[danny]

Originally Posted by ward

I wonder how much HP you loose as the boost is vented during shifts?


BMW knows what they're doing, so you're sacrificing power for style (sound)

but hey it's your car so have fun.

he's right. you are venting boost pressure between shifts... that is what the jap cars do.. Porsche and I assume BMW (since they don't have a bov either) instead recirculates the boost pressure while keeping the turbo impeller spinning.. this gets you into boost faster after you shift than with a bov.

[JEllis]

The purpose of the BOV is to REDUCE lag, always has been. Its not really required on the 335 which has basically no lag to begin with but to say that a BOV is robbing the 335 of Hp producing boost is an incorrect statement. There is probably no benefit to putting a BOV on the 335. Some have said that it might provide even more protection to the turbos by further reducing back pressure but that has yet to be seen.

Jason

[BoostedBMW]

Originally Posted by danny

he's right. you are venting boost pressure between shifts... that is what the jap cars do.. Porsche and I assume BMW (since they don't have a bov either) instead recirculates the boost pressure while keeping the turbo impeller spinning.. this gets you into boost faster after you shift than with a bov.

You are right, but at the same time you are wrong in assuming that any of those "jap cars" come from the factory with a BOV that vents to the atmosphere, that would never pass emissions. Just like Porsche and BMW, they use a recirculating/bypass valves, and although with a BOV you are venting boost pressure between shifts or when you let off of the throttle, the turbo is still spooled. A BOV helps prevent compressor surge, whether or not you view that as helping the turbo spool faster is up to you, but I don't think that they help reduce any turbo lag over a recirculating valve that can handle stock boost pressure adequately. I currently have one of those jap cars with a turbo/BOV (turbo s2000), and when I am WOT and shift I am at full boost as soon as I am back on the throttle with almost no delay so I wouldn't worry too much about a BOV hurting spool time or performance, but at the same time aside from noise they aren't adding to performance either. The only time they are detrimental is if you start to throw MAF's into the picture where they are expecting at least some of that air to be recirculated. Basically, if you like the noise then by all means go for it, but don't expect to justify your purchase by saying that its decreasing turbo lag or improving performance over the stock unit that performs its job fine.

[Ado]

Hey quick question, what size are those rims and did you lower your car even more then what it was already?



This looks pretty damn low, anyone else think so?

[Jason]

Originally Posted by Ado

Hey quick question, what size are those rims and did you lower your car even more then what it was already?

This looks pretty damn low, anyone else think so?

Here's jp335i's thread which will give you the info on the wheels (Beyern) and springs (eibach)

http://www.e90post.com/forums/showthread.php?t=32091

[RetroGamerJP]

Car is lowered w/ eibach coilovers about 1.75 all the way around. Wheels are 20x8.5 in front and 20x10 in rear.

[super88ta]

Originally Posted by leitrim

No HP loss for BOV, but of course no gain either. It's really just a safety measure (especially if he ends up increasing boost from other mods) to vent unwanted boost during shifts and/or decreasing speed. If there were no BOV or some sort of valve for releasing pressure you would have air being forced into the intake when you don't need or want it ie. slowing down.

While I'm talking about safety, two mods that I think would be a good idea is a turbo timer and perhaps an oil catch can. Turbo timer will keep the engine running for a set amount of time before shutting down to prevent oil cooking, which can damage the turbine and/or compressor.

The catch can will catch the blow-by oil from the PCV valve to the intake tract.

The electric water pump continues to circulate coolant through the engine and turbo assembly even after you shut off the car. No need for a turbo timer, it already has one....thermostatically controlled too!

[Jonn335]

if all you want is the sound, you dont need to go and buy/install a new valve, you just need to re-arrange the vent pipe of the standard valve to vent to atmosphere, and block off the hole it used to go into. The tuners won't tell you this because they want to sell you something.
This also has the advantage of not cutting anything up, so when you take the car to the dealer you can put it back to normal

[HID]

I am from the Audi crowd and when people put BOV on Audis, VW, Volvo, Saab, Porsche, Subaru, and countless other cars with complex ECUs, they usually run rich for the moment that the ECU does not sense the recirculating air.

When you want the sound, you just buy a good free flowing intake.

If for some reason the stock diverter valves cant hold the amount of boost requested, you upgrade to stronger diverter valves.

I will post a video of a properly functioning DV valve.

[calvino]

Bump

[HID]

Its not my car but it sound the same way.

[eninetytwo]

I like...Sound's clean...

I know its kinda off topic but i like the cars setup..anyone know what Rims/Tire size jp's runnin? As well as suspension?

[ahnh77]

on small turbo cars...bov doesn't really do anything..just makes sound...

[HID]

Yes it does, it makes them run rich, now a diverter valve holds and recirculates boost, so when you let of the gas there is still boost on tap.

Ps: Also prevents compressor surges, and over boost.

[Walked U]

If you want I can give you direction to a place near me, like my place or somthing. Since everyone will most likey meet around here.

[Panoz]

Originally Posted by HID

Its not my car but it sound the same way.

To be honnest with you..i didnt expect such a nice sound...Weldone mate,enjoy it.

But..I'm not still so sure if installing a BOV is the right thing to do on the 335i

[IMJUSS2NASTY]

I just really want the sound. As long as it doesn't hurt my 335i in any way im fine with it. Not really looking for mods until my warranty is over. Maybe just the xede. But thank you all for your insights.

[myst]

off-topic, but what rims are those?

[LOLrance]

Beyern Mesh

[HID]

Originally Posted by myst

off-topic, but what rims are those?

RS4 replicas

http://www.audizine.com/forum/showth...ght=onyx+black

[Tmac911]

Originally Posted by HID

RS4 replicas

http://www.audizine.com/forum/showth...ght=onyx+black

those are not rs4 replica's, hell it aint even rs4 rims man LFMAO

[HID]

Sorry I thought he meant the A4 not the 335I

Stock Dv with Carbonio Cai