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TD04-13G turbo, flow mapped for the EA82


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Hey guys

 

In my never ending search for the non-existent compressor map of the RHB5-VF7, I found one for the stock WRX turbo (TD04-13G). I figured I’d see how well it matched up to the EA82, since it’s been proposed at a possible up grade. Well guess what… it matches VERY well! For boost pressures between stock (7psi) and around 15psi (about all I’d want to push the EA82) the flow stays within about the 75% island.

 

The first table is the flow estimates in CFM and cubic meters per second (CM/s), the big margin for error in these numbers is the volumetric efficiency, but should be fairly close, if anybody has a torque curve for the stock EA82T we might be able to get a bit more accurate.

 

1.jpg

 

The graph shows the flow numbers over the compressor map for the working RPM range of 3000-6000. Note that the 7 to 15psi flows fall right in the heart.

 

TD04-13Gwithflow.jpg

 

The real bonus here is that “take off” low mile WRX turbos can be had for less than the cost of rebuilding the stocker. The down side in higher minimum boost RPM and increased lag, but I think mods to open up the intake and exhaust will buy back most of the loss. There are some mounting issues beyond changing flanges, but they could be addressed while creating better flowing up and down pipes, dose anyone know if the TD04 is clockable like the RHB5?

 

Anyway, thought some of you might want to see this stuff.

Gary

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good stuff,

 

I have not yet installed the one I picked up because I need to swap to a WRX intercooler .

 

and no its not really clockable due to the mounting of the waste gate actuator. but the good news is that a stock wrx down pipe fits perfect in a ea82 body and I have a plan for the up pipe mountinng flange.

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You make me feel stupider and stupider! I haven't heard of "clockable" before... define, please? (And keep it simple, as I can hear my brain cells dying.)

:-p

 

Clockable means you can rotate the inlet and/or outlet housing (scroll) to line up with the plumbing. The center cartridge must be oriented so the oil drain is vertical (or very near), clocking makes the install much easier. Some turbo have indexable clocking because of a bolt pattern, so you can turn the housings tell the holes line up again, the RHB5 and many others use clamping plates and can be rotated to any angle.

Gary

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WRX Turbo Upgrade: What it takes to play with the big boys.

 

The Car: '87 RX 3dr.

 

Engine Specs: Freshly rebuilt lower end to stock specs. Polished crank, knurled pistons. OEM quality bearings and rings. Mild cams from Delta Cam. Gen 2 heads. NGK Iridium spark plugs. NGK 8mm wires. New cap, rotor. Stock coil. XT6 flywheel and clutch. Spider intake. WRX turbo and downpipe. WRX intercooler w/GFB BOV. Boost controller.

 

How I converted to the WRX turbo: First, I bought a WRX turbo, downpipe and uppipe. Then, I had Qman help me weld the WRX flange directly to the top of the stock existing turbo flange. As most know, most of the holes line up, except the rear one. I opted to do the flange instead of messing with elongating the hole on the turbo which looked more difficult.

 

With the turbo mounted to the engine, I found that the stock oil supply line works with the TD04. So I used it, it all lined right up. The oil drain tube was right were it needed to be. The lower coolant tube matched up well with the tube coming of the head... required just a touch longer hose than stock. The upper coolant tube also is a touch off, but just a little bit more hose and that problem is solved.

 

The WRX downpipe fits (in my configuration) prefectly. The bracket for the trans even lines up like the stock one.

 

For the air intake, you need a sharp 90 degree rubber bend. I got mine from Overboost.com. Was like $15 or so. This is connected straight to the MAF, the MAF has an adapter with a 3" cone filter on it. All straight through, except the last 90 degree turn into the turbo.

 

Coming from the turbo to the IC to the TB was a touch harder. I purchased a used Samco silicone Y-Pipe for a WRX. Roughly $50 (new is $100) I then cut the 90 degree end off of it that attaches to the turbo outlet. This allowed me to plumb in a piece of steel tubing between the 90 degree piece and the Y piece. So that I could push the IC back a bit (otherwise it sits to high cause of the brake lines and AC lines)

 

Ran into a big problem with the TB. The fast idle solenoid ( I think...) hits the 90 degree outlet tubing off the turbo. No good. So I rotated the throttle body 90 degrees. So the throttle cable was pulled not from the drivers side, but from the top. Yes it still clears the hood. This gave plenty of room for the 90 degree turn tube from the turbo to the IC. It is then a straight shot piece between the IC outlet and the TB.

 

I'll work on getting pictures of it.

 

Oh, BTW... Car is running again. 4 cylinders with compression will do wonders for performance! Turbo Legacy's and WRX's beware, you're being hunted.;)

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:-p

 

Clockable means you can rotate the inlet and/or outlet housing (scroll) to line up with the plumbing. The center cartridge must be oriented so the oil drain is vertical (or very near), clocking makes the install much easier. Some turbo have indexable clocking because of a bolt pattern, so you can turn the housings tell the holes line up again, the RHB5 and many others use clamping plates and can be rotated to any angle.

Gary

bear in mind that that is only true if you dont need the wastegate actuator to line up with the holes. to get mine where i wanted it, I had to modify the bracket.. cut and shut it.

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Tex, Great info on the install, you lead, we will follow, your post reads like my wish list. Couple of questions, what’s the minimum boost RPM and lag compared to the stocker? How much boost are you running, any plans for supplemental fuel? It seems that stock ECU runs very rich at WOT/full boost, I wonder how much boost we can add before the stock system starts to lean out? Are you running an AF or EGT?

 

Thanks shadow, I’ll be happy to share whatever work I do. My VE numbers are based on typically accepted “standards” for traditional 2 valve heads. I don’t have a torque graph for the EA82T, nor am I exactly sure how to extrapolate the VEs from it. If you have the graph and the theory/formula (or just better numbers) I’d love to know what you know. Was it Garner that used the angled “adapter” on the up pipe?

 

Russ and majjjord, so is the TD04 clockable if you mod the waste gate mount?

Gary

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So any one got an extra Tdo4? :rolleyes:

 

The Wrx turbo really does work great on the Ea-82 engine, i've ridden in tex's rx, and it feels great. He hits boost close to the original boost minimium, near 3k, but it pulls a whole hell of a lot better than an ea-82 turbo running ten pounds, he's still running stock boost and it feels awesome. It'd blow me outa the water.

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I figured I’d go ahead and map the EA82 flows on the only available map for the stock turbo (RHB5-VF7). The map doesn’t tell much but if you in vision where the efficiency lines might be you can see why it struggles at higher boost levels, in fact all the flows are near the edge. The map shows two compressor trims, I’m assuming the Subaru version is the 393B or similar.

RHB51.jpg

Gary

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  • 4 months later...
  • 2 weeks later...
  • 1 year later...
Mine isn't that recent.

 

But it was fun wile the motor lasted.:D

 

I will have to agree with Caleb. It was very fun while my engine lasted and with the stock boost that the TD04 puts out (I forget what it is) got my RX to move very nicely off of lights and such.

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