Exhaust Sound/Note

[DasBaldDog]

Originally Posted by Brutale arancia

And if I could produce the pipe with high-flo cat with a bung for O2 sensor, would it eliminate the need for a tune?

If there were no other changes, yes I'd imagine you wouldn't need a tune, though you'd definitely benefit from it (I'd really consider it an essential part of the process).

I mean, if you're not tuning afterward, why are you doing it? (Honest question). If not tuning, I'd personally leave the stock downpipes.


And as for whether or not it could be made, any custom exhaust shop could probably whip them up in a few hours without much effort.

[Brutale arancia]

Originally Posted by DasBaldDog

If there were no other changes, yes I'd imagine you wouldn't need a tune, though you'd definitely benefit from it (I'd really consider it an essential part of the process).

I mean, if you're not tuning afterward, why are you doing it? (Honest question). If not tuning, I'd personally leave the stock downpipes.


And as for whether or not it could be made, any custom exhaust shop could probably whip them up in a few hours without much effort.

I have more power than skill in stock form. I just love the sound and want a little more without drawing too much attention. Been considering long tube headers but no labor on my part and lower cost is appealing. I suspect catback options would just make it sound like the jacked up FWD trucks that fly by house daily.

[DasBaldDog]

Originally Posted by Brutale arancia

I have more power than skill in stock form. I just love the sound and want a little more without drawing too much attention. Been considering long tube headers but no labor on my part and lower cost is appealing. I suspect catback options would just make it sound like the jacked up FWD trucks that fly by house daily.

Ahh, then you may be good here then.

I can't say how it sounds because no one has done it so far as I know (we all just seem to dive into the deep end of the header pool). I, for one, would be super interested in how it turned out.

[Yessa]

I think the Z/28 stock manifolds move exhaust freely. Boring or porting out the Manifolds is a good idea to save money. Maybe 1/2 hp but seat of the pants maybe more.

[pzero]

OK guy’s mystery solved. Recap: I got my stock exhaust manifold removed and installed Kooks 1-7/8 long tube with stock H and stock Z mufflers. Basically running straight pipes without cats or resonators. Sounds badass. By the way it's been tuned after install.

Problem is it pops whenever I decel. When in high speed, it pops even more at decel.
A lot of Z owners gave me advises but I really didn't want make changes to the sound nor did I want to spend more money (things are tight due to this stupid shit called C-19).

Well one day I decided to put the fuse back in and go for a drive. I drove fast, I drove slow, and at anytime I decel....no popping noise.

Mystery solved. My 2 cents educated guess is that when the fuse is back in the out side muffler's valve closes, letting the exhaust gases out from the inside muffler, hence it goes through the muffler's chamber muffling the popping back pressure. Now once the fuse if pulled, it opens the valve letting the exhaust gases out from the outside muffler, hence it goes straight through without any muffling making the popping noise from the back pressure.

So to solve the problem, I installed a remote module to where the exhaust fuse goes and now I can control the valves to open or close just with a push of a button. I tested with the remote module on and when it's on (open), its loud but it pops. When it's off (closed), it not so loud but no popping noise at all.

Well there you go, I think I'll keep it just like that. Turn it on to feel like an 18 year old kid, turn it off to feel like an old man. Wouldn't it be nice to able to do that to my girl...on / off. Shoot keep on dreaming...

[pzero]

Forgot to mention, before we go on rambling about the fuse in and fuse out. Lets clear out all the debate.

Fuse In:
When the fuse is in the valve will open up during the cold start. Even when it’s warm, it’s still open. Once you reach 2000 rpm, the valves will close. Even at 3000 rpm the valves are still closed. Back down to idle, the valves will open.

Fuse Out:
When the fuse is out the valve will stay open all the time, no mater what rpm you’re at.

I’ve seen on this forum where people say, when the fuse is in it will close and open at certain rpm. Not the case, I’ve had my son on driver seat and I’ve seen and tested it with my own two eyes, with a flashlight, and some exhaust gas poisoning.

[VOIT]

Originally Posted by pzero

Well there you go, I think I'll keep it just like that. Turn it on to feel like an 18 year old kid, turn it off to feel like an old man. Wouldn't it be nice to able to do that to my girl...on / off. Shoot keep on dreaming...

same here, all our problems solved, LOL

[MX621]

It’s the H pipe causing the poping on decel. I’ve went through this on my c5 vette. Xpipe and the poping stopped.

I have a flap control I made on mine too, running ARH catted short system, factory H pipe it pops a good bit on decel, sometimes loudly. Even flaps closed it still pops on decel some you just can’t hear it really at all. I’m sure as OP stated, forcing through the muffler is creating a difference in differential pressure inside the exhaust, so it is less.

[pzero]

Originally Posted by MX621

It’s the H pipe causing the poping on decel. I’ve went through this on my c5 vette. Xpipe and the poping stopped.

I have a flap control I made on mine too, running ARH catted short system, factory H pipe it pops a good bit on decel, sometimes loudly. Even flaps closed it still pops on decel some you just can’t hear it really at all. I’m sure as OP stated, forcing through the muffler is creating a difference in differential pressure inside the exhaust, so it is less.

In your opinion, what sounds better? H pipe or the X pipe. I know they create different sounds. In my opinion, H pipe has the old school chop to it and the X pipe has the smooth euro sound to it. Would like to hear your thoughts on this before I change it out.

[Flannel-On-A-Camel]

https://youtu.be/7xQtAiu6V7M

This is my car, if you skip to the middle it has a few full throttle pulls. It's running the ARH w/cats, x-pipe, and factory mufflers.

[MX621]

Originally Posted by Flannel-On-A-Camel

https://youtu.be/7xQtAiu6V7M

This is my car, if you skip to the middle it has a few full throttle pulls. It's running the ARH w/cats, x-pipe, and factory mufflers.

Good video; compared to my car, that car virtually has no decel pop like mine does and sounds a fair amount diff during engine decel. Very noticeable to me at the 2:30 mark in the vid. Part throttle, lift off on shifts, mine will pop, that car virtually nothing.

The pop on decel is the pressure equalizing between banks through the tiny H, the x pipe allows the pressure to equalize much more naturally as they merge together at the X connection.

[pzero]

Originally Posted by Flannel-On-A-Camel

https://youtu.be/7xQtAiu6V7M

This is my car, if you skip to the middle it has a few full throttle pulls. It's running the ARH w/cats, x-pipe, and factory mufflers.

Ya! That's a Hennessey...That's like Pro football vs High School football.
We're dealing with High School footballer here. I don't have extra 17g to make it sound perfect like that.

I'm not worthy, I'm not worthy.

[MX621]

Originally Posted by pzero

Ya! That's a Hennessey...That's like Pro football vs High School football.
We're dealing with High School footballer here. I don't have extra 17g to make it sound perfect like that.

I'm not worthy, I'm not worthy.

They use the same parts as any other shop ( in this case ARH) . Your paying for a name brand.

[Yessa]

This is my car, if you skip to the middle it has a few full throttle pulls. It's running the ARH w/cats, x-pipe, and factory mufflers.

Your Z/28 has No Cats and No Resonators? And you kept the stock factory x pipe and mufflers ... Only added American Racing long tube headers. No decel pops or nauseous gas odors?