ClubWRX Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
344 Posts
Discussion Starter #1
Can anyone comment from experience on how much of an issue it is to pass inspection with a catless downpipe in Pennsylvania?

My dealer (Colonial Subaru) offers free lifetime inspections. Any experiences that relate directly to this dealer would also be helpful. I could take it somewhere else if I had to...BTW, its a 2012 WRX hatch.
 

·
Registered
Joined
·
280 Posts
I live in philly. I've had my downpipe (catless) and exhaust for about 2 years and haven't had any problems.
 

·
Registered
Joined
·
344 Posts
Discussion Starter #4
I live in philly. I've had my downpipe (catless) and exhaust for about 2 years and haven't had any problems.
Did you have to get inspected at a specific shop?
 

·
Registered
Joined
·
902 Posts
It depends on what county you live in. We have visual inspection here but the next county over has none. I have someone that just throws a sticker on for me so I could run catless but didn't because of the smell and possible over boost issues.
 

·
Registered
Joined
·
344 Posts
Discussion Starter #6
Yeah, I got the itch to go Stage 2, but funds are tight. So, it'll be catless for a little bit.
 

·
Premium Member
Joined
·
4,376 Posts
It depends on what county you live in. We have visual inspection here but the next county over has none. I have someone that just throws a sticker on for me so I could run catless but didn't because of the smell and possible over boost issues.
This is only partially true. Every county should have the anti-tampering check to my understanding. Just depends on what inspection that it is part of.

When a county does not have emissions requirements, the anti-tampering (visual) check is moved into the safety inspection to my understanding. For example, on my safety inspection print out, it is marked as 'N/A' on the anti-tampering check criteria because it is done in the emissions check. Either way, unless your car is >15 years old, it 'should' be checked for all the normal stuff (air pump, cats, cut outs, etc).... Whether a specific shop actually performs the inspection as it should, well, that seems to be a grey area in some cases.

I read through all the source documentation I could find, and that's what I came up with at least. I think I found evidence of the above in both the emissions paperwork and the state safety inspection process.
 

·
Good news, everyone!
Joined
·
3,856 Posts
Yeah, I got the itch to go Stage 2, but funds are tight. So, it'll be catless for a little bit.
If you're saying you're going to put the downpipe on without tuning, I'm going to advise you against it. You will have a much higher risk of engine damage if you do this.
 

·
Premium Member
Joined
·
4,376 Posts
If you're saying you're going to put the downpipe on without tuning, I'm going to advise you against it. You will have a much higher risk of engine damage if you do this.
+ 1. You will probably over boost first time you floor it.. And your engine will most certainly knock all over the power band due to the now excessive timing.

... Highly advise a tune as well.

Even after playing with mine for a while I am still over boosting with my catless down pipe. Had to pick up and Ewg kit for it. Even at just mechanical spring pressure I was getting 18psi of boost by 5k.
 

·
Registered
Joined
·
344 Posts
Discussion Starter #10
+ 1. You will probably over boost first time you floor it.. And your engine will most certainly knock all over the power band due to the now excessive timing.

... Highly advise a tune as well.

Even after playing with mine for a while I am still over boosting with my catless down pipe. Had to pick up and Ewg kit for it. Even at just mechanical spring pressure I was getting 18psi of boost by 5k.
Maybe I should have specified, but i'm going to run a TP Stage 2 tune for the DP....
 

·
Premium Member
Joined
·
4,376 Posts
Maybe I should have specified, but i'm going to run a TP Stage 2 tune for the DP....
Sounds good. Make sure the tuner knows it's a catless down pipe if you go that route. Be careful in the cold and keep an eye on your boost gauge =). Your car may be okay with one. It seems that it's 50/50 with boost spike/creep issues with 'em.

Enjoy =)
 

·
Good news, everyone!
Joined
·
3,856 Posts
Maybe I should have specified, but i'm going to run a TP Stage 2 tune for the DP....
It isn't so much which tune you're going to use that I'm worried about, it's whether or not you're going to drive around with a catless downpipe without a tune for a while. When you install the downpipe the tune needs to be done ASAP. Your post made it sound like you planned on driving around with the downpipe installed and waiting for a tune.
 

·
Registered
Joined
·
510 Posts
i have a quick question.... full catless turboback + accessport = no issues? or is a tune still a must to avoid overboost and engine issues
 

·
Premium Member
Joined
·
4,376 Posts
i have a quick question.... full catless turboback + accessport = no issues? or is a tune still a must to avoid overboost and engine issues
It's at least safer in terms of timing and normal driving =).

As far as waste gate duty cycles and such, it's probably way off still. I could be wrong though.
 

·
Registered
Joined
·
510 Posts
It's at least safer in terms of timing and normal driving =).

As far as waste gate duty cycles and such, it's probably way off still. I could be wrong though.
and what would i have to do to avoid those issues?
 

·
Premium Member
Joined
·
4,376 Posts
and what would i have to do to avoid those issues?
If you can log data, log a third gear pull from 2k-5k or 2k-redline (if you have a boost gauge to watch). Make sure to log boost pressure or manifold pressure, wgdc (waste gate duty cycle), and all boost corrections (on mine its proportional and integral - different models vary).

It's not too hard to determine, but you have to do some thinking if you aren't familiar with it. Basically if your negative wgdc correction maxes out, and your boost doesn't drop as you approach your higher RPMs, you are having some boost creep issues. The car is trying to lower the boost solenoids duty cycle to allow more air to get to your waste gate actuator - when more than ~9psi presses on it, it should open and allow air to bypass the turbine. So as you lower the duty cycle, you are lowering the amount of air that is 'with held' from the actuator diaphragm, and preventing air from bypassing the turbine.

I'd expect some fairly large corrections. Hopefully it's not too bad though. Not having a cat really messes with the waste gate without a specific tune for it. Fixing the timing and such though with a standard stage II tune is a good thing at least.

I'm not a professional tuner by any means by the way. Just what I have picked up so far from books and my personal experience.
 

·
Registered
Joined
·
510 Posts
i have some serious reading to do because i really didnt follow much of what you said. still a n00b when it comes to all of this
 

·
Premium Member
Joined
·
4,376 Posts
Few more goes at the explanation.

Boost pressure is just a restriction. You need air mass, not pressure.

A wastegate is what it sounds like. It opens a gate to allow unwanted air to bypass the turbo turbine. Less air over the turbine, slower compressor speed.

A boost control solenoid controls the amount of pressure the waste gate actuator sees. If it's off, the waste gate sees the manifold or boost pressure. At full duty cycle, the wastegate actuator thinks the engine is still in vacuum. Hence will not open.

The issue with the wastegate and going catless... The amount of air going through a waste gate is highly dependent on any resistance. That's why external wastegate setups dump it right by the gate. The difference of having a cat or not will be most apparent when working with the wastegate due to the mild change of airflow resistance

... Hopefully helps the big picture a bit. It is a lot of info though.
 

·
Registered
Joined
·
510 Posts
Few more goes at the explanation.

Boost pressure is just a restriction. You need air mass, not pressure.

A wastegate is what it sounds like. It opens a gate to allow unwanted air to bypass the turbo turbine. Less air over the turbine, slower compressor speed.

A boost control solenoid controls the amount of pressure the waste gate actuator sees. If it's off, the waste gate sees the manifold or boost pressure. At full duty cycle, the wastegate actuator thinks the engine is still in vacuum. Hence will not open.

The issue with the wastegate and going catless... The amount of air going through a waste gate is highly dependent on any resistance. That's why external wastegate setups dump it right by the gate. The difference of having a cat or not will be most apparent when working with the wastegate due to the mild change of airflow resistance

... Hopefully helps the big picture a bit. It is a lot of info though.


i think i follow you... for the time being (mainly due to money constraints) i have to go with just the up pipe, tbe and AP. no money to go with an external wastegate. but i see that may be next on my list.
 

·
Premium Member
Joined
·
4,376 Posts
i think i follow you... for the time being (mainly due to money constraints) i have to go with just the up pipe, tbe and AP. no money to go with an external wastegate. but i see that may be next on my list.
Hopefully not. Depends on the car. You'll enjoy it though :)
 
1 - 20 of 23 Posts
Top