Best Exhaust Setup for a WN Caprice with OEM Parts?

[VFSV6FORME]

Mine doesn't have any uneven gaps at all, they sit perfectly centered in the exhaust cutouts, otherwise I would have modified it as well.

Is you Centre pipe 2.1/4 or 2.1/2. Mine is strangely 2.1/2 ?

 

[R32GOJIRA]

Is you Centre pipe 2.1/4 or 2.1/2. Mine is strangely 2.1/2 ?

The Maloo centre pipe is 2 1/2". Which is what i now have.

 

[VFSV6FORME]

Mine doesn't have any uneven gaps at all, they sit perfectly centered in the exhaust cutouts, otherwise I would have modified it as well.

The difference was from the bi modal muffler pipe to the quarter panel and the 2x chrome pipes on the passengers side were closer to one side of the bumber bar hole by 8 to 10 mmm so by offsetting the two pins by I say 8Mm not 10 mm as the studs are 8 MM it bough the Chrome pipes in the middle of and each chrome tip had the same gap. Who knows maybe the End of the centre pipe on that side has been bent a little which would cause this for the rear muffler to point outwards.

 

[VFSV6FORME]

The Maloo centre pipe is 2 1/2". Which is what i now have.

Now its time to do the Electronic work for you to do. Take you time, Read what I wrote about this before Xmas

 

[R32GOJIRA]

The difference was from the bi modal muffler pipe to the quarter panel and the 2x chrome pipes on the passengers side were closer to one side of the bumber bar hole by 8 to 10 mmm so by offsetting the two pins by I say 8Mm not 10 mm as the studs are 8 MM it bough the Chrome pipes in the middle of and each chrome tip had the same gap. Who knows maybe the End of the centre pipe on that side has been bent a little which would cause this for the rear muffler to point outwards.

Thats a possibility mate, as mine needed no modification at all and bolted up perfectly and centered.

 

[RevNev]

i installed a Maloo mid pipe with the SS Ute electric bi-modal mufflers.

I tried that with 340 headers and resonated cats. It was a lot louder but the note's lousy (tinny and raspy) with SS bimodals and they're also flow restrictive. In the end, I cut the X-pipe and hot dogs out of the Maloo mid pipe and fitted 4 15" Lukey stainless hot dogs with a balance pipe (H-pipe) between them. I cut the SS bimodals open and used twin 2" perforated tubes from an expansion chamber at the muffler entry and packed them with fibreglass. This sounds magic and the closest I've heard an LS engine sounding like an "old school" V8. It's "notey" with the bimodals closed, but quiet enough to sound pretty stock with no drone.

This is far from a "bolt on" application and the cost involved is likely more than most could justify spending on a custom exhaust, however with the experience of fabricating exhausts and race car mufflers since 1978 and having the equipment to do it, it was something I needed to do as there's nothing much available in aftermarket exhausts designed in a way to maximise the quality of the note without being way too loud and droney.

 

[RevNev]

I could have got a set of 340 header but some beat me there. Arrrrrgh well there will be others one day.

You can modify the non-340 2.25" outlet HSV headers to 340 spec. You just cut the 2.25" section out at the collector and weld in a piece of 2.5" pipe and flange. You can also buy the Pacemaker shorty headers that are virtually a copy of the 340 headers.

 

[Hq King]

I tried that with 340 headers and resonated cats. It was a lot louder but the note's lousy (tinny and raspy) with SS bimodals and they're also flow restrictive. In the end, I cut the X-pipe and hot dogs out of the Maloo mid pipe and fitted 4 15" Lukey stainless hot dogs with a balance pipe (H-pipe) between them. I cut the SS bimodals open and used twin 2" perforated tubes from an expansion chamber at the muffler entry and packed them with fibreglass. This sounds magic and the closest I've heard an LS engine sounding like an "old school" V8. It's "notey" with the bimodals closed, but quiet enough to sound pretty stock with no drone.

This is far from a "bolt on" application and the cost involved is likely more than most could justify spending on a custom exhaust, however with the experience of fabricating exhausts and race car mufflers since 1978 and having the equipment to do it, it was something I needed to do as there's nothing much available in aftermarket exhausts designed in a way to maximise the quality of the note without being way too loud and droney.

Any photos or a sound video please

 

[Hq King]

I tried that with 340 headers and resonated cats. It was a lot louder but the note's lousy (tinny and raspy) with SS bimodals and they're also flow restrictive. In the end, I cut the X-pipe and hot dogs out of the Maloo mid pipe and fitted 4 15" Lukey stainless hot dogs with a balance pipe (H-pipe) between them. I cut the SS bimodals open and used twin 2" perforated tubes from an expansion chamber at the muffler entry and packed them with fibreglass. This sounds magic and the closest I've heard an LS engine sounding like an "old school" V8. It's "notey" with the bimodals closed, but quiet enough to sound pretty stock with no drone.

This is far from a "bolt on" application and the cost involved is likely more than most could justify spending on a custom exhaust, however with the experience of fabricating exhausts and race car mufflers since 1978 and having the equipment to do it, it was something I needed to do as there's nothing much available in aftermarket exhausts designed in a way to maximise the quality of the note without being way too loud and droney.

I have been trying to get hsv 340 system and was wanting to alter the headers where they go from the 2 to 1 it is basically straight away I was thinking of extending the 2 pipes so similar to the pacemakers 421s long tube ( hope this makes sense) any comments ideas good or bad ?

 

[RevNev]

have been trying to get hsv 340 system and was wanting to alter the headers where they go from the 2 to 1 it is basically straight away I was thinking of extending the 2 pipes so similar to the pacemakers 421s long tube ( hope this makes sense) any comments ideas good or bad ?

With a full length exhaust on a road car, providing the headers transition nicely into an exhaust of adequate flow, it doesn't make a whole of difference what the header configuration is. Header configuration and design is beneficial on race engines that operate in a narrow RPM band when searching for maximum horsepower and torque in that RPM band. The 340 headers work well, but the cats are restrictive with the stock HSV set up. Increasing the exhaust flow potential is where HSV found the power increase on the 340kw engine by increasing the exhaust from 2.25" to 2.5".