would like to try cherry bomb glasspacks -- need info

John,

1. glass packs are fiberglass packed type mufflers. See Link.
http://www.racerpartswholesale.com/tbolt1.htm

5. any muffler shop can do this for you.

I bought stainless steel glasspacks 14" from Magnaflo.....I also had some polished stainless steel tips custom made for my setup.....total cost was under $600 if I remember correctly.

Im sure others will chime in on 2. 3. 4.

It will sound great!!
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YEEEEEE-HAAAAAA!

Never thought I'd see this on a Ferrari. I love it. Ferrari design has always been about form following function. Many a time have I looked at one to see a substandard part and thought "what the ...?!?".

But, you've got a very nice set up there. I like it in stainless steel. johng, you can get the resignator tips directly from ANSA. I'm willing to bet that this very expensive aftermarket exhaust below isn't much more than a "glass pack" either. The sound chamber(s) isn't that large and are about the same shape. This leads me to believe that they're a straight through flow with the same general internal construction. I.E. expensive glass pack.
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www.maremont.com/prod04.htm Those are the classic red ones. For a 308 you will need two, one per cylinder bank.. Carry them to any good muffler shop and they can plumb them in and you can have them weld in the tips off your old OEM muffler or weld in some custom tips.

 

There are a variety of manufacturers that make aluminized and stainless steel flow-through packed mufflers and tailpipes for your application. General rule is the more case volume to the muffler, the lower the tone and volume. Open tips keep the loud sound while resonated tips take the brapp-like 'edge' off. Should keep same diameter as header exit through to tips if possible as a general rule. If you are like me and have a single inlet from single cat, can split to about a 1/2" smaller diameter tube or so in the muffler. For carb cars ideally may have to very slightly change jetting, but not as neccesary day-to-day; FI automatically compensates. As you can see, to go back to stock just unbolt off and bolt the stock back into place. Very simple.
Good luck and have fun.
rt
Check out the mufflers and universal products at:
www.dynomax.com
www.magnaflow.com
For single cat QV and 3.2 owners, here are photos of a s/s Magnaflow flow-through with dual 3" open tips and a larger volume ( and uncleaned - sorry) Dynomax flow-through with quad Ansa 10" x 2.75" resonators (365 GTB/4 Daytona size tips). There was NO sig. difference in dyno hp between these and the previous tubi, which I found a bit high pitched and loud for a daily and road trip car. The fabrication welding on both is excellent. The Magnaflow had a bit lower tone and volume than the tubi, but still with the 'brapp' racer-like canvas-ripping edge. The Dynomax/Ansa note was lower still, more bassy like an older V-12 with the Ansa resonators smoothing out the tone. The Dynomax/Ansa is somewhat muted at idle and low throttle openings (i.e. cruise), but deeply howls when the butterflies are opened past halfway. For me it is the perfect Grand Tourismo sound.
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John
This is not a big deal really in my experience. You're doing great.
With the short curvy exhaust systems on the 308, you'll get a little back pressure reduction, and it will DEFINITELY fell rev-happier and will DEFINITELY be MUCH lighter in weight.
The back pressure is not going to change to the amount where you will notice any real torque loss. Great recent comments on this by Solly in the other current 'What is the best exhaust' thread. Ferraris in my dyno experience tolerate a wide Air/Fuel (A/F) mixture range and you may not even notice a difference. If you just feel you *have* to change the jetting, put in 140 mains ( 30 - 40 minute job, $60 in parts) if you cannot get to a chassis dyno to gnat's ass the A/F. Not much value added for something simple like this anyway, but it is great fun...
A 78 will need two mufflers.
The case size is the actual volume of the muffler. Classic cherry bombs have very small volumes, while larger diameters and sizes are available. Remember though, there is not that much room back there anyway.
Again - smaller muffler=LOUDER; Larger muffler =quieter (relative term with flow throughs to be sure!!!!!!! It will never sound like a Buick).
To make it simpler, if you want to sound like Boy Racer, use open tips. If you take trips or commute, may want to consider resonated tips for a bit smoother sound.
Lots of other smart folks that have done their twin muffler systems on the board with Magnaflow and even Flowmasters. Thread search on Magnaflow and Dynomax and you'll find a wealth of info.
It's really all quite easy and fun.
best
rt
FerrariChat Conventional Wisdom - you buy a muffler mainly for the sound, not for promised hp increases.

 

call around to good racing shops - they usually have a fabricator. If you are near DC there is a great performance place near Lorton I think, or as a second choice Springfield Automotive. They'll know or even have the tips already - that is not a problem as they are not uncommon at all. Hooker makes a nice smaller resonated tip if you want to keep some growl.
Good luck and have fun.
best
rt

 

johng,
my glasspacks are 14" and stainless steel.

 

Member EnjoyTheMusic (Steven R Rochelin) has a pair of classic cherrybombs on his car. Believe there's a pix by the PO in the old Fchat archives. Since he's got it the sound has increased significantly. He did say something about blowing 'grey moss' out of the exhaust(Heheh).

Last summer at dyno day, when the revs came into the power band his car was definitely the loudest car tested. 1st time my ears have ever been hurt by a Ferrari. However, It isn't too noticeable while driving. Never mind Tubis, this system beats them hands-down for 'presence'...

JWise used to run a pair of home-made mufflers built using SS universal cat converter housings. Were probably next loudest.

 

308chas,

My car is also a 4 valve euro 308 which now has the stock muffler installed. Before, I had a custon exhaust made from two hollow cats with a perforated pipe running through the middle of each. I noticed a drastic reduction in burbling and popping on decelleration with the stock unit.

Does your car pop when you back off the throttle and the car is in gear?
I didn't mind the popping (it's actually quite nice) but was told that it can be a little tough on the exhaust valves. I also miss the scream at 7000 rpm!

I still have the custom "muffler" and will put it back on sometime just to hear her roar.

Anyone else with this glasspack/open muffler experience loud popping?

Any input on it being bad for exhaust valves? Any other problems?

I do know that my car idles smoother with the stock muffler.
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I also like SuperTrapps. Go to www.supertrapp.com and click on the automobile section. Be sure to read the Technical bulletin which explains how the tunable disc system works. There are sound clips for you to listen to on that site of a 4 cylinder car which sound pretty good, of course a Ferrari with Supertrapps sounds much better . Also, you will note that they are sized per the HP and CC of your engine. So, you will need to divide according to whether you will use 1, 2 or 4 mufflers. I have heard 4 Cherry Bombs on a BB512i and they made it sound like a BB512LM. I have heard 2 Supertrapps on a 308GT4 and it they made it sound like an F1 car. Both of those systems sounded much better IMHO than the same models I have heard with high-dollar Tubis, for a small fraction of the price.

 

That's the advantage with the Supertrapps. You want it loud, run 15 disc. You get tired of the noise, run 5 disc. They are tunable to your liking at any given time.

 

I like my cars a bit louder. So I really like to run cats after the header which are very restrictive regardless of what people say and they have internal baffles that cut noise. Then run resonator tips and no muffler or glass pack at all. Now that sounds better than a tubi IMO and is smog legal.

 

Yes mine does pop when I'm off the throttle. Good question, I'd like to know about the exhaust valves as well.

Chas

 

Johng....Try what I did:

Go to a good muffler shop and have them cut the resonator off of the muffler and weld a straight pipe to the tip. The sound difference was night and day and I get a lot of compliments on the sound. This was the best $50 I have spent on the car for a mod. Do this and you still keep the original look of the stock exhaust setup.

 

I went with 2-1/2" inlet and outlet.............any good muffler shop can adapt them with reducers if required. Its not a big deal.

Make sure you buy the stainless glass packs, they look nice IMHO !!

Best of Luck
Charles