I have a set of 460's, but have access to a set of 550's if needed. What would you guys go with if you had the Link? Also have the RM downpipe and huge FMIC.

 

FM used to supply 440cc injectors with all their 1.6 turbo/link setups. 460cc injectors should get you pretty close to the SAFE limits of the stock 1.6. Should be able to hit 240-250whp with that fueling and still have a little headroom.

This assumes at fuel pressure of 50psi, .55 BSFC and 80% duty cycle. And that the Miata loses 25hp to the drivetrain.

 

If I had a link, I'd use whatever was a saturated/high impediance injector so I wouldn't have to run a resistor pack.

 

I'm assuming that the 550 and 460 injectors he's talking about are from an RX7, they are plug and play.

I'll be using 460cc from an RX7 with my link

 

Why not just go with the 550cc if you have access to them and have the extra headroom and run lower duty cycles?

 

Idle quality issues? Dunno. I'd opt for the largest.

 

About how much HP would be possible with 550's for a 1.8 ?

 

Probably around 300whp. Not to say it will, but it will have enough fuel to get AROUND there. 4 550cc injectors on ANY Turbo motor would be good to this level.

 

The turbocharger itself will run out of steam in the 265-285rwhp range.

 

Yeah I was never expecting to make anything like 300 HP with my current T25 setup.

 

I'm running 440s on my setup. Haven't dynoed the car yet, but it's a Greddy manifold and turbo with a 2.5" downpipe and exhaust and a homebrew FMIC. At 13PSI, I've seen up to about 70% injector duty cycle, which tells me that assuming I don't miraculously find some added efficiency somewhere, this is just about the right size for this application. (this is on a stock fuel pump with no secondary FPR).

Larger injectors will of course work too, but as you increase the size of the injectors you are limiting the capability of the ECU to accurately control fuel flow at very small levels, such as idle.