I have a 1987 z28 350 auto with a 3" single exhaust with a flowmaster muffler and I am thinking of doing a new setup in the spring going to true dual btu i feel like a 3" is really too much like not enough back pressure causing a loss of bottom end torque right or wrong? what would be an ideal size btw i have edlebrock headers dont know much more about them as there were on the car when i got it

 

A true dual 3" system probably would be counter productive
for any street-driven 350 set-up. Beyond that, third-gens
are very space restricted, such that mid-body mufflers become
ground clearance problems. Without trying to start a religious
war, a 3" transverse mount muffler should be adequate for
less-than-very-radical 350's.

 

well if i went true dual it would only be like 2" i know space is an issue anyone have thoughts on cherry bombs or glass packs?

 

Bumb any idea/opinions?

 

Before going glass packs, thought of 2" true duals, using something like this piece mounted in the stock muffler location?



Ok, most don't quite like Dynomax products, but it's the first picture I found. Other brands carry similar products.

Using a set of small cats mounted under the passenger seat would get that issue solved as well, without encountering clearance issues.

 

Your best move would be to upgrade your headers to some stainless 1.75" units, and run a stainless mandrel bent 3" cat-back. That's about as good as it gets for car like yours.

For a larger or more radical engine, something that pulls to high RPM or has a manual trans, then 1.75" full-length headers and dual 2.5" pipes can show a power improvement if the exhaust is well executed.

I have seen glass-packs work, but you have to watch that you don't add excessive back-pressure in the process. Many are more restrictive than they look, but dual 2.5" packs shouldn't hurt power on what you've got.

I understand some people go with full-length headers, true duals, and glass packs for the sound. I have to admit that the ones I have heard like that do sound pretty good.

 

There was a guy on youtube who ran true duals on his camaro with that ultra flo max muffler and I thought it sounded good, I think his name was tieoneon.

 

man look into mufflex

 

If your going true dual go with a moroso spiral or bullet. If you want the sound toned down throw in high flow cats.