What headers for a VF SS redline

[RevNev]

The rear had big cans, almost the same size as the OEM mufflers but with more rounded edges.
I have no idea what they were packed with.

Bigger cans on the rear minimises drone and tells you the exhaust manufacturer has designed their system intelligently. Muffler deletes, hot dogs and small resonators will likely have a lousy note and potentially drone. The older cars were ok with unmuffled tail pipes with room to fit 10 x 5 oval mufflers 18" long before the diff, another reason it's hard to duplicate the "old school" V8 note in the LS engine Commodores.

However note wise, you need this (below) inside the muffler and if the perforated tube has different hole sizes and spacing and different packing, the note quality will be compromised. I discovered the perf and packing differences trying to get race car side exit exhausts to pass the decibel meter when they're short on room to fit big enough mufflers.

 

[Ron Burgundy]

I've got 340 headers and cats, R8 Maloo midpipe (2.5") and modified bimodals, centre chambered and fibreglass packed Lukey style.
Here's a video with the bimodal valves open

Why does that sound a bit V6ish ? Is it quieter than stock ?

Unless my ears are shot, that sounds worse than OEM S2 setup...It may sound better in real life though..

 

[RevNev]

Why does that sound a bit V6ish ? Is it quieter than stock ?

Unless my ears are shot, that sounds worse than OEM S2 setup...

Ron, as Panhead and I discussed in an earlier post, it's difficult to capture exhaust sound on a video to reflect what a car really sounds like in the flesh particularly a stationary video free revving the engine. What mine sounds like in the flesh, is a louder and smoother version of a 340 Maloo. I guess it should when other than the bimodal (rear muffler) mod, it's an R8 Maloo exhaust. HSV cars with the X-pipe exhaust sound more like a straight 6 than a V8 down low and that's the typical difference between an X-pipe and H-pipe. The stock 2.25" system has an H-pipe configuration in both intermediate mufflers and has a more traditional V8 beat to it.

The bimodals sound hollow and raspy (truck like) with the valves open because only 4" of the inside pipe is perforated tube and the rest is straight (unmuffled) pipe on the valve side. For sound to reach the non valved side. it has to pass through the perforated tube and some fibreglass packing so the exhaust flow is virtually blocked with the valves closed, the most garbage bimodal design I've seen.

With the valves open, my (modified) muffler flows into an open centre chamber like a Lukey design and exits equally via twin 2" perforated and fibreglass packed tubes. With the valves closed, it exits via one 2" tube and that sounds like an R8 with the valves open noise level wise. Mine's louder with the valves closed and still notey but quiet and legally not offensive.

Basically, mine's super smooth, louder than the stock SS exhaust with a 340 R8 note. Here's the inside of a stock/HSV bimodal design (below).