QSC Posted March 31, 2008 Share Posted March 31, 2008 Interesting..... not being too technically minded can someone explain how it manages to do that. I'd have though since it was decatted, running no restrictor ring that would be mine running as high as it could go. You're in the same boat as me - you don't understand why your boost level isn't higher since you've done everything you've been told & it still isn't working. I just don't appreciate having the piss taken out of me for not understanding how all this works - that is why I said & I quote "Ask Andy Hannah" - those of us who are not up on the technical side of things are all pretty much at the mercy of the experts on here, and, until someone can prove to me that what Andy says is not true, I have no reason to disbelieve him... Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 A boost controller can't lower the amount of boost a car is producing naturally, but it can certainly raise it. If not you're doing it wrong You mean Andy Hannah's doing it wrong, not me. He couldn;t get a boost controller to work on my car - I don't even know how to wire one up in the first place ... Quote Link to comment Share on other sites More sharing options...
Nic Posted March 31, 2008 Share Posted March 31, 2008 People are not taking the piss, it's just you are arguing about something that by your own admission you do not understand. Here's the turbo system explained in simple terms. The exhaust gasses from the engine turn the turbine, which turns the compressor forcing air into the engine, creating a positive pressure or 'boost pressure' in the intake To control the boost pressure there is a valve called the wastegate on the exhaust side of the turbo. At a certain pressure the wastegate valve opens bypassing some of the exhaust gasses away from the turbine. The wastegate is basically a pressure valve which controls the flow of exhaust gasses going through the turbine and subsequently controls the boost pressure to the engine. In very simple terms, all a boost controller does is fool the wastegate into thinking there is less boost pressure than there actually is, so the wastegate stays closed longer allowing more boost to build up. If the wastegate was kept completely closed, then the boost pressure on a stock turbo system would go sky high and the engine would basically self destruct. This is why a boost controller can only increase boost and not lower boost, as it can only stop/slow the opening of the wastegate valve, it cannot not force the wastegate to open. Have a read of these articles if you want a more details explanation. http://www.streetracersonline.com/articles/turbo/ http://www.streetracersonline.com/articles/turbo/wastegate.php http://www.streetracersonline.com/articles/turbo/boostctrl.php Quote Link to comment Share on other sites More sharing options...
JohnnyW Posted March 31, 2008 Author Share Posted March 31, 2008 Great explanation! Thanks Nic. P.S. How much can you supply them for Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 People are not taking the piss, it's just you are arguing about something that by your own admission you do not understand. FAIL. I would say that the above post is taking the piss, and I am not arguing about anything - I am trying to find out the solution to a problem both I and the OP are experiencing, and cannot seem to find an answer that everyone agrees on - can you explain why a boost controller was fitted to my car and did not raise the boost ? Quote Link to comment Share on other sites More sharing options...
hiten55 Posted March 31, 2008 Share Posted March 31, 2008 can you explain why a boost controller was fitted to my car and did not raise the boost ? in all honesty, it would be a bit difficult for him to do that from hong kong dont you think mate? i mean without looking at the car? Quote Link to comment Share on other sites More sharing options...
Nic Posted March 31, 2008 Share Posted March 31, 2008 can you explain why a boost controller was fitted to my car and did not raise the boost ? You have either got a boost leak somewhere, the wastegate is sticking open or the boost controller isn't working. It shouldn't be too difficult to determine which it is. Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 As I have already said, I took the car to Miami GT and was given an explanation which no-one else on here agrees with. I don't understand why, & no-one seems to be able to explain it. This has got more than one person stumped & I just want to get my car sorted - Johhny W obviously has a similar problem. Can anyone address my previous question ? If all you need to increase boost level is a boost controller, why do we all go to the expense of decatting our cars, thus technically making them illegal ? Quote Link to comment Share on other sites More sharing options...
Nic Posted March 31, 2008 Share Posted March 31, 2008 I give up Quote Link to comment Share on other sites More sharing options...
Thorin Posted March 31, 2008 Share Posted March 31, 2008 Perhaps you just got the wrong end of the stick at Miami GT? You have said yourself you don't know a lot about these things. Can anyone address my previous question ? If all you need to increase boost level is a boost controller, why do we all go to the expense of decatting our cars, thus technically making them illegal ? It wouldn't be very good for your EGT's running 1.2bar with the cat's still in, removing them also helps spool up, and makes a nice noise. Quote Link to comment Share on other sites More sharing options...
Scott Posted March 31, 2008 Share Posted March 31, 2008 Decatting the car lets it breathe more easily (like tunes). Backpressure is, from what i understand, not a good thing to have on a turbo car. The more backpressure you have the more work your exhaust gas is having to do to work the turbine. If you remove the cat's from the car you let the turbo spool up more freely and faster. This is how i understand it in my own head. I don't know the facts as such.... If there is a restrictive exhaust/cat etc then it will take more force to turn the turbine. This means that it will take a little longer for the turbo to spool up. The pressure created in the system before the wastegate will open is constant so if there is negative pressure from the exhaust system you will be losing some positive boost from the turbo and therefor your car won't boost as high as it can without decatting. When you stick in the decat pipes there is a lot less back pressure so therefor its almost all positive pressure opening the wastegate resulting in higher boost levels before a boost controller has even been added. Just a guess though lol Scott =op Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 Andy said the problem with my car was the exhaust, which is very restrictive, probably more so then stock - he said he replaced the exhaust with one of his and had the car boosting nicely at higher levels on the dyno. He also advised me to take the boost controller off because it wasn't making any difference to the boost levels. Quote Link to comment Share on other sites More sharing options...
Scott Posted March 31, 2008 Share Posted March 31, 2008 Oh, i would guess the wastegate to be the problem. Either that or something silly like a boost leak. What does the first turbo boost to? Scott =op Quote Link to comment Share on other sites More sharing options...
Scott Posted March 31, 2008 Share Posted March 31, 2008 Andy said the problem with my car was the exhaust, which is very restrictive, probably more so then stock - he said he replaced the exhaust with one of his and had the car boosting nicely at higher levels on the dyno. He also advised me to take the boost controller off because it wasn't making any difference to the boost levels. That sounds like the boost controller wasn't doing its job and the wastegate was opening at the same pressure as stock. Scott =op Quote Link to comment Share on other sites More sharing options...
Thorin Posted March 31, 2008 Share Posted March 31, 2008 Andy said the problem with my car was the exhaust, which is very restrictive, probably more so then stock - he said he replaced the exhaust with one of his and had the car boosting nicely at higher levels on the dyno. He also advised me to take the boost controller off because it wasn't making any difference to the boost levels. So which exhaust do you have on now? The one Andy put on? That sounds to me like he put a new exhaust on and it was already hitting 1.0-1.2bar therefore no need for the boost controller (not that the boost controller wasn't working). Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 Oh, i would guess the wastegate to be the problem. Either that or something silly like a boost leak. What does the first turbo boost to? Scott =op To be honest, I don't know what the first turbo boosts to - maybe Andy can be persuaded to chime in on this, because I'm only repeating what he told me...there certainly doesn't seem like any leak or anything, plus it worked OK with a different exhaust he said... Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 So which exhaust do you have on now? The one Andy put on? That sounds to me like he put a new exhaust on and it was already hitting 1.0-1.2bar therefore no need for the boost controller (not that the boost controller wasn't working). I still have my original (restrictive) exhaust on, Andy only fitted his to test it - Quote Link to comment Share on other sites More sharing options...
Scott Posted March 31, 2008 Share Posted March 31, 2008 To be honest, I don't know what the first turbo boosts to - maybe Andy can be persuaded to chime in on this, because I'm only repeating what he told me...there certainly doesn't seem like any leak or anything, plus it worked OK with a different exhaust he said... Oh sorry, i didn't mean yours lol. I meant the original poster. Your problem just seems to be that the exhaust was too restrictive and the boost controller didn't seem to want to work properly. I'm pretty sure a mechanical boost controller is infinitely adjustable so you could tighten it right up and that would let the wastegate stay closed constantly. Don't know about an electronic one though. Scott =op Quote Link to comment Share on other sites More sharing options...
QSC Posted March 31, 2008 Share Posted March 31, 2008 I'm pretty sure a mechanical boost controller is infinitely adjustable so you could tighten it right up and that would let the wastegate stay closed constantly. Don't know about an electronic one though. Scott =op That's intersting, maybe I could try that - apart from not keeping it closed completely, is there any reason why this shouldn't be done do you think ? Quote Link to comment Share on other sites More sharing options...
Scott Posted March 31, 2008 Share Posted March 31, 2008 Well a mechanical boost controller is fine as long as its set properly. It won't hold boost exactly in all temperatures but as long as you leave enough wiggle room it will be fine. Having the wastegate constantly closed will result in catastrophic engine failure though Put it in, give it a few turns, drive the car and as soon as you see the boost go too high, stop and losen it off a turn. Keep going until its at an acceptable level. Scott =op Quote Link to comment Share on other sites More sharing options...
QSC Posted April 1, 2008 Share Posted April 1, 2008 Thanks for that, I'll give it a try - I have a RR fitted so that should keep things sensible at least. Quote Link to comment Share on other sites More sharing options...
tDR Posted April 1, 2008 Share Posted April 1, 2008 People are not taking the piss, it's just you are arguing about something that by your own admission you do not understand. FAIL. I would say that the above post is taking the piss, and I am not arguing about anything - I am trying to find out the solution to a problem both I and the OP are experiencing, and cannot seem to find an answer that everyone agrees on - can you explain why a boost controller was fitted to my car and did not raise the boost ? Hi QSC, My dry humour in the above post was really to quickly say what you posted was very wrong. Not really taking the piss out of you but yes if Andy H can't set up a boost controller properly then I'll take the piss outta him Others have suggested what the problem may be. To quantify, you could tell us what exhaust system you have on there and what decats? What boost controller was fitted, by who and from where was it supplied? Without digging into your other posts to find out - are we talking about a JDM or UK spec car? There are two seperate topics here which I think you are confusing - the first being the fact that a JDM car overboosts by default with exhaust restriction removed because of it's small wastegate opening causing unregulateable (think I might have made a new word?) boost pressure. The second topic being how to raise boost with a boost controller - again as highlighted by others because of the design of turbocharging systems and how pressure is regulated it is quite easy to raise boost through means of 'fooling' the actuator that controls when the internal wastegate flap opens to regulate boost levels. The way this is achieved is by bleeding boost away from the actuator so it thinks it still sees 'X' amount of boost (what it was manufactured to operate at whereby the rod coming from the back of it then moves and opens said wastegate flap) when really you are producing 'Y' amount of boost which you have determined is what you want to run. How much is bled away is what your boost controller with it's solenoid valve takes care of according to how you set it up with a target boost level in mind. It does sound very much like your boost controller wasn't set up properly when your own exhaust was on your car. If it is more restrictive than the one Andy H tried then yes your car will need help in raising the boost levels through use of the boost controller. Hope this helps? Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
Nic Posted April 2, 2008 Share Posted April 2, 2008 Hope this helps? Well that's at least 2 of us who have taken the time to explain what is what, perhaps this time he'll listen to and appreciate the advice given, rather than just dismiss it. Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted April 2, 2008 Share Posted April 2, 2008 What condition & how old is your SMIC?.. Still sounds like you might have a slight boost leak and it can't hold the increased pressure.. Quote Link to comment Share on other sites More sharing options...
QSC Posted April 2, 2008 Share Posted April 2, 2008 OK, here goes - Nic, I'm not dismissing anything - I do appreciate advice that's given on here by you and everyone else, I'm just repeating what was told to me by an expert who has worked on my car, & I'm rather frustrated that I've had the car in to two different "turbo specialist" places and it still isn't sorted. Brian - many thanks for the time you've taken to reply - let me fill in the details : The car is J-spec, fitted with Chris Wilson decats (both). The cat-back exhaust is a custom twin outlet job which Andy states is very restrictive. I have a new brand new FMIC supplied by Nic, there doesn't seem to be any sign of boost leak (there was some a while ago, but this traced to a pipe joint and fixed at the garage) - the car was dynoed a few weeks ago & showed no signs of leakage. The boost controller is a SARD one bought from n-boost on here, I had it fitted at ART in Wakefield (supposedly a turbo specialist), and he said that, no matter what he did, he could not raise the level of boost. Thinking that perhaps he hadn't fitted it properly, I asked Andy H & his dad to take a look at the car & try to figure out what was wrong with it. While Andy said the boost controller was fitted correctly, the real problem was the exhaust, and substituting his own exhaust for mine solved the problem. Andy then removed the boost controller. The problem I have is that I don't want to lose the twin exit exhaust system (the trial rear has been adapted to cope with the two exit pipes, so it would make a real mess to only have one pipe) - Envy said they might be able to make one up that fits the same, but may not be able to guarantee that it will result in more boost. The upshot of this is : will fitting a boost controller do the job, and are there inherent problems if you fit one without changing the cat-back exhaust ? It's been tried once, and didn't work. Quote Link to comment Share on other sites More sharing options...
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