Saturday, September 15, 2007 - 01:09 pm, by: Ben Kelly(Ace)
Ok so i know NOTHING about exhaust, but i was told to remove the rear cat from my stock exhaust in the expectation that it would provide more of a v8 sound and perhaps some marginal increase in power. A mate will do it for me but i was hoping someone might be able to give me the pipe size and length as well as info on how to get the correct flanges so that i can bolt on the pipe. note i dont have the money for headers, or other exhaust mods, i just wanted a bit more rumble on the cheap.
Saturday, September 15, 2007 - 01:48 pm, by: Peter Nitschke(Pen)
Cheapest way to get rumble would be to cut out the centre resonator and middle mufflers and just replace with 2 straight through pipes to the rear mufflers. Removing the rears makes very little difference to the noise.
Saturday, September 15, 2007 - 03:09 pm, by: Phil Bonning(Bonbon)
Hi Ben, I have taken the last 2 mufflers off my V8 soarer,(behind the rear wheels) and it did make a better sound. Doesnt sound loud inside the car when just cruising but definetely changed the attitude of the sound when giving it some. Has improved preformance, ecomony doesnt seem to have changed. Your standard exhaust could be all stainless so it be ashame to loose that too. Mine is all stainless from factory. It cost me $100 to have it done to my car with mild steel pipe with chrome exhaust. Cheers, Phil.
Saturday, September 15, 2007 - 06:18 pm, by: Ben Kelly(Ace)
stainless? hmm that would be surprising, it looks pretty ugly. isnt removing the the rear mufflers very loud and would it make it a cop magnet? Peter do you know the pipe size of the stock exhaust?
Saturday, September 15, 2007 - 10:32 pm, by: Peter Nitschke(Pen)
Ben, stock is stainless, you won't find any rust.
Maybe we should clarify what it is you want to remove.
Normally there are the manifolds, 2 cats, a single resonator, 2 middle mufflers and 2 rear mufflers. Sometimes compliancers replace the resonator with a cat rather than replacing the real cats. Either way, I am now thinking that this is what you are wanting to remove.
If so, do it, and remove the middle mufflers at the same time - which is what I suggested previously.
Sunday, September 16, 2007 - 06:06 am, by: Phil Bonning(Bonbon)
Ben It isnt loud enough to be cop bait and you might want to look at how it will be held up by the brackets once you remove the middle sections too. What i did was discount the rear and start it and that will tell you what the sound be like. Simple as that.
Sunday, September 16, 2007 - 03:15 pm, by: Mike Beck(Gold_40gt)
Its really pretty simple Ben. When I did a dual cat back with straight through mufflers it was not too loud in my opinion.
Removing the rears Ive found made little difference so you would have to do more than just that for a decent sound.
Also its imperative the middle resonator with the two Y joins is removed as I find its the real bottle neck in the system and gives a horrible exhaust note if straight pipe is joined up to it.
Sunday, September 16, 2007 - 05:34 pm, by: Ben Kelly(Ace)
ok so as a simple measure how about JUST the middle resonator? (im looking to do this on the cheap at the moment as i still have plenty of other bits to sort..also im looking at keeping the car very much stock (and seeing as the exhaust is stainless im pretty impressed as it sounds like it wont ever need replacing))
Sunday, September 16, 2007 - 07:05 pm, by: Mike Beck(Gold_40gt)
Well If your wanting to keep it stock dont touch anything!
But yeah.. If I was you I would remove the Centre resonator as well as the two middle mufflers, replace with two straight pipes at 2" and keep the rear mufflers.
Monday, October 01, 2007 - 05:24 pm, by: Ben Kelly(Ace)
Not yet kevin, its now pushed a bit further back on my to do list as i have had some transmission gremlins re appear and have decided to get emv repaired...and then if im not totally broke or reduced to selling my ass for coin..i will definately do it. If you do it first, let me know how goes. Hey you should check out Ken Trans ride. he is in lidcombe next to you.
Tuesday, April 29, 2008 - 05:06 pm, by: Ben Kelly(Ace)
Hi all, thanks for the assistance. I have finally removed the centre cat. there was no resonator. And it has made only a little difference. Therefore i will do as peter suggested and remove the middle mufflers. Interestingly there has developed a bit of a tinny rattle/scraping sound when giving a bit of throttle although this is only evident when outside the car in neutral. Anyone know why? Its a bit similar to the sound of having a worn transmission mount.
Tuesday, April 29, 2008 - 10:00 pm, by: Ben Kelly(Ace)
Thanks peter, the factory cats don't seem to have any real heat shielding, at least not like the usa manufactured cat that was taken off the centre. If they do rattle can they be fixed? or do you think the new pipe could be hitting the transmission train? I had a similar sound on my previous soarer when i had a new transmission mount installed and apparently it brought it closer to the after market exhaust setup. thirdly if i remove the middle mufflers should I still take a pipe from a y intersection or should it track from each factory cat directly to the rear mufflers?
Wednesday, April 30, 2008 - 01:58 pm, by: Peter Nitschke(Pen)
Ben, I squeezed some high temperature silicon type stuff into the gap between the cat and the shield and the rattling stopped.
There is no way that anyone can really do a remote diagnostic on where a noise is coming from. You may need to employ trial and error, looking for wear marks, duct taping a friend under the car, etc to really locate it.
Though as it happens in neutral, you can probably just have a friend listen under the car without the duct tape procedure. Use jack stands if anyone has to get under the car though.
Wednesday, April 30, 2008 - 07:09 pm, by: Mike Beck(Gold_40gt)
My celsior Cats rattled badly, new owner removed them thankfully. Actually had a chat with the owner again today, its all going well but upper control arm bushes have gone as expected!
Hmmm just thinking about exhaust for the v8s in generally,, nothing to my liking was better than the setup what Peter did on his Soarer...
Which after a few email chats I decided to do also on my UZZ30. Was really simple, cost effective and sounded brilliant. I have yet to hear a V8 soarer as soothing and smooth, yet aggressive at full throttle...
Was also good for seeing what coil pack was playing up when the left bank put unburned fuel down the exhaust and cooked the cat! White smoke out the left exhaust pipe only!
I might try a dual separate system on my 3.0GT motor see how effectively two 3 cylinders sound like! Hmmmm
Wednesday, April 30, 2008 - 10:32 pm, by: Ben Kelly(Ace)
Ok thanks heaps guys. As i previously mentioned Im a complete idiot when it comes to exhaust (and probably in general). I had the mid mufflers removed (as well as stupid middle cat) and i am fairly happy with the result - although its nothing like my previous soarer. I'll just let nial have a look next time i have it over there, see if he can see where the rattle is coming from. Im thinking it may be even some blobs from the mig welder somewhere in there.
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