Exhaust upgrade questions

[Silver71]

I guess the main question I have is when upgrading exhaust, do people keep the stock O2 sensor setup? When I look at downpipes and aftermarket exhaust systems, they don't always mention whether or not it has a bung for an O2 sensor or not. I'd like to keep my car as street-able as possible.

For example, I need a new cat-back system. While I'm at it, I'd like to get a high-flow cat (I do NOT want to run a test-pipe, and I'd rather not re-use my stock cat, as it has 121,000 miles on it). Since I'm doing that, I may as well upgrade my downpipe and get the whole shebang done, 3".

Now, there are O2 sensors somewhere, there is at least 1 under the car (I know because mine is leaking...) Which systems can I buy to utilize the stock O2 setup?

I would like a downpipe, high flow cat, and cat-back exhaust, 3".

On the RRE website, they have downpipes and high flow cats. I believe I'd need the short DP with the Cat, but what is this business about the EVO O2 housings? What do I need? And that only bolts up to A'PEXi N1 and a few others. If I used my stock cat, would any brand bolt up to it? What dimensions is my exhaust stock? 2.25?

Then again MAP has the A'PEXi N1 downpipe, but again, I have no idea about the O2 housings.

I guess I'm wondering what other people usually do for their setups? I'm guessing a lot of people just get a long downpipe and bolt it straight to a cat-back exhaust huh? But what about the O2 sensor? And no Cat?

 

[idkiliketurbos]

Pretty much every downpipe made for your model car will have the o2 sensor bung. If you don't have emissions testing where you live I personally would run a cat-delete downpipe straight into a catback. You will most likely get a check engine light from the rear o2 sensor telling the car that there is not a functioning cat, but there are ways you can get around this if the check engine light bothers you.

 

[Archer Fabrications]

The megan dp doesn't come with a bung, I'm in the stock location though using narrowband sim.

 

[idkiliketurbos]

The megan dp doesn't come with a bung, I'm in the stock location though using narrowband sim.

Are you talking about a bung for wideband or the rear o2 sensor that goes after where the cat should be? If so, I did not know that megan didn't have a bung in their downpipe.

 

[FIBA M - EC17PSE]

almost every exhaust system will have a bung for your o2 sensor at the rear unless its made custom and you dont want one! the DP is also dependent on brand for bungs etc as i have seen brands come with one for widebands and egt sensors but on our cars no brands have that option!

on the length section they are either cat deletes or a cat bolt on so if you want a cat or race cat then you need a DP that will not eliminate your car! if you want 3" then go with a magnaflow cat and have some some custom weld flanges on for you.

the o2 housing will always have a bung for an o2 sensor whether its higher up or in the stock position they are a good upgrade and even the evo3 o2 housing will work for you as no one makes a 3" o2 housing thats mitsu flanged now so its either custom or just get a 2.5" which will be plenty enough. i have the punishment racing unit but if i had the extra money at the time i would of 100% got the JMFabrications unit as it just looks amazing and quality seems a little better,

before you go 3" all the way through check this link out on boost creep just so you know what it is and understand what problems with a 3" system can cause. if your on the stock t25 its not that bad but still read anyway http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html

http://www.dsmtuners.com/forums/bolt-tech/109324-finally-going-explain-boost-creep.html

 

[sauminator]

I would go Evo III o2 housing, rre short downpipe (so you can keep cats), and an apexi n1 exhaust. These will all work in conjunction.

 

[AK Maniak]

Thermal R&D cat back fits the stock cat and it is IMO the best sounding cat back for DSM's.

 

[99ECLIPSEGSXDSM]

I run RRE downpipe with a test pipe (swap to a high flow cat for emissions) with a Apexi n1 catback. Love the sound but thermal sound amazing as well. Keep in mind that most downpipes for dsms start out at 2.5 untill the flex pipe then 3 inches back.

 

[Silver71]

Thanks for all the helpful tips on this. I've got things to think about. Mainly, how I don't want boost creep and def. don't have the bits to port and polish with right now.

You know, I think I'm fine with 2.5" to 3" after flex. If you haven't seen my other thread, I'm only shooting for 350 reliable horsepower for my DD. I just want quality parts and to do it right. I'm not sure that an upgraded o2 housing is what I'm ready for just yet. But downpipe and cat-back are easy. Will keep things updated as time progresses.

 

[99ECLIPSEGSXDSM]

Thanks for all the helpful tips on this. I've got things to think about. Mainly, how I don't want boost creep and def. don't have the bits to port and polish with right now.

You know, I think I'm fine with 2.5" to 3" after flex. If you haven't seen my other thread, I'm only shooting for 350 reliable horsepower for my DD. I just want quality parts and to do it right. I'm not sure that an upgraded o2 housing is what I'm ready for just yet. But downpipe and cat-back are easy. Will keep things updated as time progresses.

If your shooting for 350 I would go for a 50 trim turbo or a mhi 20g. If you don't want boost creep I suggest you get an external wastegate also.

 

[AWD1997TALON]

If you are sticking with a cat boost creep should be manageable with the 3" system. Porting is a good plan. That said 2.5" is adequate for 350hp.

Even if a new exhaust doesn't have a bung adding one is cheap. As long as the sensor angle is correct any decent welder can do it.

My 3" Megan Turbo cat/back did have a hanger installed in the wrong position which meant that the installer had to relocate it. That added cost offset the good price that I had originally bought it for.

 

[etalon75]

Need answers on where I could get a good priced cat back and header for a 420a that will perform and sound good at the same time.

 

[AshyBone]

I'm glad the theramal r&d is getting so many good reviews. It's what I'm going to be aiming for. On a side note as well punshment racing has a true 3" downpipe.
PUNISHMENT RACING 3" DOWNPIPE FOR ECLIPSE/TALON - Punishment Racing
Don't know why this isn't mentioned yet.

 

[Silver71]

Hmmm... punishment racing downpipe does not fit the stock O2 housing though...

I think I will focus on a downpipe that starts 2.5" and widens to 3" after. Even if I do get a different o2 housing in the future, there are ones that bolt up to 2.5" or 3" either way. Seems like the best route for me.

 

[turbolover10]

Thanks for all the helpful tips on this. I've got things to think about. Mainly, how I don't want boost creep and def. don't have the bits to port and polish with right now.

You know, I think I'm fine with 2.5" to 3" after flex. If you haven't seen my other thread, I'm only shooting for 350 reliable horsepower for my DD. I just want quality parts and to do it right. I'm not sure that an upgraded o2 housing is what I'm ready for just yet. But downpipe and cat-back are easy. Will keep things updated as time progresses.

You would be fine with 2.5" piping all the way back at the HP range. Having it 2.5" before the flex section isn't going to hurt you one bit I wouldn't worry about the o2 housing just yet.

PS. I've never had creep on a t-25, just sayin.

 

[Silver71]

You would be fine with 2.5" piping all the way back at the HP range. Having it 2.5" before the flex section isn't going to hurt you one bit I wouldn't worry about the o2 housing just yet.

PS. I've never had creep on a t-25, just sayin.

That's good to know. I think I can go ahead and upgrade my exhaust now then, and worry about porting/upgrading o2 housing after I upgrade my turbo.

 

[turbolover10]

That's good to know. I think I can go ahead and upgrade my exhaust now then, and worry about porting/upgrading o2 housing after I upgrade my turbo.

Eactly

The 2g manifold and o2 housing can be ported significantly too so if it where me and those where my HP goals I would pick up an EVO 3 16g and the tools to port the Turbine on the EVO3 16g. "There's plenty of DIY's out there for this." while there off and you have the tools get to porting the manifold and 02 housing and you have yourself a turbo upgrade and full exhaust. This is assuming you've done all the necessary maintenance and 350 is your ACTUAL goal. Most of us want more but for a stock build I think thats the perfect way to go!
I ran 12's in my talon powered evo3 16g and it was a blast! Spool was incredible and pulled hard.

Another option is to do all your bolt ons before the turbo upgrade so you can handle the boost level of
25-30psi

 

[DSMbabyy]

Thermal R&D cat back fits the stock cat and it is IMO the best sounding cat back for DSM's.

SOOO TRUE!!


and worst case senario, any exhaust shop can add a o2 bung for you for a few bucks if your new exhast doenst have both

 

[Silver71]

Eactly

Another option is to do all your bolt ons before the turbo upgrade so you can handle the boost level of
25-30psi

THIS. I plan to do my supporting modifications first, ending up with the turbo upgrade/porting. I'm still in the planning phase though

 

[aajj1987]

just my 2 cents my exhaust shop that I go to removes cats on my personal vehicals for me but hes got a magnaflow high flow cat and a stock cat off my 96 corvette on display cut in half and there is no difference... I repeat no difference in the interior design. now im sure other brands make do different setups and all but if your going aftermarket cat IN MY OPINION just get a cheap one from a parts store instead of spending the big bucks. it will serve the same purpose and be cheaper. but that's just my 2 cents I got 3 inch from the housing back with crush bending and it flows awesome to me. mandrel bending isn't worth the money till you get to the 400 hp range from the flow tests ive seen on my lt1z28 when we did the befor and after pulls... ill see if I can find the dyno charts to post just for visuals

 

[Smeed78]

When my car was finally running again it this summer I put the megan racing 3 inch downpipe on (yes 3 inches as it is the version 2) and I had already had a greddy exhaust but it was 2.5 inches and the small exhaust leak where the pipes met up was super annoying. After some researching I purchased a thermal system from SIM and had them cut off the 2.5 inch inlet and weld on a 3 inch stainless inlet. It came out perfect and sounds mean. My rear o2 sensor is in but had to be disabled in dsmlink as it was throughing a code triggering the check engine light. Just getting that different exhaust made a suprisingly noticeable difference. And best of all the thermal system literally bolts right up, no problems.