Im thinking of getting a VF34. Groupe-s has them for about $700 shipped. I have a friend who just did a turbo upgrade on his STi. He wants to know if I wanted to buy his Turbo with 2000 miles on it. What would be a good price for the turbo. ANd will his injectors fit or are they side fed? I would also get the STi topmount. IS the VF39 worth getting for like $250 to $300? Or should I just waite and get the vf34. What other upgrades do I need if I get the STi turbo? I have the STi uppipe, Hks Dnpipe w a custom divorced wastegate pipe and STi exhaust. Thanks Mikal

 

the STi side feed injectors will not fit in a WRX without some serious modification. The STi turbo (IHI VF39) will work ok, but might have a little less power on the top end compared to a VF34. The topmount is a pretty good idea, but the stock WRX IC will work just fine with either turbo.

With either turbo, and either intercooler, you're going to need larger injectors, fuel pump, and engine management. it looks like your exhaust is up to the task, so those are fine. the most common and proven route is to go with JDM STi (pinks) top feed injectors, Walbro fuel pump, and EcuTek or AccessPort reflash.

 

IIRC a guy on www.clubwrx.net just posted dyno charts a couple days ago for a VF39 on an EJ20. I'd do a search there and maybe ask him how it compares to other turbos. I've seen VF39s for ~$550, so $300 would be quite a good deal.

 

MikalsWRX,

RussB is correct, I'm in the process of doing my Vishnu stg 2, but will be going with modified stock injectors, thats if Vishnu is able to work with them. IMO sounds like you got a great deal, VF39 will be great, especially if you P&P it out, and you should ask yourself what your trying to do with your car, a VF39 is great for Autocross and daily street, especially if you need to jump into traffic, but if you plan on trying to take out the Vettes on the freeway or Road Race, your gonna lose out at the top.

Good luck.

C

 

hey thanks for the info. I wanna have a quick car for street. Be able to take out most cars for a short distance and have a decent car at the track 1/4 mile. Top end would be nice. So I do need injectors? Fuel Pupmp? and a access port? Sorry for all the questions. Thanks again. Mikal

 

I think you've misunderstood their replies. With a 2.0 liter WRX, you won't have a car that can be modified for both low-end torque and top-end power. Yes, that would be great but every mod level has compromises. This is especially true of turbo upgrades. It's important to know what your car's intended usage really is. Is it your daily driver? How often do you intend to autocross, go to the drag strip, or road course? For true racing use, these turbos are considered mild but really big upgrades make for a miserable day-to-day driving experience unless you've got good transmission gearing and are willing to keep the revs in sweeter part of the RPM band all the time.

--
0==WW==0
"…axles of evil…" - george w. bush

 

yes, you need injectors, fuel pump, and some sort of engine management. if you have close access to a tuner, i'd suggest a EcuTek reflash. If not, you may want to look at the Cobb AccessPort. The STi Pink injectors and Walbro fuel pump are direct bolt on replacements that are proven and every tuner knows how to tune for them.

as for which turbo, I've never seen a VF39 on a WRX before. it comes down to the tuning. I have a VF34 on my Automatic WRX and it's pretty responsive and actually has more low end grunt than the stock turbo and tuning did. Scott@S-Squared has a VF22 in his Manual WRX and it's got a nice powerband and doesn't seem as laggy as those turbo's are made out to be.

 

How does a vf30 compare to the vf39? i'm looking at a vf30, sti injectors, and a walbro pump.
Thanks, Todd

 

You can usually get VF39's the cheapest, especially on NASIOC where STI people are just throwing them away. I've seen 3 different ones on sale, each for around $300.

 

Ive heard that you get a little better top end with the 34, laters mikal

 

todd, what are you talking about? how's the vf39 better than a vf30?

vf34 and vf30 are the same except for the center bearing- the vf34 theoretically spools a bit faster.

anyway, vishnu and cobb both say that there's no difference in spoolup time. @ least on a dyno and most people that have ridden in cars with the vf34 and vf30 say that spoolup is about the same.

anyway, the vf39 is smaller than the vf34 and the vf30 (which again, are the same except for the bearing). so, it should spool up faster, but it will not match the top end of either the vf30 or vf34 (b/c top end of these two are the same).


with a good tune, a car with a vf30 or a vf34 will put down better numbers than a car with a vf39.

ok, rant off.

 

Yea VF30/34 use the P18 exhaust housing while the VF39 uses the new, smaller P17 housing. This would indicate better top end on the former exhaust housing, but from Jermaine's dynos from TXS, it seems that the 39 is a formidable turbo and can even exceed 30/34 power levels.