? about BOV/auto tranny performance..

[thez99]

Hey guys, Ive been running the ER chargepipe with the HKS SSQV BOV with my 2010 135 for the past 4 months now, no problems at all, just curious on something.

I know for a manual tranny obviously the throttle is let off a bit between each shift as you hit the clutch, etc. However with my steptronic, I basically dont have any throttle lift that I notice thru the shifts, even in manual mode. So if Im going WOT thru 2nd, 3rd and 4th, i never lift off the accel pedal to shift and therefore I dont really hear the BOV sound I.E. boost pressure release. Is this not so good for the BOV? Thats not really all my question, im really wondering if im not getting all there is to get out of the BOV because I drive the steptronic rather than a MT.

The car pulls hard as hell thru the shifts like it should so I dont see a drop in boost or anything, i dont have a boost gauge to tell for sure, but ive driven turbo cars for a while now and i can usually tell.

Main thing is, I know with a MT car with this same setup, u usually hear the BOV releasing boost pressure in between shifts, whereas with the auto you do not. Only real times I REALLY hear the BOV is when im in a higher gear and I go WOT for a sec to boost up and completely let off the accelerator, or if I start out in a gear with heavy throttle n let off the pedal after. Otherwise I hardly hear it, I know its releasing pressure but obviously not as often or noticeably as with a MT. So am I putting more pressure on the BOV and possibly loosing some boost because of this setup vs the same with a MT 1er? Not like ill be changing cars for this, just curious what everyone has to say bout this, maybe others with aftermarket chargepipes/BOV's with the steptronic or even DCT trannies.

[bmwmike335]

Originally Posted by thez99

Hey guys, Ive been running the ER chargepipe with the HKS SSQV BOV with my 2010 135 for the past 4 months now, no problems at all, just curious on something.

I know for a manual tranny obviously the throttle is let off a bit between each shift as you hit the clutch, etc. However with my steptronic, I basically dont have any throttle lift that I notice thru the shifts, even in manual mode. So if Im going WOT thru 2nd, 3rd and 4th, i never lift off the accel pedal to shift and therefore I dont really hear the BOV sound I.E. boost pressure release. Is this not so good for the BOV? Thats not really all my question, im really wondering if im not getting all there is to get out of the BOV because I drive the steptronic rather than a MT.

The car pulls hard as hell thru the shifts like it should so I dont see a drop in boost or anything, i dont have a boost gauge to tell for sure, but ive driven turbo cars for a while now and i can usually tell.

Main thing is, I know with a MT car with this same setup, u usually hear the BOV releasing boost pressure in between shifts, whereas with the auto you do not. Only real times I REALLY hear the BOV is when im in a higher gear and I go WOT for a sec to boost up and completely let off the accelerator, or if I start out in a gear with heavy throttle n let off the pedal after. Otherwise I hardly hear it, I know its releasing pressure but obviously not as often or noticeably as with a MT. So am I putting more pressure on the BOV and possibly loosing some boost because of this setup vs the same with a MT 1er? Not like ill be changing cars for this, just curious what everyone has to say bout this, maybe others with aftermarket chargepipes/BOV's with the steptronic or even DCT trannies.

Probably the only reason why i never got a BOV on my 335 even though i wanted i thought about it. this car, and this has been discussed a zillion times is not recommended to function at with a bOV. the release of extra air into nowhere just to hear a psshhh is not worth the engine hassle it creates. typically that air goes BACK into some duct and is used up (recycling situation). With the Manual Tranny, i doubt the difference is going to be alot, maybe just a faint louder when the gear is dropped, but again only in higher rpms in 3rd gear and up, in lower rpms probably no sound...i think the turbos and turbo system in the car were designed to not release all that air so therefore.. i dno i guess it just doesn't have as much waste air to release as a wrx sti for example - (total whistle blower) lol

[thez99]

Well the reasons for the BOV are clear, I wont go into them now cuz I dont feel like it, but adding a BOV with an aftermarket chargepipe to any factory turbo setup will result in faster spool and slightly great torque due to the air not being recirculated, but rather dumped and new air immediately sucked it. Thats my not so technical layout of how it works, but I looked into it a great deal before buying so I know it works, just wondering more about the differences between MT and the step tranny.

Cuz like I said, i know its releasing the pressure, just not as loud between shifts cuz of the step tranny. Also I know the psi's have something to do with it, i was running 23 psi in my previous GTI and my aftermarket DV even sounded louder at times, but that was of course due to the higher boost level and more consistent need for boost due to it being a 2.0L 4 cylinder vs our 3.0L i6 sexiness.

So perhaps some of the reason why I dont hear it as much is cuz the car isnt putting out as much boost as say a STI or something similar, etc.

I dunno, i could get a gauge, i just dont see the need for all that hassle. If I was getting boost dumps and less performance I would surely notice this during WOT pulls, which I do not.

And btw, the noise was pretty much the least of my reasons for going with this. The main reasons were faster spool and the much better constructed chargepipe allowing for more boost with zero flex and leakage (HKS valve is guaranteed leakfree as well)

[bmwmike335]

as long as your happy with it thats oool dat matters.. but yea MT is gona be only slightly louder... and could just as well be from the MT car being in higher revs = more boost = more air bla bla bla so on n so forth.

oh gawd i miss hearing those turbos... there is a BMS SCI in my room as im writing this.. i should maybe put it out of sight so i dont go into daydreaming everytime i see it lmaoo

[thez99]

Eek, open air intake?

I still want some input on others with similar setups on the subject