I think you're going to be dissapointed by the exhaust bypass or side exhaust.
Reason #1) Short run exhaust pipes or extreamely large diameter systems are meant for one thing, moving a massive volume of gases. Turbo charged applications or high RPM circle track engines are good for this. The sacrifice is (as stated a few times earlier) low end torque. Aside from the other obvious side effects, the lack of low end torque will drive you nuts on the street. Chevettes will eat you up at stop lights. By changing the exhaust runner length and diameter, what you are losing is a "scavenging" effect. (Very fundamental exhaust & header design)
Keeping things simple;
Too small of a pipe diameter, and the exhaust gas builds backpressure. Exhaust pulses of spent gasses can not escape to atmospheric pressure quick enough before the next pulse is released from the engine.
Too large of a pipe diameter will affect lower rpm engines in this way. Exhaust pulses escape to atmospheric pressure too quickly creating a theoritical vacuum behind each pulse. (A low pressure following a high pressure.) If this pull is too great, part of the intake charge is pulled through the exhaust valve at the moment both intake and exhaust valves are open. The exhaust valve shuts and the cylinder is left with a partial air/fuel charge before the compression stroke.
In short, (too late),until you actually put more air into the engine, you don't need to open up the exhaust. Trust me, Toyota takes this into account during engine design. We have designed systems with them where slightly increasing backpressure will cause a major shift in the torque curve. This is why some aftermarket exhaust systems offer little performance gains. They sound awesome, but little to no gain. Couple this with a less restrictive intake or better yet, a CAI setup when cooler air can form a more dense air/fuel charge, then you are taking advantage of low restriction exhaust.
Reason #2) As everyone pointed out, this is highly illegal to change the exhaust configuration to eliminate or bypass emission control equipment. (Ok this isn't a show stopper if you can get away with it. But side pipes will attract the Police to you and write you up for the violation.) If you had loud exhaust with it exiting in the rear of the vehicle, they may not notice the converters missing.
Reason #3) Side exhaust is hell on your hearing. Ask any hotrodder that runs header mufflers. An hour or so cruising around with the exhaust coming out by your door will make your ears ring. It's huge difference inside the car when the exhaust runs out the back. (Even if there's no muffler on the car) Owners of the first gen Viper had the same issue. This is why the GT-S had exhaust out the back. My buddy at work designed the second Gen Viper exhaust and DaimlerChrysler tasked him with side exit exhaust that meets the 95dB passby regs. This could only be done by taking the driver's side exhaust and crossing it in front of the rear axel over to the passenger to exit before the rear tire. The same was done on the passenger side to exit before the driver's rear tire. If you ever have an opportunity to stop by a Dodge dealer and look under a new Viper, it's a real work of engineering. With all that exhaust tuning, we were able to squeak out 500hp and gobs of low end torque. And for the reasons meantioned in #1, I would only rip that system off if I was doing road racing with sustained high rpms.
Reason #4) Your paint will hate you for side exhaust. Remember the 1997 Ford F-150 V-8? The OE exhaust came out on the passenger side just before the rear tire. This was a HUGE cost savings to Ford. Until they realized the the heat and fumes from the exhaust ruined the finish on the right rear wheel and side of the pickup bed. 1998 F-150s had the exhaust out the back. Ford still dabbles with this design on SVT Lightning and Harley Davidson F-150s. The twin tail pipes may have helped to dissapate the heat.
Now if you actually read all of this, you're a diehard interested in pushing your car's performance to the edge. If you skimmed though it not learning a thing, then the automotive fashion consultants of JC Whitney are awaiting your order.
LOL
by DatSRBoi » Thu Jun 23, 2005 10:38 am 
Great idea...
A rumblin' V6!!!
