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MISHI's blog: The mishi and the BOV....

Posted: May 23rd, 2008, 10:25 pm
by MISHI
So as most of you know by now, yours truly had acquired the venerable, if not famous PBN 701. It was always the dream to own an evo.... well no, not really... it was a Mclaren F1, but let's be realistic here... I love the Evo series. Reason?

Jackie Chan.

Yep you heard it, Jackie Chan. That white IV they used in the "who am I" movie. If you didn't know an evo before, you knew it then.

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Well anyway, I didn't come here to flap my lips like the national flag in the breeze about the love for evos... I came to talk about that which blows...

So when I bought this lovely, well made piece of machinery, it felt really good in the boost, yet when shifting gears I found I caused the car to jerk quite hard... sometimes even stalling at the light. I began to wonder if I still had my old driving instructor's phone number so he could teach me again, before I realised he's been dead for over 9 years...
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But there was one thing about the car I liked... the previous owner installed a blow off valve... loud I might add. I also noticed something else... it had the odd, if not horrible idle at times. I know the usual term is that a turbocharged car had a cold with the ability to "sneeze", but to be "coughing" as well? this was ridiculous... I couldn't afford to catch that virus myself.

It was time to see if Dr. MISHI could remedy our little blue friend's viral infection. Now mitsubishi employs what is called a Mass Airflow system, or MAF for short (lazy bastards...) which relays to the ECU the volume of air, so that it can add fuel accordingly... especially in a turbocharged car this can be quite important.

But Mitsubishi in their turbocharged trim, setup the intake system, to route the air out the turbo back into the intake, when the throttle closes off. This is what they call the recirculation valve. This helps to keep the turbo from getting what they call "compressor surge".

Now before you go out in a panic to buy the latest surge protector strip at your nearest electrical store, compressor surge is what happens when the boost pressure shoots back to the turbocharger, when there is no other way for it to escape. It can cause the compressor to stall... even causing major damage... or so I heard...

So then comes someone with the idea... "Let's make a valve that goes PSHHHHHT! so we can scare the piss out of people walking by"... And the vent to atmosphere valve was formed... at least it's how I see it.

But there was one problem... on a MAF system the car idles horrible. The erratic readings cause the ECU to force the car toa rich fuel setting... this in turn causes the stalling. I've heard of people saying as well that a bad or improper BOV on a car can cause bad mileage, boost problems, even engine damage...

NAAAAHHH!!!!! or perhaps I was fooling myself...

But coming back to it all... I decided to remove it and reinstall the recirculation valve... well thank goodness the last owner had the decency to leave it in. So out with the BOV and in with the stock setup. Now it would be good to note that the BOV was a Tial sport 50mm... or so it looked. What I had in my hand was a secret agent disguised for the job at hand... in translation, a cheap knock off...

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Mind you, this thing looks the part. But of course no name on a brand... not even "made in this country" was on it...

translation... CHEAP!.... did I mention.... CHEAP?

So then... off for a drive... My God! you wouldn't believe!......

It was quiet. What? were you expecting some magical increase of speed? Well truthfully, the car felt better in acceleration and somethig else I noticed... It didn't jerk much when I shifted gears. So I saved myself calling my dead instructor to ask him to teach me again... hooray!

Also, the car idled perfect. No hiccups, no coughs, nothing. So it would seem that the cure had been applied.

But this was strange... I have an 1800 turbocharged car that has a small knock off BOV... not piss scaring loud, but noticable. But I have no problems with it at all. So I decided to install the Tial knock off in it...

Let's just say that if my driving instructor was watching from the heveans... or the hells... I could see him shaking his fists in anger, calling me a failed jackarse for not even being able to move the car from a stand still... you heard me... stand still. The car absolutley REFUSED to idle... I found myself bucking the car. I prayed no sexy woman was walking by then, else my reputation would surely be shattered.

So back in with the cheapo small BOV. Now it's good to note this little bugger is only about 2.5 inches in diameter and the shaft about 3/4 of an inch. It can safely fit in the shaft of the tial knock off...

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She purrs like a kitten... if you discount the hydraulic lifters trying to be attention whores...

"Look at me! Look at me!"

So, what does this tell you?

Atmosphere BOV's CAN cause your mitsubishi to idle bad. If a poorly built cheapo knock off, you may find it leaking, causing the idle problems, the fuel issues and all that madness to become a reality.

If you're one of those who wish to cause people to run for the nearest restaurant bathroom, it's better to go with a proper brand... translation.... ORIGINAL brand.

But all of this will mean not one pint of piss if you don't research which BOV is best for your car. Even the brands have different stiffness of springs or adjustment settings for each application. So do your homework and do it right.

As for me... I'm not into the "scare the ladies bladder into a wet mess" With a BOV... just the look of the car should cause them to bring their own lubrication in order....

Posted: May 23rd, 2008, 10:36 pm
by Dave
ways, please tell me u ain't gonna be making more posts like this

if u say no, then don't ever come back here :lol:

good write up man, u really feel is your car when u do stuff on it :wink:

Posted: May 23rd, 2008, 10:40 pm
by fras
What about a 50/50 BOV... half to atmosphere other half back into intake?

http://www.alldayperformance.com.au/prod11.htm

Posted: May 23rd, 2008, 11:07 pm
by MISHI
Dave wrote:ways, please tell me u ain't gonna be making more posts like this

if u say no, then don't ever come back here :lol:

good write up man, u really feel is your car when u do stuff on it :wink:


:lol:

I'll be good...

Posted: May 23rd, 2008, 11:34 pm
by MISHI
fras wrote:What about a 50/50 BOV... half to atmosphere other half back into intake?

http://www.alldayperformance.com.au/prod11.htm


It would work, as some air is being sent back... though I'm not sure how effectively.

Posted: May 24th, 2008, 1:44 am
by Shaka
good info. :wink:

Posted: May 24th, 2008, 5:59 am
by DEVI
Yay Mishi .....you have just discovered one of the first mistakes most turbo charged guys make.....i have recirculating valves in the 6 and Mirage.....6 has an HKS and the Mirage an original Evo 9.....which BTW is made of metal and supposed to be stronger than the plastic ones. Do some more research and you'll see the BOV actually causes you to lose a little power and BTW congrats on owning two VERY NICE MITSUS.......

Posted: May 24th, 2008, 9:17 am
by MISHI
^ Thanks man....

Well it's not now that I know about it. Always knew that BOV's on mitsubishis have issues... I just couldn't help but play the arse and post someting that Jeremy Clarkson would be proud of... :lol: :lol: :lol:

Posted: May 24th, 2008, 9:33 am
by fras
Been looking at some vids with recirculating bov's :lol: ... sound very close to my knock off greddy :lol:
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Posted: May 24th, 2008, 9:46 am
by MISHI
If they didn't have the Pod filter on, you may not hear it at all...

Posted: May 24th, 2008, 4:51 pm
by Skanky

Posted: May 25th, 2008, 9:32 pm
by W2J
DEVI wrote:Yay Mishi .....you have just discovered one of the first mistakes most turbo charged guys make.....i have recirculating valves in the 6 and Mirage.....6 has an HKS and the Mirage an original Evo 9.....which BTW is made of metal and supposed to be stronger than the plastic ones. Do some more research and you'll see the BOV actually causes you to lose a little power and BTW congrats on owning two VERY NICE MITSUS.......


nothing is wrong using a non China crap vented BOV with a MAF once you have it adjusted properly and able to tune for the extra unmetered air being discharged. Half you guys put on Walbro, cams and run a safc what you expect I surprise there are so many of you that have not suffered catrostophic engine failure. After correcting all that was done by previous owners and want to be tuners to the car I purchase recently I did some logs and noticed that the stock 560cc injectors are no good above 19psi on stock OE bolt on's. In ending be very careful what is recommend by MECHANICS they are not tuners.

Posted: May 26th, 2008, 7:37 am
by hmph
MISHI, saw the car when i was in Tobago, real clean, both times i saw it.. good stuff and is true about the BOV causing real pressure.

nothing is wrong using a non China crap vented BOV with a MAF once you have it adjusted properly and able to tune for the extra unmetered air being discharged. Half you guys put on Walbro, cams and run a safc what you expect I surprise there are so many of you that have not suffered catrostophic engine failure. After correcting all that was done by previous owners and want to be tuners to the car I purchase recently I did some logs and noticed that the stock 560cc injectors are no good above 19psi on stock OE bolt on's. In ending be very careful what is recommend by MECHANICS they are not tuners.


this is Trini mentality...u could say this a million times and some mechanic will do it again :D :D

Posted: May 26th, 2008, 2:25 pm
by crazybalhead
Mishi, instead of going through all that headache, you coulda just come on a lil sitre called "trinituner.com", ask a question and we...ahhhhm I mean "they" could have told you that from the start.

0X




:lol: :lol: :lol:

Posted: May 26th, 2008, 3:24 pm
by MISHI
^ what headache?


I just was bored and had too much wine. Watched a clip of Top gear with clarkson being sarcastic as usual and decided...


"Hey, why not write something ridiculous, yet informative....

:lol: :lol: :lol:


On another note, figured the BOV was leaking so I bought some new rubber seals and serviced it fully. When I opened it up, whoso ever had that BOV wasn't too sure what they were doing...

Spring was cut... which in itself not bad, but they had a stupid plate that was bent, causing the thing not to properly work.

Gonna test it again on the lancer to see if I have to hold a seyance and bring my driving instructor back for some tips... :lol:

Posted: May 26th, 2008, 4:36 pm
by venum
congrats on the acquisition pal

Posted: May 27th, 2008, 10:06 am
by wagon r
....way too much avi fuel in your blood pallie.....but love the write up

Posted: May 29th, 2008, 12:02 pm
by Langdon
Mishi i said it before you are a fool but the thread was entertaining and informative.

Posted: May 29th, 2008, 5:36 pm
by MISHI
Langdon wrote:Mishi i said it before you are a fool but the thread was entertaining and informative.


Why thank you :lol:

Posted: June 3rd, 2008, 7:25 pm
by R. Mutt
congrats man Mishi....really happy you've gotten her. On my recent trip with an VIII I observed first hand how many problems an externally venting bov can cause. It was an HKS ssq in my case that caused everything you mentioned (erratic idle, temporal rich condiition between shifts) plus random stalling issues in first gear and reverse.

Posted: June 8th, 2008, 7:53 am
by dgobo
^^ that sounds pretty similar to my car, also with an HKS