wastegate vac source
 

k, i've heared a couple different answers to this question, so if someone knows for sure, please clear this up for me. some people say that it's fine to hook your wastegate vac source into a barbed fitting on the compressor housing, and some people say not to. why, and does it really make a difference?

Re: wastegate vac source
 

the difference is that if you hook it up to the compressor outlet, your wastegate is going to see less boost than your engine is seeing, therefore you wastegate will open up a little early and you won't get the full boost that your spring is set at.

this is cause you get a pressure drop across your intercooler. maybe 1-2psi

If you tap into the intake manifold, your wastegate will see the same amount of boost that your engine is seeing.

Re: wastegate vac source
 

EDIT: Dam buddy beat me to it

You can hook it directly to your compressor housing, but the psi it opens at is the pressure right there

There is a pressure drop through your charge piping intercooler so if you take it off of the intake manifold you will know the pressure youre engine is seeing

Make sure the wastegate gets a direct line as well, dont tap into it

Im sure someone can explain it with a more technical answer

Vacuum manifold can be your best friend

Re: wastegate vac source
 

i understand now. seems like a stupid question now that i know the answer. :-X would it really matter though if i was using a mbc? just turn it up a little to make up for the 1-2 psi lost? or am i missing something obvious again?

Re: wastegate vac source
 

Run it off the compressor housing instead of the IM. Use the MBC to adjust for the pressure drop over your IC and pipes.

The shorter the line, the faster the wastegate response. Running the line to the IM tends to make for longer lines, ie: the possibility of spiking because of a delay.

Re: wastegate vac source
 

i am looking to make my own EBC(prob less then $75) i was thinking to take boost pressure from just after the IC to compensate for the press loss and to keep the line short, does this make sense? or am i an idiot?