PURPOSE: to shoot flames, but maintain low end with minimal volume increase.

CAR: 1991 N/A Coupe

SET UP: OEM manifold, hollowed p-cat, Superflo, RB catback

PLAN: to achieve free-flowing exhaust status, i plan to replace my Superflo with an RB p-silencer or RB resonator.

QUESTIONS:

1. whats the diff between a resonator and presilencer if any?

2. being that i have an S5 with my 5/6 ports activated a different way (not back pressure), will removing the main cat still affect my low end torque? will they still open?

3. abit of a personal thing. what will it sound like? the last thing id like is the civic fart-can sound or something high pitched too much.

thanks guys,
Carlos

 

I don't know why you'd want to shoot flames. Kevin set an SUV on fire with his... Also, it's a cop magnet. If this is your DD, then NO WAY!!!

 

^
i think that line sums up the 2nd gen forum nicely
j/k

as for sound...the sound of an unrestricted 13b is very 'unique', but at the same time very LOUD. i am going to be going straight pipe shortly (getting test pipe fabricated in place of the cats), with Apexi N1 mufflers, but i will be deciding whether i will be using that on the street or just at the track...i'm sure after i set off a few car alarms i'll realize it is too loud
again, i say the tone is very unique, and is far from being what the noise a riced out civic makes. at the same time it's no Ferrari. it's actually not a very smooth tone at all, a little hollow for my liking. kind of a mix between gas-powered trimmer and a Cessna, lol...but it's one of a kind

 

Your ports will open just as they have before. Like you said they are on a different system than backpressure. As far as torque, you should gain with an opened up exhaust on it. I started with a cat-back, then had a straight pipe put on, then went to RB and got a header/presilencer. The cat-back had a better tone than the stock mufflers. The test pipe made a whole lot more noise, droned a bit, but sounded pretty good, and not like a honda(I think it somewhat depends on type of mufflers though), with a very noticable power increase at all rpm's. After putting on the header/persilencer I had another noticeable power increase, less drone, but more noise overall. It still doesn't sound like a honda - but it does sound a bit raspy at high rpms. Shooting flames began with the test pipe - only small pops and little flashes. Now I have a thump from under the car, but I've never actually witnessed it from the rear of the car(I'm always driving ).

 

Backpressure on the exhaust increases torque. That's why people put those wierd disk thingies on their mufflers. you will probably lose a little low end if you but not too much.

 

if I have an S4 and I get rid of the stock cat and replace it with a straight pipe, and go to an apexi n1, will my ports open? Probably not ...

 

if you mean go with an Apexi N1 catback, then they should probably still open, assuming you are going to keep your stock catalytic system. only thing that might happen is your ports opening slightly later or not as fast...
but remember for you S4 intake manifold guys, you can rig it up in several ways to open up regardless of exhaust backpressure. there are cheap to expensive ways. i will posting a write up shortly about how to do it tapping into the main airpump hose. doesn't cost too much, and will work just as good as the stock setup...

 

The RB presilencer has a pickup facing the engine - it should work even with a fairly free flowing exhaust. It looks like it's a "ram-air" pickup more than a pressure pickup.

-=Russ=-

 

Hell No.

Exhaust velocity incrases torque. Those "disc thingies" are a fancy way of tuning the sound of a system, not its torque. Oversized exhaust cause losses in torque because they cause a loss of low engine speed exhaust velocity, not back pressure.

 

Thanks for the reply, but I live in a country where there are no emissions testing, so I will be having the least amount of restriction possible, and hence, no catalytic converters of any kind. I will be looking for your 5/6 port writeup soon :P

 

Well, you could always use straight pipes, but those are a bit loud... I don't think any places have no noise requirements, and even if you didn't have any where you lived, if you ever go to a city that does, you'd have problems.

I'd go with the RB presilencer (so you have the 6th port pickup) and then some low backpressure racing mufflers.

-=Russ=-

 

What I need to know is if all of these parts will bolt up with the stock headers... No point in getting something that will need competely new headers :P

The system I'm looking at right now, would be stock header, Rb presilencer, and some single exhaust. What are some good high flowing exhaust systems that would bolt up to the rb presilencer and give me some good power gains? :P

 

i removed all 3 cats on my s4, then threw on a universal 3-way high flow cat and piped back the air line, the 5/6th ports open fine

 

you could always wire a spark plug to your exhaust pipe.. thats the easiest way to shoot flames without attracting unnecesary attention

 

if you live in Kelowna, BC, then you are in Canada. don't say that we don't have emissions testing in this country dude, we here in Ontario get raped with it!
unless you are in another country, but i've never heard of a country called "Kelowna" before, lol...

anyways, look for the write up in a week or two here in the second gen forum...
if you want me to remind you, PM me and i will PM you when i post it up.

 

I said country? oops, I meant to say province. I came from Alberta about a month and a half ago, they didn't have emissions testing. And I was expecting to get e-tested when I insured here in the Okanagan, and nope, nothing. I guess there's only "AirCare"-ing in the Vancouver area. You should move here, I pay 125$ a month for insurance and no e-testing! woot!

:P