Looking for some feedback on their downpipe and high-flow cat for under the car (instead of racepipe). A little concerned that I don't see any kind of a flex section.
Anyone have one of these installed?
I currently run a stock DP but this DP is on my list to get as its a shorty DP with cat. This UR DP offers the ability to slap in a straight pipe or stock mid-pipe with cat depending on emmision checks without having to mess with removing with the DP. Looks like a quality unit.
Not sure if anyone has been able to fit a cat on a CS short DP with the divorced wastegate dual pipe design. The ATP shorty DP comes with the flex section but doesn't come with a cat but sure someone has replaced the flex section with a cat but don't know of any experiences with that. These are the only other two shorty DP's on the market that I know. But IIRC the folks at UR mention that you don't need a flex section when using a shorty DP since there is that additional donut gasket that is reused with the short DP's which they say allows sufficient movement to prevent issues. I haven't heard of any issues of the many who use the CS DP and report no issues without using a flex section as well. If you put one in let us know your experience with this.
EDIT: Check out the review by user: MajesticBlueNTO over at the "other" forum in the vendor section as UR is a sponsor vendor over there.
Maybe not responsive to OP's question, but I think the flex section in each part of the TurboXS downipipe and the race pipe are very beneficial. They ease installation considerably in lining up everything. They help make sure that when you are tightening things up that the gaskets and flanges are pulled together without producing any leaks. Also, they help isolate the exhaust and reduce intrusion of vibrations into the cabin of the car.
Now, I'm running catless, but there's no reason not to put a high flow cat in the racepipe, or to run the stock midpipe with its cat, if you need to do so. Or at least swap to it come emission testing time.
Let me say this: The restrictions in the exhaust system are significant. They are not, as we know, significant in the CBE. The problems are higher up -- the stock downpipe's pancake shaped chamber and sharp angles are very restrictive, and those two low flow cats are too. By the time the exhaust gasses get to the CBE they have cooled down enough that the reduction in pipe diameter does not produce any meaningful reduction in flow. But a 3 inch pipe closer to the turbo is very helpful. Also, because of the shape of the K04 turbo's turbine discharge and the wastegate suggest that a big bell mouth shape for the initial part of the downipipe will help reduce turbulence and, therefore, backpressure on the system at that critical point. Look for a downipipe with a good open bell mouth shape and a more gradual curve as it turns downward toward the midpipe section.