The search for 20v 4age headers

[whitezenki]

Hi all,
After a few weeks of research and more googling than i care for I have come up with a few questions for some of the more knowlegable and experienced guys on here, in the hope I can track down a solution for my car.

I have a RWD AE86 with a BT 20v to be installed.

As the motor will be in stock configuration, I am led to beleive that 4-2-1 TRI-Y configuration is the most ideal for this application as the car will be legal, and for street use mainly.

The suitable options I am aware of are as follows:
OBX
http://www.ebay.com/itm/151003324309?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
CXRacing
http://www.ebay.com/itm/CXRacing-Equal-Length-Racing-Header-85-87-Toyota-Corolla-AE86-4AGE-16V-20V-/181046789759?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a273ac67f&vxp=mtr
Powercraft
http://www.rhdjapan.com/power-craft-exhaust-manifold-header-n2-spec-4-2-1-ae86-51693

I consider the powercraft to be the best option available however $1173 plus delivery to AUS is certainly not a very effective money vs performance ratio.
This is why I have looked into other options such as CXRacing and OBX.
The problem is, I understand from speaking to various people that ideally for the 4age in street form a primary length of 600-800 mm is ideal for more torque and no-where can i find a header with this spec. If its such common knowledge why do all the aftermarket headers only offer such short primary lengths?

Can anyone suggest an alternative header that is available for under $1000.
Is there anyone out there that can make a custom job a high standard in this price bracket?

I wonder is it that the difference in performance is considered so minor that people dont bother and just use the TRD 4-1 copies for convenience or has everyone else also faced this problem?
As a side note I dont have an affixiation with stainless its just that all the correct tri-y options seemed to be this way.

Any help well appreciated, thanks

[McLEVIN]

If you do a search for exahausts the general consensus is that trd copies are ideal for performance vs cost. Especially for a stock engine.
Anthony from kaizen garage sells them from here.

[whitezenki]

Hi, Thanks for your reply.
I have read every topic on this forum regarding headers and although Im sure they are ok for the money, they are not 4-2-1 which is what I am looking for.





If you do a search for exahausts the general consensus is that trd copies are ideal for performance vs cost. Especially for a stock engine.
Anthony from kaizen garage sells them from here.

[McLEVIN]

I right my bad. I thought they did both.

Have you gone into a performance exahust shop. I had custom headers. For my ae86 done by an exhaust shop. The whole system cost 1200. Headers to tips. That way they can build it how you want and your engine.

[collins]

I bought the OBX ones for my 20v conversion but i came across a couple of issues with them,

-first thing was the actual mounting flange the 2 outer bolt holes were off and needed to be filed out to fit.
-The pipe after the collector is from memory 2.5" which is way to big for most purposes.
-If you already have a exhaust kit from the headers back these headers will not line up with it.
-But my main issue was i had the Sam Q gearbox spacer in which tilts the engine forward for more clearance from the fire wall which caused the rear flange on the headers to foul on the chassis.

Overall the quality was okay but just be weary of these things as they will need some work to fit otherwise.

[pen15]

if you are running a stock motor i can almost guarantee you will not feel the difference if the headers are 4-2-1 or 4-1 the motor is an NA and for any difference to be made you will need to make some pretty substantial mods to notice any difference with my motor i just got any pair of headers and put them on they love it

[Jacobxxx]

Lots of headers would suit you that come for 16v, not hard to mod the 16v ones to fit

[Sam-Q]

if you are running a stock motor i can almost guarantee you will not feel the difference if the headers are 4-2-1 or 4-1 the motor is an NA and for any difference to be made you will need to make some pretty substantial mods to notice any difference with my motor i just got any pair of headers and put them on they love it

I know someone who had a lightly modded silvertop and he had a significant gain in the mid range going to 4-2-1

[Celica RA45]

guys look at the std rwd 4age cast iron manifold and the pipes that attach to it .they are good for 200 hp as they had to use them in Group A car racing

[Sam-Q]

guys look at the std rwd 4age cast iron manifold and the pipes that attach to it .they are good for 200 hp as they had to use them in Group A car racing

the man has a point, at least that way you won't end up with a dog-shit collector design in a shiny wrapper.

[whitezenki]

Ok thanks, yes that will probably be the next option researching and finding a good exhaust shop that make custom headers. cheers


I right my bad. I thought they did both.

Have you gone into a performance exahust shop. I had custom headers. For my ae86 done by an exhaust shop. The whole system cost 1200. Headers to tips. That way they can build it how you want and your engine.

[whitezenki]

Hi, thats all great info, thanks for your reply.
I agree I also thought that 2.5" was too large for the collector.



I bought the OBX ones for my 20v conversion but i came across a couple of issues with them,

-first thing was the actual mounting flange the 2 outer bolt holes were off and needed to be filed out to fit.
-The pipe after the collector is from memory 2.5" which is way to big for most purposes.
-If you already have a exhaust kit from the headers back these headers will not line up with it.
-But my main issue was i had the Sam Q gearbox spacer in which tilts the engine forward for more clearance from the fire wall which caused the rear flange on the headers to foul on the chassis.

Overall the quality was okay but just be weary of these things as they will need some work to fit otherwise.

[whitezenki]

Hey, so have you had both versions on your 20v? 110rwkw is impressive btw. Yeah im aware that the difference will be minor I just figured that if the consensus is that 4-2-1 are better for street and bottom end torque I should logically go with that design.


if you are running a stock motor i can almost guarantee you will not feel the difference if the headers are 4-2-1 or 4-1 the motor is an NA and for any difference to be made you will need to make some pretty substantial mods to notice any difference with my motor i just got any pair of headers and put them on they love it

[whitezenki]

Hi, thats a good point, i suppose its only really the outer bolt holes that would need modifying.
I also understand there may be differences in lengths though due to block height and clearance of bellhousing and firewall.


Lots of headers would suit you that come for 16v, not hard to mod the 16v ones to fit

[whitezenki]

Hi Sam,
This was my expectation also, It generally applies with all engines as I understand.


I know someone who had a lightly modded silvertop and he had a significant gain in the mid range going to 4-2-1

[whitezenki]

Hi, yeah that given, does a HP rating necessarily mean it will give the same or best torwue characteristics in a certain rev range.
I understand it wont limit the engine up to 200hp or thereabouts but surely it doesnt rule out where in the rev range the torque is made as this is determined by primary and secondary length amongst other things.
hahah yeah Sam I realise that most of that shit on ebay is knockup stuff, but as people have said any set of headers will do perhaps even a cheap set with the correct specifications will outdo the other options available such as trd copies etc..


guys look at the std rwd 4age cast iron manifold and the pipes that attach to it .they are good for 200 hp as they had to use them in Group A car racing

[SamsTA22]

Is it me, or do the CX racing headers look wrong?

They look like they have to front two and the back two paired together...

[Sam-Q]

no their right, the collectors are on top of each other instead of side by side

[SamsTA22]

They may be on top of each other, but it looks like the back two go into the top collector, and the front two go into the bottom collector.

[pen15]

i would be more worried about throttle length than exhaust runner length a set of the trd copy extractors from kizen and some 150mm stacks should give you a nice street 20v my car on the other hand has very usable track power for the street keeping the revs lower it feels like more of a stock 16v until around 3500-4000 then its party time

[whitezenki]

Actually you could be right, I just had a closer look its kind of hard to see but they should be paired 1+3 and 2+4, it does look like the 3+4 are paired doesnt it...
hmmm maybe ill have to accept there are no good 4-2-1 headers off the shelf for the 20v under a grand and the only option is to get a custom job..still keen to hear from anyone else, or anyone who can do a custom exhaust for under a grand for this config..



Is it me, or do the CX racing headers look wrong?

They look like they have to front two and the back two paired together...

[SamsTA22]

Actually you could be right, I just had a closer look its kind of hard to see but they should be paired 1+3 and 2+4, it does look like the 3+4 are paired doesnt it...
hmmm maybe ill have to accept there are no good 4-2-1 headers off the shelf for the 20v under a grand and the only option is to get a custom job..still keen to hear from anyone else, or anyone who can do a custom exhaust for under a grand for this config..

Actually, 1+4 and 2+3 is the proper way to have them. On closer inspection I don't even think they're equal length, and the amount the welding protrudes inside the pipe is atrocious as well...

the OBX headers looked OKish, hardly worth the price tag.

and the powercraft look pretty good. The long primaries would help a lot for a strong mid range. But again, for that price, its competing with custom headers that a guaranteed to fit.

Well designed and built 4-1 headers will outperform 4-2-1 in the midrange if the 4-2-1 headers have a poor design / build anyway. Its not like they restrict power at any rpm.

Also, the TRD copies are a good match for the short intake runners of a 20v

[whitezenki]

Yes sorry your right, 1+4 and 2+3.
They claim equal length but again your probably right, i have asked them twice already what the primary length is and the answer i got was 1.5" the first time (obviously the diameter) and second time i asked i got a shipping quote lol
Yeh OBX same same really.
Powercraft are nice but I think probably better suited to a modified engine, not to say they wouldnt work anyway but not worth a grand as most agree in terms of bang for buck.
Ok so I may have to revisit the kaizen copies idea or go custom.
Could you elaborate what you mean by a good match for the 20v intake runners.
thanks alot



Actually, 1+4 and 2+3 is the proper way to have them. On closer inspection I don't even think they're equal length, and the amount the welding protrudes inside the pipe is atrocious as well...

the OBX headers looked OKish, hardly worth the price tag.

and the powercraft look pretty good. The long primaries would help a lot for a strong mid range. But again, for that price, its competing with custom headers that a guaranteed to fit.

Well designed and built 4-1 headers will outperform 4-2-1 in the midrange if the 4-2-1 headers have a poor design / build anyway. Its not like they restrict power at any rpm.

Also, the TRD copies are a good match for the short intake runners of a 20v

[McLEVIN]

http://www.k-m-s.org/ex1.html

[whitezenki]

They look pretty good, interesting way to merge the pipes. ill see if i can find out any more


http://www.k-m-s.org/ex1.html

[pen15]

i was waiting for someone to post up kms lol

[whitezenki]

So they are replutable are they? do you have any other feedback or info?
Im going to email and ask for specs and delivery prices


i was waiting for someone to post up kms lol

[SamsTA22]

Yes sorry your right, 1+4 and 2+3.
They claim equal length but again your probably right, i have asked them twice already what the primary length is and the answer i got was 1.5" the first time (obviously the diameter) and second time i asked i got a shipping quote lol
Yeh OBX same same really.
Powercraft are nice but I think probably better suited to a modified engine, not to say they wouldnt work anyway but not worth a grand as most agree in terms of bang for buck.
Ok so I may have to revisit the kaizen copies idea or go custom.
Could you elaborate what you mean by a good match for the 20v intake runners.
thanks alot

Because its a tuned length, it'll have a resonant frequency. Judging by the length of the runners, the rpm where that occurs is probably at a similar point to when the intake runners have resonance. That's what I mean by a good match. But I may be completely wrong, its just a guess, as I don't know how long the TRD copy runners are.

[McLEVIN]

He probably dosn t speak english

[whitezenki]

Ahh ok interesting, that is a factor of header design I am not aware of..


Because its a tuned length, it'll have a resonant frequency. Judging by the length of the runners, the rpm where that occurs is probably at a similar point to when the intake runners have resonance. That's what I mean by a good match. But I may be completely wrong, its just a guess, as I don't know how long the TRD copy runners are.

[whitezenki]

Thats ok, google translate works a treat :) as long as i get the right dialect lol


He probably dosn t speak english

[chopchop]

They look pretty good, interesting way to merge the pipes. ill see if i can find out any more


5cent thoughts:

secondaries look very short and abrupt, it looks like a nice primary length/ resonance, possibly covering 6-8rpms, but the secondary length/ resonance ie 3-4 rpmish will be short lived? hence not amalgamating into the primary reso too well? (6rpm an upish)

I am a muso, i think of brass instruments/ digeridoo playing and multiphonics as a key, could be so totally wrong...
at 8000rpm = roughly 280 pulses per second
half revs = half pulses, ie 8000rpm @ 280 = 4000rpm @ 140 pulses
possibly, the way these merge, the same as overtones or multiphonics, indicates the possible flow characteristics (phase?) between the two resonances,
blah blah, so if the secondary is too short, then theres a small resonant 'sweet spot' in secondary resonance, and then a gap before the primary resonance kicks in??????

i have now idea what im trying to say.

.. as the relatively low pressure pulse (and high pressure head of slow pulse) at low-mid rpm (and climbing) works its way down the length of the primaries, and as faster rpm into the secondaries, the crossover between the two should be a 'smooth as possible' transition to allow both high and low (fast and slow rpm) to merge and have an allowance for exhausting all the different possible pressure pulses evenly- creating a large primary and secondary resonance range. this would create an even exhausting (scavenging???) effect thru the revs - possibly helping the induction of fresh air into the piston chamber = more (even) power thru the revs.

more thoughts:
a brass instrument ie trumpet, is designed specifically to play a series of harmonics ie 1-5-10 intervals or something. this should be the opposite for an exhaust, as to create many more possible 'harmonics' so that every possible range is covered ie any revs are exhausted evenly (free flowing).
ie, playing a tempered piece of music (12 tones in tune at octaves) on a set of extractors SHOULD be impossibly hard to get individual notes in tune, they should encompass ALL the notes blended into one another to account for all the different rpm's evenly. (possible phase cancellation tho??)

the 'exhaust ultimate power valve' in some recent Yamaha motorcycles adjusts a valve in the exhaust collector in conjunction with revs to adjust the pressure wave formation to alter (restricts flow) the characteristics of the low revs (more torque), and then fully opens at high revs. this achieves a max flow and induction throughout the revs - it somewhat tunes the resistance and flow according to the revs and resulting pressure pulses. this enables max flow (and sympathetic induction) exhaust at all revs..

jesus im full of crap. strictly just thoughts. anyone have anymore exhausting thoughts?

[whitezenki]

Thanks everyone for their comments and thoughts, I think the solution will be either a custom job or accept the perhaps 5% power sacrifice by using an adhoc exhaust system.
For me it will be the former, custom means I get what I want an avoid any fitment issues from chinese made stuff.


[QUOTE=chopchop;915586]5cent thoughts:

secondaries look very short and abrupt, it looks like a nice primary length/ resonance, possibly covering 6-8rpms, but the secondary length/ resonance ie 3-4 rpmish will be short lived? hence not amalgamating into the primary reso too well? (6rpm an upish)

[LittleRedSpirit]

I had a pair of old 4-2-1 headers on my silvertop until recently. I switched to the trd copy ones due to the 4-2-1s cracking up with age and rust.

I dont like the power delivery as much even after retuning. Its lost that pop in the midrange although it pulls smoothly up to peak power above 6500 where it was a bit hesitant before. I prefer it with more useable power considering its a street car with a stock engine.

The 4-2-1s were a very long set.

[whitezenki]

Interesting. I do agree that 4-2-1 will be a better option.
I have come across these HKS headers
http://jdmhunter.blogspot.com.au/2010/12/hks-4-2-1-header-for-4age-20valve.html

They seem to get good feedback...



I had a pair of old 4-2-1 headers on my silvertop until recently. I switched to the trd copy ones due to the 4-2-1s cracking up with age and rust.

I dont like the power delivery as much even after retuning. Its lost that pop in the midrange although it pulls smoothly up to peak power above 6500 where it was a bit hesitant before. I prefer it with more useable power considering its a street car with a stock engine.

The 4-2-1s were a very long set.

[Delazy]

Interesting. I do agree that 4-2-1 will be a better option.
I have come across these HKS headers
http://jdmhunter.blogspot.com.au/2010/12/hks-4-2-1-header-for-4age-20valve.html

They seem to get good feedback...

They are also to suit a FWD..

[LittleRedSpirit]

Toyota equipped every 4age they ever made with 4-2-1s.

[LittleRedSpirit]

HKS and TODA R. have awesome options for rwd ae86 fitment, if you can find them and afford them.

You could end up with just as nice a set if you get custom headers made, which is really the only way to achieve similar equipment for less money.

I disagree with the 4-1 trd copies being a good option. :yeah: I think TRD would be pretty insulted by that description of those pipes. Its an easy option but not one based around getting the best out of a stock 4age. Having owned and used 2 sets Im qualified to say.

Theres nothing wrong with wanting to do it the way you want, its what cars are all about. I went on a torque binge at one point and went to 4-2-1s and necked down my inlet and the exhaust was 2 inch. Made all its power (120hp) at 6500rpm instead of 7200, but it really hauled up to those revs. Was a tonne of fun. Found the best overall setup was the 4-2-1s I had with decent ttt trumpets. With stock ae101 20v that is.

[Delazy]

I ended up with 4-1 purely by accident, had ordered 4-2-1 from Japan but somehow they got mixed up and I ended up with 4-1..too much hassle sending them back so decided to go with them..being that my motor is a high comp built 20v 7ag I figure it'll have plenty of mid range regardless of header choice, the 4-1 should promote more top end grunt ontop of this..in my uneducated theory anyway

[fantapants]

plus delazey will be much happier with the ones i make him and prob sell the powercraft for next to nothing :D

right??

[northy]

I had powercraft n2 on my bt 20v with an adaptronic and came across a set of powercraft tornado headers (4 into 1) I've got a slight flat spot when it's cold but think the gains would be more noticeable on a engine with bigger cams etc.

[chopchop]

plus delazey will be much happier with the ones i make him and prob sell the powercraft for next to nothing :D

right??

--Delazy and Fantapants, you guys are in taz, where and what are the options for header and exhaust fabs? Know of anyone or options? (4-2-1 custom fab headers and exhaust)

[fantapants]

well ill happily make you some, but im a bit far from newy mate :D

xero was very happy with the custom set he had made in sydney, but im not sure on who he used....

ps those stainless ones pictured by someone with the weird merges.... they are the devils own shit. atrocious design from someone who clearly cant read....

[Delazy]

^^^^ bloke above knows nothing, I wouldn't let him weld a diff let alone build me decent extractors :p :p :p

[chopchop]

nah nah im in tassie!
just came back after a short stint in newy, mainly to buy my brothers sprinter off him: :sunnies: dammd .. i fell for the old girl BAD

yeah so thats a REEALY nice offer mate, I'm also trying to find decent 4-2-1's for 20v. which there are none of.
Im in Hobart and your in 'other', but I guess being in tas thats only a few hours away max..

Perhaps i could learn how to PM on this and send you a msg to discuss it all

Agree on the 'devil pipes', way too many about and aint gonna waste 1g on lumpy ass shiny crap.






well ill happily make you some, but im a bit far from newy mate :D

xero was very happy with the custom set he had made in sydney, but im not sure on who he used....

ps those stainless ones pictured by someone with the weird merges.... they are the devils own shit. atrocious design from someone who clearly cant read....

[Delazy]

if you want some custom pipes made in hobart, the only people id speak to would be Jake Crawford @ GTGarage or Aaron Martin @ AzCustom/Tas Mobile Mechanics... Aaron is a fellow 4ag/ae86 owner while Jake has an Sr20 ke70...

[Sam-Q]

They look pretty good, interesting way to merge the pipes. ill see if i can find out any more

this is a similar way to how they are done on really high end collectors, although it does look like a more rushed version of it. The potential of these might be ok

[fantapants]

ahhh makes more sense then chop...

as per lazy comments, the lads in hobart are winning. can vouch for az quality of work from personal experiance.

[fantapants]

sam do u mean the kms headers?

from what i have read and researched, that form of merging creates all sorts of performance based issues and, well, is simply horrible??

happy to be corrected, but in terms of creating resonance waves and producing performance enhancments, junction angles and expansion angles are critical. the way they appear to be done on the kms is to point the tubes, and effectively the pulse waves, at each other, which in my mind would prohibit any proliferation of resonance waves?