help titanium exhaust
#17
Evolving Member
Ok, I was unsure about that part tbh, but I did read an article about maintaining gas velocity and something called the scavenger effect and having too large an exhaust is bad. If I'm wrong and an exhaust does nothing to help performance why do drag cars and NASCARs where no one gives a **** about noise even have exhausts if they are nothing but a possible restriction? I'm not trying to be argumentative and if I'm wrong I'm wrong, I just like to know what I'm talking about when it comes to this sort of stuff
#18
Evolving Member
iTrader: (6)
Ok, I was unsure about that part tbh, but I did read an article about maintaining gas velocity and something called the scavenger effect and having too large an exhaust is bad. If I'm wrong and an exhaust does nothing to help performance why do drag cars and NASCARs where no one gives a **** about noise even have exhausts if they are nothing but a possible restriction? I'm not trying to be argumentative and if I'm wrong I'm wrong, I just like to know what I'm talking about when it comes to this sort of stuff
#21
Evolved Member
iTrader: (21)
Ok, I was unsure about that part tbh, but I did read an article about maintaining gas velocity and something called the scavenger effect and having too large an exhaust is bad. If I'm wrong and an exhaust does nothing to help performance why do drag cars and NASCARs where no one gives a **** about noise even have exhausts if they are nothing but a possible restriction? I'm not trying to be argumentative and if I'm wrong I'm wrong, I just like to know what I'm talking about when it comes to this sort of stuff
NASCAR and F1 and such like that is probably a bad example to compare to as they are likely using the exhaust to route air around the car most efficiently and aerodynamically
#22
Evolved Member
iTrader: (22)
Negative ghost rider. I'm grossly oversimplifying this but if the gas that has already passed the turbo are unable to exit the system quickly enough they end up meeting the next round of gas particles and so on. In an extreme case this ends up killing the velocity of the gases by the turbo and thus its ability to spool. That's why ideally you want the exhaust as large as possible so that you don't ever run into this problem. So the velocity of those gases is important up to a certain point.
To the OP, as others have pointed out is that past 3" unless you are running something ridiculous it won't make much of a difference so if you want to do it to say you did then fine.
#24
Evolved Member
iTrader: (126)
How does everyone here who has said 3" is enough know for certain that 3" is in fact enough? Are you all just saying it because someone else said it at some point in time?
Although this isn't an Evo, it may be worth reading:
http://www.superstreetonline.com/how...ust-test-tech/
I'm apt disagree with that, but I don't claim to be an expert on the subject. What codgi said sounds pretty right-on though, based on the little I have learned. Too bad Full-Race Geoff is banned from here, otherwise I bet he'd happily post docs, diagrams, and other related info from his engineering books to prove what is true on the topic either way. Maybe someone should email him for an answer...
Although this isn't an Evo, it may be worth reading:
http://www.superstreetonline.com/how...ust-test-tech/
I'm apt disagree with that, but I don't claim to be an expert on the subject. What codgi said sounds pretty right-on though, based on the little I have learned. Too bad Full-Race Geoff is banned from here, otherwise I bet he'd happily post docs, diagrams, and other related info from his engineering books to prove what is true on the topic either way. Maybe someone should email him for an answer...
#27
Evolved Member
iTrader: (21)
Negative ghost rider. I'm grossly oversimplifying this but if the gas that has already passed the turbo are unable to exit the system quickly enough they end up meeting the next round of gas particles and so on. In an extreme case this ends up killing the velocity of the gases by the turbo and thus its ability to spool. That's why ideally you want the exhaust as large as possible so that you don't ever run into this problem. So the velocity of those gases is important up to a certain point.
To the OP, as others have pointed out is that past 3" unless you are running something ridiculous it won't make much of a difference so if you want to do it to say you did then fine.
To the OP, as others have pointed out is that past 3" unless you are running something ridiculous it won't make much of a difference so if you want to do it to say you did then fine.
#28
Evolved Member
iTrader: (22)
Because you can calculate at what point that 3" is going to be a restriction and years ago this calculation was done on this forum and testing was done and confirmed by several shops at the time. The 3" has worked on successful rally competition cars, track, HPDE and TA cars and even drag cars that went into the high 8s. If it can do all of that without imploding the car it seems to have proven the point. Now with this new crazy 1/2mile and mile stuff going on where folks want to chase GT-Rs, Lambos etc. then you'd need to do the maths again and see. But if the OP is that serious about that kind of stuff it seems best to get hooked up with a legit shop who can answer the question.
#30
Evolving Member
Join Date: Nov 2012
Location: Brisbane Australia
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What we are saying is 3" is good enough size for weight, power, etc. Its been proven, I'm not saying it because others are mentioning it. There is no need to going bigger.