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Quiet Screamer Pipe


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I don't mean to spoil the party but if you place a Cat in the screamer pipe how do you keep it hot enough to do its job ?

It makes me wonder if there is such a thing as a twin pass single cat converter as this would make it easy to run a big and slightly smaller set of exhaust pipes - and keep the bad gasses acceptable emissions wise .

The reason why plumbed back WG's hurt performance is the pressure rise south of the turbo . Ideally you want as close to atmospheric pressure as you can get behind the turbine but its very difficult to achieve with much more than a megaphone behind its outlet .

From an engineering point of view I think finding some way of plumbing the gate back into the front of a very low restriction cat and exhaust may be the answer .

A few years back there was talk of automotive power system voltage climbing from 12 to 36V , I think part of the reason was to have high enough voltage to rapidly heat cat converters up to working temp for cold start emissions reasons .

Without some gas going through them all the time I don't think they work properly if cool .

Great thread , cheers A .

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Yep spot on...I didn't bother with a CAT because it would run way to cold and actually pose a significant restriction because it is cold....It would cool exhaust gas very quickly and in turn the gas viscosity would increase...So it wouldn't work and also pose extra restriction...I have insulated the tube leading up to the muffler to try and keep it warmer..Ideally I would have run the WG along and welded to the main dump pipe but just not enough room...

I wasn't attempting to keep it legal anyway...Just not as detectable....It does reduce emisions...Noise emisions though... :)

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yeah i know all this about cats... i passed the emissions test remember? lol

Anyway I might just leave mine how it is but introduce a bolt on bolt off system so i can go to a full screamer for the track.

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"Quiet Screamer"

Hmmm, an oxymoron they call it?

Well not quite...I am not using Screamer as an adjective such as in 'screamer pipe'; I am using it as a pronoun 'Screamer Pipe'...So in this case it is not really an oxymoron in the true sense....I used to be good at English...Now I are excillent!!! :laughing-smiley-014:

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.

A few years back there was talk of automotive power system voltage climbing from 12 to 36V , I think part of the reason was to have high enough voltage to rapidly heat cat converters up to working temp for cold start emissions reasons .

Without some gas going through them all the time I don't think they work properly if cool .

I know that in recent years the car manufacturers have started to use cold start tuning that is really rich with retarded ignition so that the CAT gets up to temperature quicker...Makes a lot of sense...Using more fossil fuel with aim of reducing emmisions a token amount

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Come on paul, you know you want to develop a ignition booster system for the RB25DET series 2... you know you want too :P

Maybe trying to give them a better power source might help with your objective :)

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Come on paul, you know you want to develop a ignition booster system for the RB25DET series 2... you know you want too :)

Maybe trying to give them a better power source might help with your objective :)

Do you have an M14 x 1.5 tap???...I am gonna put an extra plug in each cylinder...Gap one at 0.75 and one at 1.05...Best of both worlds... :P

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HYPERFORMANCE™ SPARK PLUGS 400-300_SparkPlugs_001N.jpg ZEX™ engineers realized early on that factory style spark plug designs are very prone to detonation in nitrous and forced induction engines. Factory style spark plugs tend to have a high heat range and a long ground strap. This is fine for stock combustion pressures and temperatures, but it is very dangerous in a nitrous or forced induction performance engine. Under nitrous use or boost, factory style spark plugs tend to overheat in just a few seconds. This overheating causes the spark plug ground strap and center electrode to turn into a "glow plug". This condition causes air and fuel in the combustion chamber to pre-ignite and detonate, causing engine damage. ZEX™ is the only nitrous system manufacturer with specific spark plugs manufactured for the unique requirements that nitrous and forced induction engines have. ZEX™ Hyperformance™ spark plugs have an optimal heat range and ground strap design that maximizes the safety and performance of your nitrous or forced induction engine.

82003-1

Single Plug

82003-4

Set of Four Plugs

82003-6

Set of Six Plugs

280-35_SparkPlugFeaturesFlash_001.gif

Have you seen these before???

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I don't mean to spoil the party but if you place a Cat in the screamer pipe how do you keep it hot enough to do its job ?

It makes me wonder if there is such a thing as a twin pass single cat converter as this would make it easy to run a big and slightly smaller set of exhaust pipes - and keep the bad gasses acceptable emissions wise .

I did mine like this:

http://www.skylinesaustralia.com/forums/in...st&id=63577

The cat has no flanges; I just cut into it till it was the diameter I wanted...

Regards,

Saliya

Edited by saliya
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I might try and find an Aussie distributor of those plugs over here...I have seen something similar but they were not Zex...I have to do something with my plugs anyway so if I can get with a similar design I will try them...

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I did mine like this:

http://www.skylinesaustralia.com/forums/in...st&id=63577

The cat has no flanges; I just cut into it till it was the diameter I wanted...

Regards,

Saliya

That looks good. I also had this idea of making a 4" dump pipe and plumbing the WG pipe into it but where it enters the 4"pipe continue the 2" WG pipe inside the 4"pipe up to the cat..This would ensure that the WG gas is close to the same temperature as the main exhaust and it would be travelling in the same direction therefore reducing turbulence...

You will never get a plumback system to perform as well as a 'Screamer Pipe' (non plumback) unless the cross sectional area (CSA) of the overall system after plumback is greater than the CSA of the WG pipe plus the main system...

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Arent they just cold, multi electrode units, i don't get it.

Yeah thast probably all they are but they may less prone to breaking down at high boost levels...

Has anyone tried any other multi electrode plugs?? If so how did they go??

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