fastazzf22

What is the difference between the two . I have both valves and I dont know which one is best for my application .

Can someone shed some light between the two .

full Circling

same thing

awdgsx96

I think the difference is that a bypass valve is for MAF cars, and bypasses air from charge pipes back into intake pre-MAF sensor.

Blowoff lets out air unmetered, as well as bypassing it from charge pipes.

So I guess main difference is one vents to atmosphere, and one doesn't?

Kyle R

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by awdgsx96 &raquo;</TD></TR><TR><TD CLASS="quote">

So I guess main difference is one vents to atmosphere, and one doesn't?</TD></TR></TABLE>

That's the only "difference".

fastazzf22

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by trashcanrepairman &raquo;</TD></TR><TR><TD CLASS="quote">

That's the only "difference". </TD></TR></TABLE>

So then which one should I use , for a boosted f22b1 ? Or does it matter .

awdgsx96

Either or.

Either way, they will dump air out of the charge pipes.

Put it this way, bypass valves are specifically for MAF vehicles such as DSM's. When the blow/bypass valve releases air on a stock DSM, it is rerouted via tube back into the intake before the MAF sensor.

Both dump air, and you don't have to reroute your bypass valve. Use whichever one you like more

spets

supercharged applications like the JRSC also uses a bypass valve.

Deo

Back from the dead.

Are there any issues with plumbing the vented air back into the intake on our map based cars?

I'm interested in getting rid of the BOV noise, do aftermarket bypass valves tend to make a noticeable noise?

alex_s817

on maf based cars the air is recirculated after the maf in most cases. this is why when those cars run an atmospheric bov the cars run rich between shifts. the ecu is set to see so much air and add fuel accordingly. the maf will read the same air coming in, but since it is before the recirc point, the ecu has no idea that the air from the bov isnt coming back in. just thought i would add that since i had to deal with it with my wrx. i dont know how much it would do on a honda but it would be super quiet and maybe aid a little with pickup/spool between shifts.

wantboost

iTrader: (2)

on my sr i put setup the maf as a blowthrough on the cold pipe and put the bov on the hotpipe... car ran like a dream

alex_s817

yea i was gonna do that with the subaru, as long as the maf is after the bov, it should work fine

HiProfile

Recirculating on a MAP based car may help when shifting (forcing air into the turbo inlet), but in will also raise IAT's because that air is usually hotter than ambient air pulled through the filter.

"Bypass valves" are function-over-form BOV's that have an outlet with a bolt-on flange or lip to allow some sort of tube to connect to it. OEM valves aren't designed for huge turbos. You can silence a normal BOV if it has that same type of outlet, so long as you add a length of tubing onto it, even more if it dumps into a sort of chamber (like the stock intake resonator). Adding tubing/resonators to anything will help reduce noise.

TunerToys

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">Recirculating on a MAP based car may help when shifting (forcing air into the turbo inlet), but in will also raise IAT's because that air is usually hotter than ambient air pulled through the filter.

"Bypass valves" are function-over-form BOV's that have an outlet with a bolt-on flange or lip to allow some sort of tube to connect to it. OEM valves aren't designed for huge turbos. You can silence a normal BOV if it has that same type of outlet, so long as you add a length of tubing onto it, even more if it dumps into a sort of chamber (like the stock intake resonator). Adding tubing/resonators to anything will help reduce noise.</TD></TR></TABLE>


Well stated. Further, the help when shifting comes from that bypassed air being forced into the turbo inlet, helping to maintain the shaft speed, instead of dumping that energy (in the form of pressurized air) into the engine compartment, where it does no good.

&lt;soapbox&gt;

I personally say, MAF, MAP, or what have you, that it is always better for driveability to route the bypass air back into the turbo inlet. The only reason not to is heat, and the loss of that PSSSSHHHH sounds that some many seem to love. For me, PSSSSHHHH just means lost energy.

&lt;/soapbox&gt;

Craig

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