...more "exhausting" questions.

[Meanmyz]

My car is currently at Marc's getting his 350/510 package.

After doing much thinking on the subject of exhaust, during the time frame of our first SW group buy, I decided on:

- SW headers (factory connection) with cats.

- Corsa exhaust


One thing I have learned since then, and please correct me if I am wrong, is that:

- Having headers with the factory connection point means that they NO LONGER are considered "long tube headers" as talked about on Marc's site for power upgrades.

Is this true?


Also, in reading some comments in another exhaust thread about headers without cats being VERY loud..."annoying and attracting unwanted loud attention", I am now wondering...

1. Will my SW headers with factory connection points, attached to high flow cats and Corsa exhaust, be "annoying and attracting unwanted loud attention"?

2. For the fact that my headers have factory connection points, (which makes them "shorty headers"?) will they have an adverse effect on torque band and horsepower?

(I understand that cats will slightly drop HP but might help with less tinny sound)

For "those in the know", I appreciate your input. Thanks!

[We Gone]

I can only comment on adding cats, I also have Marc's 510 package. I have SW long tube headers. I went from Flomasters with high flow cats to Corsa without cats.
It sounded great at WOT but I did not like the hollow tinny sound at low RPM's. Before I went back the Flowmasters I added the high flow cats back to it. Sounds much better lost most of the tinny sound and has a deeper sound.

[edram454]

get rid of the cats if you can. power robbers. get a resonator to get rid of the drone. try to use the long tube headers as "long tube" headers should be used, dont cut them. by cutting them you will lose some of the benefits of scavenging heat and the cats just suck up power. On my c5, the cats insides were blown out the exhaust pipes during dyno tuning. As soon as the guts blew out I picked up 25 horse.

ed ramos #3028.

[Schrade]

You adding the pipes there Meany? Or is Marc?

If you're doing it, post snappics if you would... I'm gonna' add OBX's pretty soon here.

Anybody else got shots of pipe-work install? Tips?

(not tryin' to boost your thread here Meany)

[mike100]

SW does sell adapters to hook up to stock cat-back/ factory connections that you can use on long tubes (not running cats). shown in link below- theoretically no welding -maybe on the passenger side, but I can attest that the ball flange on the driver's side works like a champ mating to the stock pipe set or on a Corsa.

http://www.stainlessworks.net/catalog/product/gallery/id/516/image/1294/


You can run cats on long tube headers if you really want to bad enough:
more recycled Z06 parts- LS7 catalysts using what was left of my SW adapter tubes (slip on collector fit).
http://i29.photobucket.com/albums/c265/mschrameck/2c4dfc37-1c17-4b4c-a3ea-cb485eaa9cce_zps5544f9c7.jpg~original

[Bob Eyres]

I understand that cats will slightly drop HP but might help with less tinny sound


If you are environmentally sensitive, or live where there are strict emissions laws, cats are a good option. But I would not choose them to affect sound quality. An X pipe does more to smooth out sound, and improves performance.

My car (below) has a "no compromise" system. It's quite loud, and resonant in the 18-2,300 rpm range, but note the trap speed in the quarter mile, and indication it is putting out very good hp. (for an otherwise stock engine).

Marc is the best judge on how the length of your header tubes will affect performance. He's building it for you, pick his brain.

[WARP TEN]

My experience with five or six different systems over 2 Zs and 20 years is that having cats softens the sound. They also cost several horsepower, from about 5 to 10 hp depending on high flow vs stock type ceramics. Marc can provide the power info, and he also has noted improvement in sound with them. After a total of about 15 years with Corsas (and cats), which I liked the best, I have now gone back to a stock system with no cats and cutouts. --Bob

[Kevin]

friend of mine had a headers/no cats/corsa car and it was great to drive, quite inside, loud but not obnoxious outside and sounded good...if you like the sound of corsa

[bradley]

my 90 runs with a 21/2 in dr gas set up x pipe and spin tec mufflers ,car has jeal headers corey henderson tune and plenum and injector housing porting .its run 12.10@119.47 mph in 90 degree weather @ famoso in mac farland ca. . this run is on you tube. if any one wants to hear how it sounds .

[Meanmyz]

Thanks for all of your responses guys. I appreciate your input.

For sure, with cats, as it has been written many times (and on Marc's site) with cats, expect to lose around 8 HP. I'll just expect at worst 10 and hopefully it will be less.

My biggest "enlightment" since buying headers, is that MY headers are not considered "long tube headers" for the fact that the tubes have been cut, a foot or so, short for the cats.

This sounds "common sense" but for my un-enlightened case, I assumed that headers, (as produced for the ZR-1), are "long tube headers" (I have seen other headers for other vehicles that definitely for most obvious reasons, can be nothing OTHER than "shorty" headers.

The newly learned point for me being: for "long tube headers" the length of the primary at the back end is of some importance to HP or torque variation, before the collector. Right?

My other question was whether in your opinion, you found my exhaust combination "too loud". I know this is subjective, but I have appreciated your inputs.

[Meanmyz]

You adding the pipes there Meany? Or is Marc?



Sorry Schrade. I gave Marc everything so that once installed, I could get the best "tune".

[We Gone]

Long Tube with cats, I had Marc redo this setup back to a slip fit on collectors and a longer cat as these were about 6 years old and I still have to pass emissions in Ga. for a few more years.

http://imageshack.com/a/img844/5773/u9n4.jpg

[Meanmyz]

I'll add some thoughts on "why cats".

My point in this excercise of going to 500HP (other than it being fun :-D) is that when GM produced this car, they left a whole lot of "potential" on the table, and walked away (but not without having learned some things).

I have been a ZR-1 fan since its inception. The way it was introduced and the impression it had on me was it being the "be all, end all" Corvette.

So, without changing displacement ($$$$), I am going at it like "what if GM had done more"? What if other than the enthusiastic engineers, that the bean counters and higher management at GM too, would have all been on board, at making a truly, most badass statement (even more than so), and had taken the car closer to it's horsepower potential?

That is my dream of what I want my car to be. In all it's high tech, highly sofisticated (for the time) glory, cats and all, taking the car closer to the "nth degree" as an example of what it could have been.

Ok, I'll get off the soap box now. If I was a big drag racer, I would probably be looking for every edge (take off the cats, or ANY restrictions I could find) in my efforts or goals to go faster. Any car can usually be made faster (especially if you dump all of the emissions crap), but that is not what I wanted this car to be.

[Meanmyz]

Long Tube with cats, I had Marc redo this setup back to a slip fit on collectors and a longer cat as these were about 6 years old and I still have to pass emissions in Ga. for a few more years.

http://imageshack.com/a/img844/5773/u9n4.jpg

Thanks Steve. Those are definitely an example of "long tube" headers.:cheers:

[mike100]

I suppose i could get 5 peak hp more if I ran without catalysts, all else being equal, but I chose to put them back on the car so my eyes wouldn't water every time i stopped at an intersection with my windows down.

observations seat-of-the-pants wise: Running headers without cats with my stock cat-back (no resonator) felt a good bet less powerful on top vs my 3" StainlessWorks system running the LS7 cats.
It is all in the mufflers and pipes. Properly sized catalysts have a smaller restriction on the overall picture. If i dyno out at 396 rwhp, I would not pull them off for the sake of round numbers or bragging rights.

[Meanmyz]

Geez, I must have been drunk when I wrote my last posts. I went back in and edited. Note to self: don't post if you don't have time! :rolleyes:

[mike100]

Geez, I must have been drunk when I wrote my last posts. I went back in and edited. Note to self: don't post if you don't have time! :rolleyes:

I was on the same page- I thought it was ok.

[ZR1North]

Very timely post (We Gone); that's just the set up I am looking for.

[Bob Eyres]

After a total of about 15 years with Corsas (and cats), which I liked the best, I have now gone back to a stock system with no cats and cutouts. --Bob

A good choice, (and cheap too). The best of both worlds at the flip of a switch.