aight here's the scoop: im working on piecing together a turbo
kit for my car, planning on going with a "stage 3"
setup (forged internals, p&p head). ok my problem is this:
im gonna run a T-25 turbo (go ahead and laugh but lets see you
refuse a turbo in excellent condition thats just given to you)
from a 98 GST. i personally dont wanna mess with the wastegate
on this thing cuz it looks like a bit*h to set it up for lower
than a stock GST boost pressure (heard its like 12 psi- can
anyone confirm this?) and im just wondering if the stock
injectors on a 420a will support that much boost, or if i need
to go bigger, and if so, what size should i go w/ and what all
would i need to run em, since the stock computer freaks out
with bigger injectors. im hoping that this wouldnt require a
stand alone setup. could a SAFC potentially do the job? also
on a side note, id like to get some opinions on EBAY fmic's
since i want to run a FMIC... looking at one that is sized
18x6x2.5, is this too big/small since i know nothing about
intercooler sizing relative to application. TIA

some would say *search* on this one. Yes, stock gs-t is set at 11-12psi. Will your injectors support 12 psi, sure, wise?, no! hope you're not planning on using a stock fuel pump. Our computers can support 450's with a regular fmu and still be fine, any bigger and you'll need something else to control them. Ebay IC, i've actually been thinking of going this route myself. There's been a few reviews on tuners saying they're pretty decent, so it's up to you.

just do yourself a favor and get bigger injectors, and a bigger turbo :P

hey didnt you say the you had forged internals, p&p head. If you have a build motor you can handle the 12 psi just buy a MS

as far as build up goes, i was planning on going w/ a walboro setup, im loosely basing my build up on the one done by GSgoing fast, except im using a different turbo ( i know i know its a shitty turbo but free is cheap enough). so our cars can handle 450cc injectors with just a standard fmu...would those support 12 psi of boost? i would just go with MS, but i dont wanna mess with a EMU as of yet since i dont know anything about them other than that they seem like a pain in the butt to set up.

why not buy a vortech sfmu, 30lb injectors, and a walbro.
run a feed from injectors to sfmu and return to tank..
problem solved.

or you could go with the 440cc's and an sfmu and run like 15-16 psi?

Originally posted by DSMTalon
so our cars can handle 450cc injectors with just a standard fmu...would those support 12 psi of boost?

Would turbo DSM's come stock with 450's if they couldn't handle 12 PSI ;-) It's all about airflow as far as what injectors can handle. The more air you flow, the more fuel you need. The equation is as follows:

Fuel Injector Flow * 4 * Maximum Duty Cycle * SG * (1kg/1000g) * 2.2 lb/kg * Air/Fuel Ratio = Maximum Airflow Capacity for a given injector size

So, for 450's @ 100% duty cycle tuning for 11.0:1, it would be:

450*4*1(100%)*.76(the specific gravity of fuel is typically .76)/1000*2.2*11=33.1

So, they can support up to 33 lbs/min of airflow. A completely maxed out 14b will flow at most 33 lbs/min. A 16G can easily hit high 30's, and an Evo III 16g can flow more than 40 lbs/min. But this is at a much higher PSI. Basically, if you are only running 12 PSI, you will have nothing to worry about, as you will not be flowing enough to overrun the injectors. Hope this helps.

the type of person who goes to great lengths to use things he gets for free ends up wasting a lot of money. the T25 blows ASS. a LOT of it. it SUCKS. sell it, if its in such good condition, and at the very least get a T3 flanged turbo

so 450cc injectors will be plenty, and i could probably get away w/ 300cc injectors, and i wont have to worry about any sort of management for them except for the standard sfmu, and maybe a safc? you guys got any reccomendations for brands to go with on the injectors... ive seen the ones on www.modernperformance.com but im not sure if they are any good. advice? and thanks for the info so far its been really helpful

Sell the T25, or make a jet engine out of it! I've always wanted a cheap/free turbo to do that.

Originally posted by ner947
Sell the T25, or make a jet engine out of it! I've always wanted a cheap/free turbo to do that.

T25's are good for chainsaws and 49cc mini bikes :P

Oh shit. I have a t25 :P

And the ecu CANNOT handle 450's and just an SFMU.

Okay, I guess it will run at low FP but your fuel trims are fucked.

st -25
lt -25

That goes to show the ecu WILL NOT handle that large of injectors but if you like running 11:1 at idle then go ahead.

well then what should i do aside make a turbo go cart w/ that t-25... no not really, i mean in regards to the injectors... i think that the 300cc's will work for my application but im really not sure, and i definitly dont wanna mess up my engine first rattle out of the box... on a side note does anyone know the dimensions of the intercooler you get with the hahn stage 2 kit?

you could get the 310 cc injectors for pretty cheap and they're considered the next step away from stockers. Your ecu can handle them (ie: trim fuel enough) to make them idle like stock but perform better under boost. With the 310's you;ll still need a rising rate fuel pressure regulator or SFMU.

as far as injectors are concerned, i think im gonna use some ford injectors... i found a write up earlier concerning those injectors, and i have a hookup at a dealership who can get me set up. but im still unsure should i go w/ the 310's or possibly 360' or so, or should i just go for broke and try and get some 440's to work?(even though i think id be a little overkill, but it'd probably be safer... but harder to setup...)

Originally posted by Blizare

Originally posted by ner947 Sell the T25, or make a jet engine out of it! I've always wanted a cheap/free turbo to do that.

And the ecu CANNOT handle 450's and just an SFMU. Okay, I guess it will run at low FP but your fuel trims are fucked. st -25 lt -25 That goes to show the ecu WILL NOT handle that large of injectors but if you like running 11:1 at idle then go ahead.

I ran 42# injectors just fine with an SFMU. idled at 14.7 afr. On the first startup after the ecu has been reset it would idle in the 13 afr range but in about a minute or two it would go up to 14.7