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Advice on turbo upgrade

6K views 23 replies 8 participants last post by  acqui 
#1 ·
I've researched this a bit and come to the conclusion that I would rather stick with an IHI VF series turbo since after installation, I want to flash it using a standard Cobb OTS map and then get a protune at a later date. I was set on a VF34 but they seem impossible to find (in great shape anyway) so I have kind of narrowed it down to a VF30 or VF39. I was wondering what you guys would recommend of the two? The problem is that only the VF39 seems to be readily available. Does anyone know where I could possibly source a new VF34? I am currently at stage 1 (it's an 05 Saabaru) and have already sourced a Prodrive axle back, STI TMIC, Cobb catted dp. So now all I need is a turbo, pinks, and a Walbro. My goal is for a reliable daily driver with around 275-285 whp/tq with good midrange punch. Car has 42,000 miles, with about 4000 miles on stage 1.
 
#3 ·
The only modification currently on the car is a flash to stage one. Those are all of the parts I have so far. I was contemplating just going to stage two but after driving a couple of stage 2 cars, I thought I would want a little more so tuner suggested doing it all at once.
 
#5 ·
"stick" with an IHI turbo? Your stock turbo is a Mitsubishi turbo. Cobb has maps for several turbos made by Mitsubishi.

VF34 is overpriced. It's not that different than a much more common big 16G which generally costs way less

VF22 is old tech. Slow and doesn't have much top end.
 
#6 ·
VF22 has the most top end of any of the IHI VF line. :p However, if the only reason you're wanting to go with a VF is because Cobb has OTS maps for them, I would say you are wasting time and money.

OP, you need to upgrade your suspension and brakes before you get a larger turbo.
 
#7 ·
I should have mentioned that the suspension was done. I was focusing more on the power upgrades. I've got a matched Whiteline sway bar setup with Kartboy end links, Epic springs, with stop tech brakes.

My problem is more sourcing the IHI VF series turbos. Very few places seem to have them in stock and the majority of them I am finding are the VF39s. As I said, I would be very happy with about 275whp on a Mustang dyno. I know the Dynojets read a bit higher. My budget for the turbo and install is around $1500-2000
 
#10 · (Edited)
Get a 39, they are a dime a dozen and with putting you within a few pony's of the others.. I would say its worth it. I have a VF30 and love it. If I had to hunt for a replacement. I would probably get a 39. Just sayin'
 
#14 ·
So I was able to source a low mileage (18000 mi) VF34 but now I am debating whether or not I should go to Stage 2 first and see how that goes before doing the VF34. As I am reading more and more about these two stages, the two things that give me pause are the strength of the tranny and the other, to a lesser extent, the spool characteristics of the VF34. I seem to read as many threads saying that the VF34 seems to be much more laggy than the td04. While there are others that say it's only minutely more laggy. At this point, the tranny is the thing that's worrying me the most, though I don't track the car, I also don't want to have to go into a 5k transmission upgrade just for a daily driver. For anyone who has the VF34 setup, what are your thoughts on the driveability in comparison to the stock? As I said, if I can get 250whp/tq with a wide, flat powerband from around 3300 to 6000, I would be more than happy with that. I realize I will have to get a protune after installtion so hopefully the tuner can sort out those things.
 
#19 ·
I have and of the two cars I drove, one was very good in terms of acceleration and the other didn't seem to be such a big jump over my stage 1, so I think I wouldn't mind just a slight bit more and figured since I've got everything I need, why not just go ahead and do it all at once and save some cost on the installation. I realize the tune probably has a lot to do with how the cars drive. I believe Cobb lists their stage 2 OTS map crank hp at around 285. I am wondering with a protune, what the total crank hp might be? I think I would be satisfied with around 300 crank hp/tq but I am not sure if a stage2 with a protune will get me there.
 
#22 ·
When I was stage 2 on my car (stock fuel pump injectors and intercooler). We tuned my setup to max just to see what we could get. I got close to 270AWHP on a mustang dyno. Of course we didnt even think about leaving it there as the injectors were maxed. But tuning is the money maker on these cars, hands down.
 
#23 ·
Josh makes a valid point here, but I'd also like to add the fact that every car is different and even the same car will make different numbers on the same dyno on the same day. Truthfully you should seek out what your end goal with the car will be and follow that path. Somewhere someone has done the same thing your doing and could give you advice on what to and not to do on your car.
 
#24 ·
So I finally got everything installed by AZP Installs in NJ (they did a fine job) Did a VF34 with all supporting mods and got tuned at PAS in Long Island by Dave Brown. I wanted something conservative because of what I read about the transmission failures on these cars with high torque numbers. Anyway, final numbers are 266 whp/ 233 lb/ft torque at 17.5 lbs of boost. I am quite happy. The power is really very good in the upper rev range (60-120 mph) I would have liked a bit more torque down low but I'd gladly trade it for a bit of longevity in the tranny. Initially, I thought the Prodrive axleback with the Cobb dp would be too loud, but I have really come to love the sound of this particular muffler. I rarely turn on my radio now :D
 
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