Surprising difference...

[Shant Fabricatorian]

...to the noise, that is.

The Beta had its rego renewed today, and part of the service required a new muffler to replace the (aftermarket) Lukey unit that had been on the car for at least a dozen years - a nice finger-sized hole had worked itself through it.

New muffler, then, and a nifty new exhaust tip - and the difference in the noise is amazing. Gone is the ever-so-slightly farting tendency at low revs, a result of the old unit's tip having a slight lip which curved in on itself and meant the sound echoed within the pipe itself. You'd think that a solid muffler would be less noisy than a holed one. In fact it's even louder...and I like it. It's throatier, a deeper basso profundo type of sound, and it makes a surprising difference to the fun factor. Oh, and the noxious fumes being rather more isolated from the cabin is always nice too... :D

[SubGothius]

I was similarly surprised at the audible difference when I replaced the stock air filter cannister on my carb with a free-flow unit. It's oval with a steel mesh dome holding the element in place (simlar to the RamFlo (http://www.ramflo.5u.com/[/url) 600 model), so there's no metal top plate to block/reflect the "induction music", adding a raspy baritone growl on-throttle when the choke's open and rounding out my Zag's sound quite nicely.

When I got the car, the PO had been dissatisfied with the silence (more berlina-apropos) of both a stock exhaust and a FAZA 3-muffler sport system he'd bought, so he was tinkering with mix'n'matching bits from both (thx to a friend at an exhaust shop who let him bend pipe afterhours at cost 8) ), finally settling on nothing aft of the cat but the center transverse FAZA muffler alone and straight (well, considerably mandrel-bent :) ) pipe for the rest, ending in a nice chromed tip. However, he still wasn't happy with the note that, while audible, had too much of an agricultural putt-putt quality to it. That air cleaner finally set things to my satisfaction, much to my surprise.

However, I may be ditching that air filter setup, as various tests (here (http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm) and here (http://www.bobistheoilguy.com/airfilter/airtest1.htm)) indicate that foam filtration (oiled or not) may not be up to snuff -- indeed, holding my element up to a light, I can see pinholes shining clear thru! Plus, there's the risk of a backfire thru the carb setting it on fire! 8O (RamFlo claims their elements are flame-resistant, but mine's a knockoff, so I'd definitely wanna at least get a RamFlo element pronto if I were keeping mine.) I'd prolly move to as large-diameter a circular filter as I could find (more media surface-area = less airflow restriction and longer time 'til it gets plugged), with a Holley-style, open-sided top/bottom plate holder, mounted to the Weber with an adapter plate (http://redlineweber.com/html/application_guide/DGV_Snorkle.htm) (bottom part of snorkel kit available separately for this purpose), prolly with a Wix (http://wixfilters.com/) pleated-paper filter or possibly an Airaid (http://airaid.com/) filter, which looks promising (at least superior to K&N).

Back to exhausts, I'm still curious to try a straight (bent but unmuffled ;) ) pipe aft of the cat and all the way back, ending in a tunable SuperTrapp (http://supertrapp.com/) muffler tip, but that experiment will have to wait until I have a few hundred bux to spare not otherwise better-spent elsewhere on the car. :roll:

[SubGothius]

[deleted duplicate post -- forum acting up again :roll: ]

[cthargiss]

Tye, BTDT with the straight pipe to a supertrapp. With eight discs it sounded like a very loud fart, and had no power. With 13 discs it had good power, but a REALLY loud fart. :oops:

[Shant Fabricatorian]

Very interesting post Tye, it's got me thinking. My car had the stock air filter when I bought it and one of the first things I did was replace it with a Ramflo 600. After reading those links I'm not so sure, now.

Still, the Ramflo setup is beneficial in at least one aspect, and that's under-bonnet engine access, which is hugely improved with the aftermarket item - that, and the much-improved soundtrack, are the real benefits more than any minute horsepower increase (if indeed there is one, not so sure after reading those articles). The standard filter housing is hopeless in this respect.

Regarding the Wix/Airaid items, the theory sounds good, but will it physically fit underneath the bonnet? The Ramflo doesn't have a huge amount of space left above it and going by the photos both the Wix and Airaid look rather taller.

[SubGothius]

Very interesting post Tye, it's got me thinking. My car had the stock air filter when I bought it and one of the first things I did was replace it with a Ramflo 600. After reading those links I'm not so sure, now.Say, if you hold a clean, actual RamFlo foam element up to a light or shine a flashlight/torch behind it, can you see pinholes shining clear thru? Just wondering if the genuine article may be better in that regard than my knockoff... BTW/FWIW, K&Ns have this pinhole issue as well, whereas Airaids and S&Bs (http://sbfilters.com/) purportedly and reportedly do not.
Still, the Ramflo setup is beneficial in at least one aspect, and that's under-bonnet engine access, which is hugely improved with the aftermarket item - that, and the much-improved soundtrack, are the real benefits more than any minute horsepower increase (if indeed there is one, not so sure after reading those articles). The standard filter housing is hopeless in this respect.Agreed on all counts. For easy access, the RamFlo type is indeed hard to beat, altho' the Holley-type filter-housing adapter for Webers makes things easy as removing one big butterfly nut or knurl-head bolt and pulling the entire filter housing off in one swell foop. :D I thought I'd noticed improved throttle response and rev-happiness after installing my RamFlo-knockoff, but perhaps the old filter element was overdue for replacement and/or I just enjoyed laying into the throttle more, the better to hear more of that aria! 8)
Regarding the Wix/Airaid items, the theory sounds good, but will it physically fit underneath the bonnet? The Ramflo doesn't have a huge amount of space left above it and going by the photos both the Wix and Airaid look rather taller.Don't hold them to the example sizes displayed on their sites alone; Wix in particular make replacement filters of most every OEM size, including for our factory stock filter housing -- I'd started considering the Wix pleated-paper elements based on the balance of their characteristics measured in Spicer's Duramax filter test -- and Airaid and S&B at least make many popular sizes (obviously not including our OEM size! :roll: ) and several generic sizes. I'd just be using a generic-size circular filter element in an aftermarket housing resembling our factory stock filter housing, a variation with open sides (i.e. top/bottom plates only) and perhaps a wider diameter for better breathing and longevity.

[Shant Fabricatorian]

With the proviso that my element is pretty knackered and up for replacement, the shining light test revealed pinholes.

But (and you'll have to forgive me if this is a really dumb question) can such small holes really allow in that much and do that much damage?

[SubGothius]

Aye, there's the rub. Given that some premium oil filters strain down to 10 microns (apparently restricting oil flow in the process, however), lesser brands down to 20 or 30 or so, and a human hair can range from 20-180 microns (scalp hair median 100 microns or so), we're talking about particles smaller than you can really see, whereas you can certainly see those pinholes. As big as those pinholes are, that's at least how large of an airborne sediment particle can enter your engine. That sediment tends to get trapped by your engine oil, and circulates thru your lubrication system as a very fine abrasive until the oil filter traps it (note that oil filters have a pressure-relief bypass valve, so bear in mind that your circulating oil isn't always being completely filtered, nor would you want it to be during cold starts or when the filter's clogged), or until you change your oil. Then you also have the issue of microscopic pitting of your valve seats to consider, as the sediment is inhaled or exhaled by your engine. Exactly how much airborne sediment, and what size sediment, is acceptable or even likely to get into your engine? Some would answer, simply, that less is always better and preferable.

I guess it's a matter of conscience, and whether that Aria is worth the probable (perhaps nominal?) increase in engine wear (crank and rod bearings in particular!). Also depends on whether superior filtration options would diminish the aira appreciably at all. For instance, I wonder just how nice an open-sided circular filter setup, as I described, might actually sound, given that the quieter stock setup is an acoustic trap, almost entirely enclosed in sheetmetal except for its restricted "snorkel pipe", which isn't even pointing toward the cabin! Perhaps the top'n'bottom plates of an an open-sided filter housing would simply redirect most of the induction music laterally? Consider that, with the RamFlo style, your hood is blocking much of the vertically-directed sound anyway...

Food for thought, fuel for combustion... 8)