best blow off valve location

— ok – most popular being on the upper charge pipe/cold side … i have a rather thin gauge metal cold air intake pipe and a HKS SSQ BoV…and will maintain the stock battery location … keeping this i will probably need to have the BoV welded to another location instead of on the upper charge …has anyone heard of placement on the hot side b4 intercooler ?..most likely i will opt for the area between jus after intercooler and piping that will pass thru the ‘resonator box location’… any other ideas or suggestions

ass near as possible to the throttle body

between the IC and Turbo. the hot side of the IC

placing it as close to the TB (at least 6" away) as possible will result in the best operation of the BOV period.

You can put it on the hot pipe though and still get good results; just not as good as closer to the TB. Just make sure its at least 6" away from the turbo outlet, IC inlet/outlet or TB inlet and you are good to go.

curious as to why you think this is true?

please, if u can jus expand a bit on your explanation

with the bov being on the hot…that would make the bov sound diffrent right??? b/c i was thinking of doing so.

No i don’t see why it would change the sound of it. Unelss you have a massive pressure drop after the intercooler then ya… :stuck_out_tongue:

Full race kits have the option to put it on the actual hot side of the intercooler, not the pipes,but on the side of the intercooler

actually if you buy the full kit that’s the only place you can put it. and being that full-race is owned and operated by no fewer than 6 engineering degrees between 4 people, i have a feeling they know more than the average forum teenager (not you speed, others in the thread ;))

please feel free to explain why “as close to the TB as possible”, mister drifty, is the best place to locate the blowoff valve. :up:

edit: just so i’m not misunderstood, here’s my reasoning why you don’t want it as close to the throttle body as possible:

When you have the blowoff valve at the compressor, or intercooler location it allows for the maximum amount of air to be dissipated to the atmosphere. You get far less compressor air smacking onto the throttle plate. Its far more efficient right after the compressor outlet.

exactly, but im pretty sure you can opt to have the bov placement on the chargepipes if you want, but it is reccomended to get the “back door” IC set up

closest to the TB:
when the TB is closed, the pressurized column of air stacks against the TB and begins to travel back toward the compressor. Since the BOV’s purpose is to prevent compressor surge, it is best to release this column of air before it begins to build up and travel back. Therefore, closest to the TB would be ideal.

hot side (after the compressor & before IC):
this location also works. Pressurized air will still seek atmosphere (equilibrium) and it will seek the easiest path. With the bov in front of the compressor, the air can’t travel past the bov, and bounce on the compressor.

imo, all locations will work. as long as you place it where the housing won’t get damaged & the vac line won’t develop leaks, you can’t go wrong.
remember that if you decide to use it on the hot side, you would have to run a lengthy vac line.

wrong.

the full-race kit comes with a vac line around 18" (maybe even less) for the BOV which sits on the hot side endtank of the intercooler. seems to be working fine for lots of people. :shrug:

What vacuum source do they suggest you hook the other end of that 18" line to? I cant think of anything near the front of the car that would have solid vacuum.

this post brought to you by the letter “T”. :wink:

lol so it’s actually about 3 feet of vacuum line. hehe

im pretty sure you can T it off of the Wastegate, which is pretty darn close to the bov location.

You need a vacuum/bosot source for the BOV to operate correctly. not just a bosot source. You need the vacuum source to physically pull the valve open to aid in opennig it.

the vacume hose has to come from after the TB to the BOV and its good to have the BOV 6" away from the TB is because the bends in the piping cause a drop in boost and so does the temperature of the engine bay. if the BOV only gets a boost signal will it ever think to dump when the closing throttle makes vacume and the motor doesn’t want boost? the wastegate is the only one that needs to have a boost only signal. if you dont believe me just try any other way and let me know how it turns out.

the bends in the IC pipping shouldn’t cause a drop in boost at all unless your entire setup is very inefficient and also temperature does not cause pressure to drop.