I've recently fitted the Berklee / Pex 2.5 inch Sports system for E series / AU live axle to my EF so for the purpose of anyone looking into doing their exhausts I figured I'd more or less review it.

This is the system:
http://www.bestmufflers.com/bshop/produ ... fd4684c20f

- I've used that link to show the system, not push Best Mufflers - it's just that their site is a great resource for Berklee stuff - ie. great range of mufflers shown WITH cutaways that show exactly what they really are. I bought my system across the counter at a local muffler shop for $406 - not thru Best Mufflers. I have bought gaskets and flange plates off Best Mufflers tho and received excellent service.

Near as I can tell the rear muffler is one of these - ie. it's a perforated / louvered pipe thru the body of the muffler - no baffles or chambers:
http://www.bestmufflers.com/bshop/produ ... fd4684c20f

The main muffler is something like the following link, but the louvered pipes seem to extend thru to the opposite walls of the chamber - ie. when you look into each opening you see a louvered pipe that ends against a blank wall. I was surprised - technically it means the main muffler really isn't a "straight thru" type. I don't know what the go is exactly because I can't find a berklee cutaway that quite matches what this system's muffler looks like - so I don't know if it is THE one in the link below and the cutaway is slightly wrong or if both types actually exist. The shame is that I think a muffler like the one in the link with open chamber would induce very nice decel burble:
http://www.bestmufflers.com/bshop/produ ... fd4684c20f

Fitting was straight forward and it hangs adequately - tho having it fitted by a proper workshop WITH instructions to do whatever's required to get it up as snug as possible would be a good idea for lowered cars - ie. when u fit it yourself it fits up ok, but a muffler shop could slighty bend it here and there for a really improved and tweaked fit.

Something I didn't appreciate until I fitted this system is that altho the flanged rear section coupling is easy and robust, slipjointed type systems possibly allow a bit better flexibility for final positioning of the tail section by allowing you to twist the joint to some degree - something that's simply not possible with the flanged coupling. Seems obvious but not something that had occurred to me until I came to actually work with it.

Sound wise, here's a clip from Youtube of what I think is this system - as usual, due to limitations in recording device the clip doesn't quite convey the real sound so it just ends up pretty much like any other I6 with 2.5 - but I think it does convey that it's a DEEP note, not a high pitched rasp like many can be - IRL it's actually at least one octave lower in pitch again than this clip with a nice rumble underlying. On heavy acceleration under load it does develop a very gratifying rumbly growl. The twin tip is not part of the Berklee system:
http://www.youtube.com/watch?v=g7-tMyxEb5k

On the road it has a very pleasant overall note with absolutely no resonance anywhere. At cruise - ie. 80k + it's noticeable but very easy to ignore and quickly become pretty much unaware of, but if you're listening you CAN hear it well enough to enjoy the note.

Round town (in traffic) it has a very pleasant and healthy deep throaty murmer which isn't OVERLY loud or noisy even at WOT / high revs but is significantly louder than factory. Decel burble is very muted - as I mentioned above, a proper open chamber I think would induce much more of that.

On my ED I essentially had this same system - ie. the tail section WAS this same part number Berklee section but I had an Aerochamber main muffler with forward hotdog - custom fit - ie. not actually the Berklee fwd part number section but with aerochamber - but essentially that's what it ended up being identical to. That system had an absolutely gorgeous decel burble - and in fact "burbled" overall much more "V8-ishly" than the Berklee system - but overall was maybe 15% quieter across the board than the Berklee system - maybe even a little more quiet than that (comparatively) at WOT / high revs.

Many years ago I was window shopping car yards one Saturday and asked a dealer how much he'd give me for a trade on my ED - he took it for a drive and when he got back his comment was that it was a nice car but sixes were more popular in general than V8's - especially mildly worked ones - which really only held appeal for enthusiasts - he was really surprised when I pointed out it WAS a six...

This Berklee system is well made, has deep basically pleasant note and doesn't seem to show any decrease in performance over the 3 inch system that came off the car - but I think I'm going to be replacing the main muffler with an aerochamber sometime in the new year

That system is, in hindsight, what I should have bought a few years back for the old AU.
I asked for a system that wasn't going to be 'P plater' loud, but something that was more like 'upper class loud', Just enough to let you know there really was an engine under the bonnet.

I was sold a Berklee system with a small resonator/muffler right at the front and main muffler with no tail pipe muffler. As soon as I started it the first time I knew it was going to too loud.
It droned badly and it did it right at the point around 1700 to 2200rpm (the revs you use ALL the time when just driving around.)

Ended up with having to fit a muffler in the tail pipe but still couldn't get rid of the drone, It was embarrassing when I had other people in the car.



I'm in two minds about buying an off the shelf system for our BA, I don't want to end up with s stupid loud system again. I'm seriously thinking of building one with two try-flow mufflers. There is plenty of spacer under the car to do it and talking with my Orbital rep, they have a tune for the BA 6cyl to go with the extractors and system.

Hey, thanks for the superb write-up. I've had my eye on the same system (but IRS version) for my AU XR6, but wasn't sure how it would sound. Now I know , and your description is what I'm looking for. The local distributor (Chase NZ) charges about twice what you pay in Oz, so I have requested a quote on freight costs from Best Mufflers, as they ship to NZ.

Thanks heaps.

No worries glad it's helped (thumbsup) - keep in mind there's no guarantee the type / s of mufflers will definitely be the same, but surely the IRS setup would be basically the same just slightly different pipework.

We need people to do the same for Lukey and Redback - including covering the various configurations of tail sections - ie. just straight pipe / with hotdog / with second muffler.

Hey Tickford6 - was the forward resi the oval factory looking one? I've wondered about the way there's two factory equivalent looking Berklee forward systems (ie. they both have that factory looking oval resi at the front) but one is $100 dearer then the other... perhaps the cheaper one uses a perf pipe thru body type main so ends up nasty without something else to interupt / deflect sound propagation along / thru the gaspath?. Your planned system should sound sweet!

Yeah it was an oval shaped resi, Not sure on internal construction But it was WAY loud.

Sounds like it was one of those systems - they both look practically identical to each other and to factory std - ie. with the oval front resi - but like I say, there's $100 price difference. I always assumed the difference in sound would be quiet vs REALLY quiet - go figure!