33mm exaust valves

Started by G40_POWER_AD, April 07, 2013, 08:21:18 PM

Previous topic - Next topic

G40_POWER_AD

benefits that we have to increase the exhaust valves to 33mm?

hayesey

do you mean in comparison to increasing them to 31mm ones or just in general?


G40_POWER_AD


hayesey

I could've sworn I typed a reply to this yesterday!

hayesey

basically said:

when we were doing the mapping on my car which has a k03 turbo, standard bottom end & a head that has been ported and has 31mm exhaust valves, Robin was doing mapping on his too.  We hired a rolling road for a few hours to get the maps finished off properly and do power runs.  Robins car is the same spec but 1341cc bottom end with a standard head.  Both cars made almost exactly the same peak power (mine was actually 0.2bhp more haha unlucky Robin!).  robins made more power in the mid-range thanks to the extra cc's and increased compression ratio.  But his ran out of steam in the high RPMs whereas mine carried on increasing power thanks to the head capable of flowing more. 

So yeah they definitely make a difference, to an otherwise standard G40, probably not so much but if you are increasing the boost significantly then it's a good idea.

G40_POWER_AD

hum i understand now mate...lets kick tanks hayesey