NA6 TRI-Y EXTRACTOR PIPE LENGTHS

adrianciaff · Postby **adrianciaff** » Mon May 09, 2011 9:31 pm

Hi all, was just wondering if anyone could give me a hand with measurements on a set of good quality extractors such as x-force headers or loch stewart type etc.

I just need the pirmary pipe and secondary pipe lengths, any help would be very kindly appreciated!

thanks guys

Matty · Postby **Matty** » Tue May 10, 2011 1:19 pm

Presumably so you can make some knockoffs?
If you're at the level of development where you want to use other people's dimensions, then the dimensions probably aren't that criticial to your end result. Just make sure they're not plugged up anywhere, have good radius bends, and don't get in the way of anything (mounting bolts etc)
If you want something that makes maximum power, then for a road car on street cams it doesn't make a massive difference one or two inches here or there. If you have a race car, well then you'll need to design your exhaust to suit the rest of the engine.

adrianciaff · Postby **adrianciaff** » Tue May 10, 2011 1:56 pm

Thanks mate your input is appreciated,
I was just curious so see whether those ebay knock offs are actually made to copy the design of quality made and tested applications or not,
The pipe widths are the same but usually it depends on the legnth of the secondary and primary pipes which determine any gains, so i have been told anyway.

I have a street purpose car/ occasional track use, so cams are not a option at this point in time.. my big nose NA6 engine (93) is on its way from adelaide and wth a fair bit of money spent already on parts for this engine before it goes in, i was curious to see whether these pipes are similar design as my budget is starting to go a bit over..

I have been told that there is an extra 20-25 KW to be found when upgrading the "breathing" of the engine itself, that is loch stewart style intake, and full exhaust upgrades. I udnerstand it may differ from car to car, but from my understanding, 25kw gain is alot for an 83kw motor. If these extractors are copying the designs of well known brands, apart from quality welds i dont see the point in paying for someones university degree in automotive engineering.

Matty · Postby **Matty** » Tue May 10, 2011 5:21 pm

20-25kW (24-30%) from intake and exhaust mods is dreamin'... 10-15% would be realistic from a full intake/exhaust system.

What you're paying for, apart from a reputation, support, and manufacturing quality, is someone's time and effort to design a part that fits well, installs easily, and works well, and ideally has had some effort put in to optimising its output. So that choice depends on your ethics (and wallet) really. The end result will probably be similar - pulse tuning using carefully designed/tested runner lengths as I said has little impact unless you have a lot of cam duration and overlap. Most of the benefit on mild (OEM) cams just comes from opening up the flow more.

By the way in my opinion it's probably not worth worrying about extractors unless you do other engine mods to open up the breathing some more. They are third on the list after intake and cat-back. The OEM system is pretty good frankly.

I'll dig up my copy of "Modern Engine Tuning" tonight and copy a couple of pages, it has some good opinion on this matter.

Postby **NitroDann** » Tue May 10, 2011 5:27 pm

You need to cut open a 20yo cat if ypu think cat back will help at all.

Dann

Matty · Postby **Matty** » Tue May 10, 2011 5:44 pm

NitroDann wrote:You need to cut open a 20yo cat if ypu think cat back will help at all.

Dann

cryptic comment is cryptic.

manga_blue · Postby **manga_blue** » Tue May 10, 2011 8:20 pm

Matty, I think he's saying there's not much point in putting a new catback system behind a rooted catalytic convertor. My old one was about 25% blocked after 150,000 and 12 years. That's one of the main reasons my car first dynoed at 45rwkw. CAI, new cat and exhaust took it up to 68, +23rwkw but admittedly mostly through replacing failed components.

Tedsmx5 · Postby **Tedsmx5** » Tue May 10, 2011 10:02 pm

Ceramic coated headers (Liverpool Exhausts) and a large cat with a 2.5” exhaust gave me a 10% increase in torque across the rev range on the Dyno with a standard NA8.
Ted

adrianciaff · Postby **adrianciaff** » Wed May 11, 2011 4:29 pm

Thanks nmatty, you have a valid point. Like i said i was just curious, i guess it would be better just to spend the money and get something with a history. I know the extractors aren't a top priority mod but i plan on doing the lot at once, with the exhaust. And i already have the cold air intake... just debating whether to open up the pipe that connects the AFM and throttle body or not.

I have also been told that the 1.6 responds slightly better to modifications (oem cams) than the 1.8. Can anyone confirm this?

The cat on my car at the moment looks pretty F#@&ed.

Teds, how much did livo exhaust charge extra for ceramic coating?

Matty · Postby **Matty** » Wed May 11, 2011 5:09 pm

manga_blue wrote:Matty, I think he's saying there's not much point in putting a new catback system behind a rooted catalytic convertor. My old one was about 25% blocked after 150,000 and 12 years. That's one of the main reasons my car first dynoed at 45rwkw. CAI, new cat and exhaust took it up to 68, +23rwkw but admittedly mostly through replacing failed components.

Well as a comparison mine was basically perfect after nearly 200000km and 10 years. But any comparisons are only valid against standard parts in proper working order. Otherwise Dann might equally have said that a catback won't make any difference if the injectors are fouled up.

pcmx5 · Postby **pcmx5** » Wed May 11, 2011 7:07 pm

Our dyno testing supports the fact that the tubular OEM headers are pretty good but but there are gains to be made fitting extractors to cars that came standard with cast headers Ie. 1.6 and 1.8 Na's .

There is no doubt that a good cat improves the power as demonstrated`by both Chris h (35000klms NB8B) and Johnd (1500000 klms BBR turbo NA6) which each gained over 4RWKW just by removing the standard cat and replacing it with a steel high flow one.Both cars had freeflow exhausts but the gain was on top of that.

Obviously some cars cats will not be as stuffed at certain Klms as others but a a car over 15 years old would be pretty suspect in my experience and 10 years would be lucky to be efficient..

Sorry to be repetive but Chris h's NB went fronm 72 RWKW on Dyno dynamics to 86 with a steel cat and high flow exhaust and his starting figure was consistent with the data that Techno collated over 3 years at Caulfield Jags MX5 club of Vic's dyno days.It has a standard intake.

Peter.

Postby **NitroDann** » Thu May 12, 2011 8:10 pm

Matty wrote:
manga_blue wrote:Matty, I think he's saying there's not much point in putting a new catback system behind a rooted catalytic convertor. My old one was about 25% blocked after 150,000 and 12 years. That's one of the main reasons my car first dynoed at 45rwkw. CAI, new cat and exhaust took it up to 68, +23rwkw but admittedly mostly through replacing failed components.

Well as a comparison mine was basically perfect after nearly 200000km and 10 years. But any comparisons are only valid against standard parts in proper working order. Otherwise Dann might equally have said that a catback won't make any difference if the injectors are fouled up.

Except that the exhaust with a high flow cat might improve power with sticky injectors, but it wont if you dont replace the cat.
The cat is the biggest restriction wether its fouled or 'perfect'. You wouldnt widen your driveway because you cant get past your trailer, youd move the trailer off the drive first, right?

Dann