I have a CT, and get 306HP in 95F heat on stock SOS boost. An exhaust will drop your boost (i max 5psi), but that's not a bad thing. If it drops your boost, that means more air is going into the motor, all else equal.

The CT won't make the absolute most power, but it won't be obnoxious, either. I found the Invidia obnoxious.

 

Ditto

 

What do you mean an exhaust will drop your boost? I don't see how an exhaust has anything to do with the amount of air the blower is pushing to the intake manifold. I have gone from stock exhaust to an Amuse R1000 (single 70mm header back)to my current T1r 70r em Dual sparrow 70mm and have never notices a drop in boost, and that was non aftercooled. Even after I installed the Aftercooler a few weeks ago, I noticed no significant drop in boost. So if it drops your boost more air is going into the engine and that's better? so if it drops it to 1psi that's good? I don't fully understand what ur saying.


To the OP, a 70 or 76mm single will give you some good gains but will be loud. If you want to get the most HP of of an exhaust go with those, the straighter the better, bends will cause more back pressure.

"The Best" is going to give u many opinions and you will still be left to make ur own choice. For me, the Asura and T1R are two of the best duals for the S, both making some great power, and both sound nice not rice lol. If you have a good amount of S owners around you, I highly suggest you see and hear what they have, go on some ride alongs. Videos do not do exhaust justice, but when I get a chance I will take one of mine. Good luck

 

Free flowing exhausts will lower the boost with a supercharger by freeing it up. That is why some larger exhausts people have seen a loss in power. If you bump it back up to the same psi there will be a nice gain from the new exhaust.

 

If, ALL ELSE EQUAL, your blower/turbo is putting out the same amount (moles, which is 6.022 * 10^23 molecules) of air, due to the removal of any restriction, your motor will be able to take in more air (making more power...usually), reducing volume, thus removing pressure at the manifold. PV = nrT (n and r are effectively constants). The number of moles in your manifold dropped (because some of the air went into the engine), thus volume in the manifold dropped which results in reduced pressure AND temperature.

http://en.wikipedia.org/wiki/Ideal_gas_law

An aftercooler would lower boost because it removes heat...you have to balance the other side of the ideal gas equation, so pressure drops.

You are less likely to lose pressure with a turbo, as the impeller speed is not locked to engine speed. Also, the amount of pressure after the impeller will have an effect on how much air the impeller can flow. So, there are 2 vectors...the removal of restriction decreases air volume and pressure in the manifold, BUT the removal of pressure would allow the impeller to "squeeze" a little more air in, especially if impeller speed is variable. The net effect of the change could be large or even a wash depending on many factors.

Also, adding a large exhaust may enable more airflow, BUT an engine needs some backpressure, so you may lose power by over-doing it...and you should still lose boost.

It's just not a well-known concept that boost and power are always positively related. At its fundamental level, boost pressure in the manifold is how much is NOT going into the engine. You can remove pressure, and still make more power. Restore that lost pressure, and you will likely make EVEN MORE power, though.

Thanks Moddiction, you probably put in a better explanation than I did. I'm on a stage 1 SOS kit, so I may not have the option to "restore" the boost since I may not have the fuel headroom.

 

THIS CAR IS LOUD...Best gains with a quiet exhaust is OEM, if you want just a little more sound...Do a test pipe. If you need more, do a Greddy exhaust. Dont go near invidia N1 lol

 

https://www.s2ki.com/s2000/topic/817...ube-sc-header/

 

Mugen

 

https://www.s2ki.com/s2000/topic/710...erent-exhaust/

 

Best gains would be from leaving the stock exhaust and advancing the exhaust cam 3 degrees. Quiet with increased power.