Test pipes are not always the answer. You still need a little back pressure. With the S2000 struggling to produce torque, the cat aids the S2000 in this catagory. Yes, the straighter the flow the better the go....at least that is the theory. By adding a test pipe you should increase horsepower, but you will ultimately loose torque (in theory). Just depends on what you are looking to accomplish. The only way I would add a test pipe is if I could gain horsepower without loosing a bit of torque.


On a side note, I remember reading an article written by Ben Schaffer (the real JDM) and how the "trend" in Japan is high flow cats over test pipes. I'll try and dig that article up and post it.

 

there are definately cheaper (than those jdm ones on bulletproof) cats out there like the ones posted. i have several friends with test pipes and one with a high flow cat - the test piped cars smell, have black soot on the back bumper, and sound really bad. the guy with the high flow cat has NONE of these problems. just a little insight if you're thinking of a test pipe instead of a HFC
-Chris

 

I don't see how you can lose torque and gain HP because HP is proportional to RPM & Torque. So unless your Redline drops (which makes no sense)... I don't see how you can gain HP and lose Torque at the same time.

Andre

 

NA engines usually benefit from some exhaust restriction down low. Replacing the cat with a test pipe usually makes you lose some low end torque, however at higher RPMS where flow becomes more critical the test pipe flow more, letting the engine produce a little more torque, which will in turn raise the high end HP or peak HP. That's how you can lose torque but gain HP, it happens at different parts of the power band

 

Oh yeah... that I know... but I thought he was saying overall.

Andre

 

Tracy Sports has a high-flow cat available for the S2000

 

well said

 

The problem is that any modification to the emissions system is illegal...thus high flow cats are technically as illegal as a test pipe, it's just less likely that you'd get caught w/ one.

 

If aftermarket cats are ineffective, chrome plate or powder coat the stock cat. Wouldn't accomplish anything but it would look pretty

 

im very confused as to why you would do that - and its been stated multiple times that there are affordable cats that outflow the stocker. when people talk about the stock cat being a HFC, they're saying that its very high-flowing compared to other factory cats, but it doesnt mean that there are no aftermarket ones that cant outflow it.
-Chris