Z/28 Exhaust Inquiry

[MX621]

If I was in your area I’d deff give www.fasterproms.net a ring

[Yessa]

Originally Posted by Grüne Hölle 1LE

I went with the ARH Long System with cats and kept the stock rear mufflers

I forgot to inquire, you said you kept your stock Cats right? And the Resonators? Reviewing this thread, I think Amer. Racing long tube headers AND keeping my stock catalytic converters and my stock resonators and mufflers is probably the ideal way for me, for a little more power, but keeping noise reasonable hoping no horrible gas odors.

[pzero]

Yessa, I think I know where you are confused at. I know this is a lot but that's why the forum is here to share and exchange ideas. Short headers and long headers are two different make all together. Short headers are actually short and the long headers are actually long. (Pic 1)

Now short system headers are just that it's headers only not really the size of the headers. (Pic 2)

Now long system headers are headers with mid pipes X or H up to rear axle not really the size of the headers.
(Pic 3)

Now axle back is another system from axle to the rear, most of the time it's the muffler system.

Kinda like ordering hamburger...some like lettuce, some don't, some like pickles, some don't, some like cheese, some don't...you get the idea.

Hope that helps. If you go with ARH long system, you will get the headers, mid pipes (this case X). If I were to do ARH, I would go long system with ARH cats in 1-7/8", ditch the stock cats / resonator, keep stock NPP muffler since you can control the valves open or closed. Now about the gas smell, can't help you there buddy. Once you change to open headers, you're going to smell. If you can't stand the smell, just stay stock all together. Good luck. I'm quite sure if you go with ARH long system you have to use their cats.

I really like the ARH. I wish they had mid pipe config in H as well as X. If they did I would of gone with ARH long, no cats, H mid pipes, and stock muffler. Since they didn't I went with Kooks headers($300 cheaper), no cats, straight pipes, stock H, and stock muffler.

[Grüne Hölle 1LE]

Originally Posted by Yessa

I forgot to inquire, you said you kept your stock Cats right? And the Resonators? Reviewing this thread, I think Amer. Racing long tube headers AND keeping my stock catalytic converters and my stock resonators and mufflers is probably the ideal way for me, for a little more power, but keeping noise reasonable hoping no horrible gas odors.

The gasoline smell was the reason I went with the ARH Cats, which are supplied by HKS in Germany.
I am very happy with my choice, since most people suggested the no cats exhaust system.
Hope this helps.

[47Ronin]

Has anyone ever weighed the OEM headers or the ARH and the Kooks?

[pzero]

Originally Posted by 47Ronin

Has anyone ever weighed the OEM headers or the ARH and the Kooks?

OEM short system = 23.5 tons for one side
ARH / Kooks short system = 17.5 lb for one side

Pics from another member:

[47Ronin]

Thank you, Pzero!

[Yessa]

Understood .... Thank you.

[Jeff71]

Originally Posted by pzero

OEM short system = 23.5 tons for one side
ARH / Kooks short system = 17.5 lb for one side

Pics from another member:

Not saying it'll make much difference in weight but that is not Z/28 exhaust hardware on the top of the first pic.

[Yessa]

I've decided to do the following but stay stock.

- Bore Manifolds
- Back Seat Removal
- Explore (cut some plastic) direct Air to Air box
- Tune

This should give me a little extra hp without the extra noise or gas odors.

[Yessa]

Exhaust Manifold Porting Video

https://youtu.be/xJxmQtt8qyg

[pzero]

Originally Posted by Jeff71

Not saying it'll make much difference in weight but that is not Z/28 exhaust hardware on the top of the first pic.

If I remember correctly it’s from SS 1LE OEM.
Darn close. Mine from Z looks just like the one from the picture.
Maybe little different but very close in weight and dimension.

[ariZona28]

Originally Posted by Yessa

I've decided to do the following but stay stock.

- Bore Manifolds
- Back Seat Removal
- Explore (cut some plastic) direct Air to Air box
- Tune

This should give me a little extra hp without the extra noise or gas odors.

For the minimal benefit you will get from boring ( I assume you mean porting, cleaning up) the exhaust manifolds it may not be worth the effort unless you have them off for other maintenance. Entire back seat assembly top and bottom is approx 40 lbs or so. With driver on board and 1/2 tank of gas car is over 4000 lbs. Might not give you much gain power/weight ratio and now you have a valuable seat laying around. Cutting plastic to MAYBE increase airflow to one of the best factory intakes Chevrolet has made? Could make things worse and might be costly to repair if unsuccessful. If there was anything to gain from intake mods the aftermarket is always all over it. I don't know much about tuning. Maybe crank it up for 93 octane. If you've done some serious mods (heads, cam, exhaust) then I would say a tune is a must, that much I know. My car is all stock (for now) and I enjoy the strong acceleration and minimal maintenance required for 505 hp/481 ft -lbs of tq. I guess the point I'm trying to make with all of my ramblings is that if you really want noticeable power gains with the LS7 you're going to have to plunk down some cash and do some serous wrenching.

[Brutale arancia]

Originally Posted by ariZona28

For the minimal benefit you will get from boring ( I assume you mean porting, cleaning up) the exhaust manifolds it may not be worth the effort unless you have them off for other maintenance. Entire back seat assembly top and bottom is approx 40 lbs or so. With driver on board and 1/2 tank of gas car is over 4000 lbs. Might not give you much gain power/weight ratio and now you have a valuable seat laying around. Cutting plastic to MAYBE increase airflow to one of the best factory intakes Chevrolet has made? Could make things worse and might be costly to repair if unsuccessful. If there was anything to gain from intake mods the aftermarket is always all over it. I don't know much about tuning. Maybe crank it up for 93 octane. If you've done some serious mods (heads, cam, exhaust) then I would say a tune is a must, that much I know. My car is all stock (for now) and I enjoy the strong acceleration and minimal maintenance required for 505 hp/481 ft -lbs of tq. I guess the point I'm trying to make with all of my ramblings is that if you really want noticeable power gains with the LS7 you're going to have to plunk down some cash and do some serous wrenching.

A very polite way of saying don't turn a very well engineered high performance vehicle manufactured in limited quantity into something less than it is in current form.