Originally Posted by philpak

Hi everyone.

We are Importsports Performance, a performance shop in Denver since 1997 and have a 2008 RDX Tech project test car. We have built a custom PROTOTYPE downpipe for the RDX. This dp is PROTOTYPE but very similar to what the final will look like. Final product will be T304 stainless steel to ensure quality and to prevent rusting for all those along the ocean line. This downpipe will eliminate both catalytic converters, and that will be the only option that we will produce. It is made with 3" true mandrel bent pipe which will include the flex pipe, all gaskets and hardware necessary. The secondary oxygen sensor will have an extended bung (approx 1.5") from the b-pipe to trick the computer for your P0420 code check engine light. Optional bung downstream for air/fuel sensor or additional oxygen sensor or whatever you wish to use it for.

We have installed this downpipe and have been driving with it for a few days now with no issues. With the exception of a K&N intake, this car is completely stock. So far, after a few days of driving, we have noticed a big increase in throttle response and the turbo lag seems to have been diminished. The car feels more alive, and pulls much better when applying even half throttle. We will continue to daily street drive for about 1 week while monitoring the air/fuel ratios using our Prologger air fuel / datalogger. We want to make sure that this downpipe will not affect the stock settings, and the median air/fuel results will not be too affected and be safe for the Hondata reflash, which will be our NEXT step. After we see the median air fuel results with the Hondata reflash, we will post again. We are an authorized Hondata dealer so we will be getting the reflash done very soon. But since there is not enough feedback on the air/fuel ratios with the Hondata reflash and downpipe that we can find, we want to do some more testing to make sure it will all be safe. Yes, we can dyno all this stuff and call it a day but we want to give you guys real life driving feedback. We also have never dyno'ed the car when it was stock and I dont have the factory intake anymore to give true results, therefore we are not using they dyno since we cannot give you true numbers.

We have seen some dyno results from Pang_CO, and believe that they are very close to what we should expect.


This will not pass any kind of emissions/smog testing whatsoever, it will be for off road use only.

As you can see from the photos, the current b-pipe is flanged down to a 2.5" flange to mate up with the stock exhaust. We will have other options available for the flange, it can be a 3" 2 or 3 bolt flange, or a straight thru b pipe if you are planning to make a custom 3" exhaust. Otherwise it goes to a 2.5" as shown to fit the stock exhaust.

A jig is currently being made, this is not a "will we make a downpipe thread," this is in the process and once finished we will test fit it and make sure its 100% before it sells. We are limiting the first run to 10 so let me know fast. E.t.a. before they will ship is 3 weeks from now. This 3 weeks will include datalogging the air fuels with K&N intake and downpipe, <--- also with Hondata, also with the final 304 stainless Importsports downpipe.