Okay, so I was talking with a friend the other day who got ticketed for a loud exhaust. Loud exhausts are cool, but can be annoying (and costly). Then I remembered these remote-controlled exhaust cutouts I had seen a few years ago, mainly marketed towards musclecars and trucks.



http://www.streetpro.us/
http://www.quicktimeperformance.com/QTEC/

Would something like this be worth looking at for our cars? Everyone's always asking for sound clips of this exhaust or that, worrying that it will be too loud (or too soft). With something like this, you have a **** inside your car that controlls a motor attached to a butterfly valve--basically giving you a volume control for your exhaust. You could drive around wide open, and then for long trips (or around cops) turn it back down to stock volume. I guess you could even keep your stock exhaust to save money, and have the muffler shop weld this in front of the muffler. You'd have a third exhaust pipe, maybe running through the rotor symbol in the middle of the bumper? Or, you could design a catback exhaust, where one muffler is quiet, another is outrageously loud, and you switch between the two.

Thoughts?

 

I've heard bad things about un-muffled rotaries. What these are really for (more than sound control I think) is for people that want to get a good boost in the top end.

What you do is put that a little less than halfway under the car, so that it is fairly close to the exhaust manifold. Then, when you have the valve open, the exhaust can flow out right below the car, which will give you a big boost in high rpms. It'll be loud as all hell (I know, because I drove around with an open exhaust for a while), but you will get a lot out of it.

 

I was about to do this, but since i already have a race pipe/cat-back... the gain would have been very minimal.

If you still have a stock cat/exhaust - this is a great way to get maximum power from behind the headers. Just realize... your car is going to be louder than all hell with that engaged. When they say its not meant for street use... they are not joking.

I had to do a few 3rd Gear pulls with no cat on my car... and i still kick myself for not doing a sound clip. It wasn't the best sound i have ever heard. The turbo spool plus engine fury was orgasmic... it was L O U D. My friend who lives two blocks from where we did the pull said she could hear it loud and clear. Just realize, with that thing on.... any cop in your zipcode is going to be able to hear it, and the fine for driving with no CAT is HUGE!!!

I wouldnt bother with getting an extra exhaust put in. Just get a dump pipe to send the fire into the ground. I wanted to route it out my side skirt so i can shoot flames at ricers who tried to rev at me. But never got around to doing the mod.

-hS

 

http://www.apexi-usa.com/product_exh...=251&pageNum=1

http://www.apexi-usa.com/product_exh...=227&pageNum=1

 

With the Apexi Unit I believe you still have to buy the valve.

Here is the unit i was looking at before...
http://www.quicktimeperformance.com/...ct_detail&p=25

-hS

 

yes, but you have the option for manual operation with just the valve only, or with the DECS unit there are multiple ramp programming functions if you tie it into the tach signal

an open dump valve doesn't do much on an RX-8 except make every cop within 20 miles pinpoint your location, might as well have an inline valve like the Apexi

 

Yeah, a complete bypass of the muffler would probably be too much (although maybe if it were just cracked open a little it would be okay), and bypassing the cat would be just insane I imagine. Still, we have room for two mufflers, couldn't you have a Y-pipe and then use this to switch between the quiet muffler and the loud one? When I say "loud muffler" I don't mean "wake up the whole city" loud, mind you, just something loud enough to annoy you on long trips.



Another idea: instead of chrome or stainless tips, how about ceramic-coated faux-chrome. Like what they coat Cobra replica side pipes with. It doesn't turn blue or gold over time.

 

would it really be worthless to run our 8's open header??? i currently don't have any exhaust upgrades. the only thing holding me back is the loudness that accompanies it. if i had an on/off switch that took care of all the power & noise issues of an exhaust system... i think i'd have a pretty good solution!
i'm also curious as to how much more power this could give over an 8 w/ a cat delete pipe already installed. would bypassing everything behind the header make much more difference? or just more noise?

 

I used to have the quick time cutout on my RX-7. It didn't stay there long. There is an Australian guy who has a similar product but his goes inline to restrict the flow altogether. His unit never closes completely. It runs off of pressure in a vacuum pot instead of an electric motor. As the engine load rises, the valve opens more and more. He claims that at low rpms and load levels it helps keep noise down considerably which allows him to run the louder straight throgh mufflers without getting into too much trouble.

 

Instead of wiring it to the tach signal... i'd rather just have an on/off switch and use this only on the track.
On the street, i really dont care how slow I am.

I guess the APEXi system is a lot better for most people who want to use this on the street and maximize their performance in that aspect.

-hS

 

BaronVonBigmeat,
Most power loss is in your catalytic converter. Eliminating one muffler canister won't do much for performance.
In my opinion, the only way to utilize any power gain from this is to place the cut out before the cat.

http://www.racingbeat.com/FRmazda4.htm
As you can see there with your CAT still on the car and no muffler.. the power gain is only 5 hp.

-hS

 

DONT do it man!!
________
Web shows

 

Yeah I have heard that, I was just thinking of a way to make a little noise now and then, without having to live with a droning exhaust at all times. My first sketch there was in front of the mufflers, mainly because I figured that dumping right after the header, with nothing to muffle the sound whatsoever, would be ear-splittingly loud.

But how about a catalytic convertor bypass, which still goes through your mufflers? You could go from totally stock to fairly loud (or really loud, depending on what sort of catback you have).



Fred, why did you take yours off? I haven't heard much about them good or bad.

 

I literally had it dumping out with no muffling. If you've ever heard an unmuffled rotary, you'd know why I took it off! I felt like some ricer at the track. You know the ones. They take off their mufflers for more power and still run a 16 second quarter mile. That's what it felt like. All noise and no performance.

We all know the mufflers aren't terribly restrictive so you can have a decently quiet system with good flow. The largest restriction is with the cat. You diagram above is valid to get more flow but it should be modified slightly. Your inlet and outlet pipes are aimed at the cat with the cutout being on the loop around it. Rearrange this so that if the valve is open, air goes straight through it and let the cat be off to the side of the main flow area. That would be more effective. Basically in your diagram, swap the cutout an the cat around but leave the pipes the same.

My old Qtec went on my girlfriend's dad's Camaro. He is going to take it off soon. My friend Jim also has one on a Camaro that he is going to remove. If you need one to play around with, I'll see if I can get one of them for you.

 

Bypass 2.0:



I was just thinking though, I wonder if the motor would be exposed to too much heat?

 

Would be good for scaring the crap out of the riders of those "so called" loud Harleys

I'd thought about the cat bypass before, but I don't know if there's enough room.

 

http://cgi.ebay.com/ebaymotors/ws/eB...m=170038919911

i was thinking about getting this cut out installed instead of buying an exhaust. the reason behind it is that i really like the quietness of the 8 as it came from the factory, yet, sometimes (actually quite a few times) i wouldn't mind running my car extremely loud.
i know it will be extremely loud.....trust me, i used to drive an integra with open header.

my real question is, how REALIABLE are these things? anyone have first hand or even a second hand experience with electric cut outs??
thanks.

 

I'd at least buy get one from Jegs first.
http://www.jegs.com/webapp/wcs/store...tegoryId=10245

Doug's is suppose to be really good... but you'll pay ALOT for it.

 

I have a cutout on my car. All I have to say is that its awesome to have that switch to be loud when you want and quiet when you want to be stealthy. But you'll get hooked and you'll probably wind up wanting a full system.

I don't know about warranties from the previously mentioned companies, but I can tell you that mine has a 4yr warranty on the motor. The typical problem is that the motors burn out after so much time but its really just a matter of luck.

-Edit-

$500 for a cutout? Uhh for that kind of money the thing oughta sing and whistle dixie and be guranteed for life!

http://www.dmhperformance.com

This is the one I got. Only two things to be aware of: A) His site order form didn't work last time so just email him directly with your order if it doesn't work, B) You need to know the length of cord needed for the 8

 

$500.00+ for noise!

 

I wouldn't say just noise. I'm sure with a cutout bypassing the cat and exhaust itself will give you atleast a little bit of a hp gain. Especially since most people say replacing the mid pipe or getting a cat deletion pipe for the 8 gives you the most hp increase.

 

Plus it gives you another nifty switch to play with in your 8

 

Here is another option... cat bypass

http://www.atpturbo.com/root/releases/release091004.htm

You may have to lay some ceramic paint around where it opens up as you will get some flames hitting the ground.






Here's a vid: http://www.atpturbo.com/root/release...ust_System.wmv

 

It'd be loud as @!)#%@)#% on a rotary, I dont think you should do it just for the noise factor... turbos muffle the sound...

On a rotary, it'd sound like angry bees...... VERY VERY loud angry bees haha...
________
Carol live

 

It is for turbo applications.

Nice thing is it is not run by an electric motor but by the boost pressure.

The turbo would quiet it down considerably.





I have heard that the sound of a rotary without exhaust is similar to an air raid siren.