Jump to content
HybridZ

Twice Pipes


TurkishSquirrel

Recommended Posts

Ok, so I used the search function to look up on info on installing twice pipes, (ordered them and they're at my house). And I saw some different stuff, such as losing low end torque, and eventually they'll get insanely loud. I have a 1978 280z, so am I going to need to do any welding, and do you have any tips on trying to prevent the torque loss, or will it be made up for quickly, or what?

Link to comment
Share on other sites

take a look at it and see, but welding is always your best bet. The torque loss issue with a twice pipes setup is a sticky issue..

 

Did you get the MSA twice pipes system, that is built to use with headers? The issue with a REAL twice pipe system is that it would take the exhaust pulses from two sets of three cylinders and wholly divorce them from each other, using two completely separate exhaust tracts. The system that MSA sells now starts out as a single pipe where it connects to the header, and then splits into two pipes. Having this "collector" allows the exhaust pulses from all six cylinders to merge, and THAT gives you a "scavenging" effect.

 

Scavenging means this: as each exhaust pulse races out into the exhaust system, it leaves a wave of low pressure behind it, which assists the next wave of exhaust gases and has a suction effect. With only three cylinders on each exhaust "bank" you lose this effect; by having a y-pipe or collector integrated somewhere, there is no loss of scavenging effect.

 

My system (uninstalled as of yet) consists of a somewhat rusty MSA style 3-into-2 header, a brand new Y pipe for the header, and the complete "twice pipes system for cars with headers" from MSA. THAT kit starts out with a second Y-pipe splitting the exhaust into two pipes, and then the two glass packs and tips.

 

AS for assembly, welding is always the best way to go; you MIGHT want to talk to the welder about putting one or two flange fitting in so that in the future, any partial disassembly needed can be accomplished without cutting. If you are pinched for dough, you should be able to simply slip the pipes together and clamp them down, but thats really not the right way to go.

 

HTH, good luck with the install.

Link to comment
Share on other sites

well, I am NOT the guy whose words you need to set in stone.. I read ALOT, I am very skeptical about what I read, I have learned ALOT about performance engine theory.. but I DO not have a great deal of practical experience.

 

That disclaimer being out there (since no one else is chiming in) I will say that no, your exhaust system should not cause the "inherent loss of torque" that is the typical issue put forward on the twice-pipes system.

 

The confusion comes up because "twice pipes" in its most technical definition means that half the exhaust gets one pipe from engine to tail.. so to be precise, this MSA system is not EXACTLY proper "twice-pipes."

 

Whether you, installing this exhaust, onto your engine, will cause a gain or loss of power or torque, remains to be seen; most likely it will not effect an otherwise stock engine very much in either way. ITS Biggest impact is the sound, which I personally love.

 

hope this helps,

 

shawn

Link to comment
Share on other sites

  • 1 month later...

I know it's been about 2 months since this thread started, but I just got my engine to rum more or less, and I have the MSA twice pipes and just took a video this morning.

 

 

Keep in mind, the carbs arent syncronized, so I had to ease the throttle up. I reved it to about 3k RPMs the first two times and then up to 4500-5000 rpms the last.

 

Sounds pretty decent IMO.

Link to comment
Share on other sites

The original 432 Exhaust is segregated front-to-back, though it 'appears' they share a common resonator, the piping is separated and baffled.

Original BRE and other Nissan-Supplied racers used segregated pipes as well.

 

Scavenging has as much to do with pipe size and velocity as anything else.

 

A lot of this kind of discussion is titter and tatter over theoretical points that don't mean anything appreciably in the real world.

 

Look at it this way: Will 2HP really make any difference on your car for the street? Will you be happy with the sound, and can you live knowing that in a theoretical sense, your exhaust system is not perfect (and which one really is?)

 

Some years ago, texts decried mufflers. Today, engines designed around mufflers make more horsepower than those without... Things change. Beware!

 

Sounds good to me, BTW! Then again, I have a 432 Replica Exhaust under mine! LOL

 

 

Oh come ON! Guys, only FOUR views? Maaaaaaan!

Link to comment
Share on other sites

Sounds good to me, BTW! Then again, I have a 432 Replica Exhaust under mine! LOL

Thanks, and yeah, I'd love to have one of those myself. Ofcourse I'd love to have the whole 432, but I would settle for the exhaust.

 

Oh come ON! Guys, only FOUR views? Maaaaaaan!

Haha, no kidding, and I've posted it on TWO forums

Link to comment
Share on other sites

And curiously here I sit, in the middle of the day, no parts, waiting.

 

In wonderful Brenham Texas, and I realize "Hey, maybe there's a Z_Club Meeting in Houston this week I can attend!" And I see you're the 'other way'...LOL

 

Off Topic, but the thought just struck me.

Link to comment
Share on other sites

And curiously here I sit, in the middle of the day, no parts, waiting.

 

In wonderful Brenham Texas, and I realize "Hey, maybe there's a Z_Club Meeting in Houston this week I can attend!" And I see you're the 'other way'...LOL

 

Off Topic, but the thought just struck me.

 

Well, there's a Z show on April 12th in San Antonio if you're interested. Hopefully my car will make it that far by then

Link to comment
Share on other sites

the twice pipes sound sick for sure! is the MSA system aluminized??

They're just regular pipe, they flash rusted once they got wet, so I quickly did a little bit of fast sanding and blasted them with some high temp silicone paint from DEI. That's why they look so good from the bottom. the tips on the ends of the glass packs came chromed already, which was nice.

 

The bag flying by the camera is very dramatic!

haha, thanks, i did not even know that had happend till i saw the video myself, but everybody seems to like seeing the bag fly by so I'm glad it happend =P

Link to comment
Share on other sites

how is the silicon spray holding up?? that sound is what makes me want a turbo car and an NA car. i guess the lightweight fairlady will be the NA car, lol.

Not bad so far, but this car is a garage queen.... I havent had a chance to drive it more than about 4 feet yet. Got a few little problems to work out first.

Link to comment
Share on other sites

  • 2 weeks later...

I'm working on cleaning up the new(to me) motor and trans that's sitting in auxilary's garage right now. It's the MSA system, complete from header to tailpipes. N42 block and head, N36 manifolds, stock SUs(I'd have to research which year they're from, but they've got the knurled barrel nut on the mixture adjustment instead of the flat notched wheel). I'm looking forward to Ferrari noises.

 

Aux and I have kicked around fabbing out the crossover and putting in two straight pipes. Not sure what this will do to the sound(more like an exotic V-12? Less?), but as Tony said, I'll probably not even notice the difference in power, assuming there is one. I'm actually looking for mileage at this point, considering my Z is daily driven.

 

What a great sound! I hope I don't piss off everyone in my apartment complex when they finally go on.

 

Looks as if there might be a clearance issue underneath...they really hang down low, don't they?

Link to comment
Share on other sites

Well captain furious I am curious myself about the crossover effect myself and what's killing me is that it is sitting in my garage attic ready to be tried. Damn I gotta get moving on this car

 

Great sound austin!

5738_thumb.attach

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...