Originally Posted by markk
Originally Posted by coombsie66
Originally Posted by markk
Ok bad example, any application where off boost performance is not paramount. Drag racing.
Although i do stand by my comment, that in 'some' rallying applications low comp is benificial to be able to run higher boost and then use anti lag to reduce the detremental effects. If you can achieve the desired boost levels without decreasing compression then yes this is better. I thought i made that clear with my explaination. Just a bad example, especially as you have a rally cossie by the looks of things, and im guessing that it aint low comp!
you wont find any big output rally engines that have what is termed 'low comp' pal because then the performance off boost is terminal for a rally car mate, even with antilag, we try to optimise the engien to use as little als as possible to try and keep stress to a minimum, just a small instance for you, my main turbo has just come back from service, it has done 2 events since its last service, so 150 competetive miles and probably 300 road miles, and it needed , new thrust, new oil bearings, and full rebalance, thats because i run a fair amount of als and i run high comp as well,
in a fair many events now als is banned for club rallying, so the high comp is essential to maximise torque, even at high comp without als the car feels flat to me
I stand corrected
I had heard antilag was harsh on turbos, i didnt realise quite how harsh!!
Compression ratio is a non linear relationship with efficiency though, so i'd say there is merit in keeping compression ratio high to a point. I should find out in the near future anyway as i help try to turbocharge (only a mimo Gt12) a 12:1 yamaha yzf600 (20mm intake restricted) for my universities formula student car.
