Time to Build Custom Exhaust

[JONBOY345]

The new Magnaflow setup is starting to sound like the Dirty Deeds setup, must have broken in a little.

The Magnaflow stuff burns in over the course of the first 500-1k or so miles depending on how hot the exhast gasses are when they pass through the muffler.

I threw in a 2.5" Vibrant Ultra Quiet resonator in my Magnaflow cat-back setup it helped quiet a bit to help with drone. Didn't eliminate it completely, but certainly made it more pleseant in the cabin. Less than $100 on Amazon last I checked. Might be worth looking at if you haven't already.

 

[Inv4drZm]

If you're measuring up you Dirty Deeds Helmholtz, would you mind posting the specs for it while you're at it? I've done some math, and I think I might be able to convert my factory resonator into a Helmholtz on my new exhaust setup - just cut the exhaust tip off and cap the resonator, then connect to the new exhaust with an elbow. I think the volume of the resonator is originally designed to reduce the drone at appx 1900-2200rpm. I wouldn't be surprised if the volume of the dirty deeds Helmholtz roughly matches the volume of the factory resonator.

I'll post some info.

The Magnaflow stuff burns in over the course of the first 500-1k or so miles depending on how hot the exhast gasses are when they pass through the muffler.

I threw in a 2.5" Vibrant Ultra Quiet resonator in my Magnaflow cat-back setup it helped quiet a bit to help with drone. Didn't eliminate it completely, but certainly made it more pleseant in the cabin. Less than $100 on Amazon last I checked. Might be worth looking at if you haven't already.

I meant sounded like the Dirty Deeds in a good way. I still doesn't have the drone the Dirty Deeds had when I swapped to 4.88 gears.

So I guess there is no real reason to play around with a Helmholtz in my current Magnaflow setup except to see if I can change the pitch or completely eliminate the little drone there is. Experimentation mostly.

 

[doofenshmirtz]

I'll post some info.



I meant sounded like the Dirty Deeds in a good way. I still doesn't have the drone the Dirty Deeds had when I swapped to 4.88 gears.

So I guess there is no real reason to play around with a Helmholtz in my current Magnaflow setup except to see if I can change the pitch or completely eliminate the little drone there is. Experimentation mostly.

I assume you've seen all the calculations needed for the Helmholtz, right? You can basically find the RPM correlated with the sound you want to eliminate and convert it to Hz (or even better - just get something to measure the specific frequency). From there, like you've said, it's just creating something volumetrically 1/4 the length of the soundwave to eliminate it.

My understanding is that the extra geometry of a resonator (conical ends with cylindrical body) give you more opportunity to catch other waves or provide some extra margin for error in the sizing.

I think your harder part will be that the magnaflow (and Gibson, etc.) itself is kind of designed to trap the higher pitched stuff and create the deeper tone, so you may be fighting a battle to get those back to an extent. You might even try straight pipe with a resonator or glasspak and a couple adjustable Helmholtz tubes to eliminate the headache areas.

Just slip fit a bunch of shit together in that long straight section and have some fun, lol.

 

[DZNUTS]

So I’m running the DT shorty headers with cats, factory Y pipe and about 1’ of the factory exhaust pipe behind the spring bolts. Then I clamped (temporary) a 2.25”-2.5” and 2.5”-3” reducer into 2’ of 3” pipe into a SpinTech 3” 9000 series muffler. Sounds amazing. A slight drone in the cabin due to the pipe dumping right below the rear seats (temporary).

I will be fabbing up a 2.5” Y pipe (pie cutting for bends) into a 2.5”-3” collector without cats. I will then run an 6” long 3” flex pipe rather than spring bolts. After the flex pipe I will run a 3” hi flow cat into my 3” SpinTech muffler. I’m running a top secret exhaust pipe route after the muffler, which I’ll reveal when it’s completed.


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[Inv4drZm]

So I’m running the DT shorty headers with cats, factory Y pipe and about 1’ of the factory exhaust pipe behind the spring bolts. Then I clamped (temporary) a 2.25”-2.5” and 2.5”-3” reducer into 2’ of 3” pipe into a SpinTech 3” 9000 series muffler. Sounds amazing. A slight drone in the cabin due to the pipe dumping right below the rear seats (temporary).

I will be fabbing up a 2.5” Y pipe (pie cutting for bends) into a 2.5”-3” collector without cats. I will then run an 6” long 3” flex pipe rather than spring bolts. After the flex pipe I will run a 3” hi flow cat into my 3” SpinTech muffler. I’m running a top secret exhaust pipe route after the muffler, which I’ll reveal when it’s completed.


Sent from my iPhone using Tapatalk

My 2.5" Y pipe sounds amazing, not sure if it's because of the equal length legs or the diameter but you'll love it once its finished.

 

[daprotege5]

i like the idea of making your own exhaust.
did you source the materials locally or order online??
just picked up a tig and my manifolds are leaking or they broke and their not even 6 months old. thinking of just redoing the whole exhaust. thiknking of getting some JBA headers, swap the cats over, and get rid of the secondary cats.

what did you use to bend the pipes??

 

[Inv4drZm]

i like the idea of making your own exhaust.
did you source the materials locally or order online??
just picked up a tig and my manifolds are leaking or they broke and their not even 6 months old. thinking of just redoing the whole exhaust. thiknking of getting some JBA headers, swap the cats over, and get rid of the secondary cats.

what did you use to bend the pipes??

I ordered stainless bros elbows, and I think it was ebay tubing for the straight sections. You could buy all 90 or 180 tight radius elbows and cut them to the desired angle. Mark, cut, tack weld, repeat. Then finish weld the whole thing once its all pieced together. I did most of my welds without filler metal, only adding some where there was a gap in fitup.

One thing I would change is to add cats back in. I didnt spend the money and check engine light stays on and the exhaust fumes are pretty bad. Plus cats would probably quiet it down some and remove some rasp.

I made my own x pipe to save money. Lots of pics are in my build thread (somewhere).