which BPV would you get?

ttocs · May 26, 2014

The vortech kit I bought was put together but someone else but not used and came to me with the power pipe that doesn't have the blow off valve. When do you need one?

Wichers123 · May 27, 2014

You always need one with a belt driven charger, the rpms will keep the charger spinning while the throttle is closed. My bov leads air at idle, most part throttle, and when I shift.

slow90coupe · May 27, 2014

Yes. You must have a BOV or a bypass valve. My setup had dual Bosch bypass valves.

Wichers123 · May 27, 2014

I run a knock off tial 50mm.

Brian95SVT · May 27, 2014

Wichers123 said:
I run a knock off tial 50mm.

Sorry to slightly derail but which one are you running? RaceMart used to sell one but I was having trouble finding it on their site. I had a Tial 50mm on my STi and want to run one or something similar on my turbo build.

ttocs · May 27, 2014

ok so then is there a spot to put one on here?
http://www.andersonfordmotorsport.c...-vortech-s-t-ysi-trim-superchargers-af-0102c/

This is the pipe I have but there is no valve in it.

410sn95 · May 27, 2014

Vortech ships those kits with a plastic Bosch valve that is attached via hose and hose clamps to the plastic blower discharge pipe. The female threaded fitting on the power pipe accepts a hose barb that will connect to the hose from the outlet of the recirc valve. The Vortech install manual shows the plumbing/routing.

You need a male threaded hose barb for the power pipe. Anderson ships it with a plastic 90 degree one.

ttocs · May 27, 2014

guess I need to find all those parts then.... Is there any help you can give on this subj? I know even less about blow off's then I know about superchargers which is bad... Good/bad/ugly? What to get/what to stay away from?

slow90coupe · May 27, 2014

I can give you the info about my setup, though it was slightly different since I have a mod motor. There is a decently big barb on the bottom of the powerpipe, close to where the inlet that goes into the blower is. This is where you can run the bypass valve/BOV. You simply tap the little nipple on the end of the BPV/BOV into the vacuum lines and there you have it.

ttocs · May 27, 2014

at this point modular info is more then I have so all help is welcome. I don't know brands or anything about them really...

Suspect · May 27, 2014

they'll have everything you need.. http://www.superchargersonline.com/index.php?main_page=index&cPath=510

slow90coupe · May 27, 2014

ttocs said:
at this point modular info is more then I have so all help is welcome. I don't know brands or anything about them really...

For a bypass valve, a very cheap and common thing to do is run a Bosch piece from an Audi/VW. That's what I had on mine, and the good thing is if something happens to it, you can get one at your local parts store. As far as a BOV, I'd run a Tial or Vortech Mondo.

ttocs · May 27, 2014

I am building this to last so I don't mind paying for something better if its more then just a name.

kb1982 · May 27, 2014

According to Vortech, any supercharger producing over 6 pounds should run a BPV or a BOV. I say definitely run one. The deciding factor which type BPV or BOV is dependant on where your MAf sensor is going to be. MAF before the supercharger, you will need a BPV. MAf after the supercharger, aka slot style, its up to your preference. The standard bosch bypass is recomended for 6 to 12 psi according to Vortech. Anymore boost than that, and they recommend a valve that can flow more. Will the standard bosch bpv work for more boost, it has on my car that makes 16 pounds. Be aware that the standard bosch bpv cannot be adjusted. What does that mean??? Well, until your engine goes to 0 inch vaccum, the bpv keeps recirculating instead of building boost. This means, the car will have to be floored before the boost comes on. Higher quality units, both BPV and BOV can be adjusted to stop diverting air before 0 inches of vacuum. The higher quality ones will also dump more air in the case of a bov, or recirculate more air in the case of of a bpv when you suddenly let off the throttle, keeping pressure from slaming into the closed throttle body and reverting back into your supercharger impeller.

So what are the benefits of a BOV. All excess uneeed air created by the supercharger would be dumped directly to the atmosphere, so the routing of another hose back into your powerpipe is unneeded. Since air being passed through the supercharger is being compressed, it also is being heated up by the same process. Since the BOV's dump to the atmosphere, this already heated air will not be passing through the supercharger again, which would result in further heating of this air. This in trun leads to cooler IAT temps than vehicles equiped with a recirculating BPV.

Benefits of the BPV. The biggest advantage is the quietness of a BPV. Since they recirculate the air back into the intake plumbing before the supercharger, they are alot quieter. A BOV, is pretty loud when it is dumping air to the atmosphere, which is always except when you have your foot in the gas. Also, with a BPV, you can instantly tell if any or your post supercharger plumbing comes lose by the instant blowing sound you will hear. This sound is the same sound that a BOV makes constantly. Ill upload a video of the noise my car makes with the standard bosch bypass valve venting to the atmosphere. You can hear the blowing sound of air from it along with a little whine of the supercharger.

[video]http://s653.photobucket.com/user/kb1982/media/DSCN0762_zpsc254f5b2.mp4.html[/video]

ttocs · May 27, 2014

thanks...... My maf is before the charger, didn't know I had the option to move it really. Just need to figure out exactly what parts I need now. Got the line lock and vac lines sorted out, working on the catch can and this now.

410sn95 · May 28, 2014

You will be fine with the plastic Bosch valve but if spinning up for more boost eventually, a bigger valve won't hurt. Problem is packaging. The Vortech 94/95 plastic intake has limited options for bigger valves.

If you do feel like getting something that flows more and is not plastic, Forge makes a diverter valve that's billet aluminum, re-buildable and is a direct replacement. I ran one on my old s-trim setup for a long time. No issues and was able to sell it when the time came.