Hybrid blow off valves

[bluefox]

Anybody heard or know much about these hybrid Blow off valves? They went both into the airbox and into the atmosphere.......

How much difference does it make/is it damaging, to not have the air going back into the airbox and past the airmeter???

[simpsonm]

I have an HKS SSQV dumpvalve that emits totally into the atmosphere, I have had no performance degredation.

I think it all depends on where the dumpvalve returns the air. If it's before the MAP sensor then ur OK. If it's after then the engine ain't getting what the MAP sensor is telling it. This will be where harm is done.

The latter I think is how VW turbo charged engines work, they stall or have erratic tickover when dumpvalves are fitted.

[bluefox]

Simpsonm Cheers for that info, sounds as though its not gonna be a problem to fit a BOV that vents to atmosphere then.
Have you had any problems with stalling at idle?? Or is it jsut a matter of setting the BOV hard enough to stop it.

[enigma]

I have a hybrid BOV (a GFB hybrid in fact) I dont have any real problems with it at all and it sounds pretty cool as well! I have had a couple of instances of near stall conditions after slowing from (ahem) 70mph to a standstill on a motorway slip road, but I cant say for definate that this was the BOV.

The standard BOV returns the air AFTER the MAF, so it will be lost according to the ECU. However, a lot of people run vent to atmosphere BOVs with no apparent problem.

[simpsonm]

I apologise as I may have been telling porkies if what Dave says is true.


Dave you know more than me on this subject but I have a query.

If the MAF expects (x) amount of air in and the dumpvalve expells the air after the MAF won't that lost air effect the running of the engine?

[enigma]

You are likely to encounter a rich condition (too much fuel) which should not be a major problem. With an auto you wont dump between gearchanges anyway (not noticably) so its not really an issue! You can however dump at will by taking your foot off the gas, during this instant you will get overfuelling and if you are lucky may even get some crackly pops from the exhaust :-b