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Dual after-header exhaust for 83 280zx?


PhaTTy

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Anybody make a dual exhaust to hook up to the 6-2 headers w/ dual cats system for an 83 280zx? I just need either 2 pipes going strait back (I will put 2 bluestreaks inline) or one to the left side and one out the stock location in the rear. Anybody sell something like this or should I have it custom made? Also what size of pipes to run back? I have been told by several people in the racing industry and here at racing shops in town that there is no need for a larger pipe than what the exhaust ports are because it will not help anything if it is larger. Just wondering what your guys opinions are on this.. My bro has a 76 280z with lots of power and is running 6-2 headers w/ no caty and the dual bluesteaks on stock pipes going strait back to the stock location. The thing screams like crazy and just sounds like raw crotch rocket power! Anyways.. let me know. Thx

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  • 3 months later...
I have been told by several people in the racing industry and here at racing shops in town that there is no need for a larger pipe than what the exhaust ports are because it will not help anything if it is larger. Just wondering what your guys opinions are on this.. Thx

 

Shops are spot on, you'd actually lose torque most likely by altering backpressure so notably. If an NA L28 then 2.5" back from lowermost point of OEM manifold to a dynomax muffler works great, add a resonator if you want it quiet. If a turbo you may want more than 2.5" but others can chime in. 2.5" single supported lots of power with my V8.....if you like noise fine, but many allow it to confuse their power 'spidey sense' :wink: , many a thundering domestic, beedroning-deafening import has routinely beat me in at noise levels...but that's one contest I want to lose every time frankly. Every hop in a truly quiet but quick car? Helps adjust your spidey sense :wink:

 

NAL28E exhaust manifolds are very well designed and you may lose power going to that header FWIW, tuned length runners as I recall on the OEM piece. L28 responses to headers are not comparable to typical SBC header responses...(typical chevy OEM exhaust manifolds are NOT good, Nissan ones are fine in typical use.)

 

HTH

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Guest greimann

Considering that a typical V8 muscle car is suited to dual 2.5" pipes, then a single 2.5" pipe on a motor 1/2 the displacement would be just about right. I agree with Ross on this aspect. A noisy, fast car is easy to build. A relatively quiet and fast car shows the builder has a higher level of skill.

 

P.S for Ross: if you uncork that V8 with a single 3" pipe instead a a 2.5", you will pick up half a second easily. I had a single 2.5" when I originally built the car and found a lot of top end with the 3", FWIW.

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P.S for Ross: if you uncork that V8 with a single 3" pipe instead a a 2.5", you will pick up half a second easily. I had a single 2.5" when I originally built the car and found a lot of top end with the 3", FWIW.

 

RC: Well old exhaust was so poorly done/restrictive it'll be hard to have a realistic 2.5 vs. 3" comparision. They're remounting my engine (lower for improved breathing) and several other mods, new mufflers are in as well:) I can hardly wait to get it back, their install/build methods will leave me with a v. secure leakfree/troublefree system and noise should be a lot quieter:) It was your own dual cats that inspired my mid car dual bottle/muffler idea, thanks!

 

Pre mod dyno indicated 246 rwhp/256 rwtq, and I'm expecting at least 50-60 more from the mods. Will have to be quite careful afterwards to recalibrate my driving style.

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OK, should get my car back early this week.........it's now got 4 muffling devices total! 2 magnaflo's on the dual 2.5's before my merger to 3".......and one Vibrant on the downslope from the crossmember rearward towards the muffler.........and then a 5x8x18" oval at the rear:) All straightthru with SS packing where they do have packing.

 

Can't wait:))) I did hear it idle and it was a lot quieter which was great....they've got some tweaks left to do including the post mod dyno and dial-in. Been so long since I've done (or had done!) some seriuos work and this waiting is driving me nuts!

 

Y merger is a gorgeous IMO piece, I'll see if I can post up some of the pics to my gallery later today.

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