What size Injectors would you recommend?

[anton]

Hi again,
Just wanting some opinions on what size injectors I should use for my turbo kit which i am gettig for my mazda 323 1.8L? The guy reckons the stock 280cc ones should be fine however I would just like to know what people think.

cheers

[twilightprotege]

i've got a lovely little excel spread sheet that'll help

it's not matter of what size you need becuase you're going turbo, what power do you want them to give you.

if you can tell me that, i'll tell you want injector size you need.

[anton]

I would be stupid not to say that I dont want a power increase coz i do but i also want it to run nice. anyways i think ill let u tell me what u think I need :lol:

[twilightprotege]

the stock injectors can give you around 115kw at the wheels in turbo trim. safely.

440cc will give you around 181kw at the wheels in turbo trim. safely.

or if you're nuts, 660cc will give you around 272kw at the wheels in turbo trim. safely....not sure about the rest of the engine though....

also what bar pressure do you plan on running and what will your redline be? i can give you a very quick calculation on the engine kw output

[anton]

Thanks for the info.. so would you recommend 440cc injectors??

[wiredone]

well up to about 9psi your not getting above 85% duty cycle on stock injectors so i wouldnt worry too much unless your doing a full rebuild and pumping lots of boost into it... (thats with a fuel pressue regulator)

hope this helps... from a "been there done that" point of view

[anton]

Thanks for your help wiredone and others I appreciate it. so you reckon just sticking with stock injectors or going a little bit higher?

[twilightprotege]

personally i'd say go the 440cc's. anything above 80% duty cycle, esp on crappy stock injectors is not a good idea.

but also dont forget, power is directly related to the amount of fuel you burn...so keeping the duty cycle in a safe range, the max you should want to get on stock injectors is 115kw atw. any more than that you're asking for trouble

[anton]

Thanks for your help

[platypus]

don;t forget to upgrade your fuel PUMP when doing this....

no point having a bigger shovel, if you don't have enough dirt right?

[twilightprotege]

tee hee...

yes walbro 255lph pump will do the trick

[anton]

how much is a 255lph fuel pump roughly?

[twilightprotege]

from america, about $100usd + shipping.

the walbro one designed for the miata (mx5) works from memory. do a search on www.msprotege.com forum. there are plenty of threads about it

[anton]

thanks heaps for all your help twilight.. appreciate it

[twilightprotege]

no worries at all!

[platypus]

in all seriousness, do ya reckon that the pump would make a difference by itself?

[twilightprotege]

yes. i'm thinking of getting one for my car to use as a fuel pressure riser so my injectors will be ok if i ever get to my goal...