Question on Bypass valve

[va_bch_zx2]

I noticed in the “Post your turbo setups” thread that there were several PICS of turbo kits using BOV not bypass vales. I was under the impression that the waste pressure needed to be fed back in front of the MAF to be recalculated. Is this a true statement?

[Sir William]

That depends on your setup.

If you are using a blow through MAF there is no need to recirculate.

If you use a BOV like the HKS SSQV many including myself don't recirculate.

if you use another type of BOV it may leak and mess up the amount of metered air therefore you'd need to recirculate

[ZX2Fast]

Even with the SSQV you'll notice the engine wanting to stall on low RPM blow-off. If you keep foot on the gas you'll be fine.

[straightupmad]

i have an "anti-stall" fitting on my BOV that ensures the BOV doesn't leak at idle or part throttle conditions.

[Sir William]

^ that's how the ssqv is also

[Escort Pimp]

Blow through is the only way to do it right

[Unlikely Hero]

Blow through is the only way to do it right

Agreed, if your venting, you should go with the blow thru. If not you'll always get a rich mixture between shifts which can cause stalling and fouling of plugs.
=Jason-

[va_bch_zx2]

I don’t have a blow through MAF. So is there any bypass valve that you would recommend over the rest? Or if I plan to recycle dose it matter that much?

[gt35r zx2]

Im not running a blow thru, and my car runs great , If i was you I would go with hks bov and be happy

[Unlikely Hero]

Im not running a blow thru, and my car runs great , If i was you I would go with hks bov and be happy

Just because yours works doesn't mean everyones will do the same.

A good recirt thats the best bang for the buck is the 1g dsm. Holds boost well and pretty cheap. Usually can pick one up for less than 30 bucks off of ebay.
=Jason-

[Sir William]

do they make a blow through that doesn't have to be in an aluminium tube?

[ZX2Fast]

According to my tuner, we can use my stock MAF with a range extender in a blow-thru. This is great because the stock MAF is 3" and that makes this all easier.

[va_bch_zx2]

They have some Bosch bypass valves on Ebay for Audi’s and VW’s that look like they would work for about $50.
And what is a “range extender”? I got an Aftermarket MAF that matches my 42LB injectors. If blow through is better maybe that would be an option. I am working on my piping and would like to work all this out In the near future.

[ZX2Fast]

The problem with using a stock MAF with boost is that it pegs. It doesn't have enough range to show the additional air coming in. A range extender wires between the MAF and PCM to convert the signal so that you get additional range out of the MAF.

[va_bch_zx2]

I have a Pro-M MAF, could this be used in a blow through setup?

[yellow2000S/R]

I noticed in the “Post your turbo setups” thread that there were several PICS of turbo kits using BOV not bypass vales. I was under the impression that the waste pressure needed to be fed back in front of the MAF to be recalculated. Is this a true statement?

If you are recirculating, you put it AFTER the MAF. The air has already been through the MAF and if you put it recirculating before the MAF, that would be the same as venting atmospheric.

[va_bch_zx2]

Then this DWG is wrong. I saved this off the old site some time back. I try and save the good stuff.



http://members.cox.net/d.colaizzi/31300362243.jpg

[Unlikely Hero]

Stealing the picture for a sticky. :partynanas:
=Jason-