I'm restarting my build and have been rethinking the motor. I have built with the Subaru 2.0 STI motor but have been looking at the EZ 30. Was wondering what you guys think.

So many threads. So easy to search.

Dealers choice. I like the sound of the 6 over the 4 but that's a personal preference. I also wanted to keep the 4 lug Fuch's and the EZ30 was well within the limits of the OEM CV's. If it's high HP you seek the Turbo 4 would be your choice. The 3.0's & 3.6's range 218 -247 ft lb torque which is plenty for me. The exhaust system on the Turbo's takes a bit of creativity. Either way you go use the Subaru transmission. When done correctly you will wonder why everyone isn't doing this. I've got a little over 13K on mine and love it. Their reliable power plants and not too expensive to own. I've gotten gas milage in the high 30's.

I know. I have been reading and reading.

I think it is more the sound than anything . The 4 is ok but ? Also thought about going to equal length exhaust to get rid of the odd note .

Just thought I would check.

So you have a JDM STI motor? Nice thing about those is they are a twin scroll turbo which in theory is less turbo lag.

If you're gonna go with a turbo 4cyl then the JDM Ver. 7/8/9 are the best bang for the buck. The 8&9 are twin scroll turbos which are great but if you ever want to upgrade there are not as many options as there is with a Ver.7 single scroll. With the twin scroll or an equal length header like the Tomei you will get rid of the annoying Subaru rumble.

I know someone is going to chime in and say "Why not the US STI?". Honestly stock its a POS. In fact Subaru just lost a class action lawsuit about it being a POS. If you want to do a full long block build before you do your swap then maybe it's an option for you? I've driven the 2.0 STI and the 2.5 STI engines extensively and I will tell you the 2.0 is a better smoother engine.

If you're going to go 6cyl then the EZ30R is cheap and plentiful. The older EZ30D is still out there but the EZ30R offers quite a few advantages and is lighter. The EZ36R is even lighter but you lose the AVLS so if you're into that VTEC style switch over, nope but you do pick up dual AVCS which when tuned right can be very worthwhile.

Keep in mind the 6cyl will take boost but not a lot without a full build so they are better if you want to stay N/A.

Hope this helps

My STI is a V2. Old school 1994 -96 ?

no personal experience but the EZ 30 just seemd right to me from all the threads and a few u-tubes. Love the sound and grunt seems about right.

Me likee!

Maybe im outta line here but shouldn't you be asking yourself
Which subuzu engine makes the most torque .

Because after all in a porsche with the 901 style gear box .

You want an engine with good torque , that will make the car fun to drive

Or if it were me i would just find the most plentiful, cheapest subaru
Engine and that way if anything went wrong with it , i could just replace the engine with a fresh one .

German (power egg) style

https://en.m.wikipedia.org/wiki/Power-egg

Why keep the 901 trans? The Subaru trans offer more options in ratios and final drives to suit any engine combo.

I have (1) JDM Sti 5 speed and (1) USDM Sti 5 speed. Both with the same ratio but one is a close ratio (JDM).

If I keep it light the EZ 30 wins until the turbo cuts in. But its the sound for sure of the 6.

Depends on how far along you are and how soon you want to be driving.

Have you bought the cradle/mounts?
Adapter kit?
ECU/FI?
Just the motor?

I'd go backwards as little as possible.

Have the 4 motor but no a 6.
Have the tran's ,but also have the Adapter to go with the 901.(that will be for sale with the flywheel and starter )
But think the Subaru tran's is the way to go.
No cradle but can build that. I thought that the cradle builder was not doing it anymore ?
ECU will be MS ,used that on other builds.So that will work for a 4 or 6.

As Chi-Town mentioned, the real difference here is running the exhaust for the turbo on the 4. I have seen builds where the rear trunk is sacrificed in order to make that easier. I've also seen people make it work without a lot of cutting into the trunk. How well can you weld?

Definitely use the subaru transmission.

Zach

There is a possibility that Ben/MB911 may build a bulkhead engine mount like what is used on 914-6 conversions but for Suby’s. The idea is to eliminate possible interference between the mount and oil pan, axles, exhaust and engine to firewall clearance.

Just about any turbo Suby will disintegrate the 901. Not to mention the 901 and it's components is an antiquated system that would double the install price with the required Kennedy adapter.