Max power on stock B/P 4a injectors...

[--Redwork--]

Basiclly wanna know if I need to upgrade my injectors on my B/P

Engine has 10.6:1 comp.
Ported head..
288in and 272 ex cams...
Extractors and 2.25 system...

Guessing roughly around 160Hp...maybe 170 with a strong tune...

Will standard 182cc injectors cover it.??
Or should i get some 235cc small port ones.??
Or go even bigger.?????

[Sprinter86]

you can run any injectors you like when you have aftermarket ECU. the bigger the better really. You can always tune the injector pulse signal length to suit the fuel flow from the injectors.

On a side note, i think i have some smallport injectors here...

[Jonny Rochester]

... but every injector has its limit, like when you get to 100% duty cycle, the only other thing is to up the fuel pressure.

There is a rough way of calculating injector size needed. Maybe someone can search and find, or even write it themselves. There is a cirtain amount of petrol needed per kw of power (assuming fuel ratios and efficiency of the motor you have). Once you have this number, then it's easy to calculate the injector size if you know your final power output, and the max duty cycle you want to run the injectors.

No numbers sorry... someone else can do the work.

[Anthony]

very roughly its 20hp per 100cc of injection, at the flywheel.

May do it at a push with some pressure thrown in, but theyre not that good an injector anyway. I'd get a set of yellow/greens from a 7MGE or 1GGTE (285cc). Get all 6, have them tested and match a set of 4.

The ultimate injector for that setup would be a very late top feed 4 or 6 hole. from non turbo caldina (290) or beams altezza (345) etc. these injectors give you power for free. For example I can squeeze more hp out of a set of beams 345cc injectors than a set of 4agze 370s. at the same pressure.

btw, i have all of these injectors available for sale. PM me if you would like more info.

[Jonny Rochester]

So 20 x 1.82 x 4 = 145.6hp = not enough


Anthony, for N/A 20v for "200hp" (same as everyone on the forumz has) are the stock injectors fine or is it worth going to the 1JZ-GTE injectors? 380cc I think.

[Anthony]

for an NA setup I think the stock injectors are fine John.

[--Redwork--]

Cool guys...

I did a very rough calulation and I think stock ones will juuuusst handle it...
If not Anthony will be gettin a visit :)

I like the sound of free power though...