PDA

View Full Version : BoV vs Diverter Valve



Gewehr
03-06-2011, 06:29 PM
I have an HKS blow-off valve installed on my B5. I'm running a K04 with Maestro 7 software, big injectors and an inline fuel pump. (Also a 3-bar fpr.) Does it make a difference if I run an aftermarket blow off valve or do I need a diverter valve? Does it make a difference? I have mine blocked off at the moment. Any input is appreciated.

AudiNFS
03-06-2011, 06:32 PM
You could get a hybrid BOV and have it be 50/50 vent and recirculated if you still want to have a BOV sound. Otherwise, I believe they make the car run rich. Correct me if i'm wrong

Gewehr
03-06-2011, 06:35 PM
Right on, I just see everyone running diverter valves, I just wasn't sure.

Gaberossi
03-06-2011, 06:38 PM
if you have the HKS SSQ i think you are okay..but these cars require a recirculating valve(DV) in order to keep the car from running rich in between shifts...

walky_talky20
03-06-2011, 06:39 PM
There are some people who run them without issue. If you have a MAF-less file, then you've got no problem. Running with a MAF makes it touchier, and you can have problems with idle or stalling on clutch-in depending on the setup. The major factor is whether the BOV is "closed at idle". That's a biggy. I'm sure the intake plumbing and BOV location makes a difference as well. It all comes down to metered air that is escaping. The blow-off creates this rush of air past the MAF that isn't actually going to into the engine. This pretty much equals rich condition.

Gaberossi
03-06-2011, 06:40 PM
there ya go thats some good info^^

AudiNFS
03-06-2011, 06:40 PM
There are some people who run them without issue. If you have a MAF-less file, then you've got no problem. Running with a MAF makes it touchier, and you can have problems with idle or stalling on clutch-in depending on the setup. The major factor is whether the BOV is "closed at idle". That's a biggy.

Don't hybrids close at idol? Plus the great thing about hybrids is you can find one with complete adjustability.

walky_talky20
03-06-2011, 06:45 PM
The only one I've seen in person is the Forge Splitter. They advertise that it is closed (to atmosphere) at idle due to their magical "progressive rate spring". In my experience on one with a brand new "special" spring direct from them, it in fact was not closed at idle when adjusted properly. If you tightened it darn-near all the way down, it would close at idle, but then you couldn't get it to blow-off at all. The opening is quite small, though. And it did not cause any fuel-trim or idle issues on the installed car (after we bypassed the n249 - that DID cause problems when using the splitter valve).

AudiNFS
03-06-2011, 06:49 PM
The only one I've seen in person is the Forge Splitter. They advertise that it is closed (to atmosphere) at idle due to their magical "progressive rate spring". In my experience on one with a brand new "special" spring direct from them, it in fact was not closed at idle when adjusted properly. If you tightened it darn-near all the way down, it would close at idle, but then you couldn't get it to blow-off at all. The opening is quite small, though. And it did not cause any fuel-trim or idle issues on the installed car (after we bypassed the n249 - that DID cause problems when using the splitter valve).

Do you have any experience with a GFB FX stealth hybrid?

walky_talky20
03-06-2011, 06:59 PM
Do you have any experience with a GFB FX stealth hybrid?

Nope, just the Forge Splitter. But from some quick research, it seems like the GFB unit would work the same way, and is even adjustable (not just switch-able, like the Splitter).

AudiNFS
03-06-2011, 07:10 PM
Nope, just the Forge Splitter. But from some quick research, it seems like the GFB unit would work the same way, and is even adjustable (not just switch-able, like the Splitter).

Got it. Thanks Walky. No thread jack intended Gewehr

Gewehr
03-06-2011, 07:17 PM
No, its all good man. I dig the info and the input. I'll have to do some research on what I have. Thanks for all the help.

M-Hood
03-06-2011, 07:18 PM
Do you have any experience with a GFB FX stealth hybrid?

I do, with both the GFB FX Stealth and the GFB Hybrid. Had no issues with either of them while running a MAF setup.

AudiNFS
03-06-2011, 07:23 PM
I do, with both the GFB FX Stealth and the GFB Hybrid. Had no issues with either of them while running a MAF setup.

Thanks[up] Shoulda known in the first place[:p]