I have a VF39 right now with probably 60,000 or so miles on it (I picked it up used so I don't know for sure). I thought I heard a very slight grinding noise coming from it while I was on the freeway yesterday and I tried to duplicate the noise today, but I had no luck.
So now I am thinking I might need to start looking for a replacement and finally pull the trigger on an aftermarket turbo. Let me first say that I am quite happy with the performance of the VF39. There is nice quick spool up and while the power is not "big" by any means, it's still pretty nice. Edit: I found my old dyno graph and I was making 278 HP and 301 TQ on cali 91 octane.
That all being said, I wouldn't mind a nice little bump in power. If a turbo could to get me to the 320 to 330 HP range and still retain good to decent spool I would be happy. I'm not really interested in going above that power level because my car has 85,xxx miles and it's my DD. I feel these power levels are within pretty safe limits of the stock block / pistons and I like that.
Here is a little background on my power mods: 850cc injectors, fuel pump, custom upgraded TMIC, up pipe and a full turbo back exhaust but that's it. My intake is stock with a drop in K+N filter and my boost control is stock. I am not interested in adding anything to my car except a new turbo.
So here is what I was thinking for my options. I can get a billet wheel for any of these and I think it's probably a good idea because it will help spool to the best of my knowledge.
18G -TD06sl2 (7 or 8cm)
18G -TD06 (7 or 8cm)
20G-TD05 (with a 7cm, it's the "smallest" of the 20g's, but I was thinking this might have nice quick spool and decent top end)
20G - TD06SL2 (7cm or 8cm)
20G - TD06H (I really think this would be overkill, especially with an 8cm and my limited supporting mods)
So what do you think? I would especially like input from members who have experience with these turbo's and mod's similar to time. Thanks in advance.