4age 20v tuned extractor length

[shelldrake]

Hey guys,
I'm getting some headers built soon, but do not have much of an idea on how to calculate the correct length header to get some extra usable power where i want. Surely, there is an equation or a calculator where I can find out what I need to know. I am happy with 4-2-1 or just 4-1, but I need to be fairly sure about design length, pipe dia and collector length, as they will not be cheap to get made. Any help is very mych appreciated! Even pics or sizes of what you guys have found successful would be great. Thanks in advance!

[Delazy]

why not buy cusco from AJPS and know u are getting a quality and porno product??

[Gilly]

** gets a seat and waits for Sam **

[shelldrake]

I need to put it in a ta22 and extractors to suit ae86 foul on my steering idler arm.... Modification of an existing set of extractors may be an option, but it may well be neater/cheaper to get them built from scratch.

[slydar]

calculators are pretty abundant if you dig. problem is its not as simple as punching in a few numbers.

whoever is making them should really have a pretty good idea of whats needed. otherwise, dont stray too far from whats available for 4ags in 86s and you should be sweet.

[shelldrake]

<div class='quotetop'>QUOTE (slydar @ Dec 26 2007, 09:24 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=458826)</div>
calculators are pretty abundant if you dig. problem is its not as simple as punching in a few numbers.

whoever is making them should really have a pretty good idea of whats needed. otherwise, dont stray too far from whats available for 4ags in 86s and you should be sweet.[/b]


The guy making them makes excellent quality headers. He uses mandrel bends and understands the importance of each pipe being equal length, and says each will be be within 5mm of each other. He understands and uses a different pipe position in regards to firing order at the collector.

He asked the question if there were existing successful extractors on similar setups. It is possible to play with different lengths on a dyno, but obviously, this is not a cost friendly option.

Obviously there are various factors that influence the tuning of a set of pipes, but there shouldn't be too much difference between 4age 20v models. If I don't get any feedback here, I'll be going for aproxx. 700mm... As it is the only feedback I have recieved...

It just would have been nice to have some results to base this decision on, before I outlay hundreds of dollars...

[Ke70alex]

have a look through samq's build thread... he has a fair bit of detail on the design he did for his custom extractors... i think he made them himself. he listed lengths and benefits of 421 or 41

[DRFTPG]

sam where are you? hahaha also the article on www.billzilla.org about extractors may also be a help

[Gilly]

shell drake i have both TRD copies and some blining Fujitsubo extractors in my posession i'll measure up both their pipe lengths tomorrow. The Fujitsubo has longer pipes from memeory, both are 4 into 1.

[Fozz]

<div class='quotetop'>QUOTE (shelldrake @ Dec 25 2007, 08:37 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=458361)</div>
I need to put it in a ta22 and extractors to suit ae86 foul on my steering idler arm.... Modification of an existing set of extractors may be an option, but it may well be neater/cheaper to get them built from scratch.[/b]

when u say steering idler arm im guessing ur running recerculating ball steering and that ur steering rod is stopping the exhaust pipe from connecting to the manifold? i have the same problem on a 16v all im doing is standard manifold with angle grinded exhaust pipe to clear the steering rod. its not tunned but im to lazy ud have to take it to a exhaust shop for that

[Ke70alex]

All 4AGEs, including the 20 Valve, have identical exhaust ports. The 20 Valve has 4-2 factory tubular extractors, the remainder have 4-2 cast manifolds. The 20 Valve head manifold bolts at the extreme ends are in a slightly different location to the 16 Valve engines, however the 16 Valve manifolds can be made to fit quite easily.

The standard RWD manifold is a wise option, if it will fit in the car, as by all accounts there is little to be gained by replacing it with a set of aftermarket tubular exhaust headers, however there is much to be gained by going to a larger diameter exhaust system from this point back.

The standard RWD system has 28" long secondaries between the manifold and the tail pipe junction. The TRD RWD exhaust system utilises the original cast manifold and then breaks into 42 mm diameter secondaries that are 485mm to the junction, followed by a 330 mm long 50mm diameter pipe to the muffler, a 640 long section containing the muffler, and finally a 520 mm long megaphone expanding out to 57 mm diameter.

Local tubular headers I have seen are 4-1 design and have either 1½ " or 1 5/8" diameter primaries, with a 2" tailpipe. The headers are not very precise - the RWD primary lengths range from 21-28", the FWD from 12-14". I have been told that 2.5" exhaust systems on 4AGEs are very loud, and that 2.25" is a better diameter to go with.

Best I can figure (from a graph I got sent) the ideal is about 28" primaries on 4-1 headers for a 4AGE. The set I am building for my 4AGZE powered Ford 105E Anglia (1964 car) will be 4-2-1, with 14 inch long 1 3/8" primaries, 28 " long 1 7/8" secondaries, and 2.25" tailpipe. This is based on the best I can figure it out, and what I can get to fit. I am building them from preformed mandrel bends, which will be welded together, hence I have a very accurate means of establishing the lengths. The primaries and secondaries should be within a couple of mm in length to each other. I hope to get them built in the next month or so - I have designed them (only took about 40 sketches, drawings and a couple of weeks of measuring and thinking to do!), now I have to make them.

Personally I would not bother with a custom set of headers, especially in what is basically a road car, however the Anglia is too tight for anything off the shelf to fit. Also if you do not have the factory manifolds, an off the shelf set of headers, whilst they may not be ideal, will still work well, and provide a cost effective solution.


dont know if this will help, but cant hurt :2thumbs:

[Ke70alex]

sorry if the above looks like i wrote it... i didnt lol.... got it from this page :2thumbs:

http://www.geocities.com/MotorCity/Garage/8422/4age.htm

some handy info too

[shelldrake]

Appreciate all the info guys! Most people are finding between 650-700 equal length 4-1's are about right. Would love to make up 5 sets 10mm difference to each and test them all! :greenbounce: But, probably not the best bang for buck solution if I cant palm off the other 4 sets.

Gilly - Have you used these headers before? Did one perform better than the other? Would really love to see a few pics with some dimensions. Thanks a bunch mate! :2thumbs:

Fozz - Yeah, it has a steering box setup, but to clarify - The steering idler arm pivots on the chassis and connects to a steering linkage.

jinjaninja - Thanks for the info mate. I was contacted yesterday by someone who said 4 into1, 41mm pipes 650mm went well. Significant increase in rwhp. (about15-20hp)

[Gilly]

i'll get pics

i have run both on my current engine (4AGC) but different exhausts as well so its not a direct comparison

[Son_Ya]

I Have a freind who played the NA game for a while with a SR20.

If you buy a collector and reversion cone for BURNS Stainless in the U.S. I pretty should they calculate the perfect dimensions to suit your application.

And it will be the closest thing to perfect that you will get. I have seen these headers make MASIVE difference over the best aftermarket extractors you can get.
Some time the only make a small gain in total power but have awsome increas in low and mid range.

I have seen a set that made 9hp more peak but 35hp gain in other areas.

They will tell you almost allways to use a stepped style wear your first pipe off your head is the same diameter as your port and then after 10 or so inches it will step slightly for 8 or so and then step again before reaching your collector.

They usually converge the collector to a very small diameter, I think they went to 2inch on the sr one I saw and then gradually increase the 3.5 inches before sharply decreasing again to the exhaust size. Which is ALLWAYS bigger than any exhaust shop will recomend.

Check out there web site..
They make geart quiality components and now the exchange rate isn't so bad they're not sooo expensive.

[Jonny Rochester]

[attachment=20365:toda_4_1.jpg]
[attachment=20366:toda_racinglook.jpg]
Do these look good to you? The new Toda version 2 does not have the spring joints. Toda explain their design in brief on their website.

"For ultimate power the 4-1 type exhaust manifold design is the one to use.
The problem is that power is only made from 4,500 rpm in the process removing drivability.
TODA racing have designed a 4-2-1 system which restores drivability 15% more torque with only 1.5% loss of power.
# TODAs 4-1 type used for comparison.(18100-860-000)

"A bench test(Equal length 4-2-1+ Taper) Design.
Taper design is adopted from feedback from both racing and the bench testing.
Race type high flow junction.
Each section of the manifold has optimized pipe lengths, diameters,
and angles as well as high flow junctions.
Made of light weight stainless steel for both durability and looks.
Flange manufactured by high precision machining center. (exhaust port ø38mm)
Standard catalyst can be used."

http://www.toda-racing.co.jp/en/new/frame_new.html

[shelldrake]

Those 4-2-1 's look like a really good design.

[electric mic]

hot, what of $$ are you looking at for those?

[foc64]

The latest price list I could see (June 2007) listed the extractors at 98,000 yen or $999.00 AUS (converted on an on line currency calculator), you can also order a stainless steel exhaust system that uses the original RWD cast exhaust manifold (as used by some classes of racing in Japan) for 180,000 yen.........

Chris

[electric mic]

sweet, might have to put away the pennies for these babies, exactly what I need next for my car... besides tunes lol.'

[Gunner]

with the rest of ur exhaust, on the 20v's i use this system,i made about 10 kw atw and picked up a heap of midrange torque

i had stainless extractors,jasma spec, that came with the car, they were 4-2-1's, and ran a 2.5 outlet, from that i went into a 2.5 inch cat then cam down to a 2.25" inch pipe to a 2.25 muffler then on the other side of that up to 2.5 the rest of the way.

my theory is that, is has enough room to collect,enough flow thru the cat, then can pick up velocity thru the smaller pipe and muffler till it cools down ad goes thru the 2.5 (bigger allowing for more flow, cold exhaust gas flows slower than hot, from what ive been taught anyway)

seems to work well might be an idea for u

[4ac_mang]

The TODA manifold is $1450... the rest of the exhaust is $1060 but that doesnt include a catalytic converter... TODA "race cat" (straight piece of pipe lol) is $295 and is not legal for road use obviously...
This is a quote from TODA Aust.

Cheers
Daniel