I just recently ordered the CNT racing downpipe which is an OBX downpipe with a cat welded in. All of the images of the S60R's OBX downpipe online show a very strange flange where the dp attaches to the cat-back. From the pictures, it looks like the flanges will definitely not match up. I have attached the pictures of the OBX dp from online and the flange type of the cat-back system.

What I would assume is that all of the pictures online of the OBX pipe are generic photos of one of their other downpipes and that the flange will match my cat-back flange. I have spent a few days now searching forums and no one has ever reported having to customize the OBX flange to adapt to the stock cat-back so I assume I will have no problems but wanted to know if anyone could give me a definitive answer.

When I am done, I am going to do a pretty detailed write up of both the downpipe install and custom cat-back with sound clips and everything. It will look like the stock catback except the resonator section will be 3" instead of 2.25", the dual 2" will become dual 2.5" (which is equivalent to 3.5" round), and the tips will be 3" angle cut instead of 2.0" angle cut. The muffler will be deleted and the resonator replaced with a Dynomax bullet. To my knowledge no one has ever put a bullet on a Volvo so this should get interesting. Total cost of project including CNT racing downpipe, cat-back supplies, and cat-back labor will be around $650. Not bad considering an IPD downpipe+catback would run you $1800.

 

Should just get this catback system
ELEVATE Volvo S60 / S60R Sport Exhaust System NEW!!! Stainless Cat-back System | eBay

 

How does that link help answer my question about the dp I already ordered?

 

Instead of a headache trying to piece everything together and make it fit you can get a prefab piece that fits perfect. OBX does not make exhausts neither does CNTracing. They purchase their supplies from China. Piping to large causes exhaust velocity slows down and heat increases as well as drone. Do you know how to figure area? Radius (half of the diameter) squared mltiplied by Pi (3.1416). Doesn't the OBX downpipe match up to the OBX catback exhaust?

 

Piecing everything together has not been a headache. Actually most of the prefabbed components don't fit perfectly either. That is why IPD's new exhaust has slip joints. So my custom catback should be a more perfect fit than prefabbed components.

I understand that too large of piping causes the exhaust to slow but Like I said my custom catback will be 3" round which is exactly what the Elevate exhaust system is. And I don't know what point you are trying to make when you talk about area of a circle. It is not an easy task to get through engineering school without learning the formula for a circle's area. The downpipe and resonator sections will be 3" (7.06in^2) and will split into dual 2.5" (9.8in^2). The dual 2.5" pipes will be crush bent which in general causes a reduction equivalent to dual 2.25" (7.94in^2). In other words, the system will almost be equivalent to 3" all the way back just like the Elevate system.

OBX does have a catback exhaust which is fairly priced, however, the dimensions of the exhaust is almost the exact same as stock. That is why I did not want to go with the OBX. I didn't feel it would be sufficient for a stage 2 tune from IPD.

On a second note I actually just got the CNT racing downpipe installed today. The thing fits perfectly. It did not pull my catback towards the passenger side like the OBX is said to do. I would recommend the CNT downpipe to anyone looking for a cheaper downpipe that will pass emissions.

Perfect fit +Perfect welds + included cat = happy camper

 

Is the Cnt dp 3" all the way or does it taper the inside pipe tp 2.5". Thinking about that dp with obx catback for economical combo of $600.

 

I have this OBX pipe and it lines up Non problem with stock exhaust and or Any after market made for VOLVO S60R or Non R as long as it a Turbo...... The R and NON R AWD both have an Angled flange ..The T5 AND FWD have a straight flange @ turbo... Thats the difference in the pipes. The Pipe is 3" all the way threw front to back..

 

I just installed the CNT dp on my R and it is 3" all the way through. Not sure about FWD models. My guess is it probably is 3" all the way. I say that because taper down to 2.5" would offer almost no performance increase so I do not know why they would ever do that.