Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: bappy on 24 April 2009, 17:13:32
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Hi Guys,
My 'uncle' is a stainless steel artist. http://artwelddesigns.com He has kindly offered to make me an exhaust in exchange for maintaining his website.
now I know the manifolds on an x30xe are stainless, and the cats are in the downpipes so what I'm planning is to rebuild it from the downpipes back entirely in stainless.
I have some piccies that I made up wondering which exhaust design would be best for my engine. Black means stainless, grey means.... not stainless!
http://s515.photobucket.com/albums/t355/bappythegreat/exhaust%20system
I know very little about exhausts other than the current one is awful (some crap built by sabrepower - before I bought the car I must add)
I plan on removing the middle mufflers completely, and having my 'uncle' either make me a backbox by hand or by a cheap one/two (like you'd see on a saxo) from motorworld or halfrauds.
I personally think ideas 2 or 8 are best. but then I'm a retard and don't know what I'm doing.
Could someone who understands a little more about engines and exhausts tell me which option is best and why. Alternatively tell me to stop playing with my car and design it for me :D
once a design has been settled on I would also benefit from some information on pipe diameter/backbox diameter/outlet port diameter.
cheers! :y
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Dont fancy a twin system all the way back to the rear bumber then ? (one either side).
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the 3.0 has absolutly no standard stainless steel exhaust parts
manifolds are standard shitty ones!
the omega seems to run very poorly with missing exhaust components speaking from first experiance
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my 3.0 responded very well to have a remus backbox and the 2 middle boxes removed. gained just over 25bhp i think.
cat removal actually loses power from other reports and as mentioned the manifolds are crap!
so....i would recommend you make some new manifold that provide power increases
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dont want pipes down either side as navigating the fuel tank would be just plain silly.
I had heard that manifolds where stainless.... they certainly look stainless! very shiny silver they are... (Am I right in calling the bit that puts 3 pipes into 1 the manifolds?)
If I need to make new manifolds any advice on design of those? I'm guessing I can get from behind the downpipes back done soon and turn attention to manifolds at a later date if they start to corrode???
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my 3.0 responded very well to have a remus backbox and the 2 middle boxes removed. gained just over 25bhp i think.
cat removal actually loses power from other reports and as mentioned the manifolds are crap!
so....i would recommend you make some new manifold that provide power increases
Seem to remember I heard some guy on Autostormers was doing Manifold re design?, how did that work out?.
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id love to know how it went too!
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dont want pipes down either side as navigating the fuel tank would be just plain silly.
I had heard that manifolds where stainless.... they certainly look stainless! very shiny silver they are... (Am I right in calling the bit that puts 3 pipes into 1 the manifolds?)
If I need to make new manifolds any advice on design of those? I'm guessing I can get from behind the downpipes back done soon and turn attention to manifolds at a later date if they start to corrode???
Are you sure that it's the manifold that you are looking at and not the heat shields that cover the manifolds?
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dont want pipes down either side as navigating the fuel tank would be just plain silly.
I had heard that manifolds where stainless.... they certainly look stainless! very shiny silver they are... (Am I right in calling the bit that puts 3 pipes into 1 the manifolds?)
If I need to make new manifolds any advice on design of those? I'm guessing I can get from behind the downpipes back done soon and turn attention to manifolds at a later date if they start to corrode???
Are you sure that it's the manifold that you are looking at and not the heat shields that cover the manifolds?
Any pictures of your manifolds ??
:question :
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I'm sort-of going down the idea 1 road, but i am going to have a backbox on both corners.
A friend of mine has offered to make me a system, hopefully in time for the pvs, but that's the way i'm going.
2 backboxes, center sections removed.
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I would keep the two banks separate until the back box rather than having a "balance pipe"crossing over. The firing order of the V6 makes it advantageous to keep the secondary pipes separate.
Kevin
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The stainless you refer to by the engine manifold is undoubtedly the heat shield, not the manifold itself which is cast into a plenum chamber rather than a 3 pipes into one set up that you might imagine. This has been a topic of some debate on oof as to how it affects performance and how an alternative design might tune the power curve.
With this in mind and the fact that the cats have oxygen sensors and wiring which will need terminating in a way that the ecu will understand to avoid error codes and a permanently lit dash light, i would consider sticking to a cat back system?
Boring and unadventurous as it may sound, its a safer bet imho. You can always go back when further solutions become clear, esp re manifolds, and join the system in the usual place.
As Kevin says i would be reluctant to alter the original design too much re boxs and routing without knowledge of shock wave scavenging,flow rates, and how annoyingly loud it will be on the motorway at constant revs. Although its nice to have v6 grumble when you boot it, that same roar is a right pain at cruising speeds. Some manufacturers use an exhaust valve to controle this noise to give the best of both worlds but this will require ecu input that the omega does not have.(i wonder if multi ram inputs could used for this?... The front one perhaps... No probably not )
You may also want to consider the rear end esp. the irmscher style twin pipe design which exits either side of the number plate, seen some pics of that box on here somewhere. Or simply a twin pipe exit on a single box as the elites.
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cheers for comments guys.
I don't care about the noise, I just want more power.
I was thinking that idea 8 would provide best performance but comments here are making me think that idea 3 would be best??? I'm assuming that joining the 2 pipes together at some point in the system is advantageous otherwise it will be a case of idea 1.
re manifolds, you are probably right. it's probably the heat sheilds I'm looking at. I was looking up online ages ago about it and apparently some guy dropped an x30xe into a manta and supercharged it. he said he used the manifolds of the omega as they were decent stainless ones. perhaps the donor vehicle had a custom exhaust on it from the previous owner.
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I was thinking that idea 8 would provide best performance but comments here are making me think that idea 3 would be best??? I'm assuming that joining the 2 pipes together at some point in the system is advantageous otherwise it will be a case of idea 1.
Balance pipes have their advantages, mainly on square-plane V8 engines, to maintain scavenging from the exhaust ports with the odd firing order but only when their position is precisely calculated with respect to the speed of the pressure pulses travelling down the system and, even then, it's probably only effective on engines that are in a fairly high state of tune.
I would say that without modelling what's going on in terms of pressure pulses in the system you are more likely to do harm than good. A pipe without junctions will be less restrictive anyway so my inkling would be to go with something like idea 1 and keep it simple.
Kevin
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theres a member on the forum who has had a nice stainless steel exhaust system done for his 3.2 its the same as standard i believe but just s/s (catback system)
i would just go cat back and remove the centre silencers and use a Y piece to enter the backbox keeping it similar to the standard setup!
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theres a member on the forum who has had a nice stainless steel exhaust system done for his 3.2 its the same as standard i believe but just s/s (catback system)
i would just go cat back and remove the centre silencers and use a Y piece to enter the backbox keeping it similar to the standard setup!
That'll be me.
You need to bear in mind one thing on the "current" picture you have: Although the pipes would seem to conjoin toward the rear of the car they don't; the two pipes still run independently through the aft-most box.
In essence that means that your pictures "current, "1" & "4" are all the same in terms of configuration; i.e. they are seperate pipes all the way back.
Don't de-cat it, keep them seperate all the way back and noise is not equal to power! A couple of people on here have heard, and driven, my car since the set below was added and it is not a loud set up; a little more "rumbly", but very subtle. A decent diameter (2.5") all the way back through some free flowing boxes will give you more oomph.
Here's a couple of pics to show you how standard you can still make it look; the rear cylindrical box you see has actually got two discrete straight-through pipes running through the length of it. I had mine done at long-life for about £400 and built onto the car. They are a continuous line all the way back from the cats and as they are guaranteed for life they'll never need to come off.
(http://farm4.static.flickr.com/3285/2618720469_ecd0bcf330.jpg)
(http://farm4.static.flickr.com/3227/2620872838_cece2f0499.jpg)
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thanks for the advice guys. I will be going with option 1 then.
re the current set up, the previous owner took the car to sabrepower for a 'custom' stainless backbox he paid >£300 for it. idiot. it is joined by a 'Y' piece if you can call it that. I've put a diagram on the photobucket album. it litterally has both pipes directly oposing one another...
I will be going cat back with stainless pipes as straight as possible. what diameter should I got for? 2.5"? or should I encourage backpressure with a narrower pipe, say 1.75"?
My aunt's boyfriend will be making me the backboxes too so any advice on diameter of the box itself, length of the box and diameter/length of the exit pipe? I will have 2 identical boxes side by side.
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Years ago on both my RS2000 and 3 litre capri i had custom made exhausts made out of 2.5 inch copper tube, they both had a glourious sound, a sort of muffled roar for want of a better discription, far better than any Janspeed or Peco system of the time, the downside IIRC is that it is not legal for exhausts to be made from copper but back in those days we seemed to get away with far more than we can today. Bring back the good old days ::)
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hmmm.... but copper painted black with high temperature enamel?? who would know???
why does copper sound better and why is it illegal???
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Hi can you tell me how to remove the car mufflers? You mentioned here that you removed it, can you teach me how thanks
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