CandyRedRC46

1.) back pressure is a bad thing, not good (regardless if daily or racer)
2.) what you plan on doing would actually lower the back pressure (high flow cat = less back pressure, resonator = irrelevant to back pressure)
3.) yes please install a resonator, your neighbors, anyone driving next to you and the general public will thank you.

CandyRedRC46

I still say go with the pipe kit, cut and welded by muffler shop, with magnaflow muffler and resonator. It is a tried and true recipe with great results.
Bolt ons, unless talking very high end (greddy evo and apexi WS2), generally have fitment issues and develop rattles and can be obnoxious. Yokana can be decent for the price but the mufflers usually fail after a year or two, rattle/rust and then you would have been better off going magnaflow.
That $500 for custom made sounds like a bad idea. More than likely crush bends and not as precise as the kit and no mention of the muffler/resonator brands.

Javane

Yeah I still like that pipe kit better than the custom thing.
That's exactly what I didn't want, a rattling bolt on exhaust.
I'm gonna shop around for more quotes on the welding though.

When I do get a header, will need a flex pipe? Or it's just another welding job? 🤔

CandyRedRC46

I only installed the flex pipe due to concerns of the Bisi header, which have been know to crack and I wanted to keep the stress it sees low. The hangers and spring clamps between the cat and header should allow some movement. I think (depending on the header and cat that you go with) the condition of your motor mounts, will determine if you actually need a flex pipe or not. It isn't always mandatory.

If you are staying with the factory catalytic converter and just bolting a header to it, I wouldn't worry about a flex pipe, as long as your motor mounts are good.

Javane

okay that's good to know.

I'm getting the Magnaflow High flow cat

CandyRedRC46

The factory cat and header have an inner diameter of around 1.75. Are you going with a universal 2.25" cat or some type of bolt on cat? Even the DC sports header I have on my LS integra has an outlet with an outer diameter of 2.0" and inner of around 1.9". You might want to look into headers at this point.

Javane

The cat I had in mind was the Magnaflow High flow cat, it should be 2.25 right?
if that's the case do I still need to look at headers?

CandyRedRC46

Yeah I would want the header collector closer to 2 inches and then step up to 2.25 at the cat.

Javane

Damn, so I might as well go searching for a header now?

Scorchin Civic

I had that setup the whole time I owned that car. Might have been a few years and it's the same setup that I will be doing with my 2000 LS.

Javane

Nice, that's something I'll look into.

Javane

Private Label MFG (PLM) Toda Style B Series Header Honda Acura B16 B18 | eBay

So I've been looking for a good header, and I found the one above? What's your thoughts on it or any 4-2-1 replicas (wanting 4-2-1 for clearance and mid range power instead of top-end.)

Also, would you recommend putting the header and cat on before the exhaust sytem? I only ask for the fact that those can easily be put on, and I might get those a couple weeks before I get the entire exhaust system.

AYB18c

My understanding (more experienced members can correct me if I'm wrong) it's not going to hurt anything to put the headers on before the exhaust system, but you won't recognize the full gains of the headers until you open up the rest of the exhaust. While aftermarket headers may flow better, your choke point is still the exhaust. So in the long run you'll want to do both.

Javane

I figured that would be the case. I didn't expect to see much if any gain at all with just the header. I'm just trying to figure out which one to get.

CandyRedRC46

That header has a 2.5" collector.

CandyRedRC46

I like this header more, it is a full length 4-2-1 and should offer a much better powerband. It emphasizes lowend and midrange and doesn't say 2.5" so I am thinking it will be a 2-2.25" collector, which would better fit your build. This header may or may not bolt on to your catback, it might be off by a few inches, so what I would do would be:

Order the 2.25 inch piping kit
Order the 2.25" magnaflow cat, resonator and end muffler
Remove your entire exhaust (header, cat and catback)
Install the header
Make an appointment with the muffler shop and explain to him your plans in great detail
Carefully and slowly drive to the shop open header (you dont want to be obnoxious and get a ticket), with all the parts in your trunk
Have them weld the cat to the header, the piping kit to the cat and then cut and install the mufflers in the correct locations
A turn down at the end would be a nice touch

Javane

Yeah I realized that, figured welding a flang or something like that would be ok.

If you meant to show me another header, I can't see it (maybe you left the link out, or maybe I just can't see it on my phone.)

I like that plan.

Post the header you recommended, I can probably start ordering some of it this week.

CandyRedRC46

Sorry I meant to post this header:

PLM HYTECH STYLE TRI-Y RACING HEADER B-SERIES HONDA ACURA EXHAUST B16 B18 B20 | eBay

Javane

Ok, I checked it out and I did see that it has a long tube design that would eliminate my cat, which I would need for emissions.

CandyRedRC46

Do you think that you could not just cut the flange off of the outlet of the header and weld the magnaflow cat to it? I think it would work, but you would have to try to know for sure.

Javane

I'm not sure at all. Plus I don't really really wanna try for myself because if it doesn't work then I'm pretty screwed since I won't be able to return it 😂

I was trying to calculate it all and it adds up to bolt on systems I thought were too pricey 😂

CandyRedRC46

I mean, you aren't bolting on that high flow cat, are you?

Javane

Kinda got a point there.

trm4life

I've recently watched a video on road kill garage, where they compared 2.5 inch to 3 inch pipe on a v8. There was virtually no power gain. It's safe to assume, 2 or 2.25 inch pipe will give you about the same power (maybe a difference of 1hp at high rpm) but 2.5 would just be unnecessary, it would also weigh more! I have no experience with high end headers. Don't know if they make more power than a cheap set, but I'm sure the fitment is more exact. I know the OEM cast header on my 92 GS is 4-2-1, therfore, still provides almost if not equal power. The cast is just heavier, therfore quieter.

​​​​ Stainless steel, is really thin. Thin enough that it can sound like a gasket leaking compared to cast. Basically you're going to get what u pay for, however I bought a cheap cat back system, and OBX racing cat. The muffler split at the seam after about a year, so I replaced it with a Flowmaster. The piping itself though, was T304 stainless, so it's extremely durable! I've had it for about 7 years now! Nice thing is, the muffler being bolt on, I can swap between the Flowmaster and an OEM muffler in minutes if I so desire. I do personally love the sound of Pacesetter cat back systems! Had one on my gf's Nissan. I was actually jealous lol.

trm4life

oh man, it's rude. That's the best way to describe it!