Alright guys, I've decided to begin piecing together all I need to install a VF39 turbo I bought off of Discopope last summer. Hopefully I'll have everything together and installed so that I can get tuned by Jorge sometime this spring. (Is he coming up!?) What I have so far: AP stage 2 (installed and loving it), VF39, Walbro FP (and install kit on its way) What I plan to add: Deatschwerks modified WRX injectors (565cc or 650cc???), SS Autochrome (Ebay) TMIC, one step colder spark plugs (brand) Is this good? Did I forget anything? Let me know what the experts think! -Pat
I have some injectors that might be for sale in a week. Modded by Russ for 680cc. But it looks like you have everything.
Ok, what size injectors do I need? AP stage 2.5 (VF30-34) says sti pinks - 565cc. I guess I should state that this is my daily driver and I plan on doing some track (road course) driving in the summer.
When I talked to Russ about injectors for my vf 39 he was pionting me to 700s. He stated that with 700's that will leave my turbo options open for the future.
You can run larger injectors and decrease the injector pulse width to reduce fuel flow, but you can't/shouldn't overdrive smaller injectors. So you really need to decide now how much you want to modify your car in the future. Do you see yourself upgrading the engine internals for a lot more power? If so, spring for the larger injectors now.
565's/pinks are too small. I wouldn't go anything smaller than 630/650 or so. It is a good thing to have some injector head room. Russ
HP is all relative and depends so much on the dyno. So I guess I would hope that it would be compairable to a similarly modded VF34. That could mean anywhere from 220whp to 285whp - depends on the dyno. Either way, it should be substantially more than a stock STI Can injectors be too big? Would too large injectors give other problems with drivability or rough idle? Why doesn't everyone run 1000cc injectors? Just curious/ testing your knowledge...
Yes. Yes to both. See previous answer, but also add cost. Injectors have a minimum on time, about 1 ms (millisecond). A larger capacity injector will flow more fuel, and too large an injector will provide too much fuel for a low idle. You can also increase injector flow by increasing fuel pressure.
Ok, how about Perrin or GM boost solenoid? Would it help to have one? I know that you need to be tuned to effectively use it - mind you I do plan on being protuned. Also, any suggestions on spark plugs?
While that is true, you will not have that problem in your car unless you are going like 1500cc or so. I have seen people who are running 816's with the stock turbo and don't have any issues. I have tuned a couple of them and you don't even get any idle issues that need to be tuned out. As for the bcs, i would go with the gm unit. They can be had for under $40 with the pigtail and then it is just a matter of hooking it up. It will net you a little quicker spoolup since it is not a bleed system and give you a little better control. I have tuned quite a few gm bcs's and they always seem to work out pretty good. Russ
I wasn't saying he would have trouble with his injectors, but just showing that because of the design of the injector and the minimum on time, that is a theoretical limitation. With the GM BCS, he'll have to reduce his WGDC by a blanket 20-30%. Of course that'll be solved by a protune...
Nasioc has a good thread on the GM BCS. Read it here: http://forums.nasioc.com/forums/showthread.php?t=870619 The solenoid operates differently compared to a stock setup, and I have seen no public maps for the bcs. But some people here do have experience tuning for the bcs.
Well don't try and run one without a custom tune. Otherwise you'll boost spike to hell and back, lol.
Well, the stock bcs is a bleed type, and the gm bcs is a block type. So the gm will get you a little quicker spoolup since the wastegate will not see any boost till the bcs allows it. Likewise, the stocker will allow boost to the wastegate as it is generated, and the stock bcs bleeds off the "extra" to get to target boost. Russ
Found 660cc Deatchwerks injectors on nasioc for cheap. Should I go for them??? Nevermind - guy returned them
