[Chefcg1]

Stock DV's hold plenty of boost. I personaly have preasure tested mine to 30psi with no leaks.

[DurboN54T]

Originally Posted by benzy89

If it means anything to you, Shiv is using Tial on the single-turbo kits

which spring in it? the 9 or 11lb spring?

[benzy89]

Originally Posted by DurboN54T

which spring in it? the 9 or 11lb spring?

Sadly I cannot tell you, I found out after reading/looking at pics from FBIS' install. There's a photo in there with the parts list & I saw the TIAL on there. Truth of the matter is they probably haven't even decided which spring they'll go with since FBIS' car is getting dyno'd tonight-ish. I know they were planning on getting some results posted but they had some problems with the install (completely unrelated to the single-turbo kit). The battery connection was loose & the water pump never got power so they thought it was broken.

[Jeff@TopGearSolutions]

Tial for this platform comes with 11lb spring. The stock DV system is still hit or miss. Many guys have converted to either a BOV or aftermarket charge pipe and found a significant reduction in waste gate duty cycles. Recommendations should be taken on a case by case basis.

You can upgrade if you have problems or just upgrade to look or sound cool

[C ///M]

Originally Posted by 335xi Kevo

If this were true then the 2.0 fsi motors @ VW wouldn't experience this however they do, direct inject on a map based system.

The thing is ur venting off metered air. The ecu has to compensate.

I know this thread is a bit old, so I apologize if my bump irritates anyone. I thought it was a good discussion that offered at least a clear answer to whether venting a DV or BOV to atmosphere on our applications was ok or not.

I think Kevo might be used to the MAF systems BMW used prior to the e9x and the N54/55 motors. In the past, if you put an aftermarket turbo kit on any BMW utilizing an MAF setup (M5x, S5x motors), then you would experience that rich spike because it was metered air being vented out of the system.

As Fundahl mentioned, the N54/55 uses a MAP sensor (Manifold Absolute Pressure) so the ECU compensates when pressure is reduced by venting to atmosphere via a DV or BOV. At least that's what I thought, but am certainly not an expert on this particular subject.

I appreciated everyone's input here.

[Augster]

Originally Posted by Thomas@GIAC

I hesitate to name a specific company, as I would rather keep this as a discussion. What I will say is that we have had multiple customers experience underboost issues with aftermarket DV's. They switched back to the stock ones to remedy the situation.

Since we are still early in our aftermarket turbo development, I cannot yet speak for the high levels of boost that will be seen in such builds. But for everything up to our Stage 2 Race, running 16-17 PSI, we have seen no problems with the stock DV's.

And like you mentioned, some people use springs that are too stiff. If this happens, and excess pressure is not diverted upon throttle closure, you have a whole different problem on your hands.

For what it's worth, if it were me I would save the money and keep the factory DV's on a stock turbo setup.

As C ///M, I apologize even more for bringing this "dead" thread back to life, however, it brings up a serious point of contention that has not yet been satisfactorily addressed: that un-named aftermarket diverter valves are absolutely not recommended over stock or BOV.

I personally prefer the "silent" and more environmentally friendly excess boost recirculating method over a BOV from experience with my 300ZX Twin Turbo, and since there are threads that recommend replacing the stock DV and plastic charge pipe due to potential leaks and failure at high boost levels, I will be replacing mine with an aftermarket hard-pipe. As part of my Vargas Stage 2 turbo upgrade, I was planning for a BMS Charge Pipe along with Forge DV's after reading many recommendations for the Forge, but Thomas@GIAC is the lone dissenting opinion recommending against "upgraded DV's."

If there is any shred of evidence from others with concurring opinions, specifically involving the Forge DV's, then please speak up as this will certainly sway me to a BOV. Since the aftermarket charge pipe is specifically designed to work with an OEM DV setup or a BOV, but not both, it's important to determine the method of relieving excessive intake boost charges prior to charge pipe purchase.

[Jklad]

I have no evidence. However, before purchasing my forge dv's over a year ago, I called the company that developed my tune (won't name) and they said to use a dv that vents back into the intake tract as venting to atmosphere can affect airflow due to sensitivity of the Ecu. I'm not that technically inclined so i took the tuners advice, even though I would have preferred the woosh sound of a bov.

The forge dv's are definitely louder than stock, especially when combined with higher boost, dci, fmic, and removing the heat shielding under the hood. It sounds great IMO.

[whtcanbrwnd04u]

Sorry to bump an old thread, but can someone clarify which of these needs to be unplugged vs which one needs to be plugged?

[MDMA 135i]

Unplugged yellow ones , and put some plastic chair caps there.

[whtcanbrwnd04u]

Originally Posted by MDMA 135i

Unplugged yellow ones , and put some plastic chair caps there.

So you unplug the yellow ones and plug them with a plastic chair cap? What about the red? Leave those unplugged?

[tampaturbom3]

and what does that do to help anything?

[Patrick303]

Originally Posted by tampaturbom3

and what does that do to help anything?

Nothing. He's just using his OEM DV's to vent to atmosphere.

[tampaturbom3]

Ah, OK.... plug the holes in the intake side and leave the hoses open coming from the factory Valves. Does that in any way assist to eliminate turbo surge since the pressure wouldn't be sent back in the direction of the inlets?

[whtcanbrwnd04u]

Originally Posted by tampaturbom3

Ah, OK.... plug the holes in the intake side and leave the hoses open coming from the factory Valves. Does that in any way assist to eliminate turbo surge since the pressure wouldn't be sent back in the direction of the inlets?

I don't think it does anything. I just want to see what it sounds like, i've seen mixed reviews and want to try it out.