extractors

[Marishka]

Yeah quiet and fuel efficiency is the go.
There is Nothing worse than loud exhursts.

[6pac]

Hey ya Rhett so if I got this i would just need to get the Y system then that would go to the muffler? The two things im trying to achieve is better fuel and a quiet as can be....

Joshua,

Yes these work better than extractors (In my opinion) as extractors are designed to work best at 3500rpm + which is why the pipes are longer before they join together. GMH item better suited to a street application & the engine breathes much better than standard.

If you got the GMH ones you can put Y piece and a good quite muffler on to make it almost silent.

Regards

Rhett

[wendyh]

yeah Rhett ..Rays knows about them but i dont think they fit a 202,
But good for Joshua, hard to find thou i think Ray mentioned , we do know someone with a set stillattached to the long pipes..but its up here on the central coast NSW

[6pac]

Joshua,

here is another set a bit lower priced at present

http://www.ebay.com.au/itm/171497688282?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Regards

Rhett

[MaTTe]

There are a couple of things posted here that I don't agree with..

Firstly, extractors won't make an exhaust loud, they will add a deeper tone to an existing exhaust. The volume of the exhaust is dependent on the choice of mufflers and pipe diameter combined with length.

Cast iron manifolds may not rust like extractors, however they are prone to cracking which can be expensive or impossible to repair depending on the location and design.

Extractors are not designed to operate only above 3500rpm. That is a gross generalisation. Depending on pipe diameter, design (such as tri-y or 6-into-1), length of primary pipes, length of secondary pipes, exit pipe diameter, tailpipe size and restrictions, etc.

1 and 3/4 primaries for a semi stock motor will be more beneficial than those xu1 headers. Don't get me wrong, the xu1s had alot of potential, my uncle raced one to MANY victories in rallies around the country, however if the rules had allowed him to change to extractors he woukd have done so.

Making power is about allowing an engine to breathe, both in and out.

1 and 5/8 extractors woukd be fine for a stock motor, 1 and 7/8 is really only suited to a motor with power.

In short, get some headers that are appropriately sized to the potential of your motor, are visually in good condition or new, use the rest of the exhaust to muffle the volume to a level you are happy with.

[Marishka]

Yeah i didnt think extractors made exhausts loud,
I always thought it was mufflers.

I always remember in my younger days mates putting hotdogs on
Their cars,
But the performance seemed to drop dramatically and they were loud
I hated the loud sound.

A good muffler gave the motor better back pressure that seemed to get better power.
I dont really understand why back pressure gave better power but noticed a big difference.

Cheers marty

[MaTTe]

Back pressure as such is an often misinterpreted medium.

What you want is a pipe properly sized so that exhaust velocity is high enough that a drop in rpm will continue to draw spent exhaust gasses through based on the previous exhaust velocity. Imagine the difference between a 2" exhaust and a 4" exhaust, the gasses will take much longer to fill the void in the larger pipe, therefore the velocity will be much lower. The offset is that the restriction may hamper the ability to expel large volumes of gasses at higher rpm. Hence bigger is not always better, it's all about synchronisation.

[mezzmo]

Holy Crap MaTTe - we have a mathematical genius in our midst - I'm not worthy!!!

[Marishka]

Yeah that's what I recon, MaTTe. Hahaha