep up EGTs mainly and keep turbo shaft speed up.
When you want to do a proper ALS setup you should have a turbo shaft speed sensor for the simple reason that it can give a good indication whether you are heading in the right direction with ignition retard and fueling or not. More Pops and Bangs doesn't mean anything!

People saying they want ignition cut don't want their engine to last very long I reckon. Ignition CUT causes fuel residue to explode in the headers causing uncontrollable boost rise and damage to the turbines and ex. valves which could be pressed back off the seat and into the piston.

The loud banging and popping is a waste of time. Whilst it may sound cool it is just a waste of energy. The loud banging and popping indicating the mixture is ignited PAST the turbine wheel. For proper ALS drive you need to think of a smooth and continuous pressurization of the turbine which can be done with some ignition retard to have most of the exhaust energy going to the turbine.

Even with a Jacked open throttle you can idle the car normally since you can set a certain fuel cut, etc. for when the ALS is not activated yet throttle is still jacked. Usually high percentage of Fuel cut should be used here with not too much retard to keep heat out of the system.

Jura: Looking at your boost recovery on your LOGs you might want to start using FFS first to prevent those dips almost back to zero. You can keep boost almost at a straight line when shifting. Much more worthwhile for dragracing.

My 2 cents,

Jasper Kopinga
CS Racing
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