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Exhaust: Mid collected dual vs. true dual?

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Old 04-09-15, 10:26 AM
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Dak
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Here's one from underneath to show roughly where it ends.

Old 08-24-15, 05:58 PM
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^^^Has anyone used this exhaust on here? Looks incredible. Keen.
Old 05-02-16, 08:17 PM
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As an update to this, I've scheduled a couple dyno pulls to test this out. I'm going to do a baseline pull with my current rb true dual exhaust and then swap the exhaust to a friend's spare custom collected set-up.

Custom set up:
This is an RB collected header ->2.5 ID rb presilencer->2.25 ID magnaflow muffler.

The current tune will not be touched and I'll be happy to share my results once done!
Old 05-05-16, 05:25 PM
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RESULTS!!!!!!!!!!!!!!

These dyno pulls were done on the same day within 30 minutes of each other.

Here is an image of the paper copy. I'm still waiting on the digital file.




1st pull:
-Racing Beat True Dual full system
---175.3whp/ 143.7 ft.lbs

2nd pull:
-Racing Beat collected header->RB presilencer->2.5 in. ID pipe->magnaflow muffler
---179.6whp/ 152.4 ft.lbs!

3rd pull:
-Same as 2nd
---177.8whp/ 149.8 ft.lbs (not sure what happened here, intake temps going up?)

Overall, the mid range picked up nicely and the car feels more responsive. I'm convinced to go single, plus I get to lose 40+ lbs of dual exhaust!
Old 05-05-16, 06:03 PM
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No video DJ? I was hoping to hear those exhaust systems purr!
Old 05-05-16, 09:47 PM
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As a matter of fact, I have videos. I'll post them later tonight.
Old 05-05-16, 11:53 PM
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Vids. Sorry for the window size.

RB True Dual:


RB Collected Header to single exit:


Last edited by djSL; 05-05-16 at 11:55 PM.
Old 05-09-16, 02:13 PM
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Dyno file
Old 05-09-16, 02:37 PM
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Nice work! Looks good too
Old 05-09-16, 06:11 PM
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Thanks! I'm hoping my new exhaust will be modular enough that I can test it collected upstream and downstream.
Old 05-12-16, 02:36 PM
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What other mods have you done? Did you ever do the itb's?
Old 05-13-16, 11:21 AM
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Car has itb's. You responded to my itb dyno thread lol
Old 05-18-16, 02:37 PM
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I don't remember. I'm here so little now that I forget very quickly.
Old 05-18-16, 02:42 PM
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Wait, are you running the Star Mazda manifold with a dual throat tb or are you running a new manifold with 4 tb's?
Old 05-18-16, 04:32 PM
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Star Mazda with dual throat.
Old 09-05-16, 02:55 AM
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I'm a little late joining this chat but, I have about the same question... Right now I'm running the RB tru-dual setup with aero turbine resonators and aero turbine 2540i mufflers on each side. The car is ungodly loud and though it was great at first, I'm ready for something quieter. I want to stay dual but am curious about possibly welding in an x-pipe somewhere. Do the RB pre-silencers ever wear out, or should I replace the pre-silencer with something that collects within itself?
Old 09-05-16, 06:43 AM
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The presilencers are somewhat interesting in that they are not all-muffler but have a kind of terminator box in the front.

Mine are old enough to have rusted through where they were welded to the adjacent pipe but they are still quiet as long as the cracks stay puttied shut
Old 09-05-16, 09:22 PM
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Originally Posted by peejay
The presilencers are somewhat interesting in that they are not all-muffler but have a kind of terminator box in the front.

Mine are old enough to have rusted through where they were welded to the adjacent pipe but they are still quiet as long as the cracks stay puttied shut
So i guess the question still stands then? Would it be worth it to get a new pre-silencer or cut it out completely and figure out something else? I'm know for a fact I'll be stuffing an x-pipe somewhere!
Old 09-06-16, 10:10 AM
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FYI, my new exhaust (true dual header- Y pipe- Magnaflow presilencer-2.5 inch ID piping- Magna flow straight through single exit muffler) is quieter than my old RB true dual at both idle and low load. At high RPM it's definitely a little louder but not by much.
Old 09-06-16, 01:23 PM
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X pipe

The x pipe will help quiet the exhaust down because the 2 pulses will somewhat cancel out some noise . To save some room magnaflow makes a dual 2" in and out with a perforated x pipe inside ,tear there crap packing out and fill it with course s.s.wool ( mc master Carr sells it by the pound , one pound is more than enough ) . I did this on my repu with a street port 13b and did a 2" dual inlet to 2 1/2 " single outlet and it worked great
Old 09-06-16, 10:33 PM
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Magnaflow uses stainless packing.

That said, I used to have a 2.5" Magnaflow and a loooong bullet muffler that I repacked. It was NOT quiet. At all. Wasn't OMG ROTARY LOUD but still loud enough to get me pulled over every few months.

Last edited by peejay; 09-06-16 at 10:36 PM.
Old 09-07-16, 12:12 PM
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Magnaflow does not use stainless packing , they use rockwool . That's why I said to repack the muffler .
Old 09-07-16, 03:42 PM
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My exhaust is very quiet until I get on it. Unless you want stock volume levels, (which is totally fine) an x pipe wouldn't be required. If you're interested, I can get an exhaust video together sometime.




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