street unit vs corksport testpipe

[STEALTH_MPS]

hey guys had a look on here about test pipes and didnt really come up with much. Just wanna know is there any difference in the street unit testpipe compared to the corcksport one? or can one just be made up instead of sourcing it from overseas.

I also heard they are illegal? is this true??

just not really wanting to go down the whole exhaust path yet and was thinking just getting a testpipe and removing one of the resonators or both the resonators.

cheers
chris

[AD07]

The test pipe basically just removes your 2nd cat, any exhaust shop will be able to do that for you.

[STEALTH_MPS]

Sweet thanks for that. Another thing but. What is the size of the stock piping? And should i go 3" or stick to the stock sizing for the pipe????

[LYNCHY]

I asked my local shop to do this...They said theyve already done 3 and all got CEL's ....yet ive never heard of anyone getting one from either the Streetunit or coksport!

You dont have to source from overseas as MPS garage stock them http://www.mpsgarage.com.au/shop/pro...race-pipe.html

[tricache]

I know Corey ran a race pipe for a while, forgot what brand, but the are SUPER loud and good luck with passing the decibels and emissions test.

[Dark Authority]

..i was actually planning to this with my NA 3. From just looking under the car, i wont understand why deleting the2nd cat would cause aCEL. There are no sensors near is.. soo=S

According to mazda3forums, gains for an NA with aftermarket exhaust can be anywhere from 4HP to 9HP

[STEALTH_MPS]

Hmm the street unit pipe says u wont get any cells. Ive heard a few on youtube with the test pipe and one of the resonators and it doesnt really sound loud at all

[MattMPS3]

The "race pipe, or test pipe" ONLY deletes the second cat, no mufflers are removed, the sound is barely louder than stock, it does improve throttle response a bit and the car doesnt feel like its choking as much. You shouldnt get a CEL from this mod as the removed cat is not monitored by the ECU, only the primary cat has a narrow band o2 sensor behind it to measure emmisions targets, the second cat is more of a backup in case the first unit fails.

As far as the legality side of things, the camps are divided, many believe that because the car was released with 2 cats, both must remain for compliance reasons, this is partially true, but at the time of release Australia was adhering the older Euro emmisions standard (stage 3?) which could pass with only one cat. The car was designed and manufactured to comply with the stage 4 standard, which required 2 cats.

Be wary though, of the aftermarket race pipes available, some don't have the correct flanges that mate up to the stock items, subsequently these dont allow the join to pivot as it should, you would be better approaching a shop and asking them to make one up from your existing cat.

[Rooballer]

What about if you were to replace the second cat with a high flow cat.
Would that not give a similar outcome, with out of any of the potential issues associated with deleting the second cat.

[STEALTH_MPS]

So itll probably be cheaper to get one custom made then to source a branded one?

Is anyone on the forum running one or used to run one that can give feedback on it??

[MattMPS3]

I would like to think so, its only really a length of 2.5" pipe, plus some hangers, then welded up to the old flanges.

[Jmac]

So itll probably be cheaper to get one custom made then to source a branded one?

Is anyone on the forum running one or used to run one that can give feedback on it??

Hey Chris,

Im also thinking of doing this, when I get some spare time im going to head down to livo exhaust and see what they can do and how much.. GB? lol

*Edit, my goal is to get the pipe flanged and the stock exhaust flanged so I can swap them if need be.

[STEALTH_MPS]

Hey justin thats where i was planning to go as well.
Not keen on swapping the whole exhaust if it doesnt really give u any gains for the price so just gonna go for a more meatier sound n still be able to swap it back to stock wen needed

[Dark Authority]

yeh..thats exacty what i have planned. I have a resonator back exhaust in my garage and also have the flange + 2ndary car off another mazda 3. I was just gonna modify that so my stock exhaust stays in 1 peice..=D

[Jmac]

Lemme know when your keen

[STEALTH_MPS]

so 2.5" is the stock size. is there any benefit of going 3" instead or better sticking to stock?

[2XS]

The stock system on the 3 MPS needs to be cut off in front of the rear crossmember. You'll need to have it flanged if you want to refit it at a later date. I'd say replace the large centre muffler with a straight through design and delete the second cat if you want more sound, Power, now thats something totally different.

The 2 cat setup is "legally" required if your car came out with 2 cats. They even have to be in the same location. Generally the DOT don't check this, all they care is that you have atleast 1 cat. Only time will be the decider on when they chose to implement the official ruling. NSW and Vic seem to be slowly enforcing the movement of the cat laws.

Changing the pipe from 2.5" to 3" in just the cat section won't give any noticable gains.

Also removing the 2nd cat shouldn't cause any CEL. The MPS has 2 O2 sensors, 1 to measure the AFR before and 1 for after the cat. You will only get a CEL if you remove the first cat and not move the 2nd O2 sensor.

As commented above, get the correct flanges/joint fitted and you won't have a problem.

[Rooballer]

High flow cat?

[DISIMS3]

I was told by an exhaust shop that the flanges / gaskets were hard to obtain / expensive because they are not standard. So making a bolt in mid-pipe not so easy?...If it this isn't the case and anyone knows someone willing to produce a few for the MPS 3 can they send me a PM?

[STEALTH_MPS]

The streetunit test pipe has the flanges already so its a direct bolt on. Thats what it says on their website