FAQ: The Exhaust Thread

NPP is so sick

My uncle is putting a rebuilt L67 into his Grand Prix and has talked about the extra 48" or so of exhaust that our cars have. I'm not sure if he's going to go through with his plan, but he wants to route ~48" extra of exhaust piping. Should sound pretty cool if he can find a way to do it.

matt270avian wrote:

I'll just leave this here....

AA wrote:

Nice find. Never knew the V-6 Commodore sounded like that!

More awesome:



Pretty cool that our Aussie friends across the pond are tinkering with L67s just like we are!

Just listening to those cars exhaust through my computer's sound system (speakers and a sub woofer) made everything around it rattle, probably just like the vibrations felt inside the car. Not what I'm looking for. But I'm always on the hunt for something to eventually replace the stock exhaust besides what I've already replaced.
All I have is the SS Headers with a high flow Cat to a stock exhaust.
But as the stock mufflers have aged there is a better sound coming from them, just would like to enhance that sound without a lot of resonance in the cab.
Don't know if that's possible. So in the meantime I'll live with what I got.

Mildly related to exhaust. anyone know how this works?:
http://www.ebay.ca/itm/EXHAUST-PIPE-MANDREL-BEND-STAINLESS-STEEL-304-1-3-4-360-DEGREE-DONUT-SEAMLESS-/181397164359?pt=LH_DefaultDomain_15&hash=item2a3c1d1147&vxp=mtr



Its a mandrel bent seamless donut. Never mind it needs to be cut to use, but how could such a thing be made?

Umm...well...  

Let me get home and first. Then I could probably ponder up some ways

My guess is they are spun in halves, then welded together and finished on a lathe. For the price they are asking, it would allow multiple processes.

Well, after a 4 day extravaganza, I fixed up my exhaust.    

My previous setup was made with alumnized steel, and really didn't stand up to the test of time at all.
rivperformance.editboard.com/t7396-write-up-custom-y-split-exhaust-pipes

So I figured I'd better re-do it in 16 gauge 409 stainless.  Bleh, what an ordeal that was.  Normally you run a "purge" of argon into the pipe for stainless, but at over a dollar a pound argon gets expensive to do this.  Add to this that the regulator wasn't really functioning properly, I mutilated the inlets on the mufflers removing the old pipes, and that welding new stainless to old stainless(I wanted to keep the old mufflers) is a bitch; it didn't turn out with the greatest welds.  Its solid, and no leaks, but what a hassle.  Anyway, enough with the excuses, here's what pics I got:


I assure you, the fact that the above kind of resembles a set of ovaries is no reflection of the car itself.   Two mounting points on each muffler, a bracket that ties into the existing rubber hangers, and another universal muffler hanger welded on and hangs nicely from one of the bumper support bolts. 2.25" all the way out.



Ignore the mess, note the old falling apart Y pipe, complete with leftover pipe-clamps and beer cans to keep it together at the bottom right.



And hung on the car. Fits nice and snug, miles more clearance than before. Eventually I might try the "J pipe" concept in under the spare, but this was such a pain I didn't get to it.  Interestingly enough, the new setup behaves differently anyway.  I used to get a bit of drone and buzz @ 2000RPM, but now its gone.  Its got a very nice resonance/rumble now @ 2800+ RPM, and of course a growl and bellow at WOT when the flaps are fully open.  Its interesting how type, gauge of pipe and changes in routing can make such a difference with the exact same mufflers.  Overall, I'm VERY happy with how it sounds.  I'll get a few better pics later and see about some vids.

Vids of above exhaust.  Hard to capture exhaust sound, especially with a cell phone and with the compression when uploaded.  I need a bumper mounted gopro.

Typical idling vid:

sounds like a 3800 idling.

Typical reving vid:

I know reving in neutral doesn't tell you anything.

Outside, driving, part throttle and off:


I don't know why this one is sideways, various inside noises with their RPMs:


Normal driving use. The rumble heard inside is the same as outside, just louder out the back:


More fun bit, starts roughly half way in:

Looks good man. Nice, even piping.

Still sounds like a 3800 though.....lol

chitown_riv98 wrote:

Will do Matt, I saw ur review on the zzp website. Thanks for the heads up, I already marked the holes using the oem downpipe. Will the lead donut gasket seal it up good or should I also use the 97+ flat gasket?

I reused the 96 gasket but it leaks. You can try the 97 gasket and see if it fits, if it does I might swap mine out for a 97+ style. Orange RTV is your friend. You can also just try a fresh donut gasket and see how well it works out. It's pretty finnicky.

Yep I already have a victor reinz new donut gasket. I was thinking about smearing some permatex exhaust sealant paste on there before bolting it on

Uh oh.....



Bonus points to whoever knows what they're from.

Corvette

What are you putting them on? a tractor? Those are huge oval mufflers...

Karma wrote:

What are you putting them on? a tractor? Those are huge oval mufflers...

They're actually a bit smaller than stock but have 2.5" pipes. I scored them for a song and have access to a welder and any pipes I'll need, so why not? I figure they'll sound and look pretty much exactly like the ZZP setup for GPS.

Where are my bonus points.....

Abaddon wrote:

Where are my bonus points.....

Unfair advantage, but I gave it anyways....

matt270avian wrote:

Karma wrote:

What are you putting them on? a tractor? Those are huge oval mufflers...

They're actually a bit smaller than stock but have 2.5" pipes. I scored them for a song and have access to a welder and any pipes I'll need, so why not? I figure they'll sound and look pretty much exactly like the ZZP setup for GPS.

cool cool, i"m sure they just look big in the trunk with the pipes in the. also the thought of them on a tractor seemed funny. are they stainless?

Karma wrote:

are they stainless?

The tips are mostly stainless with the back part left alone so that they can be welded to the regular (possibly galvanized?) steel. The mufflers are a bit taller than stock but there's plenty of room to stuff them up in there.

matt270avian wrote:

Unfair advantage, but I gave it anyways....

You should've said "anyone except Abaddon"

would a 3" exhaust cutout make gains if you have 320-350WHP or is more power needed to see gains with a cut out?

seeing some awesome numbers on the web both those guys are starting with 4-450whp turbos.

This is the magnaflow 2.5 inch t pipe I ordered.



Needed to get this reducer to go from 3 inch to 2.5 smoothly. Link to reducer



Took my parts to a iron worker shop to get welded. I ended up cutting off the original hangers that go in the middle before the split and got them welded in the same spot.



I ordered 2 of these 90° bends on eBay Link to 90° bend


Other than that I just needed some u clamps, exhaust hangers from O'Reillys and I ordered some 3 inch band clamps from summit. ZZP stainless resonator and mufflers along with 3 inch dp.the bends worked great, they were the perfect length. The only other thing I almost failed to mention is that I had to bang the floor in where that curve in the OEM muffler is. A lil sledge hammer and clear safety glasses did the trick. This allows you to run a straight length about 4 feet of 3 inch pipe after the ZZPerformance stainless steel resonator instead of putting that curve there. I'm sure you guys have done this before

AA wrote:

Here's a shot of the Riviera from below:

Anyone still have a copy of the pic that used to be here?

charlieRobinson wrote:

AA wrote:

Here's a shot of the Riviera from below:

Anyone still have a copy of the pic that used to be here?

Charlie you ready to sell those Eibachs? 😂

69GSColorado wrote:

charlieRobinson wrote:

AA wrote:

Here's a shot of the Riviera from below:

Anyone still have a copy of the pic that used to be here?

Charlie you ready to sell those Eibachs? 😂

Highly unlikely it will ever happen