[wise]

I recently purchased the stainless steel MBRP race catback for my SS. I wasn’t quite ready to fork over the money for a high end catback or axle-back but I really don’t like the look of the big stamped single suitcase muffler. I received my MBRP catback in a box that was tearing apart and barely together. Fortunately all of the contents of the exhaust were still present. I inspected all of the piping and found it to be pretty rough looking. The welds are decent, but are not consistent throughout the catback. I’m not in too big of a hurry to put this on so I’ve decided now to take my time and polish the 4 rear pieces, and smooth out the x-pipe and two front connection pipes. I started on one piece today and so far I’m happy with the results.

I started with dry sand paper (150/240) and some light dremel work to smooth some tie-ins on the welds and rough marks on the pipes. Next, I moved on to wet sanding with 400, 600, 800, 1000, 1500, 2000, and 2500 grit. I’m happy with the results on this piece. I attached the tips and found the shine is pretty close in bright light, so it should all even out under the car. I’ll post pics of the rest as I go. The car is not a daily driver and I’m in Texas so the 409 stainless should do just fine.

Here's a quick cold start video of the exhaust completed and installed!
https://youtu.be/U9jSPXFcDnw

[Camarentino]

Wow great job

[cvpstudios]

Looks good.

I did exactly this on a corvette SLP loudmouth setup... I didn't have the car long enough to know, are you taking away the protection on the pipes by sanding it off? like would the road grime (of a daily driver) do anything to the pipe?

[wise]

Thanks! I may be wrong but I don't believe the stainless is coated in any way out of the box. The surface rust/corrosion properties will still be the same polished or not since it is 409 stainless, but it shouldn't rust on the surface for a long time. I average 500-600 miles per month and we don't have anything on the road to speed up the surface rust. I had a 4th gen Z28 with a Magnaflow catback (also 409 stainless) installed for about 25k miles and it looked great up until the point I took it off.

[wise]

Finished the other side and put the tips on just to get an idea how it’s going to look. I plan on polishing the two pipes forward of this that include the j-pipes next week. The rest of the exhaust forward of this will be cleaned up maybe to 800/1000, but not fully polished.

[peteric]

Looks great. After polishing, you can apply a sealant like Wolfgangs Metal Sealant to refine the result and add some sort of protection.

[wise]

Got everything installed today! I cleaned up all welds, burrs, and mandrel bend marks before I finished polishing exhaust. Both lead pipes and the X-pipe were only polished up to 800 grit but even at that they look much cleaner. Also I had my brother weld in Borla secondary cat deletes (part 60626). We marked everything prior to cutting and welding the new pieces in. Everything went into place just as intended. Tips still need some adjustment. Sound clips to come soon.

[wise]

Two quick shots from the rear. Polishing the four rear exhaust pieces was definitely worth the extra work. The MBRP catback was a good figment overall if you have a little patience. The Borla secondary cat deletes are actually a tighter fit than everything else.

[JonD]

Looks great!

[wise]

Thank you, sir!

[Chris C 1SS 1LE]

Loud? I've got the 60606 on order and have been thinking over rear sections. Detail work you did on pipes looks spectacular. They should come that way. Again, well done, sir.

[goata8]

I'm planning on doing the same for my headers and exhaust....if it turns out half that nice I'll be happy. Very nice!

[wise]

Originally Posted by Chris C 1SS 1LE

Loud? I've got the 60606 on order and have been thinking over rear sections. Detail work you did on pipes looks spectacular. They should come that way. Again, well done, sir.

Yes sir, it's quite a bit louder than I expected, but it's manageable. The cold starts are loud and might be too much for some. It settles down into a nice clean sounding idle pretty quick though. I can hear the exhaust through the entire RPM range and the only slight drone I notice is 1500-1600 rpm. Even at that though it is very low hum. Thank you!

Originally Posted by goata8

I'm planning on doing the same for my headers and exhaust....if it turns out half that nice I'll be happy. Very nice!

It's going to sound good with headers! The MBRP catback is solid, all the welds and connections are clean. I just wish the stainless looked a little smoother out of the box. Thank you!

Quick cold start video: https://youtu.be/U9jSPXFcDnw