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How much boost can the VF11 put out safely?

Posted: Tue Nov 04, 2008 2:10 am
by Impreza2.2T
I have seen this thing push like 25 psi and I always thought that they are way too small. I will get and IC some time so I can push 13 psi. stock everything except the cold air intake. THis is also my DD so I dont need a crazy set up.

Posted: Tue Nov 04, 2008 2:17 am
by 555BCTurbo
13 psi is pretty much as far as you can go on the VF11...they are not very efficient at higher boost levels...especially 25...

Posted: Tue Nov 04, 2008 2:53 am
by skid542
The biggest problem with the VF11 is that it cannot maintain the boost at higher RPM's. Once you hit the 12-13psi range you can just watch it taper off back down to 11 above 4000 RPM.

The other issue you will run into with the stock setup - and it drives me just mad as I'm in the same boat - is that your MAF maxes out around 13psi. Once your MAF maxes out, your injectors go wide open from which there really isn't much good that can be had.

Posted: Thu Nov 06, 2008 10:06 pm
by race_to_live
are the vf-11 turbos ball bearing? how much do they sell for? and the turbo will go on w/o any crazy ecu setup right?

Posted: Thu Nov 06, 2008 11:36 pm
by skid542
They are not ball bearing turbos.

They typically go for $25-75 depending on condition.

I do not understand your last question. The VF-11 is the stock turbo.

Posted: Sat Nov 08, 2008 5:17 am
by GeneralDisorder
Efficiency drops off after about 1 bar. The lower the efficiency, the more heat is generated.

Basically the compressor wheel is small - so to push high pressure it has to spin quite fast. Around 130,000 to 160,000 RPM for pressure's above 1.5 bar. The result is high temperatures. This WILL shorten the life of the turbo, and does bad things to your oil.

Basically the VF11 is a really poor choice for anything over 1 bar. It's not designed for high speeds like that, it's not ball bearing, and it's not rebuildable.

GD

Posted: Sat Nov 08, 2008 6:55 am
by 555BCTurbo
GeneralDisorder wrote: and it's not rebuildable.

Where did you get that idea?

Posted: Sat Nov 08, 2008 6:44 pm
by GeneralDisorder
555BCTurbo wrote:Where did you get that idea?
You can't buy kits that I'm aware of. You can replace the seals but that's all I've ever seen. The dealer says they aren't serviceable, and so does deadbolt.

GD

Posted: Sat Nov 08, 2008 9:36 pm
by Legacy777
GeneralDisorder wrote:
555BCTurbo wrote:Where did you get that idea?
You can't buy kits that I'm aware of. You can replace the seals but that's all I've ever seen. The dealer says they aren't serviceable, and so does deadbolt.

GD
I've bought a rebuild kit for the vf11 came with new bushings and everything.

Posted: Sat Nov 08, 2008 10:37 pm
by GeneralDisorder
Legacy777 wrote:I've bought a rebuild kit for the vf11 came with new bushings and everything.
Cool - who sells them?

GD

Posted: Sat Nov 08, 2008 11:57 pm
by Legacy777
I don't recall off the top of my head, but I picked it up on ebay I believe for about $100.

Posted: Tue Nov 11, 2008 6:05 pm
by race_to_live
well im not really good with turbos as you can see. i think i might be getting the VF-11 mixed up with the VF-34. my bad.