removing pre-cat and cat on '07 S3

[jpeake]

I'm thinking of getting a PC3 and having a local shop do a custom map for me. I have the TORs and TORs tune, but would like to squeeze out all I can up to a reasonable $ amount

I see Devious has posted extensive info on some header and midpipe mods but most of it is over my head.

Here's what I have gathered, please correct me if I'm wrong:

there is a pre-cat in the collector part of the header that can be removed with a little know-how. The midpipe on the '07 contains the catalytic converter and that can be swapped with a midpipe from a '05-'06.

My plan of attack would be as follows, does it sound logical:
1) remove the header, take it to a local shop (maybe a HD shop) and have them drill out out the pre-cat, weld up the holes, and smooth out the welds. (does an hour or two of shop time cover this?)

2) Find a midpipe from a '05 - '06 on ebay or the board

3) have the header and midpipe ceramic coated (there is a shop nearby that does good work for around $125)

4) BMC air filter

5) off to moto fuel for the PC3 install and dyno tune.

Am I missing anything? Has anyone done these mods and have feedback (in terms that I will understand!)?

My goal is to get the most out of the low to mid range. Some guys on another board have dyno charts showing some very impressive mid range torque gains with what sounds like fairly mild mods (although I don't know how to do much myself so would have a shop do it)

Thanks for your input.

[cheapbastard]

jpeake, have you considered a midpipe system? Like possibly the chainreactions, trident, or arrow twin can setup? This would eliminate the precat in the 07 since it is in the midpipe. Also, are you sure you have the 07 midpipe? You can tell this by whether or not yours has the funky looking heat shield at the bottom of the midpipe. You could possibly still have the old midpipe though. Alot of the early 07's came with the old style midpipe.

[jpeake]

oh, i thought the pre cat was in the header.

I do have the heat shields.

Looks like the midpipe comes off easy with a clamp at each end. If i were to remove it, can i just look inside to tell what I have?

[jpeake]

i hadn't considered another exhaust. I thnk the wife would shoot me. I just got the TOR's with the bike (not even a month old)

Not sure new pipes would fly real well!!!

[cheapbastard]

here's a pic of the heat shield I am talking about, the one at the joint of the header and the midpipe, the big ass shiny piece...



if you have that, you have a true 07 exhaust with the precat in the midpipe, I believe. I could be wrong because I don't have an 07 to verify this, but I've heard that the precat is in the midpipe on these a numerous amount of times. Would be nice to see an 07 owner verify it. :wink: :-D

[ This message was edited by: cheapbastard on 2007-05-15 10:16 ]

[jpeake]

On 2007-05-15 10:15, cheapbastard wrote:
here's a pic of the heat shield I am talking about, the one at the joint of the header and the midpipe, the big ass shiny piece...

if you have that, you have a true 07 exhaust with the precat in the midpipe, I believe. I could be wrong because I don't have an 07 to verify this, but I've heard that the precat is in the midpipe on these a numerous amount of times. Would be nice to see an 07 owner verify it. :wink: :-D

Yep, that's what I have. So is there a pre cat and catalytic converter all in the mid pipe? So rather than fooling with the header I could just have the midpipe cored out right?

If i were to remove the midpipe and take some pics inside the front and rear openings would you be able to tell what's in there? In some pics by Devious on that blue speedy the pre-cat is clearly visible in the collector after the midpipe was removed.

I will take mine off and take a look, and take some pics.

[jpeake]

looks like you can buy just the Arrow midpipe for $199


hmm.... i wonder if that would link up to the TORs.....

[Litlgi74]

Hey jpeake...

I also have a 07 S3 with the new heat shield.

As you can see the mid-pipe is not the same as the 06 version...
The reason I am showing this is because some 07 models come with an 06 mid-pipe. You just need to check to see if your O2 sensor is part of the mid-pipe or if has been placed in its new location near the oil filter.

If you do have the new style mid-pipe... You will have to wait a bit to get pipes from Chain Reaction :???: . Bob is currently trying to see if he can make his mid-pipe work on my new 07 exhaust. Because not only has the mid-pipe changed. The header has also been shortened.

This stinks... because I have owned a 07 S3 for almost a month now... and haven't put a mile on it. I won't ride her until my vision is complete. CRM pipes are so cool I just had to buy a S3 to put them on!

Just look under the exhausts skirt to see where and what you will be modding.

John

[HarriS]

Show us what is inside the new midpipe. Is there a cat or what?

[Litlgi74]

I will take some photos for you on Thursday... Still waiting to get my mid-pipe back from Bob (Chain Reaction Moto).

I think I remember seeing a very tight coil of what looked like a metal ribbon inside the new collector of the mid-pipe.

Will get back with you.

John