Well, I am all ready to buy my long awaited exhuast "package"

I wanted to purchase MSA 3 into 2 headers, as well as the Twice Pipes exhuast setup.

However, I wanted to see if there were any drawbacks or "cons" about purchasing the twice pipes exhuast. What is so special about glass-pack mufflers, and on average how long do they keep their "tone"?

MSA also never specified if the twice-pipes exhuast was 2.5" or 2.25", does anyone know off hand?

Another thing .... how will may cat converter fit with this piping?

Would I go w/o a cat converter?

Finally.... is there any performance differences between 6 into 1 headers and 3 into 2 headers?

If your 280z is not a CA model than it may not have a cat! Mine doesn't.

I don't have an CA model...

but I do have an 1978 280Z with an Cat converter...

I dunno why or how it got there... but it's there....

does anyone know if I have to cut the rear valence?

Cutting the valence is not required... but you'll have to leave the pipes hanging a bit low to clear the valence...

My advice is don't do it... in 6 months or less, the packing will be burned out of the mufflers and the noise will drive you nuts. Not only that, but the cops will just love you too...... I had the twice pipes on one Z, and will never do it again, once the packing burns out, you'll effectively have a straight exhaust.

Best thing I can say is get the 2 1/4 or 2 1/2 "Turbo" exhaust with a good turbo muffler. Even then it can be a bit noisy with headers, you might want to look through the archives a bit, I think you'll find quite a few people who put a small bullet style muffler in the tunnel to quiet it down even more and get rids of some of the resonation.

Dump the cat since you aren't in CA and required to have one, it's probably half plugged up by now anyways.

hmm

Is there any way I could get the twice pipes, and then when the glass-packs go out, I could use a normal muffler, like MagnaFLow for example?

I thought that maybe muffler shop could do that....

I have read however, that usually the glass-packs will last about 2 years or so, before they need to be replaced. So i figured every 2 years or so, replace them.

BTW, does MSA sell 2.25" exhaust? I could only find that cheap Targa exhuast with 2.25".

I would love to get the Turbo Exhuast system, but I don't see that they made it in 2.25"... only 2.5"

I have a header thru big pipe to a 2 chamber flowmaster at the rear. Its really too loud for the street with my warmed over l28 (yeah the same one that needs a total rebuild ). I heard the way to go was to put a dynomax bullitt straght thru muffler before the rear wheels and use a tunable supertrapp at the rear (the ones with the disks). I was thinking on adding the disk unit directly to the outlet of my flowmaster, so I could quiet it a little for the street or open it up as needed, any thoughts?

http://store.summitracing.com/partdetail.asp?part=SUP%2D544%2D3003

I have the twice pipes, they look the same, but were made by Thunderbird. The pipe size is 1 3/4".

My 5/1978 280Z, bought in Virginia has no cat and according to the book, only the California cars had one.

I am looking for a substitute muffler for the glass packs, but haven't found one. I want either a turbo type with dual inlet or two mufflers which can be stacked in that space.

ecp48

I've got two oval Magnaflow mufflers stacked in the back of my 240z. Magnaflow number on them is 11124. They are 2" inlet and 2" outlet. One side is centered and the other is offset. It was a little tricky, but if you use the centered as the inlets and the offset as the outlets, you can stack them so that the outlets are straight up and down coming out of the valence. This offsets the mufflers like this:

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This fits nicely where the rear quarter panel tucks in at the bottom. I'm sure Magnaflow makes this canister size with smaller inlet's and outlet's. Could be a good option for you.

I also had to curve the upper outlet down and out to get the mufflers located so that they were tucked up where they look good-- just a slight S bend though.

Garrrett

Sorry. Looks like the spaces were removed. I'll try one more thing. Visualize the below image with the x's replace by spaces.

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xxxxxxxxxxxxxxx{xOxxxxxxxxx}

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G

Now that's interesting.... definatly different

I grabbed a pic from your site..

*edit - damn I can't post it because of tripod,

but use his website, and scroll to the bottom.. and you can see the pics

http://members.tripod.com/Trueweb/Zcar/

on average how long do they keep their "tone"?

That is up to you If you run the car hard alot they will go out faster :stupid: On the good side there cheap to replace.

I have used glass packs alot and loved them. The thing to keep in mind is they take running time before you hear the true note.

The way the twice pipes are set-up they (should) last longer being they are at the tail pipes. Most of the people running glass packs have them far to close to the motor. This puts more raw fuel and heat in the pack and makes it burn out much faster.

With your cat. If you keep it (if its any good) The twice pipes should last longer. BUT with the cat on you will loose some of the sound and performance you are searching for from this system. Thats up to you.

If I was looking for this type of set-up. I would make a trip to a

exhuast shop. Take a photo of the twice pipes with and ask what they would charge to make it. It sould be less then what the twice pipes go for and installed on top of that. Another good thing about this is the shop can help you with the note or sound you are looking for with diff size packs. Oh yah plus your new system would be welded and not just clamped on.

a shop can make me an "custom twice pipes exhaust" for under $139.95? MSA charges $139.95 for the entire exhuast setup (except the headers) and it would be $14.34 for shipping.

Maybe I'll call around