1993 RX-7 FD3S, V-mount setup, High flow cat + exhaust system, boost controller and running non Seq.

Hi guys, so upon figuring out that my fuel injectors were tampered with at a shop
I was curious what you guys would recommend i replace them with, i have a pro flow top rail and bottom rail, and i was recommended by my buddy to go with 650cc for idle and 1000cc for secondaries, do you guys agree with this? im not planning for big power but since the stock fd injectors wont work in my fuel rail I wanted to see what the pros think or recommend. any advice is helpful thank you. I have also been recommended to use 4x 1000cc injectors on both rails but would that risk of my motor flooding?

 

There are as many different answers on what injectors to run as there are FDs in the world.

650/1000 is a very modest increase in flow over stock. So small that most probably wouldn't bother. But if you aren't looking to make power and just want something OEM-ish on an aftermarket rail, that's fine.

Ultimately, there are only two things that really matter:

1) The total output of your injectors is sufficient for your power goals. You can go too big (see next point), but you absolutely cannot go too small. Too small will blow a rotary real quick.

2) Your car is properly tuned. 95% of "tuning" is dictating how much fuel your injectors are pushing out every cycle. You can make a big injector only use a little fuel, but you can't make a small injector do more than it physically is capable of doing.

You can use big 1250/2000 injectors if you want. You will just only be asking them to do half as much work as they technically could. Yes, you could theoretically flood your motor if you don't tune your car, but ifbyou are running around with an un-tuned car, running so rich you flood it is going to be the least of your worries.

So don't worry as much about injector sizes as much as what your tuning solution will be. Because that is what really matters.