another exhaust thread

[426Cuda]

Foggsy,
The pipes are 2.5" I think, but I measure with a tape (not calipers).

No hint of drone, but the diff back mufflers are designed to eliminate drone. It is not loud by any account, certainly not like a W310. But in contrast to a standard SS or Redline you can easily hear the V8 at idle and it has a nice note under acceleration. I really don't want it any louder, but if I did a set of Helmholtz pipes at the rear would really release the sound, and with no drone.

 

[duaned]

So if you fitted a GTS exhaust, how did you go with the bi-modal (or whatever it is called) on the mufflers? Isn't it adjustable? Sorry for all the questions.

 

[426Cuda]

No problem, happy to share what I've found. The GTS exhaust I fitted is effectively from the headers to the diff joint, i.e. it doesn't include the rear (diff back) pipes and mufflers. As the Gen-F GTS has the same ball type coupling as the VF Redline at the diff back, in contrast to the SS and SSV's flanges, it fitted straight up with no modification required. Also there are no engine lights or other issues.
I am getting a tune this Friday, and I'm sure that will allow the computer to make use of the additional flow characteristics of the GTS system, increasing power and torque. But at present it is running fine, certainly has more grunt, and sounds good to boot. If I had to explain the sound, it's more a factory V8 sound than an aftermarket one. You can hear the V8 on start up from a good 20 metres away, but it's a nice low frequency rumble, not a higher pitched bark like a lot of aftermarket systems. I like the aftermarket sound too, but was very weary of creating drone.

When I accelerate the induction sound and exhaust note give a nice deep growl without being intrusive. At any cruising speed, virtually in any gear, I don't hear it in the cabin, and there is no drone when AFM kicks in. Just what I was looking for really! It would certainly be louder with J Pipes, or say a 2.5" diff back, and the standard 2" diff back is probably costing me a few killer wasps, but I wouldn't sacrifice the ambience of my cabin for the sake of a few extra ponies.

A E2 GTS cat back should bolt straight up to your SS flanges. The GTS is different to the Clubby cat backs I've looked at which have two hot dogs and a muffler. The GTS just has the hot dogs, with no muffler. It also has a X over where the muffler is on the E2 Clubby cat back. I've not seen a Gen-F Clubby's cat back so can't comment on those.
BTW the bimodal system on the HSV's does have a diaphragm at the rear of the rear mufflers / resonators which opens the second pipe on each side. It is electronically actuated through the IQ system AFAIK.

Cheers

 

[Ian Johnston]

The E1 GTS must be different to the E2 if what you are saying is correct, as my E1 system has the muffler, and 2 hot dogs. I think you will find the HSV cat back(E1,2,3) is the same as standard SS/SSV cat back. Maybe wrong.

 

[426Cuda]

Mine's a Gen-F GTS cat back it definitely has 2 hot dogs, no muffler and is 2.5". The E3's also have two hot dogs and no muffler, but have a H pipe and flanges, so are different to the Gen-F. I'm not sure about the E1 & E2 cat backs but would assume they are 2.5" too. The SS, SSV and Redline is much smaller dia, 2" I think. The VF Redline cat back also has a noticeable flat spot on one side just behind the cats, looks very restrictive to me.

This is a pic of the Gen-F GTS cat back:

 

[PIR4TE]

The standard 2" diff back is probably costing me a few killer wasps, but I wouldn't sacrifice the ambience of my cabin for the sake of a few extra ponies.

I wouldnt lose sleep over 2kW, and in fact being so far back I reckon you may even be better off.

 

[Ian Johnston]

Do some checking, all VE V8s are 2 1/4" pipes, including the HSV. I am not talking VF, only VE.
I used a VE SS system to cut up when I did my Chev conversion, and it was the same as my GTS system.
Rear mufflers maybe different, not sure.

 

[426Cuda]

I'll take our word for it on the E1 Ian, not sure about the E2? As I said I was making an assumption re the E series pipes. But this is a picture of an E3 HSV system, no centre mufflers, and definitely 2.5". I can assure you also that the VF SS family system is certainly not the same diameter as the Gen-F GTS system. It's all academic to me though as I have the VF GTS system ;-)

 

[Ian Johnston]

You maybe correct in that the 6.2 went to a bigger pipe. Havent had a look at an E2 or 3. Will have to check it out with my mechanic/tuner.

 

[duaned]

OK. So I have found a GenF GTS complete Exhaust (inc.headers). Will there be any issues fitting this to a VF SS and do you think there will be audible and performance improvements in doing so? Thanks.