Test Pipe? Yes or No?

Post by **KcDre** » Sun Jan 26, 2003 9:27 pm

I have a 91' 240sx. I am doing a Sr20 swap very soon but for another six months the car will be stock. I am thinking about going ahead and replacing my cat. converter with test pipe and running 3 inch piping from it back. Would this be a good idea? Please help? Would this make the car sound sick?peace,KcDre

Website · Post by **daniel240** » Sun Jan 26, 2003 9:27 pm

i did it -w- my s14 and i still have the KA motor in it. i think i gained a little bit of top end. and it sounds good!

Post by **Anand** » Sun Jan 26, 2003 9:27 pm

I know for the cat under the driver seat of mine was hollow... Don't know if that is the case with all... so a test pipe wouldn't do crap for me... I know this because when I instaleld my dual N1's I looked at it... it's a dummy cat... so it would be a waist of money to get the test pipe.

Post by **red240ne** » Sun Jan 26, 2003 9:27 pm

I had a noticeable difference in the top end. I don't know if there would be much of a HP gain though.

Post by **C-Kwik** » Sun Jan 26, 2003 9:27 pm

Black240 wrote:I know for the cat under the driver seat of mine was hollow... Don't know if that is the case with all... so a test pipe wouldn't do crap for me... I know this because when I instaleld my dual N1's I looked at it... it's a dummy cat... so it would be a waist of money to get the test pipe.

Not necessarily. The hollow cat causes some turbulence as it enters and has to fill the volume. While a test pipe will not make a huge difference on an NA motor, it will in a turbo motor. I run a pipe through the center of my hollow cat to smooth the airflow. I actually felt a gain from this. But my motor turbo'd. A NA motor may not net a noticable gain.

Post by **nissankindaguy** » Sun Jan 26, 2003 9:27 pm

where can i get a test pipe at? i am planning on goin with a turbo for the ka. but my cat. vibrates alot when im driving and revving. so please help! thanx

Post by **sixxdeuce** » Sun Jan 26, 2003 9:27 pm

C-kwik, I did the exact same thing as you with a pipe through the hollow cat and I picked up a little it felt like. Not much but just felt smoother and a slight torque increase in the mid range.

Post by **Camel** » Sun Jan 26, 2003 9:27 pm

The hollow cat is on the stock exhaust behind the first cat right? That would be a res onator, not a cat if that is the case. A cat always has the element in it or it wouldn't be called a cat. Besides, emissions would kick nissan's *** for putting on a fake cat.

Post by **sixxdeuce** » Sun Jan 26, 2003 9:27 pm

It is actually just a hollow shell of a cat that never did have the catalyst in it. It serves no purpose, its not a resonator because there in no perforated core through it and doesnt quiet the car any(at least in my case) The resonater is farther back, between the dummy cat and the muffler.

Post by **Anand** » Sun Jan 26, 2003 9:27 pm

putting a test pipe in it;s place is useless... since there is nohting in the fake cat to prevent from exhaust flowing through it.. you are just waisting your money...

In Canada, I know that the fake cat is actually a real cat so they I think have 2 of them... for them it would be a decent gain but for us US 240's it's nothing but a waist of money.

Post by **Camel** » Sun Jan 26, 2003 9:27 pm

So your saying that this was factory? I have an S14a 98' that i was thinking about replacing the cat on. Guess I probably shouldn't do that knowing this info. I also have the ApexiN1 single catback system on a n/a ka.

Post by **ShifDown96240SE** » Sun Jan 26, 2003 9:27 pm

Today i just hollowed out my real cat(the one closest to the exhaust manifold). I already had a custom exhaust made, so the resonator is already taken off. But the cat being hollow is great, i got a little mid range, and it had to be the easiest thing ive ever done.

Post by **Camel** » Sun Jan 26, 2003 9:27 pm

ShifDown96240SE - Do you think you are going to pass emissions? What will you do if you don't pass, get a new header w/cat?

Post by **Camel** » Sun Jan 26, 2003 9:27 pm

This might be of interest. It certainly was to me...

BuudWeizErr wrote:As for the cat setup in S14's...

The real cat is in the header.The "cat" is a hollow piece that looks like a cat. Word is that Nissan did this so that the owners would not get harassed for not having a cat by uninformed people when in fact, they did have a cat.

I've also been told that the hollow cat was a real cat (making that two cats) for the Canadian market. I have yet to hear a concrete answer on that, so for now, that is hearsay.

And may I reiterate this once more.

I don't want to breathe in a ton more pollutants so you beat some ricer in your town by another fender. Leave your cat in, even if you live in BFE.

Post by **Anand** » Sun Jan 26, 2003 9:27 pm

when I installed my dual N1's... I looked at the dummy cat.. it's just a straight pipe.. the real cat as stated before is right after the header....

Post by **bendychicken** » Sun Jan 26, 2003 9:27 pm

well, all I can tell you is that when I put mine on, there was alot better top end. When my friends were in the car they asked if I had "done somthing to the engine":ylsuper

Post by **sixxdeuce** » Sun Jan 26, 2003 9:27 pm

true, a straight pipe will actually help a little. Exhaust flows best when every thing is the same diameter, when it goes from the smaller pipe to the big hollow cat, back into a smaller pipe it slows down and speeds up and causes turbulence, with a test pipe it would flow at the same velocity and make a little more power. But I do not think it is really worth it, I only did mine because it was free, there are better things to spend your money on

Post by **nissankindaguy** » Sun Jan 26, 2003 9:27 pm

well thanx alot u guys that helps me out a whole lot...

Test Pipe? Yes or No?

Test Pipe? Yes or No?

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