BOV placement??

90tgpblk · October 13, 2002, 10:34:33 PM

I have read all back posts on the bov and adding one. I saw the setup on jeorge's ste.. is the lower pipe where every one is putting them.. I read somewhere that it is best placed with in 14in of the throttle body? Just wondering, cause I just got my 1g bov and am going to being getting welded this week.. so any info on the best location would be greats..
Thanks..KCP

TGPilot · October 14, 2002, 07:28:21 AM

I couldn't tell you the proper place to put the BOV, but where the STE site has it is where I put mine. I do not hear the shock wave anymore and that is what you want to accomplish anyway... 8)

LDZ5150 · October 14, 2002, 08:08:22 AM

It can be placed anywhere after the turbo and before the throttle body.

90tgpblk · October 14, 2002, 09:42:31 AM

Thanks for the info guys. I thought i t could go anywhere in between.. Just wanted to double check.. thanks again... KCP

1trucavalier · October 17, 2002, 09:32:09 AM

pictures are fundamental

TGPilot · October 17, 2002, 09:51:24 AM

Put it where the Red X is!!!! :lol:

1trucavalier · October 17, 2002, 12:00:59 PM

geocities sucks I forgot!!!!

http://www.geocities.com/motorcity/track/8015/engine.jpg

90tgpblk · October 17, 2002, 12:11:20 PM

The linky no worky...... :o

Jeorge · October 17, 2002, 12:40:33 PM

Quote from: 90tgpblkThe linky no worky...... :o

just take the engine.jpg off and get to the site...

twinturbosedan · October 17, 2002, 04:16:40 PM

i would say the lower IC pipe is a better place for the BOV than the upper pipe. first, the pressure would be relieved before having to traverse the intercooler. 2nd, there is a pressure drop across the intercooler, so there would be more pressure in the lower hose. the more pressure surge you can relieve means less stress on the turbo and you wouldn't have as much lag either. a BOV would be louder in the lower hose because of this. another small reason the lower IC pipe might be better for the BOV is that you would have more room on the upper pipe to place alcohol injection and an anti lag valve. my brother is using what the turbo dodge guys call an 'anti-lag' valve...it is a rubber flapper valve on the upper IC pipe that is open when the engine has vacuum, but closes as soon as it sees boost. the idea is to take a 'gulp' of fresh air before the turbo builds boost, rather than pull air thru the intake/intercooler/piping. anyone here using an 'anti-lag valve' on thier TGP? it's funny, on my brothers Shelby he has 3 K&N filters....a cone before the turbo, one small one on the BOV, and another small one on the end of the anti lag valve.
joshua

turby · October 17, 2002, 05:39:31 PM

Wouldn't having the BOV in the lower make make the pressure go though the IC before it gets to the BOV. Since the pressure is coming back from the motor I would think the upper pipe would be better. Get rid of the preesure as soon as it comes out. :?

twinturbosedan · October 17, 2002, 06:31:55 PM

yes get rid of the pressure as soon as it comes out. the pressure wouldn't be coming back *from* the motor, more like from the turbo *to* the motor. when the throttle plate slams shut when you let off the gas pedal, all that pressure wants to force the turbo to a halt because it has nowhere to go. so the turbo is quickly slowed down, which is hard on the turbo of course and creates more lag since the turbo has to spool up again. if you relieve it out of the BOV on the lower IC pipe, it would be relieved before going thru the intercooler.
joshua

turby · October 17, 2002, 06:57:28 PM

Coming from the throttle body the IC is before the lower pipe. It's between the IC and turbo. Are we talking about the same thing.

twinturbosedan · October 17, 2002, 09:38:48 PM

i'm not sure...the pressure isn't coming from the motor, it's coming from the turbo -> to the motor. when the throttle plate shuts, the turbo is still spinning very quickly and making boost. the boost guage wouldn't read this tho, since the MAP is on the other side of the throttle plate in the plenum. all that pressurized air needs to go somewhere so it might as well be right after the turbo on the lower IC pipe, vented ASAP before it tries to cram it thru the intercooler and up to the closed TB. mounting the BOV on the lower IC pipe will also relieve more compressor surge than the top since the lower pipe is always under more pressure due to the pressure drop across the intercooler. that is why it is louder (and more effective) on the lower IC pipe. mounting the BOV on the upper pipe will still work fine, but IMO will be more effective on the lower pipe. can someone tell me if i'm way off? i guess it makes sense in my head....
joshua

twinturbosedan · October 17, 2002, 10:26:17 PM

one thing to add tho, the BOV is opened by the vacuum signal from the manifold (vacuum when throttle plate shuts); the pressure spike itself doesn't open it. so that way, the BOV is opened before there is much of a spike to even build up. EDIT: IOW, 1st the throttle plate shuts. 2nd, the manifold sees vacuum now, which the BOV also sees at this time (by way of vacuum line) and this causes the BOV to open. this happens very quickly, before the pressure spike itself starts to slow the turbo down (or at least before the pressure spike starts to slow it down very much). that being said, the BOV would be better suited to the lower IC pipe, where it can relieve that pressure at the source, before it can cram even more air into the IC and up to the closed TB. i would never own a turbocharged car without a blowoff valve! (*ecspecially* a turbo car with a manual transmission) sure they can be mounted anywhere between the turbo and TB and still work great, but if you are doing a custom installation you may as well put it on the lower IC pipe where it will be more effective.
joshua

BOV placement??

TGPilot

TGPilot