Aftermarket EA82T Manifold

H-top · Post by **H-top** » Mon Aug 17, 2009 8:39 pm

G'day,

Wondering if anyone knows if an aftermarket
turbo manifold is made by anyone in oz?

I think i saw one made in Stainless a few months ago
on this forum?

Cheers,
Sam

Gannon · Post by **Gannon** » Mon Aug 17, 2009 8:43 pm

Nope

Anything you did see was custom

A few guys have done it, all with different designs

A member is actually making 4 bolt flanges for the manifold he is making, maybe if you ask nicely, he'll make you one too

twilightprotege · Post by **twilightprotege** » Mon Aug 17, 2009 9:18 pm

yeah i'm making one for my car shortly

H-top · Post by **H-top** » Wed Aug 19, 2009 1:13 pm

how shortly is shortly?

twilightprotege · Post by **twilightprotege** » Wed Aug 19, 2009 9:34 pm

i've got all the pipework, just need to get the flanges made up. in the process of drawing up the turbo flange right now

discopotato03 · Post by **discopotato03** » Thu Aug 20, 2009 8:29 am

My RX's next mod will be a header pipe and have to think seriously about tube size .
I've been thinking about 1.75" tube for the engine pipes and either same or 1.875 for the up pipe past the collector . The turbo flange will be a T25/T28 sized one for my spud turbo .

Cheers A .

H-top · Post by **H-top** » Thu Aug 20, 2009 10:44 am

Sounds like a goer, i was thinking port matched but anything i found was too big to fit a nut on anyway when i wanted a 2.2mm wall thickness.

Tuned length, disco?

discopotato03 · Post by **discopotato03** » Fri Aug 21, 2009 12:06 am

No , because of the port layout and firing order of these flat fours I reckon it'd be impossible to have a tuned length . Tuned length manifolds are really only a possibility on NA engines to assist scavenging at a given narrow rev range . Having a turbine housing and turbine in the exhaust system makes wave tuning virtually impossible .
I think the best you can expect is to have engine pipes a bit closer in length to time the exhaust pulses at the collector and turbo a bit more evenly .

A .

twilightprotege · Post by **twilightprotege** » Fri Aug 21, 2009 6:42 am

i'm going for 2" pipe until the sides merge, then 2.25" up to the turbo. the reason i'm going with that option is because the ID of a 2" pipe is perfect for the exhaust ports, and a 2.25" up pipe has a perfect ID for the stocko turbo

discopotato03 · Post by **discopotato03** » Fri Aug 21, 2009 10:13 am

I'm just about to put the very near calipers into a VF8's turbine housing inlet because they being a larger OEM EJ20 turbo would be a fair bit bigger than a dinky VF2/VF4 .
Ok it measures up about 44.5mm so assuming the 2.5 wall thickness on 57mm/2.25 OD tube it sounds like it's still larger than the turbine inlet at a touch over 52mm .

I remember reading on USMB that the TWE header made in the States was a bit healthy on the tube size and people suspected that it cost low down torque on EA82's .

At some cost I'm trying to get a leg up with a low friction ball bearing turbo but even these need a bit of velocity to get them going .
My personal theory is big tubes for lotsa gas flow from either a big capacity or high revving engine . These EA82 don't breathe to well and need the extra airflow from the dryer to make worthwhile power IMO . The low CR really kills them off boost and the restrictive std header turbo and exhaust - mainly the latter two prevent then revving freely on boost .

I want to be a little conservative with my header because I don't want to lose the bottom end power it has . I realise that the total exhaust port area is large but there are two in each (siamesed) and only one is venting at a time . It should be possible to make some sort of elongated cone or extrusion to match the siamesed port at its face . My mechanic/fabricator commented once that you could extend the exhaust ports divider out into the header if you had the time and money to muck around with it .

When you get your std turbo off have a look inside its turbine housing inlet , not real big by 1800cc engine stds . If you run bigish pipes you can get a pulse damping effect and that doesn't help get the turbine going . If the CR was higher you get sharper pulses and its possible to get away with larger tubes but it isn't . With programmable computers you can tune around some of the dramas , tap in a lot more advance off boost which really makes a difference torque and throttle response wise .

I think it depends on how far you want to go and how much you want to spend . The rally people got 190 fragile horsepower out of a std header and a turbo with a slightly larger turbine housing - and no intercooling . They did use long cams which made them idle badly and run like a chaff cutter . A more modern turbo and much much better engine management would have made it easier with less extreme cam profiles , current pump fuel is heaps better too - the good stuff .

Cheers A .

discopotato03 · Post by **discopotato03** » Fri Aug 21, 2009 10:51 pm

I finally got around to measuring up L Series and Vortex EA82T headers and they are mostly the same except for the the last bend and flange plate under the turbocharger . The Vortex one (Aust 87 AWD spider engine) has the O2 sensor probe before the turbo and I reckon they made this area i little larger to not have the probe as a restriction at this point .

I have the above mentioned EA82T heads here and the exhaust ports measured 49.5 and 50mm - a fair bit larger than the header flanges and tubes . The crossover pipe measures 50mm OD neat so I guess a metric 2 inch .
Genuine Subaru EA82T exhaust port gaskets measure 57.5 mm in case anyone wanted to know .

I think the way to go is to start the heads exhaust flanges and tubes at the same size as the port and have a gentle transition to whatever crossover tube diameter you think is best . Ditto for the turbo side and the forward loop to get the lengths closer at the collector .
The up pipe is going to need a bit of thought because it is ducting the gasses from all four cylinders where the primary pipes are only doing the two in each bank .
While the std up pipe to turbo flange is smaller than the the turbine housings inlet it doesn't really matter because about 2 odd cm into this housing the internal port necks down markedly from the ports size at the housings flange . I have pics from USMB of the rare 15R EA82 turbine housings port and they do it as well just not as much - very poor housing design by today's standards .
I have to measure up a T28 flange and work out what size tube can best be formed into a rectangular shape . I have a feeling we may have to have another flange joint low down on the up pipe so that the turbo and upper section of the up pipe can be removed if necessary , don't think there will be room to get at the inner two of the four studs and nuts to bolt it down . Makes flange changes a piece of cake as well .

Cheers A .

H-top · Post by **H-top** » Sat Aug 22, 2009 8:57 am

Holy crap, that's a pretty mean feat to get that out of an ea82! I could only dream of getting that from mine, i've thought of an ej conversion but i'd really like to see how far i can push my ea82 with a few mods, it's great to drive as it is but yeah, always looking for more kick.
Yeah i get your point disco, would like to see an extended port to split the cylinders, has it been done?

Cheers.

Gannon · Post by **Gannon** » Sat Aug 22, 2009 9:09 am

discopotato03 wrote:IThe crossover pipe measures 50mm OD neat so I guess a metric 2 inch.

Yeah but its a double pipe, a 40mm pipe inside a 50mm pipe. The inner pipe has a 37mm ID

H-top · Post by **H-top** » Sat Aug 22, 2009 9:29 am

Double piping is the devil.
I understand it's there for a reason. It's hard to tell what part of the exhaust is stuffed and what's good if there is a leak . Also when you don't know it's double piping, it becomes the push up bra of the exhaust world, false advertising, makes it look like it's got more size than it actually does lol.

discopotato03 · Post by **discopotato03** » Sat Aug 22, 2009 6:26 pm

Is it twin tube all the way across or just at the near side bend and the T piece ?

I guess the only way to know would be to cut it in half in the middle or drill an exploratory hole . Anyone have a stuffed header to cut up at different points ?

I wasn't intending to use any original header parts so can make to suit .
Aside from the exhaust ports and gasket sizes we can pretty much make whatever can be packaged into the car . Just need to decide on tube size and collector placement .

Cheers A .

Gannon · Post by **Gannon** » Sat Aug 22, 2009 7:02 pm

Its all the way through (if i move the inner pipe at one end, it moves at the other end)

But i can can cut it up more if you would like.

Whatta u wanna know?

discopotato03 · Post by **discopotato03** » Sat Aug 22, 2009 10:28 pm

No that pretty much tells the story , the bore of the inner tube measures ~ 35mm from what I can see in that pic or around 1 3/8 .

I suppose to go up 1/4" to 1 5/8" (41mm) bore means 1 3/4 OD tube or 1 7/8" for 1 3/4" (44mm) bore size .

41 or 44mm bore tube is probably about right and would have a significant cross sectional area increase over 35mm bore .

Cheers A .

discopotato03 · Post by **discopotato03** » Tue Aug 25, 2009 9:38 am

I've been doing a bit more thinking on header tube size and based on Gannon's measurement of the crossover pipes true bore size (37mm or a little under 1.5") I'm going to ask my fabricator about 1 7/8 tube which should be around 1 3/4 ID . This should be ~ 44.5mm ID and about big enough .
From memory I measured the std headers turbo side pipe to the T piece and I think it was 41.5 odd mm which is about 1 5/8 inch .

Was just speaking to my fabricator and he said that stainless is the better material to use because of its strength compared to mild steel . Apparently all the mandrel bending machines are set up to do 16 gauge tube where 14 gauge would be preferable . He said 16 gauge stainless has about the strength of 14 gauge mild steel so it looks like the way to go .

I get the feeling that others have done the footwork before and it's a pity that place in QLD didn't make more sets because for the money they looked really good . Was it Extreme RX that had the stainless ones made ? If anyone has contact details of the person or business that did them can you let me know please .
Or if anyone with one wishes to sell ....

Cheers Adrian .

H-top · Post by **H-top** » Tue Aug 25, 2009 10:58 am

Any pics of the sets?

discopotato03 · Post by **discopotato03** » Tue Aug 25, 2009 3:07 pm

There was a really long thread a while ago about making those stainless headers , I think it was Quik RX that chased it all up . If anyone has a link to that thread ...

Cheers A .

Found it .

showthread.php?t=3644&page=13