bov?

[Powered Bya Skyline]

my question i just recently purchased an rb20det, all stock but the intercooler that came with the motor does not have a bov. my question is there a dieverter value on the motor itself stock? if so where would that be? ive had a turboed car before but ive also had a turboed car that did not come stock turboed. so iam new to dieverter values in gerneral

[Cjmartz2k]

I don't exactly understand everything you were saying about "diverter values" but yes, the stock RB20 has a blow off valve on the elbow just before the throttle body.

[StricNyne]

i think he means the whole recirc thing compared to atmos. if your asking if there is another air outlet then no, u need one from a dsm which should bolt up right where cj said or if u vent u gunna get rich condition

[l0nestar]

"Diverter Valve" is the proper or engineering term for either a BOV or Recirc valve.

Yes, there is a factory recirc valve. It should be on the cast hardpipe a few inches before the throttlebody. I have a spare if you need one.

[Powered Bya Skyline]

sorry for the confussion on my spelling and gramer.. i have my moments.. i will have to check and see if i have the recirc. value next to the throttle body.. iam sure it does but i still gotta check.. thanks lonestar for the offer and for clearing up my post. i will get back to you on the value and so forth hopefully this evening after work.

[Drakelee]

I have been looking for about an hour for a similar topic and this thread is as close as I’ve seen, so I know where the recirc valve is and all that good stuff basically I want to replace it and the cast pipe with an aluminum pipe and a BOV. My question is will there be any down falls to eliminating the two hoses that run off of the recirc valve. I know the one is for the recirced air but not sure about the other one that comes off the cast pipe?



I want to clean up all the useless crap, I love a nice clean engine bay... so I want to do as much deleting as I safetly can.

[LeD ippen]

Okay, There are 2 Silvertop Rb20det one came in the r32 and one came in the A31. The R32 had a bov and slightly different map and better timing then the a31. the a31 did not come with bov stock. for example when on full boost the map would target for 11's while in the a31 it would target for high 10's. also if the bov is removed on a car that is orginally equip there is a lag whenever the throttle is letoff when building pressure. it won't run 100% without a slight tune, but it will run and drive.


I have a a31 ecu on a r32 engine >.> so yeah i got useless knock sensor in my block cause a31 have none. lol /cry


oh forgot something if you remove the pipes that means the metered air that went pass the the maf is missing which cause that lag because it is not "recirculated"

[Powered Bya Skyline]

so let me get this straight if you take the recir value off and replace it with same a atmospheric bov then the car will lag out of boost? so can you run a bov off the hotpipe that recirulates, plus delete the stock recir value?

[Gabes13]

I want to clean up all the useless crap, I love a nice clean engine bay... so I want to do as much deleting as I safetly can.

There are actually 3 hoses there. 1 is the recirculating tube like you mentioned, another is a tiny hose that connects from the bov to a vacuum source on the intake manifold plenum (needed if you wanna run a bov), and lastly (the one Im sure you were referring to) is for the iacv.

As far as I know, you need that hose connected to the cold pipe by the throttle body so the iacv can function and stabilize idle. The motors Ive seen with "re-done" cold pipes also retain that hose. I'm sure you could eliminate the iacv all together and control idle via throttle body, but I wouldn't bother unless you had a standalone system.

edit:
pictures of the redone cold pipes:

[TheRBguy]

You can buy aftermarket blow off valves that come with an adapter kit that will keep them in the same spot as stock.

[Drakelee]

Okay then I will most likely fabricate the new pipe to keep the ivac. Any other recommendations on stuff that I can get read of that isn’t necessary?

[90gtpony]

as far as running a aftermarket BOV, if you get one with a greddy flange like most greddys or a turbonetics raptor like i had you can angle it on the factory flange and mark where you have enough area to drill and tap 2 new holes. Thats that i did on mine when i had the raptor. Now im running the greddy rs but its still the same flange. depending on what mount kit you have if you get a bov with the adapter (bolt on not welt) for it, it might be too tall for the hood.