Looking for Twin Turbo Setup Suggestions for Subaru EZ30

Dustin_TheFordPro

Dustin_TheFordPro

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Hey everyone, I just picked up a “new to me” Funco Gen 4 with an NA EZ30 six cylinder Subaru in it. So far the car has been awesome, not bad for around 250 hp.

That said, I’m wanting a little bit more power. My last car had a turbo 2.5 making about 430 hp at the crank, and I’d like to be in that 400-450 hp range with this setup.

From what I understand, you can get around that number with something like 6 psi of boost. But I want to do things a little differently, I’m interested in a twin turbo setup.

I know some people will say it’s not worth it or unnecessary, but I want to price it out realistically and be reasonable about it:
  • I don’t need $2500 turbo's to make 6 psi or am I wrong?
  • What turbo size and brands are realistic and affordable for this power goal?
  • Who would you recommend for building a twin turbo kit in SoCal?
Thanks in advance!

This video gave me the idea...
View attachment ScreenRecording_02-22-2026 15-16-52_1.mov94AD8FD6-3500-4195-B458-029E530856F3_4_5005_c.jpeg
 
Went down this road with mine. Went single turbo and can get a reliable 600hp out of a 3.0.
Next step is johns 3.2 that has turbo cams.
14 lbs boost gets ya close to 750 hp.
 
Yeah, that’s good to know. Honestly, my goal is a reliable 450–500 hp. I’m just trying to bring my Gen 4 up to the level my 2.5 Gen 3 was at in terms of power. That car, at 430 hp, was a rocket in the dunes. I’m not concerned with straight line speed, I just want that low end, dune crushing power.
 
Dustin_TheFordPro said:
Yeah, that’s good to know. Honestly, my goal is a reliable 450–500 hp. I’m just trying to bring my Gen 4 up to the level my 2.5 Gen 3 was at in terms of power. That car, at 430 hp, was a rocket in the dunes. I’m not concerned with straight line speed, I just want that low end, dune crushing power.
Click to expand...
I know exactly what your wanting.
 
More or less I’m trying to figure out what turbos I need to make about 6 psi of boost and spool quick. It just feels like spending $2,500 per turbo is a bit much for the low power I'm going after.
 
Single turbo is all you need. Your 2.5 was single and I'm sure a lot more boost.
Kiss....
Keep
It
Stupid
Simple
 
When I was shopping for my turbo, my buddy referred me to ATP turbo. I gave them all my motor specs and they made a recommendation based on that. I have been super happy with it. Cant hurt to shoot them an email and see what they say.
 
450-500whp is only 225-250whp per turbo. This could easily be done on two GT28s, 0.64 A/R, and spool like a light switch.

That being said, the single will spool just as fast (possibly faster) and be simpler.

Also: merge the exhaust or it'll sound blatty.
 
Rockwood said:
This could easily be done on two GT28s, 0.64 A/R, and spool like a light switch.
Click to expand...
That’s what I’m thinking too. I can’t find any small turbos that aren’t internally wastegated. I’m not sure how that would work with a twin setup. Is it easy to convert them?
 
Dustin_TheFordPro said:
That’s what I’m thinking too. I can’t find any small turbos that aren’t internally wastegated. I’m not sure how that would work with a twin setup. Is it easy to convert them?
Click to expand...
Run an internal wastegate for the simplicity. Your power goals aren't gonna care much about external, and all you need to do is bolt up the turbo and run the lines to it. You might even be able to bolt them directly to your existing manifolds, or get adapters made.

If you want to run external wastegate, you can easily convert them with a T25 external wastegate housing.

If you want to run the wastegate flow divorced, that's even easier with the correct flange and some fabrication:

ipgparts.com

Vibrant Performance 5 Bolt with Divorced Ports Discharge Flange for GT25R/GT28R

Vibrant Performance 5 Bolt with Divorced Ports Discharge Flange for GT25R/GT28R Material: 1018 Mild Steel Warranty: One Year Limited Warranty - 1/2" Thick - 2" I.D. and 1.5" I.D. Ports
ipgparts.com ipgparts.com

This is what I run on my buggy. GT2560R usually has a divider in the turbine discharge as well:

1771969486588.png
 
was this the buggy that was for auction in Idaho?

don't want to rain on your parade but you should consider these facts:

stock 3.0 rods are good for 5psi max, at 8 psi I couldn't imagine motor lasting a year
to rebuild this motor and upgrade to handle boost is expensive (but oh how sweet it is)
stock injectors need to be changed as they are just enough for the stock 300hp
Ex valve spring seat pressure is a super low at 40# , one bad overrev with boost may be bent valves
if you just want to run 5psi and see how long it lasts then internal wastegates are not your friend, as you want to precisely control boost and not have to "live with" whatever the internal spring is. (the external ones have more options for boost)
the motor is already very wide so putting two turbos at the side of the valve cover will be super wide and then if you say "well I'm going to put them at the back of the engine", then you might as well make it a single turbo and make your life easier,
did you already look at oil supply ports for your turbos? (That because there almost isn't any let alone two feeds are needed for twins)
 
John@Outfront said:
don't want to rain on your parade but you should consider these facts:
Click to expand...
Alright, can you price out what I need to reliably make around 450 crank horsepower? My email is dwilliams@sunriseford.com. I’m Bobby Williams’ son, you’re currently pricing out my brother Logan’s yellow Gen 3 build lol. I originally had the faster yellow gen 3.

And yes, this is the Idaho car. Been a great car so far!
 
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