What do you do when your exhaust is too JDM? Too JDM for 56k even?

[estrada42]

So I've bought this car recently.



And the muffler is rattling like crazy. I put it up in the air and find that the cat back is barely being held on by a universal muffler strap, and the last section is just banging around.



So, I'm going to get a new catback, that's the easy part. Problem is, what do I do with this old catback. It's clearly not for an S13. After some digging, I found that it's a Nismo Sports Muffler Spec Pro Calsonic.



Some googling tells me it's for an SR20DET equipped S15. This leaves me a few questions. How does some jerk buy this for his S13, and then how does he install it and not see a problem? And, what do I do with it now? I'd hate to toss it, but I can't see myself finding a buyer. Not many S15's in my neck of the woods.

Thoughts?

[AZ89two4Tsx]

Step 1: Remove exhaust

Step 2: Give it to me

Repeat as desired.

[ZootedS13]

just cut or bend the brackets so it fits.

or you can always.

Step 1: Remove exhaust

Step 2: Give it to me

Repeat as desired.

lol

[MastaYu]

clean car. just post it up in the classifieds

[breadbox]

Nice.

[IDRFT95S14]

[leesredgt]

Just make it work.No biggie.

[estrada42]

I'm not a fan of the watermelon sized tip. I worry I'm going to find small children in there someday.

[AZ89two4Tsx]

^ Haha.

So you're just unhappy because it rattles? Why not just take it to a muffler shop so they can fix it? That would be cheap too.

[spolitte]

Metal exhaust hangers + Zipties = Quick and easy solution to rattling exhaust. And I'd agree with the others that if you don't like that muffler/tip you can just give it to me, I'll even pay for the shipping!

[estrada42]

^ Haha.

So you're just unhappy because it rattles? Why not just take it to a muffler shop so they can fix it? That would be cheap too.

I'm unhappy with how it rattles and also how it looks. It hangs down too low, gets caught on speed bumps, and the 5" tip is just unneccesary. I'm going to replace it with something tamer looking and sounding, but I'm trying to figure out if there's a market for an S15 exhaust in the states, or should I just get over it and have it fixed.

Yes, it would be cheaper to have new brackets welded on, and have it hung correctly. But that won't fix the sound or look of it.

[Afields81]

whats your payl ill give you 80.00 right now. email me

[estrada42]

whats your payl ill give you 80.00 right now. email me

I'll ned to replace it first, but I'll keep you in mind when the time comes to sell it. I' think the shipping from California to Jersey might be a little much though.

[Nissan240sx_s13]

First nissan I see....

[venomousr1993]

That is not a big exhaust...this is:





And yes it is mine on my built JDM MR2 Turbo 5sp.....right now I am boosting .8-1.0 bar..has seen 1.3 bar, but was running out of fuel.

With yours, take the exhaust off, cut the brackets and reweld / bend them to fit your car. If you still don't like it you can then sell so it will fit someone elses car with minimal problems.

[jeff420]

are you serious? you fail. that exhaust isnt too big and it would take me 10 minutes to fix the hanger problem. doesnt look any bigger than my apexi. i got a stock exhaust, because it sounds like thats about the only one that'll make you happy, you ship me yours i ship you mine. done deal.

[DMan II-40]

Bay point I see. I'm over in Pleasant Hill, I might buy it off you.

[AZhitman]

I agree. I don't care HOW "jdm" it is, it's goofy looking.

Huge tip = Fail.Huge piping = Fail.

Sell it on ebay to some ricer.

Good-looking S13, by the way... Congrats!

[White Comet]

^ the piping doesnt look that big, and even so theres nothing wrong with big piping on the proper application

[AZhitman]

^ the piping doesnt look that big, and even so theres nothing wrong with big piping on the proper application

No need. Don't make me break out the exhaust theory info.

There's simply no NEED for 3" piping on a 2-liter engine, unless you're running insane amounts of boost. It's unnecessary.

But I digress.

[White Comet]

There's simply no NEED for 3" piping on a 2-liter engine, unless you're running insane amounts of boost. It's unnecessary.

thats why i said on the proper application

[spolitte]

No need. Don't make me break out the exhaust theory info.

There's simply no NEED for 3" piping on a 2-liter engine, unless you're running insane amounts of boost. It's unnecessary.

But I digress.

Well, I've been researching exhaust backpressure/how it works/etc for about 3 hours now and have read an absurd amount of conflicting points of view (no, really, google exhaust backpressure and count how many of the hits on the first page all say different things). Well, I HAD my own preconceptions on this hot topic, but I am no longer sure that they are the right preconceived notions. With this said, I only assume that I speak for many of us when I ask you to break out your exhaust theories, omnipotent AZhitman, so we may be enlightened, as I am sure many of the nico members have conflicting points of view on the topic and that they would all love to hear your input on the subject. I have already tried to search for what you say about this topic to no avail, but if you have already posted on this topic just a link would be great; otherwise, I can see this becoming a whole new thread or even sticky I have not yet found ---- "Backpressure and Exhaust... the truths and myths!"

[AZhitman]

I have... several times. But actually, most folks here are already pretty educated on the topic.

I own an exhaust manufacturing company... So while I'm not the end-all, be-all expert, there's some common sense you can use to apply to your situation, and I'm gonna go for the "super-simplistic" version, since it's 2am and I'm loopy...

Just remember 2 things:

1) Backpressure is bad. Always. Anyone who tells you otherwise is wrong. Period, end of story.

2) Keep your exhaust hot. Hot gases move faster. Always. Overly large piping isn't doing you any favors.

Those would seem to be contradictory, right?

Nope.

OEM exhaust on one of our 4-cyl Nissans is 1.8".

Moving to a 2.5" system DOUBLES the capacity of the system... A 3" system is almost 3x the capacity.

Let's not also forget, all that piping has weight. So the few hp you may gain at one specific spot in the rpm range by increasing your system diameter THREE TIMES was just eaten up by hauling around almost DOUBLE the weight.

An extra 40 lbs in your trunk is never a good idea when power is the goal.

(1.8" piping has circumference of 5.6", vs 9.4" for 3" piping).

Bigger is not always better. Smoother is better. Taking that 1.8" system, smoothing out the bends, and using mandrel-bent instead of crush-bent tubing, is a cost-effective way of creating power without adding weight and compromising flow.

[White Comet]

why is any amount of backpressure bad? my friend wanted to make is 80s malibu loud just for kicks, so he cut off the exhaust right before the cat. it was indeed loud, but there was no throttle response whatsoever without any back pressure at all

[Fidel_Cashflo]

I thought that turbo motors didnt rely on back pressure but NA motors did rely on back pressure, other wise what is the idea of even putting an exhaust on your car...

[ZootedS13]

I thought that turbo motors didnt rely on back pressure but NA motors did rely on back pressure, other wise what is the idea of even putting an exhaust on your car...

yea thats what i thought too until i drove my friends car (sr20det) with no exhaust and then again the next day with an exhaust and felt a huge power difference.

[iRides13]

by any chance you have a side pic of your car?

[iRides13]

Some googling tells me it's for an SR20DET equipped S15. This leaves me a few questions. How does some jerk buy this for his S13, and then how does he install it and not see a problem? And, what do I do with it now? I'd hate to toss it, but I can't see myself finding a buyer. Not many S15's in my neck of the woods.

how much do you want for it??

[spolitte]

why is any amount of backpressure bad? my friend wanted to make is 80s malibu loud just for kicks, so he cut off the exhaust right before the cat. it was indeed loud, but there was no throttle response whatsoever without any back pressure at all

From what I understand ANY amount of backpressure is bad because any pressure that backs up and pushes on the exhaust gas that is trying to escape will slow it down for obvious reasons (two forces working in opposite directions of eachother).

I thought that turbo motors didnt rely on back pressure but NA motors did rely on back pressure, other wise what is the idea of even putting an exhaust on your car...

I believe the idea behind an exhaust system consists of two main concepts 1) it guides extremely hot exhaust gasses away from your engine so that they dont do any damage to anything up front (wires, plastic parts, etc) and 2) with the invention of the cat and muffler exaust is an attempt to limit the emmisions and noise we drivers leave behind.

Now, with that said, from what I understand an open header design is the most efficient because an open header basically places no resistance on the exhaust gasses trying to escape the combustion chambers (means no backpressure, which as we all know now is ALWAYS bad). As AZh explained, bends in the pipe, kinks, changes in pipe diameter, and length of pipe are all factors that change how an exhaust gas will flow as well as the temperature the gas itself is. Furthermore, hot gas travels faster. With this said, it only seems logical that an open header design that doesn't bend or kink and restrict air flow, and is so close to the actual spot of combustion that the exhaust gasses have very little time to lose heat and travel at a slower rate will always be better than having any sort of exaust system on your car. On the otherhand turbos are very fun and can help to produce more power; however, I still believe if you could aim your turbo properly so that the gasses ran out and away from your car and ran it open (with no down pipe), then this would be the ideal way to go in turbo applications (basically the same as open headers on N/A cars).

Now, even tho I believe I have a pretty solid understanding about exhaust, as I mentioned earlier draw my conclusions about exhaust from everything I have been told, experienced, and learned about the subject in my short time on this wonderful earth, and I don't claim to be an expert on this subject nor do I think I know everthing their is to know about exhausts. With that said, if anything I have posted is wrong and someone catches it please let us all know. Not only do you save others from misinformation, but it will give me a chance to further learn and correct any misconceptions I have on the subject.

[AZhitman]

^ Yep. You're on it.

Actually, a properly-designed exhaust system CAN perform better than open headers, but it has nothing to do with "backpressure".

It has to do with exhaust scavenging, and the creation of low-pressure areas in the system that actually help scavenge exhaust gases (thereby assisting in intake)...

We can go into more detail later about WC's idiot friend, but his situation was a combination of the above, coupled with the fact that old V8's have competing exhaust pulses from opposite banks (reasoning behind dual exhausts, and crossover / X-pipes).

Just remember this (excessively basic):

Run the smoothest, straightest system you can, with the least restrictions, in the smallest piping size appropriate for your application (for both weight and exhaust scavenging).