: Catted Headers + Corsa Touring = What kind of sound?



GMX322V S/C
12-14-09, 03:55 PM
Has anyone heard catted headers + Corsa Touring together? I'm more interested in flow and efficiency, not necessarily more sound--though a nominal increase without any drone would be just fine.

Furthermore, would this combo likely result in lower boost (which I could then bring back up to stock levels with a lower pulley :lildevil:) due to decreased back-pressure?

Z06ified
12-14-09, 04:12 PM
I would do the headers first, and keep the factory mufflers, and see how you like it. I've heard it's a nice combination - the headers make it a bit louder, but not too loud. If it's not loud enough at that point, you could always add the Corsas on later for more volume. I think the factory mufflers are pretty good. I know a lot of people here complain they're too quiet, but I don't think mine are. They are just a hair quieter than the AMG cars. But certainly not quiet. In fact, my neighbor thought I put aftermarket exhaust on my car as soon as I got it. I told him, nope, that's the stock exhaust. He was like really? It sounds nice! I fired it up for my co-worker, and he said wow, that sounds "HEAVY"! How much hp is this thing packing? ;)

I like my Corvette loud. This is a Cadillac - I want a nice rumble, but I don't want it too loud. I like the factory sound, although I'll probably add headers when the warranty is out. But that's JMO.

As for the boost, I don't think that will change as I think it's more dependent on engine vacuum/MAF, and engine RPM. I don't think exhaust backpressure affects boost on a supercharged engine.

GMX322V S/C
12-14-09, 04:39 PM
Thanks, but again, the sound to me is secondary to flow and efficiency. Headers are louder in general (I like the sound), but I read elsewhere in this forum that the Corsa Tourings were pretty quiet--yet claim more (dyno-proven?) power. I figured they'd offset?

wfo
12-14-09, 05:09 PM
Do Headers, CAI with an ECM tune.

I do think you will see the OEM muflers to be a bit more robust, but then, you could do after market next if not enough.

Gary Wells
12-14-09, 05:48 PM
Do Headers, CAI with an ECM tune.

I do think you will see the OEM muflers to be a bit more robust, but then, you could do after market next if not enough.

From my reading experience on this forum, but not from personal experience yet, I also think that you will be happy with the headers, cai, & tune, but I do think that I have read at least a couple of posts that indicate there is a possibility of slightly decreased boost, which some have picked back up and / or increased with a pulley change. I am kicking around the Kooks headers, factory muffs, stock box cold air mod, 9 or 9.5 pulley, & Jesse's handheld for the tune and the tranny tune.

GMX322V S/C
12-14-09, 06:37 PM
Do Headers, CAI with an ECM tune.

I do think you will see the OEM muflers to be a bit more robust, but then, you could do after market next if not enough.Thanks wfo; by robust, do you mean robust in sound? If yes, do you think the Tourings still flow better than the OEM mufflers, despite being less robust in sound?

GMX322V S/C
12-14-09, 06:41 PM
From my reading experience on this forum, but not from personal experience yet, I also think that you will be happy with the headers, cai, & tune, but I do think that I have read at least a couple of posts that indicate there is a possibility of slightly decreased boost, which some have picked back up and / or increased with a pulley change. I am kicking around the Kooks headers, factory muffs, stock box cold air mod, 9 or 9.5 pulley, & Jesse's handheld for the tune and the tranny tune.Yes, getting back to stock boost levels with a more efficient exhaust has got to be a good thing :bouncy:

Titaniumseeker
12-15-09, 03:01 PM
I have the Kooks Headers, hi-flo Cats and Corsa Touring exhaust installed and have had it dynoed. You do lose a little in the boost with the header install area but not much and it is expected. I plan on making that loss up s received by the headers with a W4M 9.5 pulley install/tune, CAI this weekend.

Z06ified
12-15-09, 03:51 PM
Can someone explain to me why boost is lost with less exhaust backpressure? In a turbocharged engine, I could maybe see exhaust mods effecting boost, but I don't understand why it would in a supercharged engine, given that the boost is belt driven, and not driven from an exhaust turbine.

GMX322V S/C
12-15-09, 03:59 PM
I have the Kooks Headers, hi-flo Cats and Corsa Touring exhaust installed and have had it dynoed. You do lose a little in the boost with the header install area but not much and it is expected. I plan on making that loss up s received by the headers with a W4M 9.5 pulley install/tune, CAI this weekend.So Ti, how would you describe the sound as compared to stock and what were your dyno numbers? Do you have any sound clips per chance? Thanks!

wfo
12-15-09, 04:04 PM
Exactly...please explain. In this engine, "boost" is, belt driven and not driven from an exhaust turbine.

Engine Gurus..Please clarify why there is a boost loss?

And yes GMX332. The OEM mufflers "sound" more robust with the upgraded header scenario, by virtue of larger diameter plumbing and better exhaust flow.

Gary Wells
12-15-09, 05:41 PM
I'm a newb here and far from a guru of anything, but some of the boost was being created and / or limited by back pressure of a "not so free flowing" exhaust system, and the installation of the headers relieved some of that back pressure, allowing more air to flow through the complete system a little quicker. Just my $.02 though.

Gary Wells
12-15-09, 05:55 PM
I don't know about turbo cars in general, but specifically on '86-'87 turbo Buicks (Grand Nationals, T-Types, Turbo-T's) increasing the size of the down-pipe works just the opposite. It generally increases the boost by about 1 lb. with just that mod. Possibly indicating that the turbo Buicks may not be as restricted by the exhaust system after the down-pipe as the Cads are in general. Sounds logical after looking at a stock Cad CTS-V exhaust system and noting all of the spots that appear to be flattened for clearance. Again, just my $.02 worth.

LITTLEELVISDAN
12-15-09, 06:18 PM
I don't know about turbo cars in general, but specifically on '86-'87 turbo Buicks (Grand Nationals, T-Types, Turbo-T's) increasing the size of the down-pipe works just the opposite. It generally increases the boost by about 1 lb. with just that mod. Possibly indicating that the turbo Buicks may not be as restricted by the exhaust system after the down-pipe as the Cads are in general. Sounds logical after looking at a stock Cad CTS-V exhaust system and noting all of the spots that appear to be flattened for clearance. Again, just my $.02 worth.That's because a turbo is exhaust driven, so increasing the volumn of exhaust going by the turbo generates more PSI,,, BUT a SC car gererates the PSI by a belt and if you relieve the back pressure on the exhaust side, the PSI drops on the intake side.

EXTM
12-16-09, 04:22 AM
i have tested both the headers on stock mufflers, and the headers with corsa. the sound with corsa is higher, and the dyno figures are higher by about 20 rwhp with the corsa on. i will post something soon.

UnsafeAtAnySpd
12-16-09, 06:19 AM
I don't know about turbo cars in general, but specifically on '86-'87 turbo Buicks (Grand Nationals, T-Types, Turbo-T's) increasing the size of the down-pipe works just the opposite. It generally increases the boost by about 1 lb. with just that mod. Possibly indicating that the turbo Buicks may not be as restricted by the exhaust system after the down-pipe as the Cads are in general. Sounds logical after looking at a stock Cad CTS-V exhaust system and noting all of the spots that appear to be flattened for clearance. Again, just my $.02 worth.

Boost creep.

Gary Wells
12-16-09, 12:57 PM
Boost creep.
Boost creep for which one?
Can't be too many turbo Buicks in that whole state. Used to be one in Riverton that I used to converse with a few years back. Too damn cold up there.

Dr. Design
12-16-09, 09:30 PM
Hello,

Here is a sound clip of what you ask for. This vehicle has the exact combo you request.

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We typically see a little boost loss when adding headers and x-pipe without our pulley upgrade. But that can be made up with our boost pulley.

Please let us know if you have any questions.

Thank you,

Dr. Design
D3 Cadillac



Has anyone heard catted headers + Corsa Touring together? I'm more interested in flow and efficiency, not necessarily more sound--though a nominal increase without any drone would be just fine.

Furthermore, would this combo likely result in lower boost (which I could then bring back up to stock levels with a lower pulley :lildevil:) due to decreased back-pressure?

GMX322V S/C
12-16-09, 10:10 PM
^^--Thanks! Wow, that's with Tourings? So Corsa Sports would be even louder?

Z06ified
12-17-09, 12:06 PM
^^--Thanks! Wow, that's with Tourings? So Corsa Sports would be even louder?

Yes, MUCH louder. Think ZR-1 loud. Even louder actually. Sounds great, but not Cadillac-like, unless you're thinking the SCCA race car.

thebigjimsho
12-17-09, 12:41 PM
So Ti, how would you describe the sound as compared to stock and what were your dyno numbers? Do you have any sound clips per chance? Thanks!If Ti was the V2 that I heard at the Behe meet, it was VERY loud...

I will be trying the headers on stock catback first myself...

Dr. Design
12-17-09, 06:05 PM
Yep sure is. The Corsa Sports with the headers will be louder. I think we have some video clips of that, but we haven't had a chance to upload it yet.

Let us know if you have any questions.

Thank you,

Dr. Design
D3 Cadillac



^^--Thanks! Wow, that's with Tourings? So Corsa Sports would be even louder?

GMX322V S/C
12-17-09, 10:22 PM
Thanks everyone for your input. I think I may follow the advice of those that suggested going with the headers/OEM mufflers first. As long as I can eliminate all of the factory crimps, dents, etc. all the way to the OEM mufflers I'll be satisfied.

So I take it both Kooks and AR header systems eliminate 2 of the 4 stock cats--is that right? Have all CEL gremlins (O2 sensor related?) been ironed out? Or is a custom tune required? I have the wait4me handheld tune. Thanks in advance for any insight...

Dr. Design
12-18-09, 12:58 PM
There will be some codes associated with adding the headers. Good tune will keep all those CEL issues away. I see you are local in Socal. Come stop by if you get a chance. We have a revolving door of caddies at the shop if you want to see some samples.

We have kooks headers for $1900.

Thank you,

Dr. Design
D3 Cadillac


Thanks everyone for your input. I think I may follow the advice of those that suggested going with the headers/OEM mufflers first. As long as I can eliminate all of the factory crimps, dents, etc. all the way to the OEM mufflers I'll be satisfied.

So I take it both Kooks and AR header systems eliminate 2 of the 4 stock cats--is that right? Have all CEL gremlins (O2 sensor related?) been ironed out? Or is a custom tune required? I have the wait4me handheld tune. Thanks in advance for any insight...

zyx5432
12-18-09, 02:46 PM
Dumb question for Dr. Design or anyone else. Is it an easy task to add the Corsa system first, and the headers later? Or is it better to go the other way around as GMS322V S/C is doing?

Dr. Design
12-18-09, 04:26 PM
Hello,
You just have to make sure you order the right system to work with the Corsa mufflers. Also you want to make sure you have a way to swedge the exhaust when you add in the headers and x-pipe. The reason for this is when you install the Corsa system on the factory exhaust it will use the torca clamps to tighten to the rest of the system. This will reduce the diameter of the slip fit exhaust, requiring you to open it back up when changing over the remaining exhaust system. Hope that helps, let us know if there are any other questions.

Thank you,

Dr. Design
D3 Cadillac


Dumb question for Dr. Design or anyone else. Is it an easy task to add the Corsa system first, and the headers later? Or is it better to go the other way around as GMS322V S/C is doing?

GMX322V S/C
12-31-09, 05:50 PM
Can someone explain to me why boost is lost with less exhaust backpressure? In a turbocharged engine, I could maybe see exhaust mods effecting boost, but I don't understand why it would in a supercharged engine, given that the boost is belt driven, and not driven from an exhaust turbine.


Exactly...please explain. In this engine, "boost" is, belt driven and not driven from an exhaust turbine...
While doing all this research on headers and exhausts, I'm reminded that the engine is basically a pump; making the exhaust system more efficient allows more flow through the engine--in other words, it allows the engine to evacuate the intake plenum better, which leads to lower maximum boost pressure.

sirjames
01-01-10, 08:08 PM
Anyone have pictures of stock exhaust manifold versus headers? I would think that GM took the flow of the headers/exhaust into account in their initial design? Thanks!