this is a free mod from kingpin. if you dont know kingpin is he is one of the most reconized suby tuner in the states. (to me anyway) this came from nasoic and is a year and a half old. i know i was in the market for injectors and now im gonna do this. all i need now is ecutek money and a dp and im rollin. 740CC injectors for free? -------------------------------------------------------------------------------- Its a tough choice on which injector to buy for your WRX. Buy STI Pink injectors? $300-$550 and you get an extra 100cc worth of fuel. PE 650 or 850's? $600-$800 a set and because these are mechanically slow you need tuning or a flash to make them work correctly. Other companies sell an option for $450 and another that requires you to solder in a resistor pack. You can skip all of this and make your own 740CC injectors for free. The Stock Blue 440CC injectors and the STI pink 540s are identical other then the end cap and the color so either injector will work for this mod. There is no advantage to having the Pink STIs once modded so sell them, Make some cash and mod your stock injectors. There are a few ways to accomplish the mod but what needs to happen is the end cap of the injector needs to be removed. You can grind it off or cut it off. Does not matter really. You can use a band saw or a dremel tool and a vice. Take your time and cut the silver end cap off where the nozzles (holes) are. Since you are removing the end cap you dont need to send these off to have them matched. There will be no adjustment a injector shop can do anyways since they are sealed units. What you are doing is removing the flow restrictor (end cap). The biggest advantage is that the stock ECU is calibrated for the correct opening time compensation for these injectors (dead time). PE's are twice as slow and need more dead time. All of the issues that the PE's bring to the table are absent with these injectors. Questions: How much will the injectors flow once modified? 740-750CC What about the spray pattern? You end up with a find disk pattern What about the idle? Rock solid idle as stock once AFR's are tuned. What about reliability? They are stock Denso injectors and you are just removing the end cap containing the sized holes. Do I need a fuel pump? Yes, Pressure at the injector is reduces since the injector body can now flow more fuel. You need a fuel pump capable of handing 740CC injectors. Walbro is fine. What if I dont have engine management will these work on a stock ECU? NO, You will nearly double the fuel flow so you will need a Utec, SAFC, Link, Gems, Flashed ECU or other EM to calibrate these injectors. I am still worried about equal flow. How Can I be sure this works? You can send the injectors To Venom performance in California or RC engineering for testing once the mod is complete. Venom will even do the mod for you and test each one but the cost is nearly $300. Why are you posting this information and not selling modified injectors? Because it costs nothing to do this mod and its better to give back to the community. If you do not want to perform this simple mod yourself there are companies out there that will take your $200-$300. Maybe one of the members will try this, report back and offer to mod your injectors for a reasonable price? $50? This way its worth his time to do it and you save a ton of cash in the process by not having to spend $450+ on injectors. Work as a community guys How many cars have you tuned with these injectors and how long have people been running them? Kingpin has tuned 7 cars with these modified injectors. All idle smooth, All run fantastic and all have low IDC's One customer has 5000 miles on his set now with out issue. Hope you guys try this and report back. I would not suggest something that I do not believe it. Some of you can flow test them if you wish and let us know the results. Let the flood gates open! Thanks :naughty: heres the link for all the follow ups. click here
yea..but on such an important part of the vehicle why skimp? that could be a very expensive mistake..ill spend the extra money on something i "know" is reliable..good luck though
I'd say that if the info is from Kingpin, I'd trust it... they really seem to know their stuff. As long as you log and check stuff after install, no reason not to try it...
The modded injectors work perfectly. Ill do a full write pu on how to do it if anyone wants it. I actuall have a better way than what everyone else seems to be doing. Matt
I have seen good and bad with the midded injectors. You just have to make sure to get them flow tested. If they are close then they will run fine. if they are not then the car will run like crap and be hard to tune.
If you mod them the way that everyone else seems to then you can run into some issues. I have a much better way that assures that no dirt or metal gets into the injectors.
Cool I really wanted to do this. That’s why I posted it. In addition it seems like a waste of money to get Perrin or someone else to do it when it’s really a simple mod if you have a steady hand and know what your doing. Looking forward to the diy matt thanks! Got a quick question. I got a ported vf39 I want to install. I know this mod gives way too much gas for that turbo or at least that’s what it says in the thread I originally posted. I wanna get ecutek I kinda like the set it and for get it functionality of it. If I do this mod can the ecu be tuned around the 800cc flow you get from the modded injectors.
you could but why chance it..just get some STI pinks and be safe..why risk the life of your engine over 300 bux..heck it will cost atleast half that to get em flow tested..but again its on you buddy either way i help ya install em
I'm all for the ghetto injector mod. If you do it, make sure to post your experience since I'm considering the same thing for when I upgrade the hairdryer. If your tuner keeps an eye on EGTs and O2 readings I don't see a reason why you'd detonate your motor even if the injectors weren't running as expected.
No problem, Does anyone have a set of stock injectors they would be willing to donate or sell cheap. That way I can do pics of the process, or maybe even a short video. Matt