Borla XR1 vs. Pro XS

[Blown353]

Anybody have any experiences with Borla's ProXS line of mufflers or know how they differ from the XR1's? I'm about due for a muffler change.

One of my Dynomax Ultraflows recently developed a 2" crack/split on the bottom of the case. I stop drilled it and welded it back up, but that's not a good sign. I also popped about 2" of end cap weld on the other muffler a while back and had to re-weld it; noticed it when under the car one day and saw a little bit of packing "hair" sticking out of the weld. Like the sound of them but they don't seem to be holding up all that well, 4 years and about 14,000 miles on them now.

I've always liked the sound of the Borla XR1's but for easy installation in my car I need an offset/offset muffler; the XR1's only come in center/center. I can get a ProXS in offset/offset, and after handling one and looking through it they appear to be the same design as the XR1's-- but there has to be a reason they are $50 cheaper. Anybody know what that is? Also, do they sound like an XR1?

I could always run round case XR1's but I worry they will be too loud...

[dendrizzi]

I had the XR-1 system on one of my corvette's and it was really loud. I wasnt running headers, it had cats, and it resonated alot. Not sure if it was just the C5 muffler design but I did not like them very much.

[Blown353]

I had the XR-1 system on one of my corvette's and it was really loud. I wasnt running headers, it had cats, and it resonated alot. Not sure if it was just the C5 muffler design but I did not like them very much.

That is the total opposite of my experience with Borla. I have one of their systems on my daily driver (Subaru STI) and while it's much deeper in tone than the stock exhaust (it will chirp car alarms in parking lots just going by at 5mph) the actual perceived volume level inside the car is only a tiny bit higher than the stock system and it's drone free and nearly silent at cruise.

Another friend has XR1's on his '66 Chevelle with a nasty 377 and they have a very good tone to them but are very reasonable in volume level, especially inside the car-- that's why I'm leaning towards them. I'm also very happy with their construction quality.

Can't decide what to do. I like the sound of my Ultraflo's but I'm not terribly happy with the construction and lifespan. Several people have recommended Magnaflows and while the construction quality is nice the ones I've heard in person I didn't care for too much, but then again they were on relatively tame engines so that probably tainted my impression of them. I'm really leaning towards the ProXS Borla's but want some info on them before I buy them and weld up the flanges, don't want to throw the money away.

[chicane67]

The 16" case Xr-1 sportsman offset's..... if they still have them.

https://static1.pt-content.com/images/noimg.gif

The ProXS is a little too small volume-wise and they tend to get a little poppy.

:banghead:

[Blown353]

Yuck... I don't like "poppy." My Ultraflo's occasionally pop during overrun and I don't like that too much.

The offset XR1's would be worse in my case than the center/centers... For best floor fitting and the least amount of bends in the pipes I need the inlet on one side of the case and the outlet on the other side, not both inlet and outlet offset to the same side as with the offset XR1's. I If they made a center/offset I could probably make that work. I *may* be able to make the center/center work but the case may hit the trailing arm mount. Guess I should make a foam-core mockup and check fit.

Any other suggestions Tom if I can't make the Borlas fit?

[chicane67]

Well.... there is this cat known for making high hp street cars quiet. I cannot recall where his number is right now, but I know this other guy.... that has all of his mufflers done, by the very same cat.

That cat is Joe Sherman (http://www.joeshermanracing.com/main.html). Give him a call and ask him about the street muffler's he uses.

[Blown353]

Looks like I'm SOL for using the XR1s, drove the car over the pit today and took measurements. No way am I going to fit them being center/center, need to have an offset/offset.

Back to square one. Still looking for a muffler with 3" inlet/outlet, offset/offset case configuration, 16"-20" case length. I figure I can easily fit a 20" case muffler, which should reduce the over-run pops I currently get with my 14" case Ultraflows.

Magnaflow is out... for 3" offset/offset I only see them offering a 22" case muffler and I can't make that fit. Dynomax has a 20" case Ultraflo which I might go back with, but was hoping to find something in stainless.

Any other ideas for straight-through style mufflers meeting those size & configuration constraints?

Also, any thoughts about running 2.5" bullet-mufflers in the tailpipes about a foot before the pipes end at the bumper?

Thanks for the pointer Tom, I'll give Joe a call next week when I get a chance.

[protour_chevelle]

Magnaflows have given me buzz bee sounds at high RPMS with my experience...

-Matt

[blown69nova]

I have an x-pipe with ProXS mufflers (all 3") with only turn downs on my Nova and I swear it is quieter than my old 2.5" flowmaster 2 chamber system (with tailpipes!). The Borla's have a nice deep growl and no interior drone, I love them! (not that kind of love).
Steve

[Wall]

I had a Dr.Gas x-pipe and borla pro XS mufflers on my 96 cobra, I loved the sound! It's a different sound, kinda quiet until you get on it. Also they were really quiet when I first put them on but after they burnt in they were just right.

[Blown353]

All said and done now, went with 18" case Magnaflows.

Didn't get the Pro-XS for 2 reasons... #1 was the too-small case size, and #2 was the pair of 3" offset/offset Pro-XS mufflers I looked at at the muffler shop appeared to have been welded by a 3-year old kid with epilepsy-- the welding on the internal tube was TERRIBLE, not to mention on the 3" offset/offset Pro-XS the core tube was only 2.5" diameter... no wonder they're so much cheaper than the XR1's. Was not impressed at all. The Pro-XS that I saw were a *huge* step down in quality compared to the XR1's I have seen and also the cat-back Borla system I have on my Subaru.

[Flash68]

All said and done now, went with 18" case Magnaflows.

Didn't get the Pro-XS for 2 reasons... #1 was the too-small case size, and #2 was the pair of 3" offset/offset Pro-XS mufflers I looked at at the muffler shop appeared to have been welded by a 3-year old kid with epilepsy-- the welding on the internal tube was TERRIBLE, not to mention on the 3" offset/offset Pro-XS the core tube was only 2.5" diameter... no wonder they're so much cheaper than the XR1's. Was not impressed at all. The Pro-XS that I saw were a *huge* step down in quality compared to the XR1's I have seen and also the cat-back Borla system I have on my Subaru.

Hey, got any sounds clips of your new Magnaflows? I have a very similar motor (Don Estel's blown 406) and am looking at which mufflers to get. Would love to hear what yours sounds like? You still happy with the new system?

thanks