Friday, April 8, 2011

Bang Bang

Did you know that on the Fords I drove, the better driver you were, the more aggressive response system you could have.  Some say: Bang bang, others: response or anti-lag.  Whatever they say, it's the action of dumping fuel in the exhaust manifold just in front of turbo impeller to keep the boost up.  This action happens when you lift the gas pedal.  Therefore, as soon as you come back on throttle, the turbo is already boosted and the power kicks immediately.

There are various levels of this, adjustable by the engineer.  The engine guy has to find the right amount of anti-lag for each driver.  You see, having a hell of a lot of fuel being dumped in will keep the turbo singing high....But the temperatures are also singing high.  1.000°C was the limit, I was told, and apparently it gets there quickly....  So, funnily enough, the more you are on full gas, the cooler your turbo is.... The more of a braker you are, the hotter it gets.  An engineer can therefore never give the same amount of response to a basic driver as he gives to a throttle pusher. 

So as a paradox, if you are not a fast driver, you don't get any more help from your turbo. 

Engineers liked to have turbo temps running around 800°C

We had our turbo lags adjusted for each rallies as it depended a lot on how fast the stages were.  Finland for example, demanded very aggressive response systems.

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