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Old 02-13-2012, 07:36 PM
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Jchiodi
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Default Question on cat delete x pipe

In the middle of doing porken chip upgrade on my 86 auto. During this process ran into a few minor problems, one of which appears to be bad o2 sensor, which i have disconnected now.

I had planned on doing the x pipe, cat delete also. I see where people mention two issues.

First, different smell. Right now, my exhaust has a very acrid, eye burning smell. (with o2 sensor off). Is that what to expect?

Also, droning/resonance issue. On an x pipe installation, It appears that i will delete the pumpkin muffler and go with two inline mufflers with dual exhaust, will that help avoid the droning issue?

Read many threads on this, and there apears to be many different opinions!
Old 02-13-2012, 07:50 PM
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danglerb
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Yes, no cats = stinks.

Drone is related to geometry and distances in connecting the exhaust pulses, not the type or placement of mufflers (not especially, and not in a high flowing muffler, sometimes a lower flowing muffler is used on one side).

What seems effective for drone is a dead end reflecting cancelling pipe. Search for exhaust drone and picts etc should pop up.
Old 02-13-2012, 09:03 PM
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SMTCapeCod
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I don't buy the cancelling 'resonance pipes', but I don't have a lock on everything that works either. As suggested above, do some searching and draw your own conclusions.

The x pipe is at the front part of the system, whether you punt the pumpkin final muffler is up to you. If you do, and you run it without cats, it will be very loud especially with the early S3 exhaust.

Depending on your goal with respect to sound/performance/bragging rights, you might search and take note of the number of folks that like to have factory 86.5/S4 mids and resonators with the x-pipe. Decisions to RMB or retain the pumpkin/final muffler when running that configuration vary. My impression is that most folks that keep the cats or go high flo, are OK with RMB, those that run without cats either enjoy rattling windows with a somewhat meager 3XX horsepower, or else keep the final muffler. In your case, to go this route you would need an 86.5 final muffler to match the provision in the bumper cover and the mid section configuration. Cheap to do if you have a local source, a bit more costly if you would be looking at shipping these parts.
Old 02-13-2012, 09:58 PM
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JHowell37
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You have an early '86, which means you have the '85 exhaust. This exhaust has two pipes that run side by side through one small resonator under the center of the car, and then through the rear muffler. You won't lose the rear muffler with a x-pipe. I would put the x-pipe on and see how you like the sound/performance before making further changes to the exhaust.

I have an x-pipe without cats on my '85. I'm using the same exhaust that you have on your '86. I'm content with the sound. For a while I was using a GT exhaust with a RMB. The resonance was annoying.

There will be a stronger odor from the exhaust without cats. Unplugging the O2 can cause a strong odor. I wouldn't describe it as an acrid, eye-burning smell. But those things are subjective.
Old 02-13-2012, 09:59 PM
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Jchiodi
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Thanks for the replies. My main goal would be to increase performance, secondary to sound quality, but i think an annoying drone would dull my fun in driving!

I do like the way it sounds stock, and i've quite a few compliments on it.

For now, i may leave it alone until i get more familiar with exhaust systems. I still have a few things i have to work on yet to get it to where i want it, electrical, suspension, etc, etc,lol


Jc
Old 02-13-2012, 10:03 PM
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Jchiodi
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Jhowell, what else have you done on yours, if I may ask? I am doing the porken chipset. could you tell the difference with you x pipe?

Jc
Old 02-13-2012, 10:04 PM
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jbrob007
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John, No cats = smelly exhaust. Go with the hi-flow cats or get used to the smell!

I'm not sure if you've actually HEARD my car running yet... I HAD the cats with NO intermediates and the RMB installed when I bought the car... VERY LOUD!!! Sounded like an Indy Car on start up and when hitting the go fast peddle, but the DROAN was an issue... after an hour on the highway, all you'd want to do is shut it down It got real old real fast...

I got a pair of S4 intermediates ($35 on here) and reinstalled. Kept the cats and the RMB too. The intermediates soften the HIGH decibels and change the sound/pitch of the droan to a much more tolerable level. They made a HUGE difference in the two hour drive to Cincy, but it still sounds great when you start her up and/or hit the go fast peddle Just not Indy Car great!!!
Old 02-13-2012, 10:16 PM
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Jchiodi
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Joel, I will check it out next time. Btw, been sick in bed since friday, I'll call tomorrow and see what your schedule is for later in the week. Hope to make it a nice day for driving!
Jc
Old 02-13-2012, 10:27 PM
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bogdann
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I have just finished the Porken Chips, S4 AFR, X pipe and hi flow cats on my car and the noise level has changed slightly. If I accelerate moderately I now notice people who are standing say 50 yards in front of the car will glance to see the source of the noise. I changed to Toyo tyres which have dropped the road noise inside so overall it is a small increase. I kept the pumpkin muffler to keep the noise level down.
The chips and x pipe are the best thing I have done to my car since I bought it. It is like driving a different car.

Norm
86.5 S3
Old 02-13-2012, 11:37 PM
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rgs944
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Is your car as loud as this?

Old 02-14-2012, 12:44 AM
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danglerb
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Originally Posted by rgs944
Is your car as loud as this?
Yes on one, no on the other. My loud car has a "I think" one single chamber 13" Magnaflow, with cats and a Y pipe.

I like my muffler near the tail pipe, sounds weird to me otherwise, kind of like a tractor.
Old 02-14-2012, 12:44 AM
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JHowell37
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Originally Posted by Jchiodi
Jhowell, what else have you done on yours, if I may ask? I am doing the porken chipset. could you tell the difference with you x pipe?

Jc
The exhaust only seems to smell bad because we're so accustomed to emissions controlled vehicles. I don't smell anything when I'm driving or sitting in traffic. I'm not one to concern myself with the feelings of bystanders.

I have one of porken's older chipsets that doesn't require the S4 regulator. I've got the x-pipe. Brembo brakes.

The x-pipe is very noticeable step up in performance.
Old 02-14-2012, 06:21 AM
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Guess I'll get that x pipe on order!
Old 02-14-2012, 01:48 PM
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jbrob007
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John, Sorry to hear your out of commission I'm in Northern Ohio all this week, but can change my schedule if need be... Let me know if / when you get up and around. Next week I'm giving multiple presentations to industry on Anhydrous Ammonia safety so I cant come down The week of the 27th is wide open though... Can you wait that long for the O2 Sensor??? It should run O.K. without it (just in open loop mode) for the time being...

Get feeling better!
Old 02-14-2012, 02:53 PM
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Rod Underwood
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I have an 82 with the cross over (x pipe) and high flow cats. I put two of the S4 mufflers with an RMB and love it. Not too loud, but nice and throaty.
Rod


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