Time to get a new exhaust system - What should I get???

[Guest mattrp]

Well, the cops finally came to my door to serve a complaint about my v8 z. With about two ffet of flex pipe leading into a pair of 30 inch long 2 1/2" glasspacks, I guess I knew the day would come. Now the question is, what should I get in the way of an exhaust system. I already ordered the summit block hugger headers, so headers are part of the deal. Id like to stay with duals, but I need some muffling cuz I cant take the horrible resonance in the cabin any longer. I also want everything tucked under well so I can lower the car even more than it is currently.

 

Should I run duals and try to cram mufflers on the side of the gas tank. Should I put resonators in the tunnel, and then cut outs behind the seats and through the side of the fenderwell in front of the rear tires. Maybe just do duals till behind the tranny and then a single 3" to the tail with a nice turbo muffler. So many choices.

 

HEHEHE

I love it.

 

What are your ideas???

 

Matt

72 500Z

[scarp]

I went with the round TURBO muffs

about the size of glass packs

fits nicely under car

nice sound

not to loud (till you romp it)

fairly free flowing and cheap

got mine from jegs or summit

looks kind of like glass packs with dents in them.

 

Stan

[John Scott]

I ran dual 2 1/2s til behind the tranny then 3 inch to a big stainless turbo. Its loud out the back, and when you're on it, but no where near as bad as some of these hollow cans selling as mufflers. My neighbor has the big high dollar stainless 4" duals. Why bother! Its so loud it shakes my glass in the house 1/2 block away. Its a really sharp note with his 11:1 comp. but I wouldn't want to spend much time in his car.

JS

[MYRON]

I have 2 flowmasters in the stock location

and it sounds great, but it does have

a resonance problem..

[Mikelly]

I'm running 2.5 inch custom duals with Hpipe and 3 chamber flow masters out the back. That is the way to go in my opininon.

 

Mike

 

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"I will not be a spectator in the sport of life!"

mjk

[Guest Anonymous]

Running a single exhaust, in my experience, is a sound issue, rather than a horsepower one. On the contrary, many racing circles are going back to single exhausts (and merge collectors).

 

Anyhow, I've seen over 800rwhp through a single 3" tailpipe.

 

That's my vote. I believe a Y closer to the collectors is better. On the other hand, a Y behind the tranny would allow for 3 mufflers total, keeping things pretty quiet.

 

 

 

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Michael Sen-Roy

Houston Performance

281-893-6080

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[Scottie-GNZ]

I agree with HPtech although my JTR had a configuration similar to Mike's except I ran 2.25" pipes and 2 small oval turbo mufflers in the stock location after "massaging" the spare tire well.

 

There is a tendency to go overboard on pipe sizes, especially for a street car. To HPtech's point, there is a 700hp GN here running low-10s with a 3" DP and a Y into dual 2.5" with straight through mufflers. Only reason he went to duals is to have the stock appearance, else he would have ran a single 3". Bottom line is you can go a long way with a single 3" IF it is mandrel-bend and has an efficient muffler.

 

I am running a single 3" and guesstimate 360hp when I am done tuning. Turbo upgrade and cam will have it over 400hp and I intend to stay with the single 3" and straight-thru muffler.

 

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Scottie

71 240GN-Z

http://members.xoom.com/Turbo240Z/scotties240zt.htm

[pparaska]

I went with dual 2.5" exhaust with large mufflers. The main reason was for ground clearance, as I knew 3" exhaust on a lowered Z was a tight fit. I used the large Dynomax Hemi Turbo mufflers since they are known to have low backpressure but very good noise attenuation and the low rumble I'm looking for. No idea how this sounds yet - haven't started it yet. I hate loud exhuast. My neighbor's and their open pipe Harley's drive me nuts, wake up my kids and wife, etc.

 

This system is not easy to fit - I hacked a good 1/3 out of the spare tire well (see my site for pics) and it's not light. Not the most efficient system in that regard. But it ought to flow well, since the mufflers are low restriction and it is all mandrel bent (I fabbed it out of MANY pieces.)

 

I was thinking about a single exhaust, but wanted t odo a 3.5" system. Hard to do since only loud race mufflers are available.

 

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Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net -

[Guest Locutus]

if I remember my fluid dynamics principals, there is a thing called attenuation, that if you make your pipe a certain length based on the diameter of the pipe you can eliminate much of the sound. I know it has something to do with the sound wave being canceled out by a sound wave that is opposite. Its hard to remember been so long, but if there is anyone that has an engineering degree they should be able to explain how its done. They use it in the A/C industry to eliminate fan noise that would normal be heard from the vents in large commercial A/C installations.

I know I have the formulas somewhere I will see if I can look them up.

 

Mike(Locutus)

[Guest mattrp]

Well, I got the exhaust done today. I ended up with summit block hugger headers into 2 1/4" pipes run till just befor the diff mount, then into a 2 1/2" pipe and into a basically wide open flowmaster style muffler. Man is it quiet. This muffler guy is good. I can hear my radio and my subs again. And the loudest noise now is the tranny wine. It is sooooooo cool hearing this thing wine through the gears. I love it, and i think I have better power, especially on the top end. It is so much smoother and winds up sooo fast.

 

Matt

72 500Z