RB Presilencer...Alternatives?
02-22-02, 11:37 AM
#1
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RB Presilencer...Alternatives?
I am getting a RB header, probally ordering it today along w/ my catback.
:thumbsup: Is there any altrnatives to a RB presilencer? $198 for a piece of pipe is a little steep! Can I get a midpipe or something? WHat is the length of the presilencer? Does it just replace the main cat? Any advice would really help! I can affore the catback and header today, but I won't be able to buy the presilencer until next week!
:thumbsup: Is there any altrnatives to a RB presilencer? $198 for a piece of pipe is a little steep! Can I get a midpipe or something? WHat is the length of the presilencer? Does it just replace the main cat? Any advice would really help! I can affore the catback and header today, but I won't be able to buy the presilencer until next week!
02-22-02, 12:21 PM
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You can put a straight pipe in there, but it'll be loud if you have a flow-through muffler, like an N1. Ppl have put mufflers in there, but it's up to you.
02-22-02, 03:28 PM
#5
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The pre-silencer is not really a straight pipe - it's more like and in-line muffler.  If you know a shop that can install a muffler between two pipes with a couple of flanges for less, have them do it.
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02-22-02, 04:05 PM
#8
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Originally posted by rico05
I have a N1 muffler. So I can use my gutted cat until I can get some $$ for the presilencer?
I have a N1 muffler. So I can use my gutted cat until I can get some $$ for the presilencer?
-Ted
02-22-02, 04:07 PM
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It'll have to be custom cut to fit between the cat-back and the header, since the header is longer( I think) than the stock manifold with the precats. I'm sure any muffler shop will do it for you.
02-22-02, 04:16 PM
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I have heard that all the RB header replaces is the precats. Anyone know? I am a little broke right now ($200 for the header and $300 for the cat back cuz I got it used) and I would prefer to use the gutted cat for a few weeks till I can buy the presilencer, or I will just have such nice new toys sitting in my garage that I can't play with yet!
02-22-02, 04:26 PM
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I'm workng on a collector that is similiar to whats used on some rotary powered planes. I'm hoping it will work well enough so that my Supertrapp can be run with out any disc or cap on it. Bad part is that it will probably not fit under the car to well and the floorboard will need modifying some. Luckily its allowed in FP for your exhaust. Going to have it exit out the right side in front of the rear tire. Part of this is also weight savings but not much. If it doesn't work I'll show some pictures. If it does work hopefully you guys will forget about this and it will be my secret
02-22-02, 04:52 PM
#15
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The RB header isn't a bolt up. Neither is just the presilencer. Its right there on the page.
''Our Streetable Header/Collector is designed for a bolt-on installation, when used with the appropriate Power Pulse Presilencer, in all 1986-92 non-turbo RX-7s. The combination of this Header/Collector and the appropriate presilencer replaces the stock exhaust manifold and all catalytic converters, along with any intermediate pieces of tubing. (In this application, the presilencer will bolt-up to the factory Y-pipe.)''
''Our Streetable Header/Collector is designed for a bolt-on installation, when used with the appropriate Power Pulse Presilencer, in all 1986-92 non-turbo RX-7s. The combination of this Header/Collector and the appropriate presilencer replaces the stock exhaust manifold and all catalytic converters, along with any intermediate pieces of tubing. (In this application, the presilencer will bolt-up to the factory Y-pipe.)''
02-22-02, 09:39 PM
#16
Rotary Freak
I could of swore your main cat would fit... Mabey not.. buy a presilenser from a muff shop and have them weld flanges. Im sure it would cost 100 bucks total. with the presilencer.
02-22-02, 10:15 PM
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What about back pressure?
Don't you need the presilencer so your Secondary ports will open correctly. I believe that it is designed as an exhaust "System" and the length is NOT the same as the stock pieces. You have to use the header AND presilencer together to make it the correct length to go back to the "Y" pipe.
Hope that helps
Hope that helps
02-22-02, 11:58 PM
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Rico, I think youre missing the point of the presilencer, its to open up the 5th and 6th ports. If you dont have to worry about them, dont buy it. If you do, dont just weld any old muffler in there.
Catback!
02-23-02, 12:47 AM
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ok this is my plan for my na RB header to custom pipe to dynomax 3" racing muffler in the main cat spot and another 3" muffler out back. Will this work? Should I go 2 1/2" for one or both or is this fine? Oh yeah street port and no 6 ports. thx
02-23-02, 10:30 AM
#22
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Stupid question: Where the heck does a pre-silencer go? eg. These silencers looks weird to me, I can't picture it attached to the rest of it. http://www.rx7store.net/apexexhausts.htm
02-23-02, 01:41 PM
#23
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It goes right behind the Header, and in front of the cat back. It essentially attaches the header to the cat back. I want my 5th and 6th ports workin, so I will just order my presilencer in a week! Thanks guys! Hopefully I can get all my stuff in and done in the next month or so!
02-28-02, 09:48 AM
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After my SP goes in, I'm getting the dual outlet header with a collector into a single muffler. I'm still deciding on what muffler, but I know I can't use and N1, it'll be way too loud. I'm leaning towards the Supertrapp PN 543-3519. It has a 3.5" input so I'll have to have a step up in pipe dia from the collector. I've been talking to Mazdaspeed7 about this system and it's similar to the one he's going to run and since he probably has the fastest NA on this board, I'll listen to his suggestions.
02-28-02, 10:04 AM
#25
I custom made a full dual for my car. To save money on the presilencers, I just took 2 glass-packs I had lying around, cut them open, repacked them with stainless steel wool, and welded them back together. (You can get stainless steel wool at a grocery store in the cleaners section) This is essentially what's in the RB presilencer minus the port actuation tube. (I took one apart to fund out)
I mounted them where the Y pipe used to be, and ran straight pipes straight back from the dual header to the Y. Its very quiet INSIDE the car, sounds great, and gave me a good power increase.
Its been on there 6 years, 100K with no problems. I just swithched the system from my old SE to my GTUs, and it still looks strong. Just make sure you use thick walled tubing (I bought mine from M-trix) --it keeps the noise down in the car, and makes the system more durable.
To keep your 6P working, make sure you get the M-trix header w/ the 6P pickup tube off the front rotor.
I mounted them where the Y pipe used to be, and ran straight pipes straight back from the dual header to the Y. Its very quiet INSIDE the car, sounds great, and gave me a good power increase.
Its been on there 6 years, 100K with no problems. I just swithched the system from my old SE to my GTUs, and it still looks strong. Just make sure you use thick walled tubing (I bought mine from M-trix) --it keeps the noise down in the car, and makes the system more durable.
To keep your 6P working, make sure you get the M-trix header w/ the 6P pickup tube off the front rotor.