Just wanted to hit this thread as I too recently got a rebuilt VF39 with a 10 blade billet compressor wheel and a PnP job. The thing is killer! I ran a VF39 on my hybrid EJ257 for a long time... this VF39 was toast. I recently installed the 6 star speed VF39 and HOLLY HAPPINESS. The car builds boost better than ever, earlier and stronger. This is exactly what I wanted. I was looking for a way to hone the already great package and better the power curve .... 6star has done just that. The car almost feels like a high hp 6 cylinder because boost is so consistent (I believe I was posting on the high side of 12 psi @ 3000 rpm tonight). After talking with the guys at 6 star they explained that they do a bunch of work for spec rally car builds (even some with anti-lag) and they have all responded very well to the billet 10 blade wheel, balancing, PnP jobs 6 star has been offering. Getting a re-tune with Dom @ Maxwell power in March and expect to see some nice gains.
All 6 star speed skeptics can be put at ease knowing they produce a great product.
Jonadobo, if I am not mistaken, the VF39, VF48 and VF52 are all very closely related (RHF55 turbos) and rebuilt the exact same way. I would say you are in safe hands with these guys. Give them a shout over email and they will explain it all to you. check this link: http://6starspeed.com/reihivftusuw.html
Here is an example email from Jonathan @ 6StarSpeed (email@example.com)
The VF39 does have its shortcomings. We have found a lot of the problems are caused by inconsistent manufacture. Early VF39's were made in Japan entirely however later VF39 and other RHF55 turbos were made mostly in Taiwan. We find a lot of issues with VF39 build quality. One common thing is that the fasteners holding down the thrust bearing plate are not torqued down properly and no thread locker used. Also bearings are small and just don't have the integrity for high speed/heat. They are quite thin so warp and seize more easily. We throw away many RHF55 bearing housings with the bearings still stuck inside. This is also the reason we abandoned the big compressor wheel for the RHF55.
The stock profile 10-blade billet wheel gives more flow and higher pressure ratios for the same rotation speed so we don't have to worry about the bearings. The billet wheel should be good for up to 40 psi without overspeeding the bearings. The compressor profile works for our restricted inlet rally guys running ant-lag. We do like the turbine side of the RHF55 however. Small mass and decent throughput. We would like to do a P20 housing for them as it would make them much better all around turbos for EJ motors.
TD05/TD06 frame is much more robust by comparison. That's why we can build them to swing 76 mm compressor wheels. We do have some housings machined for 82 mm GT3582 wheels but those are for some project big shaft TD06's with big bearing upgrades.
You can tell he does a good amount of work with RHF55 turbo platforms.
As far as pricing goes, here is my Invoice, as you can see I did a few upgrades you may not like the turbo blanket and I will be receiving a $120 refund for my blasted core.
Name Code Qty Each Options
1 958.99 10-Blade Billet Compressor Wheel
Uprade = Yes, include s Full PnP
Add a Perrin Turbo Blanket! = Yes
Factory New Turbine Housing = No
Full Port and Polish = No
Turbocharger Type = VF39 -VF39
Vehicle Application = 02-07 WRX
out the door I am sitting at a reasonable $838.99 for a well sorted turbo.