08 OBXT: To downpipe or not to downpipe

[Subytech]

Ok I kinda feel silly asking because I'm sure the answer is yes, but would it be worth throwing a downpipe on the wife's 08 OBXT even though we plan on keeping the stock catback? She hates the sound of exhausts on cars with automatics and it is our "date night" car so we want to keep it quiet. I plan on getting it tuned soonish just because I hate the factory tuning (she even notices the car pulling timing at part throttle under load on the freeway even though she doesn't know what it is lol)

[jrho]

Ok I kinda feel silly asking because I'm sure the answer is yes, but would it be worth throwing a downpipe on the wife's 08 OBXT even though we plan on keeping the stock catback? She hates the sound of exhausts on cars with automatics and it is our "date night" car so we want to keep it quiet. I plan on getting it tuned soonish just because I hate the factory tuning (she even notices the car pulling timing at part throttle under load on the freeway even though she doesn't know what it is lol)

 

I'm going to be putting on a cobb downpipe pair with the factory catback. I only want some increase exhaust noise and to free up a bit of power so I'm going this route. The stock catback probably will hold back a bit of power but like your situation, I wanted to keep things quiet. Seems like an upgraded catted downpipe should be your best choice

[Rhitter]

No, not really. Yes there is a decent amount more power. The stock catback isn't a restriction.

 

But if you just want to smooth out the tune, just get it tuned as it sets. It's a pretty noticeable and better change.

 

Going to a downpipe gives you a bigger torque hit. And also opens you up to more potential for a blown engine.

 

What are you goals? What are you trying to accomplish with a downpipe?

[Subytech]

I'm going to be putting on a cobb downpipe pair with the factory catback. I only want some increase exhaust noise and to free up a bit of power so I'm going this route. The stock catback probably will hold back a bit of power but like your situation, I wanted to keep things quiet. Seems like an upgraded catted downpipe should be your best choice

 

This is really what I was wondering about. A little more noise would be nice but not so much that the car obviously has a catback but enough that people might take notice. And who doesn't want the added power and response of the downpipe.

 

I guess my question should have been, are the power and response gains worth just doing the downpipe, especially since I plan on getting it tuned, and will it make an appreciable difference in sound level/tone?

[Rhitter]

Yes it's worth it. The catback is not a restriction with the stock turbo. If you get a catted dp there is basically no change in sound. It's that minor. Not sure about catless.

[jrho]

Yes it's worth it. The catback is not a restriction with the stock turbo. If you get a catted dp there is basically no change in sound. It's that minor. Not sure about catless.

 

That's exactly what I was going for! Now to find time to install this sucker before the weather gets too cold here...

[m sprank]

If you can feel it pulling timing under load chances are there is an issue. Throwing parts at it or even a tune might just mask the underlying problem or make it worse. Check out the car thoroughly prior to digging a deeper hole.

 

 

 

You dont go to the gym with a broken femur and do squats cause it will heal you. Same applies to a car.

[Subytech]

If you can feel it pulling timing under load chances are there is an issue. Throwing parts at it or even a tune might just mask the underlying problem or make it worse. Check out the car thoroughly prior to digging a deeper hole.

 

 

 

You dont go to the gym with a broken femur and do squats cause it will heal you. Same applies to a car.

 

I've noticed around here you guys normally call it a stumble? I've driven a fair number of stock turbo Subaru's when I was a tech and they all seem to do this. Steady throttle state, 50-70% load, freeway speeds, you can just barely feel it. I've always been hyper sensitive to these things because I had to deal with so many bitchy customers complaining about rattles and shakes on new cars, one reason I don't do it anymore. I'm no tuner but I always figured the ECU was trying to keep it leaned out and was on the edge of knock and I was feeling the car pulling, adding, pulling timing because it was right on the edge. I've felt it on PDI's and at 30, 90, 150k miles in WRX's, FXT's, OBXT's and LGT's

[m sprank]

If it is the 2500-2800 rpm stumble it is far more than being lean. It has nothing to do with that and can not be rectified with just a tune. I have driven thousands of Subarus. I have only experienced the stumble a handful of times. I have spent hundreds, if not over 1000 hours investigating and working out a correction to the stumble.

 

Also. The stumble happens at FAR less than 50-70% load. At those load levels you are on full boost. 2500-2800 rpm cruise at light throttle and load. Not 3000rpm at 75-80mph at 3-4psi boost (most drivers normal criuse).

[Subytech]

Not looking to get into an argument, and maybe I'm not describing it in a way you are understanding but whatever you want to call what I'm feeling I know it's normal. I've also driven hundreds of these cars over the years, most of them stock and felt this condition in pretty much all of them. Stumble, hesitation, small misfire, whatever, they all do it.