Fitting a GT42 on a 2JZGE with the Ebay Manifold

p5150

ASE and FAA A&P Certified
Mar 31, 2005
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Central Idaho
Ive been getting a lot of questions in my PM about this so I thought I would explain everything.


The manifolds sold on ebay dont really have a brand name. They are made in China and marketed by different vendors here in the US. This is the one I got:

http://cgi.ebay.com/ebaymotors/

Item number: 270246376920

Or you can search "turbo lexus" or "2jzge" once the listing expires.

Even if it looks like there is no slag left, go through it again with a grinder to be sure. A new GT42 turbine wheel is $300+.

In order to make the GT42 fit, I got three thick T4 mild steel flanges and welded them together to make a thick plate.

After that, I cut the flange diagonally across the face at a specialty machine shop. I also drilled out the holes in the plates so that the turbo mounting studs could tilt a bit to the left and right. This made the adapter look like a wedge and tilted the turbo towards the motor.

With the GT42, the housing will hit the strut tower if you use the Ebay mani that I used. Even re-clocking the flange makes it a close fit. The adapter plate lifts it a bit and gets it away from the tower.

Another thing you have to consider is the drain line for the turbo. This is going to be a bit expensive. The drain on the GT42 has to be a decent size. I started with a -10 made by a local hose shop but it was a too restrictive. The oil was leaking out of the turbo seal because it wouldnt drain fast enough. I stepped it up to an Earls -10 and it got better, but at higher RPMs it would still leak a little bit. I now have a -12 setup but I havent had a chance to try it yet. Been too busy to work on the car.

The GT42 in combination with this manifold puts the drain line in close proximity to the manifold. You may want to consider some heat wrap for both the hose and the manifold to keep from scorching it. Also, the turbo needs to be orientated no more than 15 degrees from straight down in order to drain correctly. This will probably require you to grind on the manifold flange a little bit in order to give enough clearance for the drain line.

You could also vary the angle at which you cut the adapter plate or re-clock the manifold flange in order to cock the inlet of the turbo up a bit and point the drain away to give a bit more clearance.

The wastegate flange is 90 degrees off as well. I ended up cutting mine off and spinning it approximately 90 degrees in order to make the 50mm HKS replica wastegate fit perfectly and point the dumptube to the bottom rear. It is a tight fit but a quick fix if you are handy with a welder.

I also built a 4" downpipe with a vband flange. The sections of the downpipe had to be partitioned up and welded together, but its all stainless and fits nicely. I also was able to double wrap the downpipe to keep the heat off of the brake lines and firewall.

Overall, I would still prefer to use and Ebay manifold. The price cannot be beat. Keep in mind that the main reason it required so much modification for me is because I was using such a big turbo.
 

adam8103

New Member
Jun 9, 2008
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Windsor
With the angle cutted on the flange to tilt the turbo towards the engine it probably made the hole of the flange bigger? or it is not as big of an angle to open these hole enough? what is the angle you have the flange cutted?
 

adam8103

New Member
Jun 9, 2008
29
0
0
Windsor
I forgot to ask, are you still running the distributer?

did anyone already compare mk3 vs sc300 engine bay... i wonder if i will have enough space in the sc300 to do the same as you did to the turbo mani with my gt42
 
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