Pat's Ebay Turbo Compound Boost Build
Thread Starter
Elite Member
iTrader: (16)
Joined: Aug 2007
Posts: 9,406
Total Cats: 559
From: Houston, TX
Yeah, that's pretty ******* terrible and I bet it has nothing to do with it being an ebay turbo. Although I've heard similar numbers from begi t2's, so maybe...
All the 1.8's can spool the larger t3 by 3K, and I can do the same on a 1.6 with corn. So why's your smaller turbo suck so much? Is something broken or did you just pick the wrong one?
All the 1.8's can spool the larger t3 by 3K, and I can do the same on a 1.6 with corn. So why's your smaller turbo suck so much? Is something broken or did you just pick the wrong one?
It sounds loud, like an open downpipe car, but not as loud.
And taco manifold too, but I did port it a bit to help it flow a little better.
The front turbo I'm using both ports. Bottom to post-intercooler pipe, top to turbo inlet. Just hook an MBC right to the bottom port? I can't do it on the top port, as that needs to be referenced to the turbo inlet.
Thanks. This went together fairly quickly, and I made a lot of custom stuff for it too. And kind of designed as I went too....
First step is turn up the boost. Then figure out how big of a magnaflow I can fit in the back and order, and decide what I'm going to do for a catalytic converter. And fix any problems that pop up. And figure out a cheap way to MS3 PWM my oil pump with RPM so that it's quiet at low speed/highway cruise.
I would plum it into the bottom line and have the exhaust that would normally vent to air vent to the turbo inlet, that should keep your ratio. So you have to use a bleed type, unless you can find a blocking type that has a reference port that you can plum into the turbo inlet.
Joined: Apr 2014
Posts: 18,643
Total Cats: 1,870
From: Beaverton, USA
I would do the 1700's. They are significantly better injector tech.
Slow spool on "small" turbo: It's not seeing as much pressure differential on the turbine as it usually would since the big turbo adds a restriction in the exhaust. So it will spool more slowly.
Joined: Apr 2014
Posts: 18,643
Total Cats: 1,870
From: Beaverton, USA
Needs an electric cutout after the first turbo that closes when you hit 4krpm. Low end spool then close it and spool the big one.
Keep it stupid simple
Keep it stupid simple
Joined: Apr 2014
Posts: 18,643
Total Cats: 1,870
From: Beaverton, USA
Thread Starter
Elite Member
iTrader: (16)
Joined: Aug 2007
Posts: 9,406
Total Cats: 559
From: Houston, TX
From a control standpoint this setup is dirt simple. Two turbos, two wastegates. That's it. About to add an air pressure regulator to the rear wastegate's top port so I can adjust the pressure on that one up. Again, dirt simple stuff that just works. No tuning PID, no electronic anything to mess with. Simple and works, I ran this same one on the GT32 setup and it worked perfect, so I expect it to work here too.
Also found a small exhaust leak upstream of the big turbo, missed about 3/8" of welding on a spot, gonna fix that real quick so might spool that guy a bit better....

I'm planning to turn up the boost on the big turbo until I run out of fuel, then figure out how to get more fuel to it.








That's a hell of a project! MacGyver ain't got nothin' on you.
