Stock Header Cat Gutting ?

[ngr2001]

Has anyone cut open the cat and gutted it yet on their stock headers. If so would love to see pictures. I am mainly interested in how the bike sounded after this mod. Were there any negative side effects ? I've heard people recommending welding in some pipes in a X configuration after gutting the cat, but that seems like it would be very tricky. Would it be bad to simply seal the cat back up and leave as one large open chamber ?

Thanks.

 

[sixpack577]

I gutted a stock gen2 converter, and the results were as expected, low rpm power loss with high rpm gain.
A very noticeable lag in low rpm throttle response, as the converter leaves a big empty chamber needing to be pressurized.
Exhaust efficiancy is based off of exhaust gas pulse timing, and to have each one push the next out, without any blockage, or open area for them to collect before being forced into the rest of the pipe.
The flow is disrupted too much.
Dyno tuning would improve it, but it would still be poor performing.

 

[ngr2001]

I understand what you are saying, but is then the same also true for an aftermarket set of headers and pipes say from Brock's. All aftermarket designs by in large are simply strait pipes, even with a tune are they going to suffer with low rpm lag for the trade off of high rpm gains ?

 

[sixpack577]

I understand what you are saying, but is then the same also true for an aftermarket set of headers and pipes say from Brock's. All aftermarket designs by in large are simply strait pipes, even with a tune are they going to suffer with low rpm lag for the trade off of high rpm gains ?

No, as the pipes are tuned to run well throughout the entire rpm range, with other factors coming into play.
Turn a converter into an empty box, and not so much.
Try it for yourself...and come back and let us know...

 

[ngr2001]

so what if I welded in some pipes inside the empty void of the cat, ideally in a X configuration.

 

[ngr2001]

I should also mention that I do have the Woolich ECU tuning box with the wideband 02 sensor. So in either setup I could tune the bike as needed.

 

[sixpack577]

Now you're talking.
So long as you continue with the same pipe diameter, it will be worth doing.
The x-pipe is a good idea to balance the 4 downpipes, and it'll flow better than an H-pipe.
You will get a hp gain, not quite as much as an aftermarket header, but for free, just having the converter gone will noticeably lower the amount of heat around your feet...as we know those things get Hot!
And of course the Woolrich will get your a/f ratio where it needs to be.
If you do this, please post some pictures and let us know how it all turns out.

 

[Ked0607]

Now you're talking.
So long as you continue with the same pipe diameter, it will be worth doing.
The x-pipe is a good idea to balance the 4 downpipes, and it'll flow better than an H-pipe.
You will get a hp gain, not quite as much as an aftermarket header, but for free, just having the converter gone will noticeably lower the amount of heat around your feet...as we know those things get Hot!
And of course the Woolrich will get your a/f ratio where it needs to be.
If you do this, please post some pictures and let us know how it all turns out.

there are kits now from fleabay to add sc project dual cans and cut the factory cat out and put a x pipe in. I was shocked. Looks like temu or wish quality kit but they are out there.

 

[Bumblebee]

How heavy is the stock header system?

The biggest gain in going to an aftermarket system is weight loss....

I believe we had this conversation in another thread and it was deemed it to be a lot of hassle to cut out the cats on the Gen 3 header and far easier to get a complete system.

 

[sixpack577]

I have seen the gen2 converter delete kits on ebay, and they look worth it to me.
I gutted the one on my gen2 years ago because the heat from it was cooking my feet.
The results were as expected, but the heat was gone, and that was while I saved for the full dual Akropovic I put on it.
Had there been a kit like that then, to where I make 2 straight cuts with a recipricating saw, and clamp on an x-pipe, that would have been a very simple solution.
As the gen2 converter was a pain to gut out, and I don't see the gen3 being any easier.
But, to just cut 2 pipes on the gen3 to remove the converter, and clamp on an x-pipe, that should be a simple fix for excess heat, and a few more hp.
Keep in mind the gen3 has a convereter in each muffler too, but there is a thread here showing a member removing them, and it didn't look too bad of a job either.
If I had a gen3, and didn't have full exhaust money, it would be a cheap and easy option to knock the heat down, and maybe feel a small gain at a certain rpm range.
My only concern with that is at what point may someone need to stock exhaust for resale, or more importantly, emissions and future laws if you want to continue to be able to street ride it.
If you look back at the Gen1, or any bike really, and usually years later, alot of people want stock bikes with stock exhaust, or at least the ability to put them back to stock.
Just something to consider.

 

[ngr2001]

Hmm, thanks for all the suggestions. I may give this a go.

The main reason is not cost though, simply put, there is no full dual exhaust kits on the market for this bike, real tragedy.

I already have the Dual Yosh R77 Carbon Fiber slip-ons, they are in my opinion one of the best looking cans ever made. I simply want to keep the dual exhaust look, but at the same time gain some exhaust decibels. The R77 cans sound good but are not very loud with the pure stock header. I have a GSXR 1000 2007 with a full dual exhaust and it simply sounds mean in comparison. I have to revise another post, but I did try the Black Widow headers but now I am no longer liking those. The sound character started to sound just off to me and I kept developing exhaust leaks and minor fitment issues, such as the pipes wanting to migrate towards the oil pan and rub against it. I am having none of those issues with the stock header, they simply fit as they should, perfect.

I live in NJ where we have both a ton of traffic and deer. I've already bit hit by a car and a deer while riding hence why I feel the need to have a loud exhaust, I need people and creatures to hear me before they see me. I can imagine how people are riding electric motorcycles and staying alive out there.

What I will likely do here is buy a stock header from ebay, bring that to a machine shop and have them gut and weld in an X pipe. This way I have a perfect fitting header, with the bonus of no restrictions, mated to my dual R77 Slips of course. At that point I would probably call that setup a full exhaust. Will back that up with the Woolich to unsure the tune matches etc.

 

[sixpack577]

You Can buy Gen3 Yoshimura full dual exhaust from Webbike Japan.
They ship to the U.S.

 

[sixpack577]

Max-Torque and Black Widow, both in the UK also make full dual Gen3 exhaust.

 

[ngr2001]

Wow, you can actually buy the full dual Yosh now, good to know. Just took a look. Comes in at almost 4 Grand and still retains a CAT and you loose the passenger pegs. That price seems a little egregious if you ask me. Also I really want to keep my cans that are full carbon fiber, simply for the look.

 

[sixpack577]

Wow, you can actually buy the full dual Yosh now, good to know. Just took a look. Comes in at almost 4 Grand and still retains a CAT and you loose the passenger pegs. That price seems a little egregious if you ask me. Also I really want to keep my cans that are full carbon fiber, simply for the look.

@Ked0607
He has a gen2 full dual Yoshimura on his gen3, and he gutted the catalyst in the x-pipe, it also wasn't $4k
He can give you the details, it looks awesome.

 

[Ked0607]

@Ked0607
He has a gen2 full dual Yoshimura on his gen3, and he gutted the catalyst in the x-pipe, it also wasn't $4k
He can give you the details, it looks awesome.

It was close to 4k after the taxes duties and shipping

 

[Ked0607]

Wow, you can actually buy the full dual Yosh now, good to know. Just took a look. Comes in at almost 4 Grand and still retains a CAT and you loose the passenger pegs. That price seems a little egregious if you ask me. Also I really want to keep my cans that are full carbon fiber, simply for the look.

You can keep the pegs Im sure That is a yosh accessory they are showcasing.

 

[pcs]

another option