ddub

before anyone tells me to use the "search" feature i already have and am just as confused...

alright so, after extensive reading/research on this forum it just seems like everyone has a different opinion...right now i have the RB header to presilencer to hks dual mufflers, but i have to pass emissions next sept so im going to be putting the bonez cat in there, now when i do that i was thinking about redoing my exhaust to yield the most power i can...at first i was going to get dual n1's but the loud factor seems too bad so i would have to use silencers and that kinda defeats the purpose after i put those on...so i did a lot more reading and research on the internet, and for a while i was thinking that the bonez cat 2.5 in/out with 2.5" piping to a magnaflow 4" round muffler 2.5 in/out with 2.5" piping to 3" chrome tips however my problem is i dont know if that would even be better than the mufflers i have now? or if there is a better magnaflow muffler to use? or is there is a better system to use? does anyone really know what mufflers or system or pipe size actually yields the most power on an N/A?


any suggestions and help would be great...im so confused...

1987RX7guy

iTrader: (3)

MAX Power+bolt on= True duals. Anyone trys to tell you otherwise better have proof.

Magnaflow is a big Let me find the links to the vids I hope sonic still has them up. :-/ Magna flow is probably way louder than APEXi which is hell aloud already.

ddub

well if i went the true duals route i'd hafta put in 2 cats then if i want to pass emissions

1987RX7guy

iTrader: (3)

its called the OL switcheroo.

JUst keep the high flow cat setup you will have and get true duals. or make your own like two of the members here have done.

Refer to this thread for the vids: https://www.rx7club.com/forum/showth...hreadid=224056 MAX's car is the one with magnaflow cans. Mine has true duals. I think its pretty easy to decide which one is quieter. I have also beaten MAX in a race so I don't doubt the true duals power.

ddub

yah i dont doubt that true duals would yield the most power, but i dont have a lift or welder or all the tools needed to put in and take out the exhaust systems each time i need to pass emissions, so that'd be difficult for me

mazdaspeed7

Wheres your proof?!?!

Ill argue physics with you all day, and you wont win. So until you get a dyno graph of true duals compared to a full, collected exhaust, you have NOTHING.

1987RX7guy

iTrader: (3)

Well consider this: once every year for one day(probably around 5 hours total) All you need is a jack and two stands. Other than that just the normal tools you use for the exhaust install. I would rather buy from mazdatrix since I am also sans welder or skills for it. Take around 1 hour to remove the duals, an hour for the other setup, hour for the test, another hour for removal of the other setup, and an hour for the duals again. Aloow another 15-30 minutes for exhaust leak checks and your don't in less than 6 hours. Not bad for ultimate bolt on eh?

1987RX7guy

iTrader: (3)

Hello? didn't I just say I beat MAX? I guess you missed that part.

ddub

well, first of all i have no jacks or stands lol...second, by the "tools you use for the exhaust install" i assume you think i'd be putting the exhaust system in myself? that'd be another no =/ im gonna be going to a shop to have em weld everything in for me cuz ill be getting custom piping made...it seems cheaper to buy the cat myself, buy the muffler/s myself and go to a shop and have them do the piping for me

1987RX7guy

iTrader: (3)

Jack and jack stands= 40$ plus tax. Simple tool kit=20$ plus tax.

And I would think you could do it in your garage or your front lawn if need be.

1987RX7guy

iTrader: (3)

mazdaspeed7- It was the same road same temp same time of day. His car has LESS miles than mine and his tranny and differential are in better condition than mine. He also has newer tires and an LSD rear end. Add to that a light TII hood. I also usually have tons of junk in my car so that negates the weight redux I have done.

Mazdatrix has a dynograph. I still have NO reason to doubt them. If you doubt them then I don't see any reason why you would not doubt me on the same thing.

mazdaspeed7

Mazdatrix compared it to a stock exhaust. Almost ANY exhaust will make more power than stock. This isnt an S2k, FC's are choked on th eexhaust from the factory. ANYTHING is an improvement. I want to see your dyno comparing a full collected exhaust to a full true dual exhaust. And its their ad anyways. Do you really expect it to be unbiased? There are so many variabled that can be manipulated, aside from the exhaust that will affect power. Im not saying they deliberately rigged the dyno, but it is as far from conclusive as your opinion.

Physics it is...
First, true duals have considerable more surface area alogn the pipes than a collected exhaust. More surface area means more friction with the flowing gasses, which slows them down, adding to back pressure. Next, true duals are NOT tuned. They totally throw exhaust tuning out the window. You cant go wrong. A collected exhaust, onthe other hand, utilizes the pulses to scavenge exhaust gasses out of the chamber. It only works within a certain RPM range, but within that range, it will ALWAYS make more power than a true dual. Also, it can be tuned to where you want it.

So tell me again why true duals are better?

1987RX7guy

iTrader: (3)

I don't have funds to buy or make a collected exhaust and drag all that stuff to san antonio to dyno it. Not to mention money for fuel, hotel room, food, and the dyno.

I know and admit that the collected makes better peek HP but what about the other RPMs? lol how big is this RANGE?

And it is just like a grading scale man. Mazdatrix has SOMETHING the collected guys like you have NOTHING. Their data beats your NO data. so mazdatrix gets say a 50 and you all get a 0 for no "work shown" lol
True duals also sound a hell of a lot quieter. I have videos to proove it now. the drone from a collected exhaust is just horrible. I would wagger to say you would get a ticket for it.

I don't really need much more proof that they are better since I beat max exahsut for exhaust. Back when I had the stock intake.

mazdaspeed7

No data? Tell me some physics behind why true duals are better. I just listed a lot for collected exhausts, but you have NOTHING. The mazdatrix dyno is NOTHING. Dont even get me started on sound. My friends unmuffled, collected FC sounded better than my true duals. Every one of my friends agreed too. The drone is from the wrong choice of mufflers. My true duals ring 10 times worse than any collected exhaust Ive seen. Do you enjoy sounding like a dirt bike or weedeater? I would prefer my car to actually sound like a car...

Would you like a cookie? There are countless variables. Did you test both exhausts ont he same car? If not, how can you say that your exhaust made more power. Your car may have, but you have no reason to assume it was your exhaust.

You have not brought up ANY valid points from a physics standpoint. Physics can explain everything that determines power in an exhaust, and unless youre looking for exact numbers, its not even that involved. You can still compare though. Its obvious which one is better by which has more positives and less negatives.

1987RX7guy

iTrader: (3)

Lets see I said they were quieter meaning LOWER IN VOLUME. Tone and what an individual likes is subject to all of our oppinions. More people like them than not atleast those that speak to me. You are an exception that I have not seen repeated much.

My car doesn't need to sound like a piston engine car for me to be satisfied. Its a rotary and sounds different. MAX's car doesn't sound like a piston engine car. It sounds loud and annoying just like all the single exhausts I have heard comming from N/a's. Physiscs ok well I am not an A+ student in that subject but you didn't state any numbers, formulas, or test results. That to me is just a theory not DATA. DATA means numbers to me not what SHOULD or DOES happen. A number speaks with power a formula doesn't at least to me. The last time I checked a dynograph was a valid way to rate the HP gained by using a specific exhaust. That IS data. Like I said I still have NO reason to think they changed **** around or tinkered with other things to gain 35hp out of them.

About my coparison to MAX's car it is obvious that it is not a gaurantee that the duals make more power but its a real test on the road. MAX weighs about the same as I do and we both had exhausts and some weight reduction. that is pretty good for me. I didn't win by a SMALL margin either.

importboi22

this is for the guys with true duals...

1987RX7guy

iTrader: (3)

I am trying to stay as civil as possible


MS7- how big is the TUNED RPM RANGE answer me!

mazdaspeed7

Proven theories speak just as loud as numbers, sometimes louder. Are you going to dispute ANY of the theories I posted?

Powerband? Me and a friend made the collector for his S4. There was a small power loss below 3K rpm, but from there past redline, it screamed. The midrange and top end was significantly improved.

About the race with your friend. Theres ten thousand variables aside from the exhaust. You car isnt identical, your motor isnt identical, etc.

And once you throw ported motors into the mix, true duals are even worse. My true duals were acceptable when I had a stock ported motor. Now, its nothing but a nuisance.

mazdaspeed7

And in the end, the numbers still have to play by the rules set by the theories, so theyre useless without the theories. So are you going to try to dispute ANY of the theories I posted, or post some that back up your point of view?

1987RX7guy

iTrader: (3)

I like numbers better.

So your saying that a SPECIFIC RPM range is a 4000 RPM range? that is really specific isn't it. Define smal power loss and screamed. I don't remember reading those in physics class or on a dyno chrat ever. nor significantly.

Like I said. That was only proof to me. since we were and still are at close stages of modification. But undoubtedly his and my engine are not the same. but I would rate his car in better condition than mine.

I didn't say anything about ported engines The true duals are made for stock ports and will not be efficient with large or extreme porting. Although I remember reading Rob from pine apple racing uses true duals on peripheral ported engines.

mazdaspeed7

The power increase is subjective. I know that, Im not going to try to tie a number to it. Butt dynoes mean nothing. His car felt much better with a collected exhaust than mine did with true duals. My top end couldnt compare when I had the same mods. But its completely subjective, and this is by NO means conclusive.

My friends collector was tuned for 6K rpm. Which is right in the middle of the powerband. The powerband is easily broad enough you dont catch a bad spot when you shift. Drivability is no worse than true duals.

Read my previous post about numbers. Numbers are just numbers. The theories are what determine how the numbers act.

Arguing this subjective stuff is bullshit. You want to prove a point, get to learning. You havent brought up anything scientific that gives an edge to true duals.

1987RX7guy

iTrader: (3)

I will not dispute anything that is FACT. but can you please show us all how much the FRICTION will detract from power. And show us the formulas and all the rest of the computations for comming up with these figures. I don't think I have ever seen them.

I already stated that I am not good nor am I taking physics in my college classes at this moment so I wouldn't even know where to start to counter your arguement or theory(s).

But like I said. PEAK HP goes off to the tuned exhaust if your theory is correct. But I would really like to see proof that a TUNED range is 4000RPMs in width, the added friction will make the duals less powerfull than a collected exhaust, and I want to see the numbers and how you got there. PROOF can't be denied. Given proof of all of that you can take your prize and go home with it. But in the many threads since you started this with me you have yet to provide that elusive proof or data that will stand up for your claim. Remember I offerend you a great deal. 1300 dollars I beleive for a tuned collected exhaust that out matched the true duals. Money for the taking given your theory. But you didn't take me up on it. You said you had nothing to proove but you keep saying you have proof. You have had several chances. Now let us have it.

Again show me WHO makes a better setup than the true duals or WHERE I can get the setup from. Wouldn't it be easy for a big name brand exhaust company to make a FULL collected and TUNEd exhaust that would be cheaper, better, and more affordable than the duals? I think we would have seen it long ago don't you?

mazdaspeed7

Just in case anyone else reading this thread doesnt know, I have true duals right now, and not a day goes by when I dont regret spending that money. I have personal experience with both, and collected is the ONLY way I will ever go. Im not trying to force my opinions on anyone, but I want the facts to be there. I cannot stand to see people spread misinformation.

1987RX7guy

iTrader: (3)

MS7 if its so easy to make a tune exhaust why haven't you sold your true duals and made yourself a collected one?

And why don't you get a video for us all. I want to hear the dirt bike. I don't think my car sounds like a dirt bike. Most people comment on how nice my car sounds. Not one person: import or domestic has said ONE not even ONE word about my exhaust that makes it sound bad or loud.


Listen to clips of the corksport cat-back, APEXi both N1's and GT are all louder than the true duals. What muffler would you use to not make them sound like crazy weed wachers? the single and collected exhausts I have listened to with the exception of one all sound like crap. Noisy and loud.

mazdaspeed7

Its not worth my time to dig up numbers. ALL that matters is that there IS more friction with true duals, and singles WILL flow better for a given cross sectional area.

Quote:

I already stated that I am not good nor am I taking physics in my college classes at this moment so I wouldn't even know where to start to counter your arguement or theory(s).

Then why are you trying to argue when you just admitted you have no background in what youre arguing? Personal preference is JUST that. Its not facts, its YOUR opinion of YOUR exhaust.

Quote:

But like I said. PEAK HP goes off to the tuned exhaust if your theory is correct. But I would really like to see proof that a TUNED range is 4000RPMs in width, the added friction will make the duals less powerfull than a collected exhaust, and I want to see the numbers and how you got there. PROOF can't be denied. Given proof of all of that you can take your prize and go home with it. But in the many threads since you started this with me you have yet to provide that elusive proof or data that will stand up for your claim. Remember I offerend you a great deal. 1300 dollars I beleive for a tuned collected exhaust that out matched the true duals. Money for the taking given your theory. But you didn't take me up on it. You said you had nothing to proove but you keep saying you have proof. You have had several chances. Now let us have it.

Again show me WHO makes a better setup than the true duals or WHERE I can get the setup from. Wouldn't it be easy for a big name brand exhaust company to make a FULL collected and TUNEd exhaust that would be cheaper, better, and more affordable than the duals? I think we would have seen it long ago don't you?

Why should I make you an exhaust? I know what works, and what doesnt. I have physics, and experience to back me up. If you cant realize that, then why should I even bother tryign to help you? If it wasnt for the other people reading this, I wouldnt even waste my time arguing with you. I could care less what you think. I just am sick of hearing this bullshit about your exhaust is best because mazdatrix says so.

You want proof? The proof is in the theories. The numbers wont make the theories change.