All Injectors are NOT created equally: why good Injectors aren't cheap and cheap injectors aren't good...
One common question I get when I sell EFI systems and fuel systems is "what injectors should I run?". Injectors are literally the last line of defense and most crucial component of your fuel system. They decide whether your motor is going to run properly, regardless of what brand EFI management you run, what pump, style fuel line, etc.
Over the last few years it seems that tons of companies have come out with their own line of high lb/hr injectors at a very appealing cheap cost. While being branded Brand X may seem like good insurance or reason enough to run them, think again (I must admit, I used to run these cheapo injectors myself).
Many of these high lb/hr low impedance injectors are simply outdated technology. These injectors CAN flow a number, but there is quite a bit more to the story. Most older style low impedance injectors go static at 80-85% duty cycle. This means, an injector at this duty cycle, the solenoid literally stays open/goes static because the solenoid cannot operate outside of its 80-85% efficiency. This can be dangerous to your tune up, and motor (read: you just lost all of the benefits of EFI as there is fuel being sprayed before and after valve events when you do not want it).
New technology injectors which are high impedance such as the Bosch EV14 style injector series are efficient to 99% duty cycle. What this means for you is that traditional injector sizing goes out the window, you can get a lot more "bang for your buck" by running a smaller injector that can be pushed further. The "smaller" injector size will also aid in tuning, drivability, and idle. There are a number of other benefits to this new style high impedance injector, but this is in my opinion the most important.
Next comes the story that most people do not know about "Brand X" injectors. Most off the shelf injectors you find, whether they are Brand X or Ebay specials is that there is a huge tolerance for flow both static and dynamic from injector to injector. The standard tolerance is up to 7% variation from injector to injector. Think about this, 7.... Percent... On a 120lb/hr injector you could flow nearly 10lb/hr different from one hole to the next. On a fuel tuneup that means that targeting 11.8 for example, you could have one cylinder running 11.8 right, and the next high 10s on the scale. Worse yet, you could have cylinders you are targeting 11.8 and they running deep into the 12s. In my opinion, injectors are never blamed enough for certain cylinders failures. But lets dig deeper into the subject.
When you are tuning on a boosted car for example a boosted SB engine with a single wideband in the downpipe, you have an averaging strategy between 8 cylinders to hit a target AFR. This means that if you have a cylinder off 7%, not only will that cylinder be low, another cylinder may have to run high to make up for it. This means that there are technically probably very few cylinders running right on target to make maximum hp. You have a few cylinders running on the lean and scary side, a few on the fat and slow side, it is just not a good situation to be in for both HP or longevity of your bottom end.
About a year ago we got hooked up with Fuel Injector Development ( FID ) fuel injectors. This is hands down the best injector company I have ever worked with, and I think you would agree if you put a set in your motor. Not only are they very knowledgable on injectors, applications, etc, their injectors flatout PERFORM. Each set of injectors is flow matched 1% static and no more than 2% dynamic from one to the next. This means that you will absolutely maximize power and safety on your combo. FID uses EV14 style injectors which allow for 99% duty cycle, meaning a smaller injector goes much further. The most important thing we have found are FID excellent customer service. Anytime someone has an engine malfunction, or any issue, we recommend having your injectors serviced, cleaned, and flowed to insure you are putting a perfect set back in your new or rebuilt engine. Each set comes with a flow sheet, and data needed to give your tuner the info they need. Their turn around times for service are amazing and they are great to deal with. To shop FID injectors click http://www.motionraceworks.com/store/c33/Fuel_Injectors.html
Whether you are in the market for fuel injectors, or will be updating your combo soon, I hope this blog brought to light some good points that may make your next combo safer and more possibly more powerful.