RB - Road Race True Duals - Does this sound right?
 

The exhaust is incredibly loud and sounds abnormal. The noise comes from mostly the engine bay. I believe I have a leak at the headers, but we double checked it twice.. I know headers are loud, but this doesn't sound normal.....or maybe it's just us?

Yes, I do have a header gasket placed.

Please view a small/quick clip of my exhaust

http://media.putfile.com/Full-Road-Race-True-Duals
^ Sounds about 2x louder in reality...

After viewing a couple clips of other ppl cars...defiently something wrong with my exhaust!

I can't diagnose what is wrong, but that does not sound good. Hope you get it fixed soon.

maybe you dont have the hole for the 6 port actuators plugged?

i know this is obviouse, but you did replace all your gaskets and ^^^ make sure the 6 port actuators are now covered/plugged? if you reused your old gaskets you could have a nasty exhaust leak.

TR

Well did you watch vids of other people's cars with true duals or collected exhaust? True duals will sound different. But check for leaks just to be sure.

Nope!! All gaskets are brand new, although, I don't believe we covered the 6 port actuators. This may sound newbie, but where is the actuator? Pictures are appreciated!

Thank you all for your comments!


http://www.racingbeat.com/photos/16326.jpg
Air Control and Check Valve Cover Plate*
1981-92 RX-7 Non-turbo


^ This item came with my exhaust system. I had no idea what it was. Is it required? If so, where does it go? Is this the part that you guys were talking about? The six port actuator?

To be honest, I couldn't find any true dual sound clips, but even then, at idle, it shouldn't sound that loud. The video clip is nothing compared to real life. It's very ANNOYING!

make sure you are using metal gaskets. the paper ones burn through in like 5 seconds and thats what they sent me.

Hmm...really? I didn't notice any major burning after taking it off for the second time.

Can anyone help....?

You need to remove the ACV and block it off with that plate you got with your exhaust. You had to have removed your air pump in order to get those headers on right? Well the ACV is the valve bolted to the side of the motor that your air pump hoses plugged into. Look at the FSM to find out exactly what the ACV is if you don't know what it is.

uh I didn't have to remove anything to install the headers... and I have the rb true dual road-race as well.

It really sounds like a leak...like all of the sound is coming from the engine bay...can barely hear the exhaust

Mind snapping a pic of the header-side of the engine for us?

sure ill get a pic up some time today...that could be the problem.

also if we can't seem to fix it...do you guys recommend a shop look at it?

my car sounded like that until i replaced the disintegreated gasket after the header, very very bad leak, i bet you can smell it pretty good too

thanks for the response! I've emailed racingbeat about my problem already, and they believe it was a bad gasket, even though I used the new one they gave me.

I blocked off the Air Control Valve with a Air Control and Check Valve block off plate. I actually took out air control and check valve, and covered the opening. I beleived it fixed the leak a little(maybe its just me) bit, it's not as loud anymore(still loud though)...but I heard blocking this off will disable my 6th actuator and cause a decrease of power(I have a S5). Is this true? Should I put this back on?

You have an exhaust leak at the header, nuff' said.

Alright!

Can anyone answer my question about the block off plate? Is it really necessary? Am I losing power?

The Air Pump just drains a little power off via the belt driven system, however, it also dumps air into your exhaust (to prevent bad emissions and those nice pretty flames you see on most RX-7's).

You can remove the air pump, and block it off, but you'll need to get a double alt pulley as your waterpump wont act right at high rpms.

AFAIR the S5's use vacuum/solenoids to run the ports, not exhaust back pressure, so you shouldnt have any problem.

Thanks..Tech! Where can I purchase the double alt. pulley?

So, it doesn't affect the 5th and 6th port actuators at all? I've read that the ports are actually runned by the air pump...

I feel a torque lost as well.

Directly from Racing Beat, you'll need to buy an extra Alt belt though.

AFAIK, the 5th/6th port actuators run off of the vacuum and a few solenoids on the rack, however I could be wrong as I haven't had a working 5th/6th combo in the past year I owned my car and I dont drive it anymore.

You lost torque because you're using a true dual system, you'll loose a little down low (and combine that with the exhaust leak, which is probbaly melting whatever gasket you had on there, ask me how I know! :D) but your high RPM power will be better than any collected system could offer (according to Racing Beat anyway) so you'll have to launch a little higher but the added power should be better.

Im pretty sure you should gain power down low with true duals...

No, the exhaust gases are seperated the whole way out, I believe the Racing Beat said something about longer primary tube than the secondary so it in turn adds for higher rpm power instead of lower rpm with collected.

The collected system is specifically tuned for low-mid rpm torque.

You need your air pump for your 5/6 ports and vdi.

I noticed more power low and high, but there was more power GAIN high. I also just kept the air pump and ACV because it's still the best way to operate the aux ports and VDI, and yes you will lose power without these. And tech geek, the ports are run by pressure from the air pump and solenoids, not vacuum. JMY952, have you checked to see if all the nuts attaching the header to the engine and to the exaust piping are fully tighened? Sometimes you really have to torque them down.

Thankyou for clarifying! I'll attach the ACV back in.

No I haven't yet...I will tomorrow. I got the car diagnosed and they have found a leak from the headers. So everyone here is right. It's either not tight enough or a bad gasket!

Finally...ITS FIXED!!! Sounds 200% better!

I'll post some sound clips pretty soon here!

BTW

Is there a way to get the 5th and 6th port actuators working without a airpump on a S5?

Yes there is. Here you go.
http://www.teamfc3s.org/forum/showth...threadid=42367

Thanks! :ylsuper:

Hmm..it says it requires a air pump though

I've had a true dual system. It's not even funny how much more power you get down low over stock. A longer tube tunes lower. A shorter tube tunes higher. Whatever rpm it tunes at is also beneficial for half and double that rpm as well.

It's not quite this simple though. Collected systems don't necessarily tune higher or lower and neither do true duals. It's all based on length. In a collected system there are many things that affect it. The collector size is one aspect. The primary length is another. After the collector also makes a difference in terms of diameter AND length. Most people don't know this though. The primary pipe diameter makes a difference. Even the muffler makes a difference. On duals, the pipe diamter and length are what matters.

There are so many things that can change what an exhaust is tuned to. You can not make blanket statements that a collected system is tuned for low rpm and a dual is not. That's absolutely false and that also holds true with the standard parts you buy from Racing Beat.

That's what I was informed of when I bought my Racing Beat exhaust, if I wanted more hi-end power go for the true dual, if I wanted more low rpm power than high go for the collected...now if you want to call someone a liar and fool who has been working on rotaries for god knows how long be my guest, but I'm just the messenger relaying what I know.

I wasn't trying to be offensive. I'm not just passing on info that I have no personal experience with. I've had both systems so I know exactly how they behave.

Do you have dynos for both systems, I mean butt dyno is one thing but actual physical numbers are another...not trying to start just curious as NO ONE has ever dynoed.

I'll try and have my GTU dyno'd before going ITB for everyone :P

There isn't a slight "my butt dyno might have felt it sensation" difference from each system. We aren't talking about an intake or an ignition box that don't do crap. The difference in each system is VERY pronounced. Enough of a difference that it almost feels like a completely different car with a different engine altogether. No I'm not exagerrating. The average power is very different and this effects how it drives. I am ignoring the way they sound. Sound tells you nothing although the duals do sound like absolute crap IMO.

I could really care less about dyno's. They don't impress me. They are only done at full power. We are using a 2 dimensional graph to try to convey how a 3 dimensional powerband looks. That doesn't mean crap. They say nothing about part throttle and the exhaust design can have huge impacts on throttle response and part throttle power. This is what you feel when you actually drive around. Full throttle is not an accurate measurement as we don't spend most of our time there. I don't care who claims otherwise. They don't really mean shit as peak power is completely worthless and this is all people here ever seem to care about. That's why they don't impress me. There is one very well known and respected rotary builder/tuner who posts his dyno sheets and will then quote the several horsepower spike in one little area of the chart if it peaks there and claim it as the total power he's made. What a worthless misleading stack of crap that tells nothing! Then you have the people who cry foul when you give them their dyno proof because they don't believe what they see. That happens too. Posting dyno's is a losing deal here. They are a waste of money unless you are tuning an ecu and most people wouldn't have a clue what they were looking at if it came with an instruction manual. I care about how the car actually drives and believe me each system drives very different from each other. I have done g-tech runs and seen noticable differences but again, people like to somehow think they know better than a piece of equipment because they have no idea how it works. A g-tech while not the most accurate device on the planet for absolute 1/4 mile runs, is a very consistent piece that can accurately show changes. That's what matters. The actual time doesn't. To make a long story short, I've given up on trying to convince almost anyone on this forum of anything. With the exception of some of the people here (not referring to this thread just the forum as a whole), for the most part this is a very closed minded, negative, doubt everything but believe the wrong guy forum. Now having said that I'm sure I'll get flamed pretty hard but they say the truth hurts so that's fine. If you believe me then fine. If not, that's fine too. I will never claim to be the be all end all when it comes to rotaries. There are many damn smart people out there and there are many who don't know crap but sound like they do. They sometimes get as much if not more respect than the others which is sad and contributes to misinformation being spread.

Just as a side note, have the experts who gave out the power information on their duals vs their header ever posted side by side dyno charts as proof? NO! I know and respect the guys there so don't think I am calling them liars by any means. I'm not. As stated in an earlier post, depending on how each system is designed, you can make either one come out ahead on a dyno. There is alot that happens in an exhaust. You can make "some" generalizations but when you compare what is available on the market as a prefabbed part, I know how each one behaves in relation to each other and why.