hey guys.
let me know please of what u think about this set up.

i am thinking about hedman long tubes with 2.5" duals into 2 pyes high flow mini cats and flow 1 chamber. i am thinking of down the road onece i have a cam and all that. to me nothing sound nastier with a cam than i chamber flows. well except for dynomax bullets. that would be an option too. i'll def retain more clearence. would i need another 02 bung and sensor for the driver side. and do the headman 68460 come with them.

thats def an option too. being to loud does not concern me. its not my D/D.
its the car thats in my sig.


all opinions good and bad are welcome. let me have it.
tanx.Jay.

 

The long tubes don't come with an O2 bung, so you'd have to weld one on the collector.

Are you doing the cats to pass sniffer? If all they care about is them being installed, you shouldn't have a problem. But, technically they are supposed to be in the factory location.

 

thanks. i thought i'd have to install an o2 bung. but do i need 2 of them. i'm not trying to pass emissions i'm not even sure i'll put them on. i just want them on for some back pressure and to act as a filter for some of the fumes.

i want it to go over the axle. i've got these killer tips that i've had for 2 years and i'm dying to use them.

 

You only need one O2 sensor.

Back pressure bad. Don't want.

Lower fumes okay.

Back pressure bad.

 

yeahi agree,but i don't want to lose any more torq than i have to.thats why i'm getting high flow cats.

 

If you do 2.5" pipes, with any chambered muffler, you should have plenty of backpressure. And cats will take away from that cool noise the headers will give your flowmasters.

If you dont need to pass emissions, cats are just something to waste money, drag on speedbumps, and eventually colg or blow out.

On another note, I dont believe flowmaster makes a true single chamber muffler. Unless you are talking about cherry bomb / IMCO?? They have the "extreme" series which is a true single chamber, and sound sweet. I have had the "pro" series, which is similar to a flowmaster 40, on my last car. They were great mufflers, alot better constructed and durability than flowmaster IMO.

This is the IMCO / Cherry Bomb extreme:


here are some clips of the IMCO mufflers I found for reference:

http://www.youtube.com/watch?v=7vQ-iubE4Kc

http://www.youtube.com/watch?v=50-KY6ejeoI

 

Torque doesn't come from back pressure, it comes from low-RPM scavaging of the exhaust. This comes from keeping the exhaust flow at the port high, which is done with small tube headers, not back pressure.

1-5/8" long tubes will be fine.

 

thanks Slow. i actually like those mufflers better. ur right the 10 series flows have 3 small baffles in them, these are the only single chamber mufflers i have seen. they will prolly be alot deeper and louder than the flows.thanks again.

yes it doesn't produce torq but it helps to maintain it.
i understand what ur sayin,but too much flow will kill low end torq and put the power way up in the power band. it belongs down low.especially for a street application where it will never see rpms that high.

i have 3.73 gears so it may not effect me that much, but i'mstill concerned about it.

now i know that this is a rotary 4cyl, but i had an 86 rx7 about 10 years ago. i put a long tube header and a high flow cat into a straight through magnaflow and a 3" I-pipe. my torq took a plummit untili got around 4500 and up rpms.
that was way too much flow for that car. the motor didn't have enough compression or h/p to warrant such an exhaust.

now if i'm wrong about these cars then i appologize. but if u tell me that i won't need any cats whatsoever,then i will take ur words for it,b/c i know u guys know more about these cars then i do.and i'm cool with that.

i've had 4-5 of these in the past but never got into modding them b/c i was young and broke.lol.

so if i can save the money and have no cats and 2.5" duals, SWEET!!!! with all that said would a 3" dual be too much for what i have right now.
i will mod the motor but it won't be right away.

i want to thank u guys so much for helping me out. i def value ur knowlegde.
Jay.

oh one more thing what should i do about the piping. should i run straight duals or an H-pipe. in other words will the flow need to be ballanced?
it will be done by a shop. the only thing i will do is install the headers.

 

ttt.

ok i've been doing some digging around here on dual set-ups.

i've notice that just about everone that has duals, has them dumped has. i can do that but i would like to go over the axles. so tell me if u guys think this will work.

i will get the summit h-pipe and the needed s-bends. at the end of the H (might have to cut it and the s-bends.) but before the axle i'll install the bullets then take it to a shop and have them bend up the over axle pipes with my tips that i want to use. the bullets i will use iare 12" long.

do u think it will be to low to the ground. i think it puts the bullets right under the rear floor pan. its hard for me to visualize. thats why i'm asking.
thanks.Jay.

oh. can u guys tell me wich 45 bend i need here,if any?

http://store.summitracing.com/egnsea...4294820497+115

 

Oh, I was wrong. I never had heard of a flowmaster 10 series. For whatever reason, you can only find it on their site by looking under the "race" category. I didnt know they even existed.

That said, if you do decide to go chambered muffler, the flow 10s would work too. Sorry.

Another muffler you *could* try is those powerstick ones from classic chambered. Stainlessworks has them too, but more expensive I think.

http://www.streetfire.net/video/7c57...d500ad90a5.htm

 

Rotary engines are more like a 2-cycle engine. What works for them doesn't work for 4-cycle engines. Back pressure doesn't maintain torque.

1-5/8" longtubes will be fine on the street for a 305.

 

i've been searching the threads for 3 hrs now.
i've come to the realization that removing all my smog **** isn't worth doing.
i am also worried that now i won't be able to run long tubes b/c there is no such thing as emission campatable L/T"S. i am not going to get rid of a cc carb. i don't want to pull to much origianal stuff out of this car. but i want a killer exhaust and later on a re-built 305 have a sweet heads and cam package. i don't want to mess with the cpu either.

i like my functioning power bulge hood. is there any way i can plug up but not remove some smog stuff so i can run L/T's and duals,and not have it affect anything?? if so what specifically, if not i'll have to pay allittle more money and go to a full bolt on system. or have shortie headers and true duals.

dude my fvkin mind is mush.i am so fvkin frustrated right now. every thing i have read is ruining my fvkin plans. i want to maintain a certain place in this cars direction. sorry if that doesn't make sence. so some things are just out of the question.

so i'm sorry. but i really need some help here. i don't have to run it throughinspection anymore. it will be tagged classic.so it is emissions excempt.
thanks.
Jay.

 

Well, being emissions exempt is a great thing. If you car is "classic," that is like giving you free roam. That is the best possible thing that could happen.

I dont know about jersey, but here in CT if you have a classic car, and especially if you have the antique tags, you can get away with anything. You could run stacks out the hood if that was your thing!

What we really need to know, is, what is the purpose of the car gonna be? Is it your daily driver? Weekend only street cruiser? Drag strip only? What is your primary use gonna be?

 

well its my nice day only/car show (when its done) car.it will never be on a track.but i'm keeping everything mostly original except for a few 2nd gen throw back items.
the motor will remain,but will be built to about 300-375 h/p. the trans will be rebuilt and so will the rear.

after all this back and forth with the headers. i've decided to stick to my original plan. it will have bolt -ons,obviously. but it will appear stock. i just don't want to cut this car up beyond the point of being able to bring it back.

i really was concidering yankin out all the emissions stuff just to have the exhaust i want,but it will defeat my overall goal for her. i guess i got caught up in the moment.

so thank u for staying tuned and all ur help. but i am goin with the hooker 2055's and the american thunder cat back. i will prolly get the mac test pipe with air tube and delete the cat. it will sound good like that too.

jay.

 

it does to a point. maybe not with a high h/p built motor. but on a stock motor built with in specs of the epa. too high of a flowing exhaust will kill ur bottom end. period. its a fact.
gearing has alot to do with it too. if ur running 2.73's and put a 4" i-pipe and c/b. well its gonna be a pig of the line. but put in some 3.73's or lower it prolly won't hurt to bad. i would to anyone who has a 4" exhaust on a stock motor like mine with the same gears,and a 3" system. i would smoke them

and yes i know gears don't produce torq either. its a feeling of torq.

and a real 4 cycle engine like my harley? well when i got it it had drag pipes on it. wich is only good for dragracing b/c its all up top. off line torq suffers baddly until around 4500 rpms. so bigger is not better unless u are on a track.

all motors air pumps so this applies across the board with differences in all of them.

too much of an open exhaust will hurt performance.