Focus ST turbos as twins. What do you think?

Like the title says. I'm not going to spend too much time talking them up, but let's just cover the basics. It's a 290whp ball bearing turbo with integrated BOV and wastegate and water cooling. I just bought one with 7,000 miles on it for $200.

Who else thinks these would make great, responsive, durable twins on a 3800 for a silly cheap investment?
 
The focus ST engine is what a 2.0L?? I would assume the turbos would be way undersized for a 3800 engine to make any kind of major difference. '

Again I know nothing about the Focus ST but just making assumptions based on the engine displacement.

You must have missed the part where I said twin turbo. So you're comparing 4.0L to 3.8L, not 2.0L to 3.8L.

The vast majority of turbo 3800s out there are making 4-600whp. A pair of these matches right up with the top end of that (according to the top 5 stock turbo dynos on the Focus ST) and would actually be responsive vs a single large journal bearing turbo.

Not saying I'm going to do it. But if I was looking to start another build I would definitely be tempted. I'm very excited to see how it does on the Miata engine in my buddy's Festiva.
 
They run out of steam around 5k-5.2k. I have a modified k03 I'm running in my ST and it pushes power out to 5.8k-6k but there are build issues (GPOP shop).

That kind of happens when a turbo is sized well for a useable powerband though. I think it's a desireable trait for a turbo car to make peak airflow in the midrange and maintain that (which feels like feeling off because your rpms are going up but power is more or less flat). I don't like peaky/laggy/too big of a turbo.
 

Mr_Roboto

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turbo wise they flow for 500hp in a pair as sold by Ford which would be a nice match for a decent 3800, and if you can get 290 at the wheels each that's quite a bit of go. They are BB which would be great from a converter perspective too.

The turbines are a bit funky which is where I get off board. Plumbing them in may be an issue in a FWD car. Based on what I've seen you do, if they can fit you can make them. I don't think you'd be asking if you didn't have an idea of how to do it either.
 
I think you will regret every second of it.
The 67 in my car lights ridiculously fast.
At 600+whp the turbo still has a bunch of head room.
Your lil guys will be running out of steam in the upper RPM's and breathing fire.

Well this probably won't happen on one of my own cars. I would love to talk a friend into letting me go to town though. I have a ball bearing "67" on my car too. I wouldn't call it ridiculously fast spool, and I still don't understand why everyone on this platform seems to be immune to feeling/being annoyed by turbo lag. Probably because automatic trans/downsift.

Mine doesn't come on until maybe 3200rpms on its own, and then proceeds to ramp up the boost so quickly it's darn near impossible to get out of the throttle quick enough to avoid wheelspin. I hate it...it's miserable to drive without the supercharger going as well due to how peaky/non linear the powerband is.

But really, I know pretty much what to expect with this. I mean on the extreme small end of things, I just did a big 16G on a Bonneville for a friend on a super tight budget...talk about underwhelming on the top end...we're talking like 350 crank HP. Boost falls off to like 5psi up top. But it does exactly what we wanted it to do, which is make the car pull/feel almost exactly like his northstar-powered Bonneville....and he's plenty happy for the $550 investment, lol. These would be a significantly more capable setup than that...easily 500hp, with minimal additional lag due to such a higher quality turbo.
 
The turbines are a bit funky which is where I get off board. Plumbing them in may be an issue in a FWD car. Based on what I've seen you do, if they can fit you can make them. I don't think you'd be asking if you didn't have an idea of how to do it either.

Most likely chop those suckers right off and make it part of the manifold. Not too worried about that...I've got plenty of experience making impoosible things fit.
 
There's a guy selling his 3.5 EcoBoost turbos for $800+Shipping. They have the upgraded billet wheels too.

15k miles on housing, 5k miles on wheels. f150ecoboost.net

Curious how much smaller those are. Twins on a 3.5 vs a single on a 2.0. Probably fairly similar. I know Ford's whole thing was to make them super responsive so they're probably just like on the Focus...relatively close to their limits at stock performance.
 

GTPpower

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The 3.5 turbos seem to have quite a bit of headroom left. Idk of anyone that has really been able to max them though.....truely max them due to the direct injection fuel system. But, I've seen quite a few that are into the 12's on stock turbos.

For reference, stock boost on mine seems to be right around 14psi.

And, if you go that route, 2013+ 3.5's got just a little bigger compressors.

They are a bit laggy though, IMO. Brake boosting seems to start building at 1700ish rpms.
 
The 3.5 turbos seem to have quite a bit of headroom left. Idk of anyone that has really been able to max them though.....truely max them due to the direct injection fuel system. But, I've seen quite a few that are into the 12's on stock turbos.

For reference, stock boost on mine seems to be right around 14psi.

And, if you go that route, 2013+ 3.5's got just a little bigger compressors.

They are a bit laggy though, IMO. Brake boosting seems to start building at 1700ish rpms.

I might have to go test drive one just to get a good look, lol.
 

Mr_Roboto

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Most likely chop those suckers right off and make it part of the manifold. Not too worried about that...I've got plenty of experience making impoosible things fit.

With the higher quality cast they're using these days I think slapping some vbands on there wouldn't be the worse option.
 
290whp is optimistic for a Focus ST. Most don't get there unless you do every single bolt-on upgrade and have good tuning.

Focus ST's K03 turbo's flow about 27lb/min I think I remember reading.

The Focus RS turbo flows 45lb/min though. :nanapunk:

All the top stock turbo numbers are in the 270-300whp range, pump gas or E85, and there are enough examples of each that I'm confident it's an accurate ballpark. Besides, I'm all too familiar with pushing baby turbos well off their map.

Link:
Highest HP Focus ST's
 
With the higher quality cast they're using these days I think slapping some vbands on there wouldn't be the worse option.

That's exactly the plan on my buddy's Festiva. I mean they're already vband exit, so why not? The entrance to the turbine appears rather conveniently roundish if you hack about half of it off. The turbo should be arriving by the end of the week so I'll try and get some pics.
 
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