I'm looking to buy this downpipe/hfc

http://www.maperformance.com/cnt-rac...-downpipe.html

I was wondering if I would have any issues bolting that up to my stock o2 housing? I'm ready to pull the trigger on a new TBE, but don't wanna order anything until I'm 100% certain it'll bolt up fine. Also is the doughnut gasket that goes from the o2 housing > downpipe reusable with a 3" downpipe?

 

I just installed the Invidia DP test pipe combo which is the same thing you are posting about. Also a complete setup for $699 shipped. PM me if you want their #. To answer your question yes reuse the donut gasket.

 

What size was the DP? 3"? The flange matched up with the one on the stock o2 housing?

 

It will work. I have the Cobb 3" DP and it bolts right up to the stock O2 housing, using the doughnut gasket and uses the spring bolts.

 

Thanks man... exactly what I wanted to hear.

 

No prob. ;-)

 

Yes 3"

 

Yes reusable but the down pipe is a flat out ***** to install and from what I've heard and not worth the money on the stock turbo since the gains are small. Just go with a test pipe.

 

How much of a difference are we talking with and without a DP? Assuming both dyno tuned.

 

I ended up doing my entire exhaust last night. One look at the stock downpipe and decided to keep it on because I didn't feel like dealing with the hassle. Probably gonna sell the downpipe I bought, and just wait until next year when I upgrade my turbo + cams to get an o2 housing downpipe instead.

 

I recommend doing a short DP if not an o2 DP mainly to seal the TP and DP rather than having a 3" TP and an OEM DP. I had a giant leak before my DP and it threw my AFR off like mad. Bought a short 3" DP and it's perfect. The leak is also annoyingly audible. Gains for both a short and o2 DP are negligible.

 

Mine sealed fine (knock on wood). Gonna go back over the weekend and make sure to retighten all of the bolts.

 

ETS makes a 2.75" to 3" adapter flange that solves this problem if you have the issue. It's much cheaper than a short downpipe. I'd also recommend using a second nut on each bolt (and maybe some wave washers) on the downpipe to test pipe (or cat pipe) connection to make sure that it stays good and tight. Mine seemed to like to vibrate to the "really loud position" even after I torqued the hell out of those bolts. Luckily the hardware flying off and hitting the bottom of your car is a good warning signal that you might have a problem (if that doesn't work the wastegate dump will let you know).

http://www.extremeturbosystems.com/M...e-adapter.html

 

i have the cobb SS dp and its nice to have for my wideband but i would look at something like ETS recirculated downpipe or anything similar for best gains. but yes a pain to install on stock turbo.

 

Unfortunately, with my horrible luck, it did not work. I used the ETS Adapter and it actually made it a little worse. I got tired of the noise and my AFR reading being off so I bought an MXP DP for $180 incl. tax.