Very rich after BOV installation on stage 1 @10 lbs ???

[rxboost05]

Just installed Vortec BOV on 05rx1, came up very rich at idle 10.5 on af reading. lots of black smoke and blubbering, this was with stock jetting, stock pilots and fuel screw at 2 turns out. Went through just about every jetting combo and fuel screw setting. I am now have 130 mains, floats set at 15m and fuel screw at 1 and 1/4 turns out. Ran it with fuel pump off untill it stalled and still rich at idle so it is not to much fuel pressure.
I run it up through the rpms on stand and it does not want to hold a steady rpm, let off gas and it will some times stumble and stall. At idle, at the jetting i have now i pull the vaccum line off the BOV and the AF reading went to 14.2 and rpms went up them started to stall, put vaccum line back on and it went back to rich idle
The reason for the BOV addition was i was blowing back some boost trail riding, causing noise the BOV seems to have cured that issue. Had intercooler and carbs off 4 times this weekend. Would likes some ideas before i pull it apart again.
This sled ran well before adding BOV,but wanted to stop boost blow back at the charger.

Thanks guys

 

[Apex]

Is the BOV venting at idle? If so that would make you rich. The engine is not getting as much air. Make the BOV spring stiffer to stop the venting.

 

[Ted Jannetty]

Where in the intercooler did you install the BOV.

The BOV should be in the charge pipe or the bottom of the intercooler.

 

[rxboost05]

Yes it is venting at idle and is mounted on the left side of the intercooler on the angled part (left sitting on sled). I guess i would need to turn in the scew with set nut to tighten the sping, what rpm should the BOV start working at?

Bob

 

[Ted Jannetty]

Yes it is venting at idle and is mounted on the left side of the intercooler on the angled part (left sitting on sled). I guess i would need to turn in the scew with set nut to tighten the sping, what rpm should the BOV start working at?

Bob

I think that is your problem, the float bowl signal is in the charge pipe, the intercooler has some restriction in it and you are venting the pressure just before the carbs.

So, what you have is a pressurized float bowls and no pressure at the carbs causing a rich condition.

The blow off valve must be in the bottom of the intercooler or the charge pipe before the intercooler.

Or you could tighten down the adjustment screw so it is closed at Idle as a last resort but not recommended.

Ted.

 

[rxboost05]

I will move BOV to the charge tube. what is the smallest inside diameter line can i run to it and still have it operate correctly.

 

[Ted Jannetty]

I will move BOV to the charge tube. what is the smallest inside diameter line can i run to it and still have it operate correctly.

1.38 inch