Electric Exhaust Cutout Kits

[Ross Smith]

Hi Guys,

I spotted these on a US site, might be an idea for those that would like to run sidepipes but are not permitted in their state. I would be neat to switch from sidepipes to underslung at the touch of a button.


http://www.jegs.com/p/Race+Ready/757...tm_campaign=07

Cheers

Ross

[sambo]

Ross,

I saw these the other week as I get the Jegs emails every so often. Assuming these are placed before the 'Y' section that divides the sidepipes from the underbody pipes, I can't see how they would divert the flow properly. At a given angle they might direct more exhaust to one side but how would they seal the other side?

Paul

[sideshow]

i think they ae made to run 2 exhaysts and u jusy block and unblock the loader or bigger exhaust
i personally think trying to run a load exhaust and quieten it using one of these will upset the cops more than just having a loud exhaust if u get caught

ive seen a similar unit on a turbo car but instead of blocking all of exhuast to flow it another way
it doesnt fully block exhaust but it blocks it by 1/2 or 2/3 and as u accellerate it opens up more

[Aussie Mike]

You could run them on a window switch. These are an RPM activated switch that the Nitrous guys use to trigger their systems. The switch would turn on at a pre set RPM and open the exhaust. This could be set to just above the RPM requirement for the noise test so the car would be legal.

It would also give a bit more back pressure down low where the engine likes it and be free flowing up top. The result might be a broader spread of power than a system tuned to work best at one RPM range.

I believe several big auto companies use similar systems in their cars. The Aston Martin V8 Vantage uses something like this as do several big sports motorcycles.

Cheers

[AMF]

I had Q-tec electric exhuast cutouts on my last car.

They're more of a novelty than anything.

I suppose you COULD set them up to open progressively or at a certain RPM, but I had them on a simple 3 position switch and with them wide open, the car actually ran slower in the 1/4.

They were however, the largest attention getter for the car. Nevermind that I had all sorts of over the top modifications done to the car, it was the cutouts that got all the attention.

With a wicked cam and the cutouts open, it sounded pretty mean and VERY loud. Great for scaring off dumb ricers at stop lights. Great for setting off car alarms in parking lots. It'll sound like a pair of harley's sitting next to each other.

Of course, if you're running pipes with zero sound deadening insulation, the cutouts won't really make a difference to you (flow or soundwise) or at least not as much to someone running longer sections of exhaust piping with mufflers.

[ls1 Ac Cobra]

They don't divert from one pipe to another have seen them on a hot rod when opened exhaust still flows out back but open out the side just for noise before mufflers.

[AMF]

Originally Posted by ls1 Ac Cobra

They don't divert from one pipe to another have seen them on a hot rod when opened exhaust still flows out back but open out the side just for noise before mufflers.

It all depends on the car/exhaust setup. If you're dumping before cats/mufflers (restrictive mufflers) then there's going to be quite a bit more flow out of the dumps than there is out the mufflers. Fluid flow will always prefer the path of least resistance. Granted there will still be some residual out the rear when the fluid friction out the dumps gets significant enough to push it out the back,

That's why I said for a typical cobra setup, I don't think it would accomplish much at all, sound or flow, cause most cobras are pretty loud to begin with (with straight through muffler design, if at all) and the flow isn't affected all that much because A) most guys aren't running cats, resonators or other restrictive components B) most cobras have shorter exhaust setups and C) lots of cobras don't run mufflers at all, and if they do they're very unrestrictive (aka loud).

Keep in mind that for a particular engine setup, there's an optimal exhaust design. Most guys think bigger is better and with respect to exhaust, it isn't always true. In most cases, you lose low end torque and in some cases, you even lose high end flow, because there's no scavenging effect with a virtually unrestrictive setup. (we could discuss scavenging in another thread altogether).

Bottom line, like I said, it's more of a trick than a performance mod. It should be one of the last things you do if you have a performance mod list. It's about like lighting the exhaust out the tips (flames)....doesn't really do anything to help the car go, stop or turn, but adds a "trick" factor to your ride.

[sambo]

Some great wisdom/insight there from all - thanks. I guess down here in Melbourne, Australia, when putting a new Cobra on the road we would all like "live" side pipes but they don't meet noise restrictions. So these cutouts will allow us to silence the pipes when needed, and with the flick of a switch, direct the flow to the side pipes.

It would seem that a lot of thought needs to be given to the placement of the cutouts, in order to maintain the low end torque and high end flow? Eg, an experienced exhaust guru who knows a bit about your particular engine setup and what works best.

[Ant]

I think anything that can easily alter the sound of the exhaust is illegal in a lot of countries. We have found that you can be really noisey but if driven quietly by a mature person, there is no problem in NZ. I am using 3' perf tube race mufflers and will interchange with a series of smaller perf tubes, there is some fancy material available for this which I am researching!

Another better alternative maybe using what the new Corvettes use a responsive exhaust the faster you go the less back pressure, I think they have a butterfly/valve setup in the rear mufflers, so when driving slowly its relatively quiet?

[boxhead]

Move to the NT, side pipes are legal

[SantaFe66]

Just saw these today at a Muscle car show in Albuquerque. The shop had many other uses for the cutouts but the best was to intimidate ricers that think they want to race you.

http://www.thecarguysllc.com/Images/image004.jpg

[ac andy]

I saw these on the inside cover of this months Street Machine, apparently they make them up to 4 inch diameter. I was also thinking of running them to switch from side pipes to under body exhaust when needed.

Andy.

[spl310]

If you want cut outs, why not get these:



http://www.jcwhitney.com/EXHAUST-CUT...2733_10101.jcw

[imagine2frolic]

Clearance, and leaks are a problem with these. I install them now, and then for customers. As AMF stated that there is a need for some backpressure for street driving.