[Former_Boosted_IS]

Is It Ok To Run A Blow-Off Valve On the 335i?

Before I start this review, I kind of feel inclined to just dispell some bad information regarding blow-off valves versus diverter or recirculating valves. In MAF or mass air flow cars, there is a significant difference between using recirculating valves and blow-off valves (BOV). The MAF car can run very rich if you choose to try to change to a BOV because of the way the air is metered. We are not a MAF car, but a T-MAP car. What this means is that the car cannot tell the difference between a diverter valve and a BOV. Now, each will have their own preference on whether they like BOV sounds or not, but remember there is no difference from a performance stand point between diverter valves and blow-off valves. End public service announcement.

I have loved the sounds of BOVs for a long time and have debated getting one for my 335i for a while. On my last car, I had a single turbo setup with an HKS SSQV and loved it! What kept me from buying one up to this point is that I have read of aftermarket charge pipes popping of the throttle body and I have never heard a sound clip that showed the BOV was really noticeable. This kind of kept me from purchasing one until now. Leaky stock diverter valve stories just got to be too much for me and I decided to make the plunge.

After searching the market, I decided on the STETT Performance Charge Pipe / Tial BOV kit. Some of the things that swayed me were:

1. Replacing the stock plastic charge pipe with a non-flexing material
2. Tial has a super reputation in the tuner world
3. STETT has taken a pro-active approach to eliminating the charge pipe from popping off the throttle body (I will go more into this later)

So, this leads me into the review...

Shipping

Chad, from STETT Performance has been a pleasure to work with from Day 1. STETT has been up front and reliable on the stock of his kit. STETT notified me of shipment and had a tracking number within 24 hours of the purchase. Finally, STETT has been very informative and a huge help in any way I needed. I always got a response within 24 hours of emailing Chad.

When the package arrived, I was pleased to see everything was boxed, bubble wrapped, and then bubble wrapped again to protect against any shipping bumps. There were no loose items at all.



Kit Contents

Once I opened the package, I immediately looked at the instruction guide and noticed that each item that was supposed to be in the box was inventoried by hand before it left STETT. You can see the hardware, piping, BOV, silicone couplers, and instructions included with the kit.



Simply put, everything was in stellar condition. I chose black silicone couplers and piping and was a bit worried it might get scratched during shipping, but it looks amazing!





The Tial BOV looks incredible on the black piping too.





Now, so many companies go "quality" on the products but "cheap" on the hardware. I am glad to say this is not the case at all with STETT Performance. They included high quality thick silicone couplers and T-bolt clamps!!! T-bolt clamps are very good at sealing, easy to bolt down, and very secure.





STETT Performance also is well aware of the issues with 335i's blowing off the aftermarket charge pipes. They decided to take a proactive approach to resolve this problem. The factory charge pipe utilizes a collar with a 4mm thick O-ring gently pressed against the throttle body and a metal lock clip that slides down and prevents the pipe from blowing off. Here is a picture of the stock pipe:



Notice the little rubber O-ring in there. That is what seals the stock charge pipe. Now, the metal color is what secures the charge pipe to the throttle body. To make sure that the new silicone coupler seals and doesn't pop off, STETT created a silicone coupler that has a "lip" to secure the coupler to the throttle body creating a nice tight seal. Then the silicone coupler is secured using the included t-bolt clamp. It seems very smart to me.





With everything in hand, I went off to the installation phase.

Installation

STETT Performance includes a instruction manual with the Charge Pipe / BOV kit. The good news is it is quite thorough, but the bad news is there are no pictures and I can see where this could be an issue for the novice. To help those, that will do this installation, I have taken extensive pictures to help you along the process. For this reason, the installation part of this review will be thorough.

When you start this project, it is suggested that you remove your stock airbox or intake. There are many DIYs on how to do this, so I will defer to them. I also would remove the stock plenum with a torx t-20 to allow more room. Here is what it will look like when you remove the airbox and plenum.



From here, you really enter the installation phase. First you will be locating and disconnecting the stock diverter valves from their respective turbo inlet connections. Here is the DV connection closer to the firewall:



The DV connection closer front on the car:



You will be twisting the grey connector about 1/4 of a turn to release each from the turbo inlet connection. It will look like this when you disconnect it:



Next, you will disconnect the vacuum line feeding the diverter valves. It is a "Y" connector that looks like this when disconnected:



Next, you move on to the infamous TMAP sensor. BE CAREFUL! I used the USB cable method. Simply slide the open side of the USB connector over the TMAP clip and slide out the plug. You can search for plenty of info here, but here is where the TMAP sensor is located right in front of the throttle body:



Next, unscrew the hose clamp for the charge pipe at the intercooler side or near the alternator:



Unclip the charge pipe at the throttle body by using a screw driver to pop off the metal clip:



Finally using a torx t-30 wrench or socket, unbolt the charge pipe:



Now you should be able to remove the charge pipe. Notice you still have the T-MAP sensor connected. Remove the two bolts hold the T-MAP sensor onto the stock charge pipe, and then re-use those bolts to install the T-MAP sensor on the new charge pipe:



Installing the new charge pipe/bov is just as simple, however it does help to have an extra set of hands here. I suggest you connect the throttle body side first personally. Get the charge pipe in place and slide the silicone coupler over the throttle body opening until it is snug. It is imprtant to make sure the "lip" seats and locks fully into the notch on the throttle body. Leave this T-Bolt clamp loose for right now. Next, insert the intercooler side of the charge pipe in. Finally, once you are happy with the orientation, tighten and secure each T-bolt clamp. Then, connect the T-MAP wire (you installed the T-MAP sensor in the last step) to the sensor in the new charge pipe. Connect the vacuum hose to the hose on the top of the BOV. Finally install the 1" caps to seal the location where the factory diverter valves once connect. It should look like this:



Yes, I agree the white caps are ugly and STETT is now replacing them with new caps that give a more stealth look. My pair should be here in the next couple of days.

Finally re-install your intake or factory box. Here is what it should look like all buttoned up:







After completing the installation, be very careful to double check the following:

1. Make sure that you re-connected the TMAP sensor
2. Check and re-check that everything is sealed well
3. Don't forget small things like the vacuum hoses

The installation is very easy with the stock intake box or aftermarket intake removed. I would suggest an extra set of hands when you are trying to place the charge pipe and secure the T-bolt clamps into place.

Performance

Time to start the car and take it for a ride. The car started without problem or CEL after the install. It was hard to wait for the car to warm up so I could take it for a ride. Revving the gear before the shift really was just big-time anticipation, then I hit the shift to second and heard the Tial BOV for the first time. It is incredible sounding! The HKS SSQV is more of a high pitched squeel, while the Tial is a sharp PSSHHTT sound. It is very noticeable too and this was one of my real concerns... that it would be too quiet or not noticeable. It sounds incredible! If do a 3/4 throttle to mid range rpms then drop off the throttle fast, you will hear the "rattle snake" sound eminating from under the hood.

Does it cause you to "lose power between shifts"? I actually felt the response between shifts was better and more crisp. Either way, you do not lose any responsiveness.

I have also had some in between shift spikes that were all but eliminated as well. I did change to the latest 8D Rev4, so it may be a combination of the tune and the speed of the release on the BOV.

Here is the sound clip I am sure many want to hear.

Conclusion

I am so excited that I finally took the plunge on a mod I wanted to do for a long time. I have the tuner sound I really wanted from the beginning and got rid of the potentially troublesome stock diverter valves. The STETT Performance Charge Pipe / Tial BOV is an incredibly well built kit:

1. High quality T-bolt clamps
2. Well designed and constructed silicone coupler
3. Patent Pending throttle body side silicone coupler to effectively seal the charge pipe to the throttle body
4. Beautiful and well built charge pipe
5. Snug fitment
6. Incredible sounding Tial BOV

In addition, STETT was very easy to work with and very informative along the way.

The only negative I can really come up with is a lack of pictures in the installation guide, but I think we have taken care of that with this review.

Simply put this is a very high quality kit in every aspect and I am very pleased with my purchase.

[WhiteSled]

sounds sweet, I can't wait to hear min for the first time this week. My only concern is running vta with meth, cause once the throttle shuts, that meth has to spray somewhere....

[Septro]

Great write up and good detail.

But DVs would be better suited for my taste.. the blow off valve just sounds too, umm how do I say... RiceeY. I'd lose my whole sleeper status with that much sound coming out the engine bay

[Former_Boosted_IS]

Originally Posted by Septro

Great write up and good detail.

But DVs would be better suited for my taste.. the blow off valve just sounds too, umm how do I say... RiceeY. I'd lose my whole sleeper status with that much sound coming out the engine bay

Let's not let this get into a discussion of whether or not you like BOVs. I do completely understand if it is not your taste though. Some like BOVs others and others don't, but we can still be friends.

[Former_Boosted_IS]

Originally Posted by got psi

great write up !!

got psi, thanks for the compliments on the review.

[enrita]

very nice review thanks!

[Denon]

Nice write up. I'm sure this will be useful to many in the future. Any video with the windows down?

[Former_Boosted_IS]

Originally Posted by Denon

Nice write up. I'm sure this will be useful to many in the future. Any video with the windows down?

The problem with rolling the windows all the way down is the sound is drown out by the roar of having your window open (on video). In person it sound incredible, but it is almost impossible to capture on video.

[TMR]

Originally Posted by WhiteSled

sounds sweet, I can't wait to hear min for the first time this week. My only concern is running vta with meth, cause once the throttle shuts, that meth has to spray somewhere....

The meth should be spraying after the BOV right before the TB.

[Former_Boosted_IS]

Originally Posted by TMR

The meth should be spraying after the BOV right before the TB.

TMR is correct here.

On a side note, I am surprised no one noticed there are more parts in the picture than just the charge pipe / BOV kit. It may give some insight into some of my intake AIT testing.

[WhiteSled]

no kidding guys, but what do you think happens when the throttle shuts and the bov opens? Being that the nozzle is btwn the throttle and the bov, its going to get shot out the bov.

[ulises 335i]

is it the gray box in the bottom right in this pic?

http://www.stettperformance.com/phot...argePipe14.jpg

[MrHarris]

That sounds tight.

[Former_Boosted_IS]

Originally Posted by MrHarris

That sounds tight.

MrHarris, thanks! I really forgot how much I missed having a BOV.

[Former_Boosted_IS]

Originally Posted by ulises 335i

is it the gray box in the bottom right in this pic?

http://www.stettperformance.com/phot...argePipe14.jpg

Nope. Notice some other parts... i.e. not a charge pipe in the picture. Also a red box is present in the picture that I purposely put upside down to see if anyone would notice.

[Zeph]

ya I noticed the K&N box in the 1st post and had to take a 2nd look (before even reading the review) as to why it was there...

love the sound btw, I will definitely be installed a TiAL style BOV soon myself. I always liked their sound better than the HKS squeel.

[Former_Boosted_IS]

Originally Posted by Zeph

ya I noticed the K&N box in the 1st post and had to take a 2nd look (before even reading the review) as to why it was there...

love the sound btw, I will definitely be installed a TiAL style BOV soon myself. I always liked their sound better than the HKS squeel.

There will be a review upcoming including a lot of data logs on some things people have been discussing for a while.

I think you will love the Tial! It is a really nice PSSHHTT

[rocketpop]

STETT CAI with K&N Filter.

[Zeph]

Originally Posted by rocketpop

STETT CAI with K&N Filter.

I dunno, unless that is just a weird camera angle that box looks too small to be an upgraded filter for the STETT "CAI".

[import36]

great write-up/review!! i had the HKS SSQV on my rx-7 and Forge DVs on my Sti. definitely considering the Tial after your review...especially with their reputation.

[KWY91]

Pshhhht! =D Great write-up!

[rocketpop]

It's a K&N RU-2820 - its plenty big enough. Plus his jpg is named "StettBOVCAIKit1"