Im just curious is anyone has the same set up as me and what size injectors they have...or what size injectors you guys would recommend. I just have a VF39 turbo FMIC spt intake turbo back exhaust and 565 modified stock wrx injectors. Im just wondering if those sound like the right size or if i would gain power with bigger one
What fuel do you intend to use? How much power do you intend to make? How aggressive do you want your tune to be?
great questions this is why such a question should be directed to the tuner. So many variables... yes, generally speaking 565cc injectors should do the trick for a 39, but there's a few things to consider...like readymix brought up. however, to give you an example.... MY04 2.0L WRX with a small 16G (505cfm) running 21.0 psi (+/-).5psi was running about 72% IDC at WOT with 690cc injectors. The vf39 only pushes 450cfm..IIRC
well the reason i posted was because the car doesnt seem to be running right. it was tuned by rs motors and made 260whp. im looking for a tune that will give me significant power and still be good for a daily driven car i was thinking about having bullwinkle look at it and tune it. My problem is that the turbo will cut out and backfire multiple times at high rpm's when i am giving it alot of gas. was i was thinking is that i could use larger injectors. i may be wrong...
Ah yeah, you sent me a PM I forgot to respond to. Sorry 'bout that. 565 CC injectors will be more then enough to run a VF39 on pump gas. You've got other issues if your car is stuttering/backfiring while you're on the throttle. Could be the tune, or (more likely) could be mechanical. Did this problem start recently, or has it done this since you were tuned? Have you changed any mods recently, or since the car was tuned?
Ok, since this is difficult for you to do, I'm going to go ahead and answer them for you as best I can given the information that I know. 04/05 WRX. 2.0L. 92octane. VF39. 565cc injectors. Daily driven. 1) Turbos don't backfire or cut out. They just don't. 2) 260whp is entirely reasonable and normal for a VF39 on 92octane 3) You might need larger injectors to the tune of 650-720cc 4) Before you retune or anything, you need to know: a) How much power do you intend to make, more than 260hp I'm guessing since you don't feel happy with that amount thus far. b) On what fuel do you intend to make this power, I am going to assume 92octane since that is what you said. c) How aggressive do you want your tune to be? I am going to assume not too aggressive since you intend to daily drive the car. I'm not trying to be an ass here, but keep in mind that a reasonable amount of good information is needed from you for any one of the local tuners or gear heads to make any sense of your problem/situation. My take on all of this? You have a 2.0L WRX with a VF39 and 565cc injectors on pump 92 octane making 260whp. That seems entirely within the bounds of your setup. You might squeeze a few more HP out of it, but at the risk of being more aggressive. I'd have a tuner log your car and look into what is causing the stumbling at higher RPMs.
yeah im happy with how much power i have i just was curious as to why it would cut out like that. its hard to describe what actually happens but you can for sure feel it when your riding with me.... and as for changing mods all i changed was a cat back exhaust system.. Bullwinkle i pmed you again...
This sounds like what i need to do. Thanks. Sorry for not giving a ton of info to be honest i dont know a hole lot but i am trying to learn....
How much boost are you running?? When does it cut out?? You may be hitting the overboost fuel cut. Stock would normally be around 20psi, and if they missed that, that would give you the afterfire, cutout. As for injectors, I was running 630cc injectors on a 18g 2.0l wrx, and at 22psi my idc's were at 90-91%. So 565's and a vf39 is a more than capable setup. Russ
Yes, you may be hitting fuel cut, although fuel cut is fairly violent. Changing even a catback can for sure effect your tune (and for that matter, cause fuel cut), especially if you went from a more restrictive to a less restrictive set up.
^^ in that case i did go from a more restrictive to a less restrictive cat back so it sounds like a tune from you could help me out.
