Update: Well, I ported the aluminum ring and hammered onto my Megan 02 housing and that fixed the problem. Unfortunately I broke a bolt in my 02 housing so I had to drill it out and rethread it. That sucked, but the car runs perfect. Its very quiet at 75 mph.

Morale of the story. If you have an ebay 02 housing, make sure you port the ring to match the lip on the 02 housing and you won't have any problems.

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I installed it this weekend and put a stock cat/cat back on my car.

The Good; It sounds sick when it is open and is stock quiet when closed. It is as advertised AT IDLE. My picky wife was impressed. My friends love the diesel truck sound it makes when the flap is open. No exhaust leaks when closed.

The Bad; starting at 3000 rpm, the downpipe starts to vibrate and by 3500 rpm it vibrates alot. I'm speculating that this is due to the lose of 1 exhaust hanger. There is a lot of weight on the side of the downpipe with the cut out, so I've been wondering if this is causing the DP to torque when the motor is under load????

If anyone has any idea, please post. My plan at this point is to try to have the other exhaust hanger bracket welded on top of the cutout and possibly exhaust wrap it.

If it were not for the vibrations, it would be truly the perfect mod though a bit pricey.

 

when you installed it, was it touching anything on the body, or did it have enough clearance? I know that some aftermarket DP's vibrate or rattle due to this.

 

I have this downpipe and have no rattles at all. Odds are you are hitting you crossmember or something. Go under the car and you should be able to tell where it is hitting.

Do you have your rear crossmember installed? If it is installed it must be spaced down. I used universal poly sway bar end link bushings from Pepboys.

I love my QTP cutout, best part I have put on my car besides the EMS

 

I am going to try to re-torque the dp. It looks like the donut gasket is a tad out of alignment which may be the culprit. I have a Megan 02 housing and that prevents me from using the ring.

My cross members are not installed at this time since my last DP required me to remove the front member and now this one looks like it its the opposite. Didn't have the front with me.

Seriously, its the best mod I have ever seen for some one like me. I hope I can get rid of this vibration issue.

 

what's the price range on these pieces? are they only sold through QTP?

 

i have just the cutout and get an immense amount of vibration. nothing is loose, it's just the fact that my exhaust now dumps under my feet

 

I would like to see a test between a normal 3" DP and then one of these cutout DP's, open and closed. With the design they use it seems there would be unwanted back pressure and turbulence in the exhaust with it closed. Would it create enough power loss to make a stink over, probably not, but just a theory.

 

I have the ebay o2 housing and ported the piece that came from qtp and made it fit. Check over everything and if your still having issues let QTP know and maybe they can send you out a new DP.

 

I'm gonna try tonight if I can squeeze under my car to do it. I'm thinking about porting that ring too.

Car runs like $h!t at WOT when the flap is closed, but if you accelerate at 3/4 throttle, it feels very normal. I think I am going to get a EBC to allow me to switch depending on if the flap is open. It should help.

 

Update...

 

good to hear you fixed the problem.

 

I did test this unit on the dyno. My car have stock exhaust and hollow cat. I made 20 whp when the dump open.

Made 5 whp over the Magnaflow Ti.

 

The worst part of the switch is the mismatched tune. If you are tuned for it open, when its closed you will probably knock. I have the same issue when I put the silencer in my 3" TBE. The car is much more quiet (probably better than stock) but it starts to knock when you dip into the throttle more than half way.

 

I can't even here my exhaust anymore. Its so weird. I have to keep my throttle at 3/4 or less or the car feels wrong when the flap is closed. Open doesn't seem to matter.

I think I'm gonna install an EBC so I can turn down boost alot when flap is closed.

 

as far as the knock issue goes, why not tune with the qtp valve closed and then just open it when ever you want for the added benefits. I know the gains would not be as great as when the tune was done with the qtp valve opened but it seems like the only way to go around the problem. Keep us informed on the EBC experiment. I'm really interested in the results that you come up with.