White-Un

iTrader: (1)

I`ve read on here that you can drill the bleed hole out on Dawes to stop overboost and even the boost out throught the gears ?

Do you drill it out or make a smaller hole ???? Also what size ?

Any help be much appreicated.

Cheers White un

john banks

Start small and work up. Makes it more of a bleed rather than quite so aggressive on part throttle boost levels. If you go up to 2.0mm you'll probably find you have a complete bleed valve and have a floor on the boost level you can run no matter how loose the Dawes is. 1.0 to 1.5mm is quite good.

White-Un

iTrader: (1)

So the bigger the hole the slower the spool up on the turbo ?

john banks

A little for the lower gears, but it is mainly how it behaves on part throttle.

White-Un

iTrader: (1)

So would it even the boost out ? or am i best to leave it as dont might the boost comin straight on .

Just wanted to stop it boostin more in higher gears and even it out,
Eg Peak 1.2 hold 1.1

john banks

It will probably make it slightly less even, the main reason is to avoid lean running on part throttle, or excessive boost on part throttle which can ruin the engine's throttle linearity.

White-Un

iTrader: (1)

throttle linearity ?? You lost me there John !!

Now i`m stuck , So would it be better to drill it out for engine runnings sake then ? more smoother running .

StickyMicky

just leave it, you dont know what your doing IMO

john banks

Throttle linearity is just a way of saying that with 50% throttle you get say 10 PSI, with 60% throttle you might get 12 PSI. The reverse is 50% throttle you get 10 PSI, 51% throttle you get 15 PSI. See what I mean from my exaggerated example?

White-Un

iTrader: (1)

Ahh see what you mean now mate, Thanx for the help .

Sticky micky thanks for the vote of confidance mate ! How hard can it be to drill an hole !!!!

I just didnt mean what john meant by throttle linearity