gutting headers

The Cat is Gutless

Anyone knows how to gut the stock pipes and baffles on 6th gen bike.
I am going to get the staintunes for mufflers
but if I can bypass spending the $500.00 for the motad headers I would. Does anyone know of a post with pix's that would really help.
It looks easy to do just cut off where the cat is right???? And fab a new pipe (know someone at a muffler shop):tape2:
I’m a little concerned about the pipes do not cross on the motad and they do on the stock, should this be a concern?
I would think no difference because they all collect to one any way (should I be concerned:crazy

OK IT'S DONE
:joker::crazy::crazy::thumbsup:
It's done gutted the cat doh this was not easy about 1.5 hours
but the gutts are out take a look lots of pics.

1. Need a friend with a plasma torch (and knows how to use it):biggrin:
2. knowing where to cut is have the battle
3. after 50 mins figured out (melt the HELL out of it):flamer:
4. do one cone and the other will fall out
5. weld a piece of medal back over holeound:
6. done:thumbsup:
:crazy::crazy::crazy:

ok but now need the .99 cent O2's
1. radio shack 1/4 watt 330 Ohm 5% tolerance (really .99):thumbsup:
2. find your o2's follow the wire back to a black and green colored connectors:hump:
3. remove your o2's the connector to you bike on the opposite side of the lock clip of the connector (pix)
4. heat sink them or elec tape (to keep water out a lite coat of petroleum jelly will do great.
5. plug your o2 holes with bolts youcan get at any auto parts store
6. now buy your PCiii or PCv for your ride.

The PCiii i bought at hard Racing for $265.00 add about 7-15 dollors for shipping/handling
I selected to get it without the O2 Sencors VFR 800 FI (Some models Requires (2) Oxygen Sensor Eliminator Kits)
I got the PCiii USB and they sent them(2 o2's) with the kit (i did not ask for them)
http://www.hardracing.com/POWERCOMMANDERS/HONDA.htm
alot of good stuff on this site (shipping was fast and order went through quickly)http://www.hardracing.com/Catalog.htm

 

I'm just doing mine ATM.
I have just cut through the catalytic converter box just behind the cat, then I drilled/chiselled the guts out of the cat, and now am waiting for a guy to reweld it.
I thought about cutting it at the front and putting in a new pipe with a Y join but it is critical to get the alignment of the exit pipe correct, and didnt want to stuff it up.

 

Got any pix of what you have did?

 

There are two ways that you can get rid of the cat and still use the stock headers. First is to cut the bottom half of the cat out, remove the catalyst inside, then weld the bottom part of the cat back on. This is the easiest to do as you never truly seperate the front and back of the headers and have alignment issues. However it is also less preferred as it creates an open area for air to swirl around in, create turbulance, and thus theoretically not giving optimal performance.

Second is to cut behind the cat, in front of the cat, and weld in a straight pipe. This is more optimal as there is no room for the air to get stuck in and swirl around... but introduces alignment issues if not welded correctly.

There is another option to the headers here that you haven't mentioned. You can in fact mount up a set of headers from a 98-99 VFR. The headers are slighly larger in diameter than those on the 6th gen (45mm vs 43mm), bolt right up without modification, and have no cat or O2 holes, The crossover on these pipes are different and they are not stainless steel, but they can be had for around $200. Im not sure if they have the stop for the center stand on them or not, but I do know that mine have the stop hose clamped on in the correct place. Not sure if this was factory for that year or not.

I scored my set of 5th gen headers for about $180. I chose this route as an alternative to the Motads and Dekelvics so that I did not have to mod the stock. I also might be going with PC5 and weld in a hole for the auto tune sensor... Not something I would want to do to a brand new set of Motads.

Hope this information helps.

 

The stock pipes actually cross in front and in back. Like Meatloaf said their are other options. Stock 98/99 headers are a good option as long as you live in an area that doesn't have a rust problem. Motad and Delkevicks both work well. I picked up the Delkevics for $275 shipped and they are stainless. They did take a little work to get the fit right.

Action

 

Here is a pic of the cat after I cut through the box. I am still waiting to get it back from the welder.
I have removed all the honeycomb material, which is tougher than it looks.

 

how u do it, torch, with long chizle and sludge hammer? thats what i've used

 

In the above post i knew a friend who has a plasma cutter
plus a arc welder i had a cutting torch my dad gave me. But you really need the Plasma touch for sure
(MELT, MELT, MELT, THE HELL OUT OF IT) Pay close attention on where to cut.
Just look where we cut it: look at and the gutted pix they show it well, plus look where it is attached.

 

thanks for the pics guys, I will have my second set of stock headers on tuesday and then I will give it a go. I'd like to weld in a new Y pipe but I will likely end up doing the gut. I'd really like to go from 4 to 2 all the way out.

 

All I can say about the Y-pipe is you must have the connection flange (Pipe) perfect or all After market mufflers and/or stock ones will be hard to mount. You would need to be a very good welder to pull this off. If you try this.....
My suggestion to this is weld two or three tack welds to the front of the cat and to the end of the pipes and then cut them with re-bar or some ridged medal that wont bend. You then need to weld in your y-pipes into the hole you just made, difficult but can be done (Need more than one set of hands here). i Have no pixs on this subject.
If you just gut them you should not have any issues of exhaust spin in that little area.
Remember when you gut them we(welder buddies) found out that cut around the cone welds and then melt away, once one comes out the other is very easy.
(((And of course i am waiting for some staintune's))) Go cheap one way to go expensive the other.
Good luck (take pixs and post) let's us know.

 

Running two pipes all the way back would be really rough. First you are going to run into space constraints trying to get two pipes back past the SSSA. Second you are going to run into problems going to each can on the back. Depending on which cans you are using would determine how rough this would be. Either way it is possible, but it would not be an easy task at all. I be doing something like that would take an easy 30 hrs of work to get two pipes back there and lined up correctly with any set of cans.

 

I've got a set of two brothers stash cans coming as well as a complete stock system. I may sell the two brothers depending on how I like the sound of the stock gut. Running two pipes all the way out is my ultimate goal but I don't think I have the skill to pull it off. If this was two years ago I would have access to pipe bending equipment and a better welder at my college. Not sure I can produce good enough welds with my harbor freight tig welder...I can probably weld the plate back on for the gut but i've never welded stainless with it. I'll have more insight when I get the exhaust tomorrow.

 

I Just got my bike back on the road. (custom Paint job)
The first thing i heard differant was the gutted cat sounded somewhat like hollow can while at idle and at some acceleration points sounds real bad.
if you get the chance and have the know how make the Y-pipe.
I am going to see if i can get my friend to open the cat back up and make a y-in there.
If you dont mind the sound change (it is not bad) the hollow can sound i mean, go for it.
it is smoother at lower speeds (assumeing better air flow)

 

Yikes, this isnt what I wanted to hear. Maybe I will go back and do the Y pipe....

 

Thats odd, mine sounds the same as it did before. ( I have Leo Vince cans no spud)

Sounds Beeyootiful.

 

I have 2 options as posted on other thread on cat gut.
1). Y pipe using the body of kitty as a jig to hold it all together.
2). a baffle w/ offset.
if anyone has stock header w/ kitty they want to donate to the cause I could do both at the same time and post the results
will pay shipping but for the header itself.

 

my motads came with o2 sensor bungs... :tongue:

 

I hope to get my Staintunes soon.
I think that the back pressure of the stock mufflers is part of the reason for the sound.
Restricting the flow and it allows it echo in the In the Kitty box untill you give it gas then it goes away (this is why i think it is back pressure) i would still suggest getting a y-pipe in there.

I also did remove the Snorkel and yes it does give a louder sound around the intake. (does it help?)
If you dont care about the sound keep it off, but from the specs that i saw posted i am going to put mine back on.
(NOTE: the sound is not bad don't get me wrong i like altering the intake sound.) To me though it dont sound right for a bike. i would rather here the sound out the exhaust not the intake.

The PCiii did round out and smooth up the lower speed of it jerking around. (very much recommend it!)

 

Is there a noticeable power difference after the cat gut, i have seen the pro's and cons but not much relating to the gains was wondering if the hassle is worth the gains... Any feedback would be appreciated

 

I cant really answer your question because I havent had the bike on a dyno.

I have no regrets however, because it does seem to spin up faster, and there does seem to be a bit more torque around 4000, but that is a subjective assessment.
You will, however need a different PC3 map, although the original one worked OK but was a bit rich, if fuel economy is an issue, but it was very gutsy on that map.
Sometimes, now, I cant even detect the vtec transition, but that could be more to do with the PC3 map.
I dont think that large power gains are to be had, even with motad headers if you look at dyno runs from people that have fitted them.
However, the bike stays cooler, the exhaust certainly stays cooler, it sounds the same as before, maybe a touch louder but not noticably louder, and I dont have to worry about the cat fouling up due to the absence of PAIR etc. and I have saved about $800 (cost of Motads in oz is about $1K)

Summing up, I would say its a reasonable compromise to buying a set of Motads if you dont want to spend a grand, and you keep your nice stainless steel pipes (as opposed to headers from 5th gen), but if you're flashed with cash, the Motads are the obvious choice.
Just my 2c.