About to put my custom kit on in the next few months and need some info on were to run the vac line for my EXTERNAL WASTEGATE. Alot of people are telling me that there should be a connection on the turbo housing, witch i don't have... I know the BOV/BOOST GAUGE plugs up to the vac line on the throttle body( I believe the other lines are for coolant) so i got the dezod vacume block, witch made me assume to hook up everything to that but I'm not to sure...

:Things to hook up:

-External Wastegate
-BOV
-Boost gauge
-Greddy pressure sensor

 

take the turbo to a machine shop and tell them you need them to drill and tap you an 1/8"NPT hole to run a vac line.

 

Buy a vac block ,connect every vac source to it

 

witch one is best to go with or does it matter? my buddy said that if I connect it to the vac block, it'll take longer to boost and if I hook it up to the turbo housing it'll boost quick...

 

wrong......if you hook it up to a vac block, youll over boost....best way to hook it up is from turbo strait to wastegate.....buy a vac block and hook your gauge, bov, fpr, etc to it. but your turbo shuold always go strait to wastegate.

 

im using the dezod vac block and it works great , basically does its job.
if u connect to the turbo housing it wont boost quicker, how would it boost faster?

 

it wont boost faster either....what it does is lags the time in which your wastegate opens.....you have more line to go through running it with a block then strait to the turbo...therefore more time to build boost before the wastegate sees it.

 

i dont get it though why run a vac line from the turbo to the wastgate?

 

it could cuase a "lag" time but seriously 2ft of hose compared to 2.4ft of hose isnt going to make a huge difference....my wastegate has never had a problem with that..

 

dont know why your running 2 ft of hose....but i have around 9 inches of hose.....compared to 2 ft. now that IS a difference.

 

so the wastegate knows what psi the turbo is at.....the turbo vac line controls when the wastegate opens. much more reliable

 

Basically what he said. I used a vacuum block to connect everything and it worked. The problem came when it was colder out, and liquid water from the combustion going into the wastegate was getting into the vacuum lines. Yes, it does spool faster when it is routed to the manifold. I have it routing straight to the turbo housing for safety as well, if something would happen between the vacuum block and wastegate....overboost time! Of course, if it was going to the compressor housing, no problems, maybe AFR would be off, rough idle, fix it...

In short, turbo housing-->wastegate=safe...

 

you could drill a hole into the intake manifold basically anywhere you want.. andd then just thread in a fitting.. Thats what i did.

 

gingles is correct, best thing to do is run your vac line from the turbo directly to the wastegate.
If you had an FIC the best way to source that is directly to the brake booster.
Everything else can use a vac block with the throttle body vac line being the source.

/thread

 

yea cause i sure do love drilling and weakening our plastic intake manifold.

 

I had the same exact questions as the OP, and after searching a lot, and asking a lot of questions from the pros, here's a diagram i put together. Hope it helps and maybe others can find it useful as well. Also if something looks like it needs to be changed please chime in and let me know. If your turbo compressor housing did not come with a barb fitting, you can tap one in no problem... or you can tap one in on the intercooler piping right under the coupling that joins the pipe to the turbo compressor outlet.

 

Its probably the best source for vaccum.. Same reason why after market intake manifolds come with vaccum ports already attached.

Our plastic manifold is actually really strong.. I made just under 350 whp before i got rid of my scion on the plastic intake manifold.. and i did drill a hole in it to supply vaccum to my boost gauge, BOV, pressure sensor, and wastegate.

 

i never said it wasnt a bad place for one.......yes having vac ports in the intake manifold is one of the best, again i didnt say it wasnt. and yes we all know it can hold well over 350hp......i just dont see how drilling it is a good idea when you can use the brake booster line for your vac source.

 

is the brake booster a good line to tap for all the vac sources? gauge/bov/wg/fic?

 

yes