So, can anyone tell me about this size exhaust. is it worth my money?
3.5"" Exhaust
GSTRFWD
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I just wish HKS made a full titanuim 3.5 turbo back for our cars.
at least a cat back.
I think its worth it, but at least a 20g or above. even with a 20g it migh still be considered an overkill.
I havent seen how they look. who makes them anyways other than rnr.
at least a cat back.
I think its worth it, but at least a 20g or above. even with a 20g it migh still be considered an overkill.
I havent seen how they look. who makes them anyways other than rnr.
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A 3" exhaust should be good enough for you unless you want to run 9s, and i think it will work even then. I think Jon Shepard uses a 3" exhaust on his low 9 second talon. Not 100% sure on that though.
This has been discussed numerous times but no matter what people say, bigger is always better with turbo cars. Since the turbo creates so much back pressure, you want the least amount of back pressure after the turbo, 0 back pressure would be good but that's pretty tough on the street. Now, do you need a 3.5" exhasut, probably not. Would it hurt, no. Could it make more power and spool faster? Yes I would run as big as i could, dp included.
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Yeah you can buy big exhausts for a lot of cars. A proffesor at my college has a 4" Down pipe on his WRX. im not really sure why he got that big, but ill trust him because he used to be a GM engineer.
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As long as he wasn't responsible for designing the Ass-tek...eclipse1gen said:
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that would cost more than most 1GsMannai said:
turbo trix has the 3.5 i believe (it could be BRs product though)
i say if the car isnt in the DDDDEEEEEEEEEPPPPPP 11s then its not worth it at all.
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YES you can get too big... If you get a piping too big for your amount of airflow, the air will actually slow down, create more drag, and more backpressure than a 3"... You need a REAL big turbo in order to flow enough to justify 3.5" i think, im talkin 10's at least... I HIGHLY doubt you will SEE ANY GAINS AT ALL (probably even lose a few HP especially in low end) if your not movin a HELL of a lot of air...Ive read this a couple places, no i havent done dyno testing, but have read it in such books as "Maximum Boost" by Corky Bell and a couple other reliable sources..
anyways that being said, I dont know what turbo your plannin on so i cant recommend one way or the other...
anyways that being said, I dont know what turbo your plannin on so i cant recommend one way or the other...
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All I know is that unless you are building a full drag car that runs 9s, a 3.5" inch isnt worth the extra noise and money.
Not to be a dick or anything but you can't go too big on a turbo car. A turbo draws it's power from the pressure drop across the turbine. It talks about it in the new scc. Not saying they are god or anything... The turbo is already producing a lot of back pressure in the exhaust system so you want as little restriction after the turbo as possible. Why do you think there is such a big difference in power if you run a race down pipe or just unbolt your cat back? It makes your exhaust system flow that much better. I'm not saying go fab up a 5" system and use it on the t25, but an extra half inch is completely reasonable. Most of this exhaust system hooey comes from old muscle car guys saying that too big of a pipe will cause you too lose bottom end power because back pressure makes torque. I have never read anything saying you can run too large of a pipe diameter on a turbo car. Remember buschur's old upgrade path? He states that a car can run in the 12s with a press bent 2 1/2" down pipe and unless you want to go faster that's all you need, but i'm sure a mandrel 3" pipe will flow better and yield more power. The point is that most cars don't need a 3.5" system or larger but most of us could benefit from one. How many guys out there run a 2.5" press bent down pipe?
Also, on the noise and money part, there is more of a price difference between different brands of exhaust systems than there is between a 3" or 3.5" system from the same shop. Also, they larger system will slow down the exhaust stream at low rpms, which would probably deepen (sp) the tone. I doubt you could tell the difference at idle between the two. If it makes it that much louder it's oly because it's flowing better!
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okay.. if you dont believe me, than you dont believe Corky Bell, i dont know but i think he knows a little about turbos...
wierd analogy, say you were blowing through a few different straws, 1 is small (i.e. 1/16") 1 is medium (2") and another huge (like 6") your "exhaust" (in this case your breath) will flow fastest out the smallest, but you wont be flowin much breath, 2" is the best combination of speed and flow, It is just big enough to flow all your breath, but not too big as to slow it down, but with the huge straw, yeh it will flow all of it, but it will exit at a much slower rate of speed.... in your exhaust its ALL ABOUT EXHAUST GAS VELOCITY AND NO BACKPRESSURE
Have you ever seen a spitball gun thats 10" in diameter? no... the best ones are the little bic pens, they make the spitball FLY...
Edit: Yes I do realize this is oversimplification at its greatest... but i hope you see the point... a GOOD 3" exhaust on your average street car flows at least 99% of no exhaust...
oh and wanna know why SCC always says you can never go too big... who pays them their salaries? advertisers.. enough said...
wierd analogy, say you were blowing through a few different straws, 1 is small (i.e. 1/16") 1 is medium (2") and another huge (like 6") your "exhaust" (in this case your breath) will flow fastest out the smallest, but you wont be flowin much breath, 2" is the best combination of speed and flow, It is just big enough to flow all your breath, but not too big as to slow it down, but with the huge straw, yeh it will flow all of it, but it will exit at a much slower rate of speed.... in your exhaust its ALL ABOUT EXHAUST GAS VELOCITY AND NO BACKPRESSURE
Have you ever seen a spitball gun thats 10" in diameter? no... the best ones are the little bic pens, they make the spitball FLY...
Edit: Yes I do realize this is oversimplification at its greatest... but i hope you see the point... a GOOD 3" exhaust on your average street car flows at least 99% of no exhaust...
oh and wanna know why SCC always says you can never go too big... who pays them their salaries? advertisers.. enough said...
need4speedtsi is right. You can have too big of a exhaust even on a turbo car. The reason we have bigger piping on turbo cars is not only to cure backpressure from the turbo itself but also from the cooling of the exhaust. When the exhaust gas cools down it loses its velocity thus traveling through the piping slower. So you increase the size of the piping so the slow moving gases dont clog up the piping creating backpressure. If you have too big of an exhaust the gases will have all that room to cool down resulting in less velocity, creating backpressure because its able to cool down to soon. So instead of flowing through the piping it gets stuck at the begining of the piping and builds up creating backpressure.
I believe you are exagerating a bit. If you are suggesting that a modded dsm owner is going to lose power from going from a 3" to 3.5" then you are mistaken. I don't know how else i can argue. I have aleready stated that you don't need to make up a huge system if you are on the stock turbo. Any one considering this seriously will most likely already have a decent amount of upgrades or at least plans of doing so. By no means am i saying the 3" system is restrctive, but on a big turboed car, there will be some gains by using the 3.5" unit. Think about it. A lightly modded car would see a small gain from switching from a 2.5 inch system to a 3" system. Are you trying to tell me that a more heavily modded car is not going to see a gain from switching from 3-3.5"?
You talk about advertisers paying in scc, but how many of the shops that make the larger systems for our cars advertise? If you are worried about other manufacturers, alsmost all of the high end systems are comporable in sizing so that doesn't matter.
The thread is about a 3.5" system on our cars. Are you honestly trying to tell me it's gonna lose power over the 3"?
You talk about advertisers paying in scc, but how many of the shops that make the larger systems for our cars advertise? If you are worried about other manufacturers, alsmost all of the high end systems are comporable in sizing so that doesn't matter.
The thread is about a 3.5" system on our cars. Are you honestly trying to tell me it's gonna lose power over the 3"?
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Oh im not saying that, if you read my first post, I said 3.5" would be good for like someone in the 10's, possibly low 11's..centxdsm said:
as for losing power over a 3", on 1 14B/16G/18G i think you would yes, above that, no probably not...
oh and for advertising, there are plenty of places in SCC that sell the Thermal, Apex, HKS, but you are right.. i dont think any of them sell a 3.5" for our cars... maybe others... but point taken...
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I will agree that you cannot have to large of an exaust on a turbo car. My argument would be why spend the extra $$ to do it, clearance sucks(my exaust rattles) and unless you are trying to make 700+ hp there isn't really an benifit. If thats what you want go for it, but don't be disappointed if someone running a 3" goes faster and makes more power.
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