Rotary Racer

<-- Jumps into the fire

First off I am not posting facts only opinions based on my experience. I have drove/rode/installed a lot of different pre-made exhausts in the N/A RX-7’s. Here is the list of exhaust systems I have had experience with to date:

- 1. manifold, bonez race pipe, hks cat back
- 2. manifold, RB down pipe/pre-silencer, hks cat back
- 3. manifold, bonez race pipe, RB cat back
- 4. manifold, RB down pipe/pre-silencer, RB cat back
- 5. RB single outlet header, pre-silencer, hks cat back
- 6. RB single outlet header, high flow car, hks cat back
- 7. RB single outlet header, pre-silencer, Greddy grapefruit shooting power extreme
- 8. True dual with RB mufflers

Out of all of them I would have to say the True dual system is the best pre-made system I have had experience with. With the ports tied open low end suffered a bit but after that midrange and top end are one smooth pulling motion that makes closure time of the vehicle in front of you very quick . For people that do not want to spend the cash and don’t want to mess with there manifold, system #4 is great. With the ports tied open the low end loss is not that bad, good midrange, and it pulled to the buzzer (but did strain a bit). A big improvement over that is system #5 though it would probably pull a little harder on the top end if it had the RB mufflers. System #7 was just annoying loud/alert all cops and small animals that you are coming buy. I know Mazdaspeed7 would rather have a custom made system (witch might or might not be the best to date not sure I have not seen dyno #’s or any other data), but for people who just want to bolt up an exhaust the true duals (though on the expensive side) are great.

rotarygod

iTrader: (1)

While I personally don't like the true duals system I can not say that it sucks. For my purposes it does but maybe not for others. I have personally had problems with a Racing Beat exhaust. I hope that it was a rare experience for them. They do have a big reputation and have done more for rotaryy development in the U.S. than probably anyone else and they did it before anyone else.

FWIW: The Racing Beat exhausts are not stainless steel but rather thick wall mild steel with a coating. This is why they are so heavy.

I personally do like to design and build my own exhausts since I have the ability to do so. It does save money. However, I know some car enthusiasts that can't change a tire without a class on it. The muffler shops around me do the crimped bends and second rate exhaust work. If I had a muffler shop that could mandrel bend I'd just give things to them. But I don't. Oh well.

Enough bickering here. Everyone has different tastes and different needs.

vectorminds

Hey rotary racer, thanks for giving your experiences will all of those different systems... definately a good thing to compair them all....

since you have heard both the racing beat and the hks mufflers, which do you prefer... and what do you think is the sound / performance difference between then

jgrts20

damn guys too much to read!! hehe : p
anyway i run true duals and luv'em(trues all the way) if u notice on my signature i run RB headers/presilencer along with a Dynomax CATback system the tone is: very deep at low RPM's and midrange tone at higher RPM's!! basically it sound like a beast all around, not no ricer crap tone augh they sound like ****!! well its up to u what u want but theres my 2 cents!! l8tr bro, PEACE!!

Capn' Wankel

I am on Mazdaspeed7s side with this entire exhaust thread and all others like it. I would like to point out two things in favor of mazdaspeed7.

1. I did lots of relearch about exhausts before I went and had mine custom welded together. I talkde to Racing Beat a lot as well.

2. Conversation with Racing Beat....the guy on the other end of the phone trying to sell me their "performance" parts had no ******* clue what he was talking about. Performance here is the key word. He told me that the headers that they sell MAKE NO HP DIFFERENCE OVER THE STOCK EXHAUST HEADER. So by that statement they sell that item for $$$ taking advantage of others. (BTW anyone who has ever taken off the exhaust manifold will see just how ridiculously engineered it truly is so that statement is a pile of ****)

3. I asked them what the distance was to the point of collection on their streetable collected header was and he couldn't tell me. Umm real performance shop that is.... He ended up taking a tape measure to one and gave me a very rough approximation as to where the collection point was. It just so happens that it was where I was told that it needed to be for optimal power band in an autox exhaust set up so I bought it.

Bottom line is that they hire monkeys to run their phones......which doesn't reflect too well on their business. Or they are taking advantage of uninformed 7 owners. Read between the lines guys.....if a gain of 30 hp is on the website for an intake then you better ask what the circumstances are because I bet with a 1000 hp 7 you can get that much with an intake. The stock exhaust manifold offers just as much flow potential as their header....if a catalytic converter is located right after it. They are a business looking to promote their products and will do anything it takes to sell those products.

-Lee

PS- If you choose to become educated about your car then you will know that spending that amount of money on an exhaust is just plain silly.

PSS- Save 1000 dollars and get a custom single built with more top end power and put that money in to the bank. You will be able to pay for all your gas for 6 straight months on that money in the worst of conditions.

3.

jgrts20

BTW the way i spent about 750 bucks total not $1000!! i think it was reasonable!! PEACE!!

vectorminds

jgrts20... i might be reading it wrong, but you seem to be collecting the exaust into the presilencer and then using a catback behind it... the mazdatrix/racing beat true duals setup keeps it uncollected the whole way, with two presilencers... each rotor gets its own exaust path and it is never collected

if i read that wrong im sorry... but using all the name brand parts i dont think it could be done for 750 to make a mazdatrix/racingbeat true dual

JerryLH3

iTrader: (11)

Whoah! Here's the part I'm interested in. So for an ideal autocross setup, the streetable header would be the best choice? I'm assuming an ideal powerband for autocross in our cars would be 4k-7k RPM?

Tell me more....

Capn' Wankel

Hehe Jerry I was given some "reliable advice" from a friend who knows his sheeite. He is actually the moderator of one of the forums here and told me not to tell anyone about this tech advice about exhaust setup because he would get PMs every half a second hehehe. I have heard though that a straight piece 3" in length straight from the block before making any bends is an appropriate start to an exhaust set up. And then 27 inches from the block is a good collection point for the exhaust to a 2.25 inch pipe which expands to 2.5 inch about 3/4 of the way down the exhaust and ending in a 3 inch pipe and muffler. I have been told that this would be the optimal autox exhaust for a stock ported 13b NA. The man is trusted by all on this forum that divulged this information to me but wishes to remain anonymous.

-Lee

EDIT* The streetable header is collected at roughly 25 inches I am told by the monkey on the other end of the phone. I am no pro Racer so I believe it is close enough to 27 inches to suit my calculations....and one of these days I am going to have a straight section 3 inches long made to fit between the header and the block so the length will end up approximately 28 inches till collection.

vectorminds

Capn' Wankel, that exaust you described what kinda powerband does it make for... how much low vs middle vs high as compared to stock or a true dual?

j200pruf

iTrader: (4)

I would again like to say please read the exhaust tech articles from Yaw Powers web site (hell read the other ones also). And if you want to learn more about exhaust tuning search the net, (2 stroke books have TONS of info). http://personal.riverusers.com/~yawpower/techindx.html
http://www.google.com/search?hl=en&l...=Google+Search

1987RX7guy

iTrader: (3)

C'mon Mazdaspeed7

rotarygod

iTrader: (1)

That shouldn't be too hard to make. The good tone and dual mufflers is already there by default so half of the equation is done. Take the duals and add one more component right before they split from their parallel paths and go two different directions... A 2" tangentially siamesed X-pipe from Dr. Gas. It would need to be custom installed since no one sells it for an RX-7. It is not an H-pipe and not a traditional X-pipe. It scavenges. It does it in a really neat way too. Then again I'm not going to pay for dyno time or make one just to satisfy one person. The important thing is that we all have the freedom to choose what we want and as long as we are happy with it then thats all that matters. Saying that, the challenge has no reason to be taken on or met. This isn't High School. Use what you like.

1987RX7guy

iTrader: (3)

Well being the fact that I will pay him for his trouble I would think that it would be worth the trouble. I am willing to put up the cash(so long as it is less than 1250 dollars) for his trouble and I will STFU for ever and no longer deffend my point. Whether he takes it or not I do not care really I just want to see REAL proof of the superiority of this exhaust. Besides I would think that if he made the BEST exhaust for our cars he would make money selling copies of this setup to the rest that want the best HP from an exhaust.

In any case I stand by my challenge/offer I think it is fair since I would pay.

mazdaspeed7

Let me explain my gripes with RB and Jim Langer. Yes, I have spoken to him before. He is a good guy, and makes some great products. But as much as I hate to say it, they are not n/a FC parts. He does know his stuff, and for the most part, has always been helpful to me. But his view on 6 port motors ruined it for me. He told me they were mild motors, and not worth even modifying.

Rarest, IM me sometime.....I want to talk about this.

But the quality of their parts are top notch, and Jim is a very knowledgabel guy.