The_Honda_Guy

I've done some researching on here for a bit now for a friend and have a few questions. First we'll start with the header setup. I know there are two different styles - a 4-2-1 setup and a 4-1 setup. From what I've read, the 4-1 setup has much much less ground clearance than a 4-2-1 setup due to the collector size. Also, a 4-1 setup will not bolt up to the stock cat if I remember correctly because of the collector size. The 4-2-1 setups are supposed to have plenty of ground clearance and will bolt to the stock cat setup. Also, I remember reading that the 4-2-1 setups usually provide better low to midrange power, but the 4-1 setup will provide much more top end power because it flows much easier. My question to start is this. How far car you lower the car before you have to start worrying about a 4-1 setup dragging on the ground? From what I've seen lowering the car at all will provide very little clearance and you will more than likely end up denting the header on a road with minimal bumps.

Nextly, I've been looking around at cat-back exhaust setups. There's quite a few different companies out there, and I'm wondering performance wise which would be the best. I know if I'm looking for something that's not really loud and doesn't look "ricer" that the Apexi WS 2 is a great exhaust setup. But all-out performance wise I'm not really sure. What do you guys suggest?

The_Honda_Guy

Nobody has anything to say on this?

mrdeadman

What are your goals and budget?

skynyrd006

For a catback exhaust, I would go with the greddy sp2 or the tanabe hyper medallion. They are both pretty quiet under normal driving, and they sound amazing when you get on them. However, they are not loud. I have the greddy on my integra and i love it

HyperX

i have like almost a 3in drop on my teg with jdm 4-1 headers. just got to drive carefully and know where the pot holes are. and believe me...i know where all the pot holes are around my immediate local area. drive cautious and you'll be alright

JdmTypeRdc2

iTrader: (1)

Ok first off....

a header's design has nothing to do with whether it will bolt up to the cat or not.

both 4-1 and 4-2-1 headers will bolt up to a certain cat. it all depends on the collector size. any 2.5 inch collector header will NOT bolt up to a stock cat. you will need either a 2.5 inch test pipe or a 2.5 inch hi flo cat.

Collector sizes range from 2-2.5 inches depending on what you get.

There are 4-2-1 headers that do not bolt up to the stock cat, because they have 2.5 inch collectors ( examples are T1R, Toda, Spoon RSR, etc)

4-1 headers that do not bolt up to a stock cat are: JDM ITR header, Mugen, etc)

About the flowing part of your question...

just because a header is a 4-2-1 design doesnt mean that it doesnt flow as good as the 4-1. Usually the 4-1 header will flow better in the high rpms but thats not because if flows better OVERALL. They are made for different purposes.

4-2-1 has 4 primary pipes, which lead to 2 pipes, then ultimately to 1. This allows the air to flow much faster, giving the car a boost in midrange power.

With the 4-1, it takes much more time for the air to flow from the 4 pipes, to the 1 pipe, therefore it allows for more top end than midrange.

Think about it this way....

Picture an hour glass, one that you play in board games....

ALl of the sand is on one side of the glass ( the bottom) when you start and its completely still. Once you flip the hour glass, the sand takes awhile to go through the little hole. Same thing with air....when you have sooo much air coming from 4 pipes, and its all trying to get diverted into 1 pipe, it takes much longer, but when it does, it provides good power.

Now with air flowing from 4 pipes, to 2, it is a much quicker response, because the air can be diverted into 2 separate places. This creates more midrange, as the air flows much quicker from the primary pipes to the others.

As for the scrapping issues....

NO header will DRAG on the ground. The car literally has to be on the floor with no wheels. It is physically impossible, because that would mean that the Oil pan would also be dragging, creating dents and cracks, leaking oil, and you wont be able to drive....

if you meant to say: "how much can i drop the car before it begins to bottom out?" the it all depends on your suspension setup.

A suspension with very stiff spring will most likely absorb the cars weight better in an event of a dip. If the suspension is mushy, then there will be more shock travel, and it might cause a problem.

However, even with very stiff suspension, a car is still able to bottom out. Your best bet is to drop the car about 1.5 inches or so when going with a 4-1. You also have to think about your oil pan....you dont wanna mess that up either.

There have been numerous amounts of HT members that have a 4-1 header, and they are fairly low. It all depends on driving conditions, how low the drop it, suspension being used, etc.


EXHAUSTS....

For a mild engine build, anything 2.36 inch in diameter will be good. It will allow for just enough flow to get you to ur desired power goal.

If you plan on building a more powerful NA motor, then go with anything 2.5 inch or even a 2.75. Exhausts like these will increase flow much better than the regular.

a 2.5 inch exhaust on a car that has intake and header, will not benefit much more than with a 2.36.

Brands for good 2.36 are Apexi, Greddy, etc

Brands for good 2.5 inch are hytech, smsp, t1r etc.

Hope this helps

J. Funk

Buddy Club Spec 2

Padawan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JdmTypeRdc2 &raquo;</TD></TR><TR><TD CLASS="quote">Hope this helps</TD></TR></TABLE>

Yes, very nice reply. Saved me the trouble of writing it all.

Uncle Willie

Any header with a 2.5" collecter...mod if necessary. Then get a 2.5 in and out diam cat from smsp. Then get T1R cat back.

infamouskillas

yeah dude that one guy was right...the design of the header doesn't matter if it'll bolt to the cat or not...it depends on how big the collector is..put it this way, you could have like a 1 - 1.5 inch collector and still be fine to bolt up to the cat...if not...if u got like a 2.5 inch opening, then ur gonna need i think a high cat converter or a down pipe...somethin along those lines i'm not really sure tho but i mean thats basically it...now as far as the performance stats for these two types of headers...i heard the same...4 - 2 - 1...gives u low to mid range the best...and 4 -1 gives u higher end performance....now the fact of ur headers sitting higher than others against ur chassis...it all depends on who is makin em and what model they are..put it this way...ur common dc ceramic 4 - 1 will probably sit normally that you would find in a stock exhaust manifold, as opposed to say vibrant performance 4 - 2 - 1 headers...they will sit up higher against the chassis...giving u safer ground clearance...so this is what i think and anyone please correct me if i'm wrong...but that's what i see...as far as ur exhaust...if ur a guy like me who likes to speed...has a fast lookin car (i don't)...then i would reccomend a ws2 catback....basically...i already got a ticket for speeding...and on top of that, the pig busted me for my exhaust...so i'm just gonna switch mine wit a less quiet one, still effective...plus a great look...ws2 from apexi..but thats just my opinion...otherwise idk if u want the ricer sound or the huge coffee can in the back...but i would take a hi power exhaust from hks or n1 from greddy i believe it is...hope this helps and sorry its long

Integra2uner

i just installed the greddy ti-c exhaust n love it. not too loud and it looks sexy. for something quiet and not n1 style, i'd go for the rs-r exmag if u can find it. their products r the shyt. I had the exmag gt2 n the design was different. str8 pipin all the way bak to the muffler hangers.

The_Honda_Guy

Alright, so my main concern with the header will be the collector size. I have to make sure it's the right size for the cat I'm bolt it to. I'll make note of that when I ask my friend what cat he's going to want to run.

I understand now about the flow. Depending on where I want the power to be will choose whether I'd go with a 4-1 or 4-2-1. Ultimately I think my friend is shooting for a little more top end power because he will be running a Skunk 2 manifold and aftermarket cams and raising the VTEC engagement point, so I'm thinking he'll probably lean towards a 4-1 setup. For a setup with a AEM SRI, Skunk 2 manifold, aftermarket cams, aftermarket exhaust, and a raised VTEC engagment would you guys recommend a 4-1 or 4-2-1?

I understand that it won't drag, but I also don't want to be scraping it all the time. I know that with a 4-2-1 setup you can usually lower the car more than with a 4-1 setup. I'm not sure yet what suspension setup he'll be going with for sure, but I'm thinking he's not going to drop the car too low. I'll have to talk to him more about this one too. I know for sure that a 1.5 inch drop isn't very much at all though and most aftermarket suspensions will lower the car at least that much.

I know he wants to build the car up, but not all out race setup. I know a 2.75 inch will be way too big. I'm thinking he'd be best off with the 2.36 inch because this exhaust needs to maintain a decent velocity. Like I stated before, the car will probably have an aftermarket intake, manifold, cams, and header and a raised VTEC engagement. I know this isn't a huge increase, but I don't want anything to be restricting the exhaust. 2.36 inch is pretty good sized for a 4 cylinder with mods and I would imagine should work well for a mild setup like what I have listed.

I remember reading somewhere that you want all of your piping on the exhaust to be the same size. If I had a header with a 2.5" collector, that would mean I want a cat with 2.5" inlet and outlet and a 2.5" exhaust correct? To me this would help maximize flow. Btw, is the stock cat a 2.36"?

InTeNsE805vp

RS*R exhaust on mine ... LOVE it because it's quiet quiet quiet

The_Honda_Guy

Alright, so we've got a few things figured out. He's going to run either a 2.36" or 2.5" exhaust. Anything bigger is out. He will also be running a 4-2-1 header for the ground clearance because the area we live in has lots of bumps and wouldn't leave much room for a 4-1 header to hang on a lowered car.

Right now my friend is leaning towards either the Apexi WS or Greddy Evo 2 catback with a Magnaflow high flow cat. I suggested to him the Apexi WS because it is quieter and looks nice and is pretty cheap. I'm not real sure about cats, but I do know that you need to get a quality converter to prevent the car from throwing a CEL.

Now, here's another question. This car is going to be pretty mild, nothing outrageous. The car will have aftermarket cams and will be geared more towards top end power. So far the plans are AEM intake, Skunk 2 manifold, aftermarket cams, chipped ECU, header, high-flow cat, and catback. I know that the car will need some back pressure to retain some of the low end. I also know that all the components need to be the same size piping to bolt up correctly. What size exhaust would you guys go with for this car setup?

The_Honda_Guy

Any suggestions on my post above?

The_Honda_Guy

Alright, so now that I know for sure he wants a 4-2-1 header setup to save on ground clearance, I need to decide which style to go with. I know there are advantages and disadvantages to ceramic and stainless steel. I know ceramic ones can crack, but also will slightly increase performance because it keeps the heat inside the exhaust. The stainless steel won't crack, but won't provide as much heat protection. What are your guy's opinions? Also, what size would you recommend for a mildly modified vehicle?

The only thing we're trying to figure out now for the cat is what size to go with. Obviously we know that it needs to be size matched with the header to keep the flow correct and for it to bolt up correctly. A test pipe is out of question because a test pipe will make the car too raspy and I also don't want the vehicle to throw any CEL's. What are your suggestions on a cat?

And now for the catback. Obviously the piping will be matched to the header and cat, and we want something that's not going to need to be cut and welded to make it fit properly and that will bolt to the stock exhaust hangers. Due to the build up this vehicle, we're leaning more towards a 2.36" size since the motor probably won't flow enough to need a 2.5". What do you suggest?

MopdiT

JdmTypeRdc2 couldn't had said it any better....