rhymes

Hi guys,

Have a twin turbo'd 350z and am thinking of replacing the BOV with a recirculating bypass valve. I have been doing some reading and it seems as though the recommendation is a bypass valve if there is a MAF (which my setup uses)in the system and BOV if it utilizes a MAP. I understand the theory behind this. My question is, will it make a difference if the recirculation tubing is a different length. The current location of my BOV is just before the MAF sensor on the intake tube before the throttle body. If I run a recirc tube to each intake for the turbos the length for the passenger side will be considerably longer than than the drivers side. Should I just make both hoses the same length and coil up the extra on the drivers side or would you recommend placing the bypass valve more in the center to ensure equal lengths.

look forward to your recommendations, input and ideas.

Conway_160

iTrader: (1)

In all reality it makes a very very slight difference, all it does is take the boost from venting to atmosphere which is louder and sounds better IHMO. To venting in your Intake which muffles the sounds but It also help keep the turbo spooled a little bit if your shiffting at WOT since the air is going back into the turbo.

If you were running a Recirc and then decide to go to a vent to atmosphere you will want to change the tune a little big for when you let out of the gas the car is expecting that air over the MAF/MAP so its adding more fuel so you will go rich for a sec.

Freise

I ran a "blow through" setup on my 240sx which meant relocating the MAFS to the cold pipe after the blowoff valve. When it dumps the MAFS reading is unaffected. I ran a Z32 MAFS which is largely made of plastic and didn't experience any issues until 14psi popped the guts out of the top of the housing. The second one I reinforced with epoxy and never ran into an issue even at 18psi. If I were to do it again I'd just take the MAFS guts and put it in a custom made metal tube just for peace of mind and aesthetics, but the sensor itself is pretty hearty in positive pressure.

rcdash

iTrader: (18)

No recirculation necessary. I used to recirc but removed the tubing. No difference I could feel in spooling b/w shifts.

rhymes

Thanks guys, I appreciate the input. I've logged the MAF voltage and it appears to be a little unstable in the cruise and mid throttle areas. I think what I'm going to do is relocate the BOV a little further away from the MAF sensor. I think what I may be experiencing is some turbulance from the BOV being too close to the MAF. Do you have any recommendations in regards to how far the 2 should be apart?

Conway_160

iTrader: (1)

Stock procharger kit has it roughly 8" away.