which exhaust x pipe to use for ess650. two to choose from

[2jzinsider]

I have two x pipes to choose from in my garage from collecting parts over time and now I'm in the process of matting one of them with my ess vt2 650 kit

1- Dinan four resonators X-pipe "I added two 200 cell cats at the primary location between the two 02 sensors to keep smell down"

2- Oem x-pipe with test pipes. Pretty much the same as the Dinan in a way Just the stock secondary 200 cell cats are at the correct secondary location and only has two stock resonators.


Which x pipe will give me the most HP for example Will the dinan be more restricted since it has the 200 cell cats closer to the header "pressure speaking" compared to the oem x pipe with the stock 200 cell cats closer to the back?


I really want to use cats to keep smell down since I Daily the car to work and back and I'm sure boss lady would be B!tchin about the smell but for what it is worth how much more HP/Power will I make if i decide to just use the Dinan xpipe and just remove the cat to bring back to fully catless. Is it worth it? "



Thanks

[CIFUM3]

Me personally I would rather have the resonators. So I'd go with the dinan..
But then again I'm straight pipes with a 625 kit

[asmazda]

Both the setups you described have resonators, which is a good thing. IMO you definitely want resonators to minimize raspy sounding exhaust. With your Dinan setup if you kept all 4 resonators in place it should sound better and less raspy than most other aftermarket xpipe that have 2 resonators or none.

Having an aftermarket xpipe with the HFC in the primary location has a few benefits over test pipes:

1. Combined with O2 extenders you may be able to keep your CEL off and pass the OBDII scan when it comes smog time

2. The cats will heat up quicker and theoretically operate at a hotter temp, which that should help to further reduce any smell

3. Aftermarket xpipes are known to make a few extra HP compared to test pipes, even if the HFC is in the primary position

On the downside, in case you are using an aftermarket exhaust or plan to do so, aftermarket xpipes are noticeably louder than test pipes. Another downside with HFC in the primary location is that you have less clearance so you could scrape on speedbumps. It should not be a problem on a stock suspension as long as you don't fly over speedbumps.

I'm personally using the Fabspeed xpipe, which is similar setup to the the HFC-modified Dinan xpipe you have. It has 200-cell HJS cats in the primary location and resonators (2 not 4). I definitely can't smell anything from the cabin. I've even stood right next to the muffler when the car is warmed up and I think it's almost like stock. Of course when you first start the car and the cats are cold there will be some smell.

BTW, regardless of which xpipe configuration you go with it might be best to not disable your cold start cycle. That will help your cats warm up faster, which will help minimize smell when you are driving around.