Muffler with straight pipe option...LOUD & quiet

[Torque King Jay]

I was looking at some pictures of a car that a friend of mine had about 15 years ago. It was an early 80s pro-street Celica Supra (yes Toyota Celica Supra... it was ridiculous fast 6-71 blown Chev 350 4-link rear lots of $$$ in it) When they had made the custom headers for the car the put a "Y" at the end of the header collector. One path sent the exhaust through the mufflers the other path had a blank flange on it that was removable. If you took it to the strip you could take the blank flange off and bingo you had instant open headers.



I'm not looking to run open headers, but I would like the sound of straight pipes for around town and still have it nice and quiet for long highway trips.



Check out the picture below. I'm sure someone has done this before, but what I would like to do is to fabricate a 4 inch "Y" that would have a butterfly valve in it. The butterfly valve would be operated by a 12v electric solenoid or a pneumatic cylinder and it would allow me to select between the muffler or the straight pipe. This would give me the best of both worlds. LOUD to over power the ricer"s fart can mufflers and quiet to cruise the highways.



Who has done this before?



Where is the best place to get 4" pipe for the bypass?



What is the 04. 5 exhaust made of ... stainless or just regular steel?



Thanks

Jay R Oo. Oo.

 

[Bartlett]

Jay, i think i remember seeing something similiar in a summit catalog some time ago but it definetly isnt for a 4in exhaust. Ithink that the 04. 5 exhaust is not stainless although not sure as my truck is still on order. if you go into a walker truck exhaust catalog or any truck shop (fleetpride etc) the catalogs have pictures of different elbows tees etc.

 

[Moterhead]

As best I remember, the thing you pictured was called a cut-out. I also seem to remember them being illegal! If you live where they do vehicle inspections, you might be out of luck.

 

[JHardwick]

some of the elders here can correct me if I'm wrong, but this has been done since the '60's or so

 

[mbaston]

cutouts have been around for some time. Some old sidepipes had a plate you could unbolt and run straight through. Others had a cable acuated valve to bypass the muffler. The cable/valve often seized.



As I understand, our 3rd gens sound terrible without a muffler anyway (hissing).

 

[JHayward]

I had a 1st gen that I built a variable muffler for. Made a resinator out of flat stock 302 stainless, and fabricated a butterfly valve and put it in the middle. Ran a cable up thru the floor and clamped it to the shifter. I could open and close it at will... quiet around town, and loud when I wanted it. I had a boost gage on it too. Stock muffler ran around 15 lbs boost. My muffler closed ran 17 lbs boost, and open it ran 24 or so. I still have the muffler - sold the truck to buy a house. Put the muffler on my 1956 American LaFrance with a 6v-53T... loud no matter what!



Jack

 

[JStieger]

Isn't TrucksTV doing that project called "Copperhead" with that mean looking lowered 2WD Chevy pickup with the monster V8? If I remember from last year they installed electric cutouts as well as a flowmaster exhaust. Can't wait till they get that project done!

 

[Chris N5CWM]

I have these on my boat. It's powered by a 502 big block chevy.

These are stainless steel 4" with an internal flapper valve controlled by an electronic solenoid and linkage.



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Captain's Call exhaust diverters.

 

[R.M.THOMPSON]

Torque King Jay,

This has been on my mind also. I'll tell you my thoughts and where I am in the process. Got a muffler from a local truck shop measuring 3 1/2 in/out X 10 X 20 , perferated tube runs straight thru with a "freeze plug looking thing" spot welded about half way in the perfed tube. Installed using stainless 3" wide straps for easy removal. Also had to turn the five foot factory inlet pipe for alignment. It sounds perfect,no hiss and is slightly louder than stock with no "braaaap" , no droning either. Did not tell my wife or friend who rides in the truck often and either of them made remark after the change out . I did'nt start the truck while they were standing next to it either,only after they closed the door ! Test one = pass. (total cost =145 $) Now for the next step, Order the same muffler in 4" or 4 1/2" and

substitute the freeze plug with a disc of 1/4" plate and mount on a rod inserted thru the muffler,supported by a pair of bracket mounted bushings. Install a crank arm and order a 4" elbow and down pipe from BANKS. I plan to leave the factory tail pipe assembly unlees someone here advises me to go to five inch. If anyone would just want to stay with the factory 3 1/2" down pipe, I don't know what differance in temps and h. p. benifit would cost. Here is my question to you. What is the best way to automate this device ?????? , and what would it be actuated by ???? Cable,of course, is the simplest and a modulating electric motor is the exterme. Given one had the proper medium to go after ie... Back pressure or exhaust temp or rail pressure or throttle position or etc. I will stick to the cable for now. In closing , if anyone would want to try out the parts I have now for a realtime listen, p. m. me. Who knows, I might let you keep it for a small fee.

Mark T.

 

[Torque King Jay]

Thanks to everyone for the input. Maybe I wasn't clear on what I was planning on doing with the rest of the exhaust system. I'm not looking for this to be illegal. All this is going to be is a muffler bypass. The bypass is still going to use the stock tail pipe.



MBaston - I was worried about having a hissing sound or a loud drone that would rattle my teeth, but I figure since the 04. 5 has the cat converter they somewhat act like a resonator and quiet down exhaust systems (at least that's what I'm hoping for).



Chris N5CWM - That's exactly what I'm looking for, but in a 4 inch version. I want to select the flow path for the exhaust, but still route the exhaust from both the muffler and the bypass through the stock 4 inch tail pipe and have it exit out the back.



R. M. THOMPSON - Boy you've been working hard. To answer your questions I think as far as automating it goes the electric solenoid will work fine ( least expensive also ). The air cylinder would work but that would mean installing a compressor and tank. Since the solenoid is pretty far back away from the motor, unlike an exhaust brake, I think there would be sufficient air flow to keep it cool so failure wouldn't be an issue. If heat becomes a problem I can turn the solenoid 90 degree to the pipe or make a heat shield to keep the heat off the solenoid. As far as controlling the position of the valve I'm going to mount a switch on either the shifter or the dash. Once I have it installed I'm going to do some exhaust back pressure testing to see just how much benefit the muffler bypass has on the system. Thanks guys



Oo. Oo.



Jay R.

 

[Chris N5CWM]

Originally posted by Torque King Jay

Chris N5CWM - That's exactly what I'm looking for, but in a 4 inch version.

That IS a 4" diverter.