Help me determine what size of injectors do I need.

[Eric Wang]

My power goal is about 300-320whp, and I am having FMIC, Supra pump, MBC, and exhaust. I will be buying EVO 16G and 2G MAF or SAFC II soon. My question is what size of injectors do you guys recommand for my power goal? Is 550cc good enough or I will need 660cc? How many psi of boosts am I looking for with the EVO 16G to reach 300-320whp in the future? Any other suggestions? Thanks very much.

[Cole Lacey]

get an intake. i don't know what the Supra fuel pump puts out, but get the 255 Warlboro. 320 is easy reachable. you could just put in 550 for that at like 22psi. you will prolley want a Clutch up grade if you are 5spd. if you are not AWD, get some 8 or 8.5s up ffront and a LSD. my car bassicly is where you want yours to be and traction is an issue for use FWD, like pinning it at 70KPH and screaching. (very impressive to the guy with the a muffler that drives a cavalier mistaking his family Economy car for a camaro)

[John Hartman]

ok, hold on here, lets keep it factual

Supra pump puts out more than a Walbro 255. He will have plenty. With that pump you WILL need a better flowing aftermarket fuel pressure regulator.  The stocker will not keep up with that pump. You will chase your tune all over the place, have drivability, economy and throttle response issues and you will have a hard time with aircare.  Plus you stand a chance of heavily carbonizing your combustion chambers.  this causes lots of knock and is very hard to get rid of.

an air intake pipe will help, but its not a huge issue at this point.  Just open up your aircan a bit, but keep the hot air out.

The cost in injectors is negligable, get the 660's.  The 550's will probably do you fine, but they will be running near or at the edge.  Plus, I know you say those goals are fine for now, but I betcha any money, once you hit that goal, you ARE gonna want more   :twisted:

as long as your exhaust is a real full exaust from the turbo to the muffler, you should be fine.

and with this power, as Cole said, you will have traction problems for sure if you are fwd.  If you decide on a limited slip, get the real thing.  They are expensive however.  As for a clutch, don't bother with a puck style clutch if its a street car.

[Michael Peng]

Supra pump puts out more than a Walbro 255. He will have plenty. With that pump you WILL need a better flowing aftermarket fuel pressure regulator.  The stocker will not keep up with that pump. You will chase your tune all over the place, have drivability, economy and throttle response issues and you will have a hard time with aircare.  Plus you stand a chance of heavily carbonizing your combustion chambers.  this causes lots of knock and is very hard to get rid of.

so with aftermarket fuel pressure regulator,will still have a problem??

and the intake pipe is the one u mentioned in another thread, the kinetics medrell bent pipe right??......any idea about the price? I tried to look on their site, but I can't find it.....and still waiting for their e-mail.

[Eric Wang]

Thanks for the help and I've one more question. Will 660cc injectors work fine with my 2G MAF without any SAFC, SAFR, or other piggybacks? I do have a used aeromotive FPR on the floor "lucky me". BTW, my car is AWD. Thanks.

[Mike Schmid]

660s will NOT work fine with a 2G mas and no other fuel control.  550s and the 2G mas roughly offset each other.  2G mas and 660s would be 100cc/min out.  Or about 15% too rich.  I'd be kinda surprised if it even idled.

[Eric Wang]

I Got it. So either go 550cc with no SAFC...etc, or 660cc with SAFC...etc. Thanks.

[John Hartman]

yep, and you would need a good aftermarket regulator for that pump.