355 F355 subdued after Tubi manifold upgrades

Yes, that is how it sounds. The stock headers do sound louder with the bypass valve opened. The Tubi headers sound good, but not good and loud.

By the way, if you want loud. Fabspeed headers, stock Y-pipe, Capristo muffler. That combo is insane in a long tunnel. I was fortunate enough to be right behind that car. However, after many years of owning and driving different models of 355 (95-99) with different exhaust system, I profess to love the Tubi headers and Tubi muffler. Loudness for the sake of loudness is no longer my thing.

 

Start by making sure the bypass valve is opening. Check the vacuum lines. The hard line between the valve and solenoid can also crack.

 

Need more details of your exact exhaust setup. 2.7 or 5.2?

 

Not sure I would consider the stock exhaust "loud" by any margin. As mentioned above, is the valve even opening?

 

Why would it be impossible.

 

I think I've maybe seen more cars that have -just- been serviced. Things not being put back together after they have just been taken apart is more likely to me than anything else.

 

Gentlemen, I just installed a set of Tubi headers on a 5.2 F355 that already has a Tubi muffler. The reason was the stock header had a big hole in it. It was surprising to me that after install, the by-pass valve when opened did not produce the loud I was used to getting. I went through all the vacuum lines, switches, and signals, and the actual valve itself, etc. I even installed a manual by-pass valve control and drove that around with the valve open ALL THE TIMES for a day. I finally concluded that the Tubi Headers do not act the same way as the stock headers. I removed the manual bypass valve control and took the car on an aggressive long drive and found that ... I like the sound. It is what it is.

 

I’ve always felt the stock 355 headers produced a nice pitch, particularly on a 2.7. There has been some discussion over the years the Tubi manifolds lose some pitch, but difficult to confirm. Might even have an effect on a 5.2, but not a 2.7. One would only have to be changing the manifolds and nothing else to know for certain.

Perhaps @johnk... can chime in.

 

I asked another member about Larini 3-2-1 manifolds vs stock manifolds on a 2.7. Nothing else changed. Has Nouvalari muffler.

“I'd say the Larinis are slightly 'sharper' and higher. The stock manifolds are hard to beat (partially because they are so thin) but I think these do. Definitely not a degradation in sound like many say about the Tubi manifolds.”

 

My car has an early Tubi muffler and high flow cats. I put Tubi headers on the car back in 2021, I think the idle has a little more of a low rumble but honestly, above 4 or 5 grand it just screams. I couldn't say there is much of a difference. As an old audiophile and speaker designer I know that comparing sounds from memory is very, very subjective. My car is a 2.7.

 

A Capristo muffler should fix ur issue.

 

Check the exhaust valve, don't trust that they did it right the first time. Even Ferrari of Fort Lauderdale let me leave with a none functioning valve after work they had done.
Tubi headers was the way to go to keep the high pitch sound.
If you want to minimize that sound then go with a fabspeed.

 

Wire the bypass open and see if it sounds the same.