I'm re-doing this post and have pictures now.

I am trying to install a RP Supercat to go along with the Borla cat-back I have and it's a disaster. To get the two to mate up the piping has to hang so low that the Borla is hitting in the back and I have to completely remove one of the chassis braces under the exhaust system. When the two actually bolt up where the piping positions should be the bottom of the piping on the Borla is touching the metal on the RP Supercat and the top of it is nowhere near where it needs to be and is causing a terrible exhaust leak. I am using the factory donut gasket and the bolts supplied in the RP bolt and gasket kit. This works for everyone else, but not me. I am DESPERATE for help!!!!



Here you can see everything looks perfect and is lining up great. Yes I'm aware it's not bolted up, as you can read above the second I bolt everything together it's a disaster. Keep looking at the pictures.



Look at how low the piping is to get the pipes to meet up perfectly. Notice towards the right of the picture how a chassis brace has been removed and how LOW the piping is.



More of the same.



Here's a close-up of where the brace should be. There's a inch or two of mid-pipe in the way now!



This is what the two pipes look like when everything is pushed up into place, the brace is installed (it still hits the brace BTW), and the hangars are all hooked up. As you can see I haven't even BEGUN to tighten it yet and already the bottom of the Borla piping is hitting the Supercats piping. You can tighten as much as you want, it doesn't fix this problem.



Notice the huge gap at the top. There's an insane exhaust leak there.



Last picture. As you can see, this is NOT meeting up at all.

I am completely lost as to what I need to do. I don't know if my exhaust system may be defective, but the previous owner of this mid-pipe ran it WITH a Borla cat-back with no problems from what I understand. There are plenty of people that run this combination with no problems. What's different about mine?

Please help.

 

I went back to the shop and had them look at it again. While they were looking at it I looked at it closer and noticed that they used the bolts supplied with RP's installation kit and not the factory ones. They re-used the springs from the stock exhaust system. Everything looks correct, however where the RP Supercat meets up with the Borla it hangs a little low and as a result hits the chassis brace every once in a while. Also, it's leaking from the top. I re-used the factory gasket which probably wasn't a good idea so I ordered a replacement one. I'll just tackle it myself in the garage tonight to see if that fixes it.

Is the low clearancewith that brace normal?

 

you shouldn't need to reuse any of the OEM bolts if you get the bolt & gasket kit from RP.
as for it hitting the braces, mine did that at one point but it was after owning it for almost 2 years.
I had my shop re-align everything and tighten it down, problem solved.

 

And they didn't. Not sure why they said they did in the first place. I had the bolt and gasket kit from RP but they didn't include a gasket for the rear. Oh well.

I plan on taking the back portion off since I'm replacing the gasket so hopefully I can fix the issue on my own then. We're in the process of packing up to move so I didn't want to have to look for tools. lol

Thanks for the reply!

 

The OEM gasket is too small for my Borla exhaust. It works for everyone else, but my Borla piping is literally just going completely around the gasket and touching the metal on the end of the Supercat pipe. I bought a new OEM donut gasket and I have the same issue. It's the same Borla cat-back everyone else has and the same RP Supercat everyone else has. I'm at a loss.

http://cgi.ebay.com/ebaymotors/OBX-H...item5adc87dbc2

I think I may purchase this one. The 3.30" outer diameter should help with the Borla piping and 2.65" isn't all that much bigger than the collector size on the Supercat itself.

 

Updated. I'm desperate guys. ANY ideas? If I can't figure it out by the end of the weekend I'm just going to take the Supercat off and sell it. I have no time to work on the car during the week and I need my car running by Friday for my bachelor party.

 

why is the borla sitting so low? you should have a hanger about 18in before the borla meets the rp. Also, when the RP is up and in place with the hanger on it shouldnt sag that low either. Seems like you have two hangers not on.

 

I have the borla and I sold you this rp pipe. I wish I was there man, seems like something isnt going on right.

 

The pipes are hanging low in the pictures because that is the ONLY way they can go and line up. Even when all hangars are connected to the pipes and the exhaust system is bolted up it still hits on the chassis brace itself. Even then they are too low. Trust me, I've checked every single hangar and the exhaust was completely bolted up.

 

After adjusting the Borla pipe I got everything to not hang nearly as low, but that unfortunately doesn't fix my issue. If anything, it makes it a LOT worse. Here's how it looks now:





You can see I now have the chassis brace installed and there's PLENTY of clearance. One issue solved I suppose.



Everything all bolted up. Look at how bad that gap is!



Without the bolts. As you can see, there's really no difference.

 

tbh that gap doesnt matter as long as the pipe is snug and there is no leak and the pipes are tight together. It looks like you can/need to tighten those bolts up

 

have you turned it on and checked for leaks?

 

After the picture I tightened the springs all the way down (until the bolts wouldn't turn anymore). Made it look even worse.

Yes I've checked it for leaks. Honestly you don't even have to check, you can hear it it's that bad.

I guess I'll cough up the $45 at Mazda to get a new donut gasket. Bleh.

 

Everything is finally together and I'm exhaust leak free. It took modifying the Borla pipe a little and a clever use of both my old gasket (modified) and the new gasket, but I'm seal free.

The power difference is insane. I had no idea how poorly my car was running with the OEM cat in place. There is a LOT more low-end power. Instead of lugging down low and pulling like a raped ape up top, it now just pulls like a raped ape the second I hit the loud pedal. It's great!

Unfortunately there is some bad news to go along with it though. I'd say I was rattle-free but that's a whole different story. The inside of the cat is rattling. I thought it was the heat shield at first but after the spot welds were re-welded by the exhaust shop it still made the noise. Nothing like buying a pipe with a dead cat in it! To be honest I didn't ask if it was or not, and who knows how nice the shipping company was with the box, but I'm still pretty frustrated. Oh well. I place the blame on myself and no one else and that's how it'll stay.

I've got my eyes on two 18" long, 3" in diameter Vibrant resonators that should keep sound down and get rid of the stupid cat that's going to rattle itself to pieces I'm sure.

Videos to come soon. I couldn't find ANY on Youtube of the Borla + RP so I made two to help others that may be interested in buying it themselves.

 

FYI...when I first bought my RP supercat, it would always rattle a bit when I first started up the car. I found that it would "settle down" once everything warmed up.

That was fine until I noticed that everything seemed a bit choked up. I later discovered that the catalyst had dislodged and was rolling/around the exhaust pipe between the mid-pipe and muffler. I never got a CEL for exhaust fumes

I am now looking at getting the BHR mid-pipe with hi-flow cat.

 

I have a question for all you RP supercat owners. Did any of you guys have the RP with the stock exhaust at first and then go to a borla or RB or anything really? I just installed my RP cat today and kept the stock exhaust on. It's really high pitch. (Almost like a crochrocket). I'm wondering If I get a RB exhaust or a Borla will the sound get deeper and not as high pitched since the exhaust is wider and not compressing the air as much?

 

I still have the stock exhaust with my rp cat. For me, the exhaust note was not a lot different (deeper maybe, but not a huge amount) even to this day. At high rpms, I'd say the exhaust is definitely louder

Are you saying that your exhaust got "higher pitched" once you installed your supercat, or you just think it is too high pitched with a hi-flow cat?

 

I'm saying its higher pitched. Defiantly louder but still very high pitched.