I'm a bit confused!!!! As most of you know I've installed new dump valves last week and have compleatly taken off the recirc ones and bunged up the original rubber pipe using 28mm adn 32 mm bungs on the pipes where the recircs came off.

 

My question is the vaccume pipe that was attached to the top of the recirc valves, is it connected to any kind of inlet pipe down there causing a possible air leak as my Z'ed as she feels slightly down on power after putting the dump valves in... It looks like the original vac pipe just connects to a small metal pipe that runs along side the big air intake pipe then as you look at the top of the engine inlets comes from a small metal pipe off them i.e there are 2 small rubber hoses connecting the original up.

 

I have also disconnect the vac pipe from the top of the engine near the balance bar as It looks like it was feeding the front recircs and connected the new vac pipe into there (The red vac piping) for the new dump valves so the old pipe in theroy is now doing nothing..

 

See pic..

 

 

Did a test and took the original vac pipe off and blew down it and could feel fresh air comming out of the other end where the recircs are connected, just need to know if I need to shove a small screw in the original vac pipe or would I just be pissing in the wind as it doesn't look like it goes any where else, just thought the small metal pipe might be linked actually into the big intake pipes or does it just run along side it??? :confused: !!!... Thanks for any help guys!!!

The two steel pipes only run along side the turbo/intercoller pipes so are not your scource of a possible leak/ power loss, the way you have the pipework arranged to the bov`s is correct.

 

You power loss could be very likely caused by the addition of the dump valves as you have inserted them INSIDE your original intake pipes, effectively you have reduced the air flow capacity of the intake by reducing the internal diameter of the pipe!

 

Similar positioned bov`s like the HKS one`s use their own dedicated intake pipe which has been so designed to NOT reduce flow rate.

 

 

Unfortunately with some "upgrade" parts, compromosise have been made to fitting design cost`s which always is reflected in the final performance results.

 

In my experience dump valves should be avoided unless big bhp is been made, otherwise as shown the benefit percentage can be so low it is actually worse than standard.

 

 

Jeff TT

Cheers Jeff, thanks for your help and clearing that up!!! Was worried that the little metal vac pipes might have actually been used for something else instead of just running along side the intercooler pipes..