[Walked U]

For you guys thinking about doing the DIY BOV please take note.

Ive had the mod done for about 3 weeks now. Just recently I have noticed very strange things going on.


Heres the story.

3 weeks ago I installed a boost gauge in my car with the help of a friend. Since I had the intake removed I thought I would just do the DIY BOV also.

As you all know I have the procede also. Now when I finished installing everything, I drove it around checking if the boost gauge was working properly.

Now when I drove it I noticed my car was peaking at 16-17 psi under load.

I didnt really think of anything of it since it did it for like 1-2 secs then droped back to the normal 12 psi then tapering down to 9.

I also saw the psi would fluctuate rapidly under load. (peak 16 then rapidly go to 13, 12 hold 12 then taper down to 9.)

Now, since I didnt have a boost gauge before I did the DIY BOV I wasnt sure if this was normal just because if it was under load or not.

Also noticed my temp would spike very easy to 250f+ and rest around 230F+ from before, which was 210 F+. Keep in mind I have 6 speed manual and sports package which = oil to air intercooler.


But just last week I installed my Cat back system from zoomers.

Deleted 2ndary cats, deleted resonator, 2.5 inch straight pipes back with gutted mufflers and 3.5 inch tips.


Now I was excited about the mod and wanted to dyno the car with both map V1.4 stage 0 and stage 1.

Scheduled the dyno day and went there.

Now heres the fucked up part.

My base line dyno
272 rwhp / 281 wtq

After procede installed.
323 rwhp / 366 wtq.

Procede, downpipe back exhaust, DIY BOV
309 rwhp / 369 wtq






.... OK... WTF just happened here.

My torque jumped a whole +3 wtq but I just lost 14 rwhp. Even throughout the power band I loss power in the torque curve and hp curve.

Now I thought to myself its 10 degrees higher than the day I dynoed my car with procede and baseline.

I called dustin from vushnu and asked him what could it be. I was using stage 1 map.

He said he could be anything, bad gas, weather, the dyno. Anything...

So I asked him which map would you run stage 1 or v1.4. He replied " I think you should run v1.4 thats what we run on our car. But in the end it just depends on what you like. "

So I switched constantly back and forth. v1.4 to stage 1. Noticed no differance what so ever.

But I kept seeing the peak PSI reach 16-17 psi under load and stay there for about 2 secs.

Now... Today I went to the dyno day and was there with my buddy jon (jonmartin) and SfValley335i.

Jon went first he got like 342 rwhp / 407 wtq. with a 11.91 peak AFR reading.
Jon does not have the DIY BOV.

http://www.e90post.com/forums/showthread.php?t=58882 please see post #1

After his runs I hop on the dyno.

Best run I could get was a 331 rwhp / 391 wtq with a AFR peak AFR reading of fucking 14.91...............







After doing a few runs with friends I knew somthing was up with my car.

Once I got home, I seriously stood infront of my engine bay for 30 mins thinking wtf could it be.

How the fuck am i loosing power from adding a less restrictive exhaust.

Jonmartin ,SfValley335i, fusionchicken and whoever else I complained to knows wtf im saying.

So after pondering wtf could it be. I said the only 2 things I did from my last dyno was exhaust and DIY BOV.

After I read this thread very carefully.

http://www.e90post.com/forums/showth...hlight=bov+diy

Please read matts post #13

I said fuck it it cant hurt to put it back.

I put back the hoses and drove the car. Automaticly I could see the peak PSI under load only boost and hold 12 psi then taper down to 9 psi.

No more fluctuating. Even under heavy load it peaks 12, not even 1 run over 12.

The car felt very alive and responsive. A lot better than it use to. My temp stayed at 210 - 230 never jumping higher than that doing very hard runs back to back.

Now to even further back my theories about this I ran my friends 390-400 rwhp 390-400 wtq gto. I ran him before when I got the procede installed he use to walk me by 2.5 - 3 CL's from 10-155 mph.

Now... When we ran again with the hoses back in place on v1.4 and zoomers exhaust. from 10-155 he would walk only 1.5 CL's from me. We did it back to back 5 times to make sure it wasnt a fluke.

Now I believe I was noticing the temp spike from before because I was hitting 16 psi blowing hot air out of the turbos which in turn cooks the oil.

Now I stay at 210-230F+ under very heavy conditions.

I will redyno my car soon with the exhaust because I know im making more than 330 rwhp and 370 wtq now.

As for a few words of advise.

Please dyno your car before and after to make sure your not loosing power with your DIY BOV. Also please have a boost gauge installed if you do, so you can keep an eye on your PSI.

[Walked U]

Oh I also know that theres no way to compare uncorrected dyno sheets. But I knew something was going on.

[Evo8MRto335I]

My summary is that for some reason that DYI BOV thing was causing the turbos to boost extremely high which consequently were putting tons of extra unnecessary hot air.

It makes sense, I have run a few turbo cars on the dyno and tested the boost range to the point in which once you exceed a point you start loosing power.

Like you said, take it back to the dyno with the stock BOV and see what happens. Thanks for the review!

[jam0321]

this has always been the biggest reason for a boost gauge. It really is unfortunate that BMW did not include this feature.

ALL boosted vehicles should have a boost gauge to read this very crucial piece of info. Especially once you start adding mods to a factory FI car.

good to hear it's running better now. Sucked it had to happen

[Walked U]

Originally Posted by Evo8MRto335I

My summary is that for some reason that DYI BOV thing was causing the turbos to boost extremely high which consequently were putting tons of extra unnecessary hot air.

It makes sense, I have run a few turbo cars on the dyno and tested the boost range to the point in which once you exceed a point you start loosing power.

Like you said, take it back to the dyno with the stock BOV and see what happens. Thanks for the review!

Ya np, I want to get it out to the community so no one blows their turbos prematurely.

I think this is where we see a lot of over heating threads happen from also.

[Walked U]

Originally Posted by jam0321

this has always been the biggest reason for a boost gauge. It really is unfortunate that BMW did not include this feature.

ALL boosted vehicles should have a boost gauge to read this very crucial piece of info. Especially once you start adding mods to a factory FI car.

good to hear it's running better now. Sucked it had to happen

Yes i wish they did.

I wish I installed a boost gauge in my car as my first mod.

[Evo8MRto335I]

I particulary have been using Defi Amber BF imperial electronic gauge with its controller. That is what I am using currently on my turbo cars and that is what I will put on the BMW.

Not only I think this gauge is a must but I also consider it a tuning/diagnostic tool. The Defi electronic series can record boost for up to 3 minutes and also record peak boost and other funtions like peak boost warning. Last but not least it matches with the BMW dash illumination.

[Walked U]

Originally Posted by Evo8MRto335I

I particulary have been using Defi Amber BF imperial electronic gauge with its controller. That is what I am using currently on my turbo cars and that is what I will put on the BMW.

Not only I think this gauge is a must but I also consider it a tuning/diagnostic tool. The Defi electronic series can record boost for up to 3 minutes and also record peak boost and other funtions like peak boost warning. Last but not least it matches with the BMW dash illumination.

Well i was reading the data logs on psi on my laptop and on my boost gauge to make sure the boost gauge wasnt messing up on me.


So what im basicly saying that from doing the BOV it made me run very lean in turn retarded my timing than made me loose power.

[jam0321]

I like that series as well.

Having an A/F Ration gauge is killer too! To bad there's no reasonable place to mount these gauges on our car.

[jam0321]

Originally Posted by Walked U

Well i was reading the data logs on psi on my laptop and on my boost gauge to make sure the boost gauge wasnt messing up on me.


So what im basicly saying that from doing the BOV it made me run very lean in turn retarded my timing than made me loose power.

sounds like the culprit. keep us updated with the new dyno results.

[Jonmartin]

I totally agree with what happend to you. I always figured something was up with that BOV mod cause I always thought BMW put it there for a reason. so you boys pay attention this info can save you alot of money and heartache in the future.I've personally seen all this go down over the pass few weeks listening to "Walked U" constanly bringing up something wrong with his car and his engine temps peak too.

[Dustin Bramell]

Good post. I never really liked the idea of adding a BOV to the car and the idea of the DIY BOV scared me even more. Hope all of you guys are enjoying your cars!

[SfValley335i]

ahhh so it was the bov... well atleast we all know not to do that mod anymore. Im sure your glad now that you solved the problem time to meet up with that e36 m3

let me know if you want to dyno again in 2 weeks after bimmerfest. I'll have my xede then.

[sillygoat]

i had a feeling the DIY BOV wouldnt be good.

[ulises 335i]

im thinking fo buying this . do you guys think its a good idea?

its from Stratmosphere its called the HyperBoost

[Eurofreak]

nice write up of your experience, this really helped clear up some questions and ideas

[fusionchicken]

glad you had everything figured out shirwin

better yet you found your problem and hopefully people in this community won't have to walk down the same path

[RiXst3r]

so ///Matt was right all along... DIY BOV mod WILL screw up your factory boost control

I wasnt gonna try it anyways, but thanks for the warning!

[BoostedBMW]

Thanks for taking the time to post your findings. I wish that someone with a BOV (ie. UR or AA) would do some similar testing and report their findings so we would know if it was just the DIY BOV or any atmospheric BOV. I can't see why a VTA BOV would be a problem, but then again I didn't think that the DIY BOV would be a problem either. Appologies to Matt for giving him a hard time about it.

[Terry335]

Hmm is your diverter valve leaking under boost? Your problems sound like a boost leak to me.

PS. Don't worry about the peak AFR reading, all that matters is your AFR under sustained boost. Looks to be from 13.5:1 down to 12:1, normal. I wonder if your car is pulling timing? Scanning software might be in order!

[superman]

I used to have a wrx, and adding a BOV always was a bad idea if the car was not tuned for it. From reading about the procede, it wasnt made to have an aftermarket BOV used with the tune. Im guessing like the wrx, there is no need for one until you start modding heavy, mayeb when people add new turbos, but with the stock turbos, Im sure the stock BOV is the way to go.

Chris

[boostedtwin]

I haven't noticed any difference with the AA. Again I do not have a boost gauge but I don't think i'm losing any power.