2008 tbSTI Owner

[senator]

Thanks for all the help guys, I will give Coyote a PM and see what he suggests. I guess since I have just got the car I am still tossing up what can and can't be done with the car. I will speak with my tuner and see what he can do and go from there.

Smart move contacting Coyote, I hear he likes tuning in the buff whilst running through fields of corns…. You have been warned.

You’d be surprised what a tune alone will do to the overall drive and behaviour of the car.

[Remnofski]

Thanks for all the help guys, I will give Coyote a PM and see what he suggests. I guess since I have just got the car I am still tossing up what can and can't be done with the car. I will speak with my tuner and see what he can do and go from there.

Smart move contacting Coyote, I hear he likes tuning in the buff whilst running through fields of corns…. You have been warned.

You’d be surprised what a tune alone will do to the overall drive and behaviour of the car.

Where does he work? Or does it have preset tunes? And I will join him, although I will miss the field of corn, those things cut you up!

What could I expect, although mine is auto I'm sure it will do alot!?

[peadya100]

Check out senator's post again. He actually built a beast. You don't need a 3 port. Waste of money. The preciseness of it is up to the tune, if your tuner has attention to detail a 3 port can't beat a 2 port. Hence waste of money and time. Up to you though.

I would caution against taking advice from people who haven't ever built a racecar. Reading posts here that an atmospheric venting bov causes the car to run rich and that loses power?? Running rich means you have more parts of fuel to parts of air which would result in more power. Also a bov doesn't quite work like that.

Running rich or lean depends on tune, not on any bolt on. Haha sorry I couldn't hold back! Goodluck mate

I think what Manaz was saying alexei is that if you put on a BOV that does vent to atmosphere without tuning for it, the car will then run rich and wont run well. I can vouch for this as my hose was left off my BOV by accident and the car back fired/popped loudly on deceleration and ran like shite. It was so jerky on acceleration and got so bad that i thought the car would die on me. MSR quickly figured out that was my problem and told me to put the hose back on.

I would assume that if the car was tuned for that sort of BOV, the AFR would have been correct and the car would be ok to run it.

[alexeiwoody]

Hey adam, I'm sorry for sounding harsh, just fixing up some uninformed advice that costs other people money. ..

You're talking about a different hose mate that's the vacuum hose and would also be on the vent to atmosphere bov. So it would work the same. If it pops off on either bov - you'll have a boost leak and you'll run lean and car will start stalling, as you described. There is another hose...

Anyway the difference between the bovs would be noticed only on idle, not on boost

[peadya100]

Hey adam, I'm sorry for sounding harsh, just fixing up some uninformed advice that costs other people money. ..

You're talking about a different hose mate that's the vacuum hose and would also be on the vent to atmosphere bov. So it would work the same. If it pops off on either bov - you'll have a boost leak and you'll run lean and car will start stalling, as you described. There is another hose...

Anyway the difference between the bovs would be noticed only on idle, not on boost

You may be right... im far from a bov expert! Just to be sure though, it was the hose about 1" in dia and when it was off my car made the big whoosh sound on gear changes. Either way, the car ran like shit with it off

[Manaz]

You may be right... im far from a bov expert! Just to be sure though, it was the hose about 1" in dia and when it was off my car made the big whoosh sound on gear changes. Either way, the car ran like shit with it off

That's certainly not the vacuum hose.

[alexeiwoody]

Doesn't sound like it and that fact doesn't excuse you giving out bad advice to people. I was going off the initial description and the more common problem. If it's 1", then we're talking about the plumb back hostess.

Sounds like a crap thing! Never seen that one pop off..but always a bunch of vacuum hoses, with running lean, jerkiness and stalling. In theory most of your problems should have been off boost, like declaration, gear changes...? on actual boost should be fine as bov's closed

Adam you're absolutely right - whether you upgrade to a plumb back or atmo, you'd need a new tune to make proper use of your new found hardware. Just bolting on a bov, whichever type, would be extremely useless.

I just don't see manaz ever suggesting a tune? Or mentioning that it's probably the most important power, response, safety and money saver mod?

Hope this helps, cheers

[peadya100]

Doesn't sound like it and that fact doesn't excuse you giving out bad advice to people. I was going off the initial description and the more common problem. If it's 1", then we're talking about the plumb back hostess.

Sounds like a crap thing! Never seen that one pop off..but always a bunch of vacuum hoses, with running lean, jerkiness and stalling. In theory most of your problems should have been off boost, like declaration, gear changes...? on actual boost should be fine as bov's closed

Adam you're absolutely right - whether you upgrade to a plumb back or atmo, you'd need a new tune to make proper use of your new found hardware. Just bolting on a bov, whichever type, would be extremely useless.

I just don't see manaz ever suggesting a tune? Or mentioning that it's probably the most important power, response, safety and money saver mod?

Hope this helps, cheers

No no, it didnt pop off, it was left off by accident when working on the car. Youre right the problem was off boost. Except when I backed off the popping woukd happen at higher revs. No need for anyone to argue about it. We're all just trying to help each other out

[Manaz]

I just don't see manaz ever suggesting a tune? Or mentioning that it's probably the most important power, response, safety and money saver mod?

I'm not sure where this came from (because at no time did I discuss tunes, but rather focused in isolation on other matters that were raised, given a tune was apparently already on the cards), but to clarify:

You must retune for a 3-port boost control solenoid. Yes, it's possible to tune (and tune well) without one, but if it helps, and the cost is really cheap (sub $200), then I don't see why you'd discount it out of hand.

You don't strictly need to retune for a BOV, particularly if you replace the stock plumb-back unit with another plumb-back unit (I replaced my own stock BOV with a Turbosmart Kompact unit, and no retune was required). As far as I'm aware (happy to be proven wrong), a tune cannot "fix" the issue of over-fueling when an atmospheric venting BOV vents.

You must retune for a turbo upgrade. It may be safe to drive short distances (to a tuner) as long as you keep boost low (I mode for post-FL cars would probably be OK).

You should retune if you replace the stock intake pipes with silicon hosing (better air flow than stock may cause leaning-out issues).

You should retune for significant changes to your exhaust (probably not so necessary for a cat-back, but certainly if you do headers and/or a turbo-back exhaust, you should retune).

And even with no hardware changes at all - a tune can be awesome (a good tune that is) just in terms of the little things it can fix (the CL/OL transition, safer AFRs, reduction in knocking), not to mention that it can also give you a significant power upgrade on its own.

Certainly, if you do any significant work to your car, you should be talking to a professional about it.

And you should seriously consider your car's ability to stop and turn before power upgrades (and frankly, I consider this to be more important than discussing tuning). If it can stop and turn well enough to deal with the power increase, fine - but it's just something you should consider.

Is that better?

And whilst we're accusing people of giving bad advice - your advice that the difference between BOVs would only be noticed at idle is absolutely 100% incorrect - the difference at idle is relatively minor, the difference is most obvious when you suddenly lift off the throttle, when either changing gear or when backing off sharply after a "power run". The BOVs job at this point it to vent boost pressure so that the sudden closure of the throttle doesn't cause air pressure to build suddenly in your intake system post-turbo and stall/damage the compressor wheel in your turbo. At this point, a plumb-back BOV vents the air back into the intake pre-turbo (but after the MAF) so that the airflow measured by the MAF is consistent with the air in the intake tract, or vents to atmosphere, where it's discharged from the intake tract entirely (it has been measured by the MAF, but is no longer present in the intake system, so the ECU fuels as if the air is still there, hence running rich momentarily).

Welcome to the glass house. Please enjoy your stay, but don't throw stones...

[kiahatsiu]

Manaz, well played sir. Advice worth heeding.

[alexeiwoody]

Hey, whilst we all appreciate you trying to give good advice, I'm not questioning your good intentions, just experience.

So please answer my question - have you done any of these tuning, exhaust, turbo mods yourself? Have you done them on a 2007-2009 (our cars) liberty gt?

While your posts are well meant, there are many a mistake, that, sorry, your google skills just won't tell you about. I'll acknowledge my mistake about the idle, you didn't mention I corrected myself later with "off boost". And yes, it can be tuned for.

I can pm what I believe your mistakes were, if you like. I won't apologise for trying to save someone else from wasting money

[bass_straitener]

Hey, whilst we all appreciate you trying to give good advice, I'm not questioning your good intentions, just experience.

So please answer my question - have you done any of these tuning, exhaust, turbo mods yourself? Have you done them on a 2007-2009 (our cars) liberty gt?

While your posts are well meant, there are many a mistake, that, sorry, your google skills just won't tell you about. I'll acknowledge my mistake about the idle, you didn't mention I corrected myself later with "off boost". And yes, it can be tuned for.

I can pm what I believe your mistakes were, if you like. I won't apologise for trying to save someone else from wasting money

Manaz is completely correct..

Have you been taking your angry pills again....

[Manaz]

Hey, whilst we all appreciate you trying to give good advice, I'm not questioning your good intentions, just experience.

So please answer my question - have you done any of these tuning, exhaust, turbo mods yourself? Have you done them on a 2007-2009 (our cars) liberty gt?

Yes, some of them are already done. And there's more to come.

I've also owned tuned NA and turbo-charged cars since my ~1988 Nissan Exa with an imported JDM CA18DET engine which ran 7psi stock and 11psi with an overboost switch (awesome car to do your driving test in incidently - the passenger cannot see the speedo thanks to the binnacle design). Whilst there are always things that are specific to a given model, most of the basics are the same no matter what car you're working on.

While your posts are well meant, there are many a mistake, that, sorry, your google skills just won't tell you about. I'll acknowledge my mistake about the idle, you didn't mention I corrected myself later with "off boost". And yes, it can be tuned for.

Sorry, Google is not the source of my knowledge (though I will admit to occasionally using it to clarify an understanding or to find a way to better explain something). Your later correct indication of when a BOV operates doesn't make your initially mistake comment on it any less incorrect.

I can pm what I believe your mistakes were, if you like. I won't apologise for trying to save someone else from wasting money

Share your advice/corrections here, so we can all benefit from your knowledge.

[alexeiwoody]

Bruce I take them 3 times daily, as the doctor prescribed. I thought you knew that after the Great 'Adulto' Tuning Catastrophy

Manaz, I'll reply in your profile, as you seem to want to talk crap, and it's not really fair on Remnofski to do this on his page. Clicky the linky viewtopic.php?f=10&t=22465

[Manaz]

Reading posts here that an atmospheric venting bov causes the car to run rich and that loses power?? Running rich means you have more parts of fuel to parts of air which would result in more power. Also a bov doesn't quite work like that.

Running rich or lean depends on tune, not on any bolt on. Haha sorry I couldn't hold back! Goodluck mate

Sorry, but this is just bad advice. Pure and simple bad advice. You're wrong on how fuel burns (and how and why it doesn't), and you're wrong on how a BOV operates. But thanks for coming.

To start with - fuel requires air to burn. That's an undisputable fact. Then, there is a theoretical ideal ration of air and fuel, at which point you get the most complete burn. This is known as a stoichiometric mixture. Generally in automotive applications, that's considered to be 14.7:1 (it can vary for various reasons that we won't go into here). That's theoretical though, and doesn't take into account a whole pile of other issues (such as timing, oxtane level, etc). Under boost, most tuners aim for something much safer (betwen 10.5 and 11. - this is a richer mixture than the ideal stoichiometric mixture, and helps prevent knocking and leaning-out, which can lead to engine problems. The result is that you don't quite get a complete burn, but you do burn most of the fuel well, and you do so under safe conditions for the engine.

Running rich or lean depends on tune only when the tune has accurate information on parameters such as fuel flow and how much air the engine is breathing. The problem with an atmospheric venting BOV is that the amount of air taken into the engine's intake system has been measured (relatively accurately) by the MAF, and it's the MAF readings that the ECU uses to determine how much fuel should be injected into the engine (depending on whether or not the engine is running closed or open loop, an ECU may also use an O2 sensor in the exhaust system to determine how completely the engine is burning the fuel it is injecting, though one thing to note however is that this measured post combustion and can only be used to make adjustments after the fact).

Now, to make things really simple - let's say you have a single cylinder engine, and that your MAF measured 147 grams of air entering the intake system for a single combustion event. To achieve an ideal (stoichiometric) mixture, the ECU would inject 10 grams of fuel into the cylinder for this single combustion event, apply spark at the relevant time, and in theory, you'd get perfect combustion, with a relatively clean exhaust emissions, and a given amount of power).

(Now please, if anyone disagrees with this, say so now).

Now we introduce a turbocharger. The turbo compresses the air, so that the same mass of air takes less volume. Let's assume we're running 14.7psi of boost (one bar), that means we have two atmosphere's of pressure in intake systems after the turbo, and let's say, again for simplicity, that this means we now have 294 grams of air in the intake system for this single combustion event (and the MAF has measured this 294g of air - it has to come in via the MAF, it doesn't appear from nowhere).

The ECU will, at this point, inject 20 grams of fuel for this single combustion event. And given that fuel has a specific power (the amount of energy released when you burn a single gram of it), we'll get double the power, because we've burned double the fuel.

So now we know how turbos work.

But what happens if we have an atmospheric venting BOV?

As we know, as the engine burns one charge of air and fuel, it continues to operate - the engine sucks air in, the turbo compresses it (based on exhaust energy from the previous combustion event turning the turbo), ready for the next combustion event.

So, again to simplify - the engine draws in 294g of air past the MAF. The air gets compressed by the turbo - and then the throttle snaps shut for a brief second. The BOV does its job, venting air from the intake system to the atmosphere - and let's say, for the simplicity of the argument here, that exactly half the air gets vented to atmosphere.

This leaves the engine in an odd position - it has measured 294 grams of air, but only 147 grams of air are actually present.

So the air enters the combustion chamber, and the ECU, thinking it has 294 grams of air present, injects 20 grams of fuel, applies spark and...

Only half the fuel burns (there isn't enough air to burn the rest). This has two major impacts.

Firstly, you only get half the power.

Secondly, you get unburned fuel in your exhaust, or more correctly, a mix of unburned fuel and partially burned fuel (which means we technically burn slightly more than half, and get slightly more than half the power, but let's keep that aspect of the argument simple.

And what does this do? Produces dirty exhaust. Soot, to be precise.

You'll note that the ECU tune had NOTHING to do with any of this. Regardless of the AFR the ECU is aiming for, regardless of the timing of the spark, the simple facts of physics can't be overcome - there's less air in the intake than the ECU expects there to be, and thus it injects more fuel than required, and you get a rich mixture, an incomplete burn, less power, and dirty exhaust.

You could, in theory I suspect, tune the ECU to know that after a sudden closure of the throttle that the BOV may have operated, to adjust fuel mixes for a period of time after the throttle opened again and thus to inject less fuel (to counter the fact that there's less air in the intake). But this would be a guess (given no BOV I've ever come across has a feed back to the ECU to indicate for how long it vented, or any method to measure how much air it vented), and could actually be dangerous, as it could result in lean burn (should the BOV not have functioned as expected) which can cause heat and detonation/knock issues), which can lead to engine damage.