I have one with a k&n drop in filter but didn't really feel a difference? i have a stock catback so i think that's the problem? It did make my car smell alot more though? thoughts, suggestions

 

nobody

 

I'm guessing thats some sort of intake system? buy a header and exhaust otherwise everything else you do won't make much of a difference. The exhaust is the first thing to modify on any rotary I think the intake is actually the third or forth thing to even worry about.

It's like a 22% power gain for a rotary with just a quality header and exhaust system added. The key is the word quality. Think racing beat! thats my opinion though for exhaust choice. Both my rx7s have them they both made a very noticable difference and both sound awesome. Everybody asks me what kind of exhaust I have but then runs away when they see the price. It's stainless you only have to buy it once its worth the money and its only relitively loud at high rpm and full throttle.

There's a book or used to be at www.foxed.ca called something like how to modify an rx7 that you can download for free I suggest anyone that needs to know the basics of rotary modification read that first. Everything in there is basic info but at least it will point you in the right direction. Hope it helps.

 

Yeah i have been wanting a racing beat dual exhaust, i plan on purchasing one soon, hope it awakes the car finally. But about the headers? Do they make any heat shiels to hide them since i live in communist california.

 

I have no idea, but I solved that problem by moving from Ca to TX LOL! I know that doesn't help you any but it sure helped me. No smog tests here just a brake and lamp inspection that costs $15 a year!

 

quality??? ?I've used RP's bonez parts for a long time and had wonderful success. just because you pay a lot of money it doesnt mean you get quality. I have paid a lot of money for parts that were expensive and got crap and bought cheaper parts to replace them and it blew the expensive parts out of the water. really when you are talking about exhaust there isnt much of a difference other than the sound and diameter. In the end all it is, is a pipe for the car to crap out of.

 

I know I'll never be able to change you mind but there's a big difference in a quality exhaust and a mid priced exhaust.

First of all I didn't say bonez is not a quality product. I've never owned anything from that company so I have no clue if its good or bad.

Second a exhaust system is way more than a pipe for your car to crap out of. Next thing your going to tell me is that a turbo car needs back pressure or something crazy like that. A higher quality exhaust is usually tested in many configuratioons before being released to the public. Things like type of metal, how many resonators there are and where they are possitioned in the exhaust flow, how the muffler is designed, how many mufflers, what type of flanges, what type of gaskets, hardware, diameter, and many more things all matter when designing an exhaust. everythign matters just like on the intake side of the engine its no different. The tone or sound of the exhaust matters a lot to most people as well as the fit and finish.

On my car the exhaust tips fit exactly in the cutouts for the stock bumper. Does it matter alot not really but its nice. The mufflers are offset upwards from the ground for more ground clearance. They cost a lot so its nice that they don't scrape the ground coming in and out of regular driveways. The hangers were exactly where they were suppose to be and it was easy to assemble and get on the car. The exhaust is also lighter than the stock one which is not surprising considering the stock exhaust manifold probably weighs as much as half the new exhaust. Like I said I don't know about bonez but If you go get an exhaust built at a muffler shop you won't get the gains or quality you will get with a real bolt on exhaust system designed for the car. Also I can buy the gaskets at racing beat or mazdatrix with ease. Another neat feature is it unbolts in sections and isn't all welded together so depending on what work is being done to the car I can just unbolt some of it and the rest can stay mounted.

When I got mine I also replaced all the rubber hangars with the package racing beat sells. The one with all the factory ones. Good thing cause about half of mine were broken anyways or almost broken. Rubber does wear out of course.

 

Oh...you sad ignorant fool...

I want to dig up one of RotaryGod's post on exhausts...but its late and my head would explode if I read one of those right now.

 

I will believe you when you have any proof that your exhasut makes a damn bit of difference after the turbo other than flow rate based on diameter bends and wether or not you are using a cat resonator or straight pipe. obviously the muffler baffles or lack of in a straight through canister can be a determing factor but that about it. Any proof? Please share.
show me two exhausts with the same bends, diameter of piping, similar muffler and midpipe designs
and then a large change in horsepower and torque numbers under similar conditions until then I say you are all talk.
However skidtron does have a point about fitment and sound can be a determining factor for some as far as sales go. When it comes to design though if you go through all of the R and D to design the highest flowing exhaust as possible yes there are a few things you can do about getting extreme in design but in the end you have worked really hard for maybe 4 or 5 more horsepower. It really doesnt make since in the end to spend so much and get so little.

 

Considering we are in the naturally aspirated section of the forum, I don't have to prove jack about a turbo back exhaust.

 

ok smart *** how about a naturally aspirated motor?

 

wow this turned ugly So anyone else know where i can get the rb exhaust for a good price? Or if they make heat shield to cover the rb headers?

 

Well lets see, we have things like headers...so there goes a bunch of theory into long vs short primaries. collected vs uncollected, then into an expansion chamber or an anti-reversion chamber, or into an exhaust box or into single exit or dual exit. Not to mention that it should be matched to the port inside the engine as well as the intake.

This thread gives lots of info from Rotarygod about all sorts of exhaust types. https://www.rx7club.com/showthread.p...hlight=exhaust

This thread gives some detail into the exhaust box, again from Rotarygod
https://www.rx7club.com/showpost.php...3&postcount=10

In this thread Hyper4mance2k picked up 51whp by changing exhaust setups and retuning. (31whp pre-tune)
https://www.rx7club.com/showthread.p...ht=racing+beat


So to say that an exhaust is just something for the car to poop out of, or that the only thing matters is diameter and bends....its just not correct. A proper n/a exhaust is much more then that.

 

The for sale section usually has some good deals. But you may have to piece it together.

My buddy has a full exhaust that he would probably sell off if you are interested. You can PM me about it.

I don't know about any decent heat shields, my friend stole a speed limit sign and wrapped it around the header as a heat shield. I made a crappy one that just bolts to the top two bolts and extends over my headers just to be a basic shield. It would be a dead give-away though.

You can also look at the racing beat downpipe instead of the header, that way it will look more like stock.

 

he changed a jet and and changed the timing also he changed the exhaust on many aspects so the test has many variables so wether or not the exhaust is actually improvving power is not able to be proven.

however i should appologize for my last post I really should be in a better mood before i start trolling the forums. so Sorry.

As far as the racing beat unit it is probably the best unit as far as making a slight power improvement while still appearing fairly stock and keeping noise down but as far a power well that depends on your setup and how much flow or backpressure you have upstream.

 

The exhaust alone made 31whp before changing the jets and timing. Of course he did go up in diameter, but the point there is the exhaust can make a huge difference.

I should also apologize for my original post, when it gets late I start to miss some of TitaniumTT's or reTed's postings so it might have come out more edgy then I usually intend to make posts.

 

huh? he tuned it with the old exhaust. strap new exhaust on, picked up 31hp, retune car to take advantage of the new exhaust, and picked up 20more.

so if he had retuned it with the old exhaust he would have lost power.

 

i use a bonez 2.5 hi flow cat , and rb 2.5 headers ... just that combination on a 88 vert already made a world of difference

 

If you still have the stock cast iron exhaust manifold on the car, don't expect gains to be too spectacular no matter what you do after it. The outlet of the stock exhaust manifold is only 2". No matter how big or free flowing everything else is, it all still has to go through this hole first. There are some gains to be had after the manifold of course but the biggest gains will be from replacing it. A header does 2 things to improve power. First of all it retunes the system to aid scavenging and second it's outlet adds needed area to the exhaust flow path. There is of course a limit and going too large will reduce power too but a 2" hole coming out of a small shoebox shaped exhaust collector is a terrible way to make power no matter how you look at it. It is a great way to help muffle the exhaust though which is why it's there in the first place.