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Discussion Starter #1
Im about to buy a de-cat pipe for my P11 Primera and was wondering if anyone could tell me if a P10 GTe Janspeed de-cat pipe will fit? Also does anyone know if a de-cat pipe designed to fit a Sunny GTiR will fit my P11?

Cheers
Neil

P.S Anyone know if piper make cams for the roller rocker P11?
 

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Neil, piper made my cams for me as a one off, but now theyve got the pattern, they should be able to knock you some up for about £395+VAT, to be honest, there wasnt a great deal of improvement, maybe about 5 BHP. I would suggest getting the new JWT S3 cams for the roller rockers.
 

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Why?

Why would you want to do that anyway? I always hear people wanting to do this, but really, you only get maybe a hp or 2 if that. Unless you are going full race or something, it is the most pointless "modification" you could do to your car. Not only that but it dumps an incredible amount of really bad pollution into the air (being a biologist, i know the amount of damage it can do). Im not trying to bash you, but I really dont understand it.:hurt: :*(
 

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Well thats rich... You live in the USA and you are complaining about me putting a de-cat pipe on my car =);) Im sure my little car aint going to push the UK polution ratings over that of one of the worlds biggest poluters!(is it the worst not sure?) THE USA :lol: What was that world treaty about polution ratings called? The one the USA point blanky refused to sign since it would cost them money..... Anyway going to order my de-cat from http://www.separts.co.uk tomoz after work.

Cheers
Neil
 

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Cats....

Ok now this is getting interesting:nerd:
First I want to say I am not attacking you or anything, I just want to flex my brain a bit, so this is all in good fun:)

I know its just 1 car, and it wont have a huge effect on the global pollution, but I cant tell you how much I have heard that excuse. I get that all the time... "Well cutting down a couple of acres of rainforest wont affect anyone, multiply that by thousands of poor farmers, then factor in logging companies with the same excuse, then those who want to develop the area, and so on. One person will never make that much of a difference, but there are alot of people out there that all believe the same thing.

The US has a pollution problem, yes, however, I have lived in England for a fair amount of my life, and to say London doesnt have air quality issues is comical.

If you are alluding to the Kyoto treaty, yea that sucks. Bush is an idiot, I'll be the first to say that, and his views aren't the most environmental, but that doesnt mean the US has the same mentality. And lets clarify something really quick here too. The Kyoto treaty deals with greenhouse gasses, one of which is Carbon Dioxide. Now this is not air pollution, we freaken exhale the stuff. Plus a big reason the US didnt sign it (and for good reason) is that it exempts developing countries (such as China) from any sort of pollution standards. Seems pretty skewed to me too, and not only the financial results.

Let me just list a couple of things that your call will be spewing all over the glorious UK that my car won't:

Carbon monoxide - posonous gas
Hydrocarbons (Volatile organic compounds VOCs) - creates ozone/smog
Nitrogen oxides - creates acid rain and smog

The point of my argument is that there are a ton of other mods that you could do that would boost performance more for the same amount of money or less, and as a bonus, you wont end up killing the earth:dead:

Have fun with that extra 2hp!:knockout:

I will leave you with a couple of quotes from various sources:

"Though it may be tempting to remove the cat altogether, don't do it. We have found time after time that cats do not hurt horsepower in mildly tuned engines. The world is rapidly becoming a small place and all of us must do our part to reduce pollution. Removing the cat can turn a clean car into a gross emitter that spews the pollution of literally hundreds of normal cars."
-SCC Project Nissan


"Unless you are turbo or nitrous only and are going for the maximum in power, do not bother with removing or gutting your cat. Unless the cat is melted it only has about 1.5 psi of backpressure or less and only affects power by 1-2 hp if that. This is even with a built NA motor. With a turbo or NOS you will lose some power. However we did run mid 12's in Ryan's turbo car with a cat and still passing California's stringent dyno smog test."
- Mike Kojima for se-r.net
 

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Neil be very careful when buying a de-cat pipe.I bought a hks one a few years ago when i had my P10,this pipe also fitted the skyline and the gtir as they all have the same cat dimensions,but the hks pipe is shorter than the cat so i had to have my exhaust cut about.So what i'm saying unless it is the same size as the cat i would get a custom one made mate.

What people seem to forget is that cats sap power and INCREASE fuel consumption as the engine has to work that little bit harder to fight against the restriction,thats why all of a sudden all the little cars in the uk started being fuel injected so they could make up for the power defecite.
 

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GT UK....

As stated in the quotes at the end of my last reply, cats are hardly a factor, they are EXTREMELY efficent and have almost no affect on fuel consumption. Comparing cats to fuel injection is like comparing apples and cows, they have nothing to do with each other:lol:. It is a technology change, fuel injection is more efficent than carburators, but they dont have anything to do with HP. This is why there are so many carburator kits on the market to replace your injectors.:rolleyes:
To say that cats sap the power is completely wrong, and there have been plenty of tests to prove this (see quotes from previous posts). The crush bends of your exhaust system have more of an effect on your engine perfomance than the cats:surprised
 

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Sorry to let the UK side down but I'm going with Freaktroll on this one.
Pretty much everywhere I've looked has said it's not worth doing on a road car, more specifically nissans, as the nissan cats are designed to hinder performance as little as possible.

I can see the point for NPMs project SE-r (go see www.nissanperformancemag.com for more) as they have a mahoosive turbo setup, but even then it's more for the fact they were using leaded racing fuel. They also drive the car on the road with the Cat in and only use a de-cat setion when the cars off road.

And them oxides of nitrogen are nasty corrosive horrible things. Not at all like nitrous oxide for those that were wondering.
 

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Sounds pretty sweet andy, maybe simon had tuned all the inefficiencies out of it!!!

Still, I think I'd keep de-cat stuff for track days, Lou's a bit of an environmentalist and I can do without the hassle :crosseyed
 
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