rowden

Now that my 13B is finally running right in my first gen, I'm in need for exhaust. There are lots of threads on this, but I want my all original car to perform as close to new as it can.
It does have a new header on it and a nice new straight pipe to the rusty muffler. I would like to not buy 3 ridiculous cats, and I don't need fire and noise blowing out the back. What is the best exhaust system I can have a shop put on the car for a reasonable price?

rotarygod

iTrader: (1)

I assume you just need a muffler since you already have a header? Are you looking to keep a cat installed? How loud do you want it?

rowden

Definately need a new muffler. And I assume I need at least one cat to keep the exhaust from plugging up and to pass emissions. I'm sure there is a trade between noise and power, I'd like to hear from folks with experience recommend a balance somewhere in the middle.

rotarygod

iTrader: (1)

It really depends if you want something that is a simple bolt on or if you don't mind having a muffler shop weld something up. Racing Beat has all direct bolt on equipment. The downsides are price and weight. Their standard setup won't really give a whole lot more power but it is easy to install and is decently quiet. A little more aggressive than stock but nothing that would get anyone's attention.

If you just need a cat and a muffler but don't mind fabbing something up, a muffler shop should be able to weld in a new cat. As far as mufflers go, you could get a Dynomax superturbo welded on. I've used these on my 2nd gen RX-7 for a while. I like them. They are fairly quiet but a little more aggressive sounding than stock and they flow well. They are also reasonably priced. The downside is that some of the cost savings go back into labor to have them installed.

Of course if all out performance is your goal, and it doesn't sound like it is, you could always design something completely custom based on the experience of others and really get some nice power gains. Of course you'd get some pretty loud exhaust in return.

pjr

iTrader: (8)

tagging along.... and a Q: which RB header is best to use if starting from scratch?

JKM

Well, if money is no object, or you are fabbing everything after the header, I'd definately go with the street port header. I just ordered the regular header myself, but that's because I have no fabbing skills and if I went with the street port header I'd have to get the whole $1200 system.

I ordered the regular header and presilencer, and I plan on getting the RB muffler when I can afford it, or find a cheap used one. My main reason for ordering it wasn't for a power increase though, it was because I have a chronic exhaust leak between the old stock manifold and my RB cat replacement pipe. I'm not really expecting a huge power increase switching to the header, I'm just hoping to end my power loss from the exhaust leak.

Back to the original post...

What header do you have? If everything header back is fabbed, then stuff made for exhaust locations won't fit, so it would be good to look for the cheap but good generic kinds of parts. I'd say Borla muffler (one of the few that can take the rotary heat), a Bonez high flow cat (again, it can take the rotary heat) and have the exhaust shop fab everything up.

rowden

Ok, thanks for the tips. I'm not sure what header I have. There don't seem to be very many manufacturers out there, so I will compare mine to their online pics.
The pipe from the header to muffler hangs very low, so it will probably need replaced. Sounds like I need to do some more research into the header over the weekend for a proper match.

Starfox07

I have a dynatech split flow muffler. It quieted it down from straight pipe quite a bit, but its still pretty damn loud. I may end up ditching my resonator tip for something a little bigger.

85 FB

I have a 2nd Gen NA Header from Racing Beat leading down to a universal cat leading to a Magnaflow muffler on my 85 SE. It's fairly loud but, I like it. It's nothing too loud, but it sure isn't quiet. The Magnaflow gives it a sort of well behaved rotary exhaust note. Nothing compared to a full Racing Beat exhaust, which I've heard from those who have it that it is purely orgasmic.

Rx-7Doctor

iTrader: (13)

If you are wanting to stick to a system that is going to be as close to quiet as stock then the only thing out there is the RB presilencer and the RB muffler. It will remove the tinny sound, give better performance be just barely above the noise level of stock. Anything else without a presilencer will be loud.



The catalytic converter has nothing to do with "Plugging" up if you don't have one on there. The only way the exhaust could get plugged up is if you had the catalytic converter on there and you did have the smog pump hooked up and operational.

Personally I would ditch the straight pipe, buy the RB presilencer and muffler. This is assuming that you have a RB header and the presilencer and it will bolt up as intended with their product. Then I would have my separate catalytic system that you would use when you had to have it certified.

Remember most states that require emission testing will not pass it with a header on our engines. It has to be the stock exhaust manifold. Won't pass the visual as there are no emission legal headers made for our engines.

LongDuck

Totally agree.

Here in AZ, I have bi-ennial (every 2 years) emissions inspections that require both visual, idle, and dyno testing. One year, I thought I'd give it a shot with the full RB header, presilencer, stock midpipe, and Powerpulse muffler. The result was a quick failure straight from visual, but they ran the idle test anyway. The RB setup had me at more than 5X the legal limit for idle CO and NOX - clearly would not pass the dyno test and they failed it right there.

Went home, installed the stock setup which came on the car (about 2hrs worth of work), drove it back and it was once again 1/2 the legal limit for smog output. Passed easily with no other changes; same plugs, same cap/rotor, same fuel, same everything.

Every 2 years, I get the express pleasure of swapping back to the stock exhaust system, then the same afternoon, after the successful test, I swap back IN the RB full exhaust. I've gotten it down to a science now, and it takes about 1-1/2 hours to swap systems one way or the other. I keep my stock system in a corner of the garage and guard it closely for rust and damage - it's the only way my car will pass emissions testing here, and keeps me from having to register it under a different class (like recreational, or historic vehicle) which has different driving, insurance, and tax implications.

I consider it a rite of passage into the realm of owning a 25 year old sports car.

85 FB

That's interesting, because my car has that 2nd Gen RB header on it and it passed visual inspection (and emissions) with flying colors. Guy never once made any mention of it. I guess it depends on the state (or where you go to). I'm not sure if it's cause the header is showing its cast iron finish and he feels it's the stock thing.

rowden

Well, I'm in luck. I think. WA emissions seem to be only valid for vehicles 25 years old or newer. I am currently licensed thru next year, so I believe I can put on what I choose.
I believe I have a RB header. I will look into a RB muffler and pre-silencer.

I'm having some trouble understanding the role my smog system. I tore into my ACV and it's diaphragms are in good shape. I reinforced them with some silicone to seal some tiny cracks. So it is working well except for the check valve leading back to the exhaust pipe, it's open. The relief solenoid and the switching solenoid are working fine.

Should I ditch the whole system? Pull the ACV, put on a block off plate, throw the air (same as smog?) pump into the garage next to the dog food? Plug the vac lines? Doc, then I won't need a cat, right?

rowden

...I think I'm running very clean already. My mix resistor has a wide op range, and the bypass on the air box is very responsive to adjustment. I wish I knew better how to set it properly. No substantial exhaust smoke. 175K miles on my grey/grey rocket.

Rx-7Doctor

iTrader: (13)

If yo are going to ditch the catalytic converter and run the RB presilencer and muffler set up then you will be removing the ACV and air pump and using the block off plate.

rowden

Ok. Will my fuel economy or cruise control suffer?