More boost with Recirculating BOV??

[cardinal]

Has anyone gone from having their BOV venting to atmoshpere to having it recirculate to find that your car is making more boost at the same settings?

I have a built S14 SR with a GT2871R that I have been running an atmoshperic BOV and a ProfecB boost controller. With the BOV venting to atmosphere, my peak boost has been consistanly about 15.4psi to 15.8psi. I just completed fabricating a new 3" intake and have recircutated my Greddy Type S back into the intake to the turbo. On my test drive, you can totally notice a much faster spool up and the car seems much happier on decel. I ran the car up to about 100mph and back and when I checked my peak boost it was now reading 18.5psi. Not a big deal as the motor and tuning are set up for it, but I don't like to run it that hard on a daily basis. I did not change my settings on the boost controller, but was indicating more peak boost.

Has anyone else experienced this or can explain why the jump in boost pressure?

[silvia-junkie]

maybe you had a leake some where and when you removed and reattached your pipeing you fixed it

[got_boost702]

how did you go about recirculating it?

[Alfa Turbo]

I just completed fabricating a new 3" intake and have recircutated my Greddy Type S back into the intake to the turbo.

Would you be more specific here? 3" intake where? Pre-turbo, pre-intake, what?

The new intake or the inadvertant repair of leaks is most likely your answer. A recirc BOV would not aid in spool time or the amount of flow produced.

-Brian

[Wedge]

this would make sense why i had to up the settings on my avc-r this weekend as i UNrecirculated my bov.. only ran down the boost at the most 2psi.. what do i know, i feel like this car makes different amounts of boost everytime i drive it..

[cardinal]

Here is a picture of what I did. The intake is all thick walled 3" tubing that was cut and welded to the proper angles to make the bends (like what a lot of guys in Japan are doing) instead of mandrel bends. The BOV recircs just past the MAF and goes back into the intake of the turbo.

Since my last post, I took a die grinder and smoothed out any rough edges or anthing that would have caused a distruption or reduction in flow from the BOV back into the intake. It is almost a miror finish on the inside of the intake where the BOV enters. I was thinking that any restrictions to flow from the BOV would cause the boost to spike, but the more I think of it I don't see how that is possible.

Either way, the car is much happier now. I am in the process of building another similar intake for my S13 track car. I do miss the cool sounds, but all the noise is just wasted energy leaving the loop.

[DrifterProdigy85]

i never had that boost increase when i recirced my Greddy Type RS. Not sure why it would increase in boost considering as long as the BOV is staying shut while boosting you should hit the same PSI being recirced or open atmosphere. Only difference i found in recircing was more response in shifts and letting off and back on throttle.