Deciding which muffler to use on a Racing Beat "streetport" exhaust in my '81. All it needs is the muffler.

I have both mufflers here to choose from. The powerpulse was modded to fit my REPU so I'd need to cut it out and reweld to make it work in the FB - kind of a bit of work and it's already in the REPU and nice and quiet... The other option is a brand new 2.5" universal muffler that I've got just sitting here.

We've all heard a complete RB exhaust. They're usually too quiet for most people, but I want quiet in a daily driver. If I want loud, I've got other outlets for that. My curiosity is getting to me though and I'd like to hear what the universal sounds like in the FB; it would be less work over all since I could leave the REPU's current system alone, and all I'd need to do is add a couple hangers to the universal, plus some sort of tail pipe (dumpy or dual tips?).

Has anyone ever used an RB universal on the end of an otherwise complete streetport exhaust? I'm not talking about the single pipe system that uses your stock connecting pipe and a collected header in only 2", I'm talking about the the road race header, the dual pipe center section, and the over axle Y collector (that I chopped off the powerpulse since it wasn't needed in the REPU).

How quiet will it be? Any thoughts?

 

No idea, but I have the full RB SP with the power pulse and I'd love to hear a video
of what the universal sounds like.

Sounds like its easiest to just try it out on the 7 so you don't have to mess with the REPU.

This isn't the rotor REV25 is it?

 

universal one is a straight through style...it going to be loud....go with the rb

 

Is it on a stock port or ported motor?

 

I would think it would be quiet. But the nice thing about the streetport system is that you know exactly how quiet it already is (or should?). I'm sure you've been around the streetport system before.

That's what I thinks. I could be wrong.

 

They're both straight-through. The non-universal one just has dual exits and a larger shell.

 

go with p/p .. the bigger shell....

 

is there any way to jamb it in the pipe thats there? as you know i've crammed all kinds of things up peeper's tailpipe. the funniest one was the turbo back presilencer + the dual resonated tip thing, sounded like quiet farts.....

 

I have a 3" universal muffler for my turbo FB. I don't have it installed yet, but i know it will mellow it out and i'm sure i'll love it. Quality is top notch.

 

The universals are awesome. They sound really good. Louder than the PP I'm sure, but the tone is very clean.

 

Okay maybe this will help i have the universal 2.5" racing beat on my 85 gsl-se it has a rb street header to a rb 12a precilencer to a 2.5" rb universal muffler and racing beat 2.5" single tip. Stock port only mods are exhaust and ignition and intake and this system sounds really good nice and deep. Now it is a little loud very docile in the low rpm range but it screams up high. Before I used to run it without the tip and it was way louder since the tip addition it quieted down a little not alot but it did deepen the tone a good amount I hope this helps and good luck.

 

I actually called racingbeat to ask them this very question. They said that the universal is much louder than the powerpulse one that has the hangers (any of them, including the model for the streetport)

They said the internal construction is different between the two, but wouldn't say any more than that about the guts of the powerpulse.

But they did say that the universal one will reduce the sound much better than other brand straight through universals in their opinion.

 

All very good points, everyone. Thanks.

Well, that's what I was affraid of. Looks like I'll have to dig into the REPU's exhaust after all. It's ok though. The REPU is painfully quiet. I had wished it was louder right after I added a final magnaflow 5x8 under the bed. Before I added the magnaflow, it was a little too loud for the street with just the powerpulse and a modded RB center section. The reason it was too loud is because I removed several of the powerpulse's key quieting features to get it to fit. It was installed backwards. The tips were chopped and fed the output of the center section. The original inlet was now the outlet. All three hangers was able to be used under the REPU. It was a novel setup with plenty of low end torque, but just needed a less capable final muffler. The final is a Magnaflow 5x8 oval 18" shell length and 2.5" straight through core. This system is way too quiet. Much quieter than a standard RB streetport exhaust hence the reason for making this thread. To see if it's worth the extra time and effort to swap mufflers, especially since I need a powerpulse now. Looks like it will be worth it.

Even though I am curious to find out how loud an RB system would be with their universal instead of the proper powerpulse, I'm not really set on finding out. The '81 needs to be a daily driver. That means stock flywheel, moderate exhaust note (not loud), decent power, decent drivability etc. I might even throw a Camden 5" in it because they're so nice as DDs on stock ports. Speaking of ports, they're only to 74 spec and the exhausts are only to T2 spec. Both technically stock depending on the year.

 

you're the only one trying to make it louder......

i remember this one time in college, we were doing something to my friends GSL-SE, and we fired it up with just the street port center section, and its LOUD.

 

Yes, I borrowed a powerpulse from my friend's car once and he fired it up and drove it around the block with just the center section. I could hear it all the way around and when he came back he revved it a little and I jumped out of my skin.

I was expecting loud, but this was LOUD.

 

IIRC the powerpulse is a baffled muffler. No wonder it was louder installed backwards!

 

It's not. We confirmed that before it went on Jeff's truck. It's just a typical straight-through, perforated core muffler with kind of a funky y-pipe for the dual exit (which was used as the collector in Jeff's setup; it actually seemed like it'd flow better installed backwards).

 

Yeah, we looked inside the powerpulse. It is straight through. One 2.375" perforated tube becomes two 1.5" perforated tubes. No baffles at all. Just perforated tubing surounded by stainless pot scrubber material.

I tested the flow by blowing compressed air through one of the 1.5" tubes. It created a vacuum on the other tube and a whole lot of air volume blew out through the inlet. I was impressed. It is a really good setup in the REPU but I know it will work just fine in the '81 (and it's the only muffler that will quiet it adequately while not choking it I'm affraid). So out it will come and a universal muffler with an external collector will go in its place. There should be just enough room. The nice part is it will all be in RB thickwall 2" and 2.5" instead of the powerpulse's 2.375" and 1.5". So maybe lose a little ultra low end but pick up more midrange and high end? Or maybe it doesn't really matter all that much.

 

Late to the thread, but I thought this may help. Please no critiqing on how slow I drive....this was more of an experiment in seeing how a cheap camera would work for a track day. Exhaust is RB's dual street port system (actually from Mazdatrix as they include the O2 bung) on an otherwise stock 13b. Gain wasn't turned up on mic so it isn't the greatest representation, but you can get an idea on the tone. The exhaust was totaly gone when I purchased this car, so it seems quite quiet to me. I would say at cruise it is pretty much the same as stock and under throttle is a little more sporting than stock.

http://www.youtube.com/watch?v=wLhnqlvtonk

 

Thanks for the video. I decided to go with the powerpulse muffler.