Hey everyone! So I have a 02 Miata with a mazdaspeed motor in it from 04. It’s fun and all but I’m wanting more power and since I can’t just turbo it anymore I’m thinking about injectors. I have no clue what size mine are but I know they are stock. I have a mega squirt3 for the mazdaspeed. Tuning isn’t an issue I just need some answers about what size injectors I should go with for more power and reliability. I’d like to have not terrible gas mileage as I drive this car about 600 miles at a time every month. If anyone has any ideas I’d love to hear them. Thanks!

 

Buy miata specific Bosch EV14 (Flow force, ID, ...) and be done with it. When you talk gas mileage, I think you use pump gas? Then go with 550cc's+.
VE table requires a retune. Injector size in general has nothing to do with gas mileage, it's all in your tune.

 

Will I need to upgrade the fuel pump?

 

Generally, no. Stock fuel pumps in good working condition can handle a moderate amount of boost. The issue is most Miata fuel pumps have grown tired by now and could use an upgrade.

A DW200 can be had for about $100 and an hour of your time to install, however. Up to you.

 

Do you know if I’ll be able to run flex fuel on this motor. The mega squirt has the option so I’m just wondering if with the big injectors and fuel pump if I can. There won’t be any problems with it right? I’m not sure since it’s turboed

 

I'm not sure about your knowledge level but it seems like you haven't done much reading/searching here. I haven't looked into running E85 but even I know you need a sensor inline to be able to switch back and forth. Otherwise, how's the MS going to know what timing to use. You don't want E85 timing on pump gas and even E85 mix will vary. For E85 with higher boost I think you'll want larger than 550cc but run the numbers to be sure. I installed FF640cc with an MS3 on my 2004 Mazdaspeed Miata. I got it idling pretty well in the few weeks before I had to put it into winter storage mode but I'm FAR from being fully tuned. I think there was a FF 720cc option, something between 640 and 1050 or whatever the larger size is.

 

What's your power goal? Modest 250whp you'll be fine with FF640ccs and stock FP.