270cc's = how much?

[spitz7985]

What psi would you say the stock 270cc's are good for?

[bbandit]

from what i've heard.. ~4 psi

[:: orion ::]

Depends on the turbo...

4psi from a T3 is WAY less airflow than 4psi from a T66.

But to answer your question more specifically...

A T3/T04E will add about 11-12rwhp per pound of boost...and 270s are good to about 185-190rwhp.

Math: (25.7 X 4 X .90) / .5 = 185 (that's .5 BSFC, 90% duty cycle)

So say your healthy KA gives you 150rwhp before you boost it...

Bolt on T3/T4, boost to 4psi (a ~45rwhp increase)...and you've maxed the stock injectors.

You maybe could squeeze 5psi from a T3 and be OK...but who knows.

Later - Brian

[spitz7985]

Math: (25.7 X 4 X .90) / .5 = 185 (that's .5 BSFC, 90% duty cycle)

thanks for the info. sorry, i don't follow the math. could you explain where these numbers came from so in the future i can calculate this myself. thanks.

[Drift]

Depends on the turbo...

4psi from a T3 is WAY less airflow than 4psi from a T66.

But to answer your question more specifically...

A T3/T04E will add about 11-12rwhp per pound of boost...and 270s are good to about 185-190rwhp.

Math: (25.7 X 4 X .90) / .5 = 185 (that's .5 BSFC, 90% duty cycle)

So say your healthy KA gives you 150rwhp before you boost it...

Bolt on T3/T4, boost to 4psi (a ~45rwhp increase)...and you've maxed the stock injectors.

You maybe could squeeze 5psi from a T3 and be OK...but who knows.

Later - Brian

Does this change if you increase fuel pressure w/ like a BEGI or Vortech unit?

[Checkered-Member]

there is a guy on here running 5 psi on stock maf ecu and injectors, that is really the max you can do

[:: orion ::]

spitz7985 -

Math is as follows: To determine max HP, you use duty cycle, # of injectors, and flow in lbs/min. To convert "cc" to "lbs/min", divide by 10.5...270/10.5=25.7.

Multiply duty cycle times # of injectors times flow rate, and divide by the BSFC...and .5 works well for turbo KA's in the instance.

So for 370s, you get:

370/10.5 = 35.2

(35.2 X 4 X .90) / .5 = 253rwhp as a safe max.

- - - - - - - - - - - - - - - -

Drift - Yes, flow changes as you increase pressure. OEM injectors are rated at 43.5psi...to get the new flow after increasing the pressure, you take the square root of the new fuel pressure divided by the old pressure, them multiply by the original injecotr size.

So if we increase pressure from 43.5 to 54...

( square root of [ 54 / 43.5 ] ) = 1.11

370 X 1.11 = acts like a 412cc injector.

- Brian

[spitz7985]

the BSFC

??

[C-Kwik]

Brake Specific Fuel Consumption

[WDRacing]

Does this change if you increase fuel pressure w/ like a BEGI or Vortech unit?

Increasing fuel pressure will allow any said injector to flow more fuel. This why the FMU's are good for adding some boost without having to do any tuning.

[spitz7985]

Brake Specific Fuel Consumption

please, excuse my ignorance. could you explain exactly what this is any why .5 is a good number for the KA?

[Checkered-Member]

There is another solution, instead of getting bigger injectors, or raising the fuel pressure you might want to add an injector (a stock 270cc) right after the throttle body, this will give you 337cc per cylinder 270cc/4 = 67cc67cc + 270cc= 337cc

if you add two:

270cc x2 /4= 134cc134cc + 270cc = 404cc

[Red-KAT]

How good does adding more injectors work?? I was thinking of doing this when I run more boost... but I fear the fuel will not be as even as it should be. with the E-manage I can add 2 easy...

Anyways what do you think?

Or is adding injectors only good for small gains, would you not want to add 2 550cc's to run big power... I could see how this would help your car run better at no boost tho. with the big injectors only on at mid boost...

[Checkered-Member]

How good does adding more injectors work?? I was thinking of doing this when I run more boost... but I fear the fuel will not be as even as it should be. with the E-manage I can add 2 easy...

Anyways what do you think?

Or is adding injectors only good for small gains, would you not want to add 2 550cc's to run big power... I could see how this would help your car run better at no boost tho. with the big injectors only on at mid boost...

Well the fuel should be pretty even I mean you are spraying mist, into air so the distribution should be ok.

You keep saying “big power” "more boost" “mild boost”, I need numbers (X psi or X hp)

2 - 550 will give you

545cc per cylinder

but then again dumping that much fuel will encounter problems, you could get raw fuel in the intake or uneven distribution

[DriFt3r]

hey, I've been running about 5-6 psi on the stock ka motor for about 20k no problems yet. I'm using a straight t3 but gonna upgrade everything else soon.

[spitz7985]

DriFt3r, could you please describe your setup in detail? thanks.

[Red-KAT]

Well the fuel should be pretty even I mean you are spraying mist, into air so the distribution should be ok.

You keep saying “big power” "more boost" “mild boost”, I need numbers (X psi or X hp)

2 - 550 will give you

545cc per cylinder

but then again dumping that much fuel will encounter problems, you could get raw fuel in the intake or uneven distribution

Ok well the way I think is... I always think of boost from 0 - 30

So low is 0-8 psi... Mid would be like 10-17... High would be anything 18+

I dont know how much power any of those would give...

Lets just use horse power... Right now I'm at 6-7 and want to run 8 on the #... So my 370cc's should be able to go up to 10 I hear...

8psi = about 250hp? with good tuning?

12psi = 320ish

Anyways whats the max power I could run if I had 2 extra 1000cc injectors? I think 1000's the max.

[C-Kwik]

please, excuse my ignorance. could you explain exactly what this is any why .5 is a good number for the KA?

http://www.westechperformance.....html

[C-Kwik]

There is another solution, instead of getting bigger injectors, or raising the fuel pressure you might want to add an injector (a stock 270cc) right after the throttle body, this will give you 337cc per cylinder 270cc/4 = 67cc67cc + 270cc= 337cc

if you add two:

270cc x2 /4= 134cc134cc + 270cc = 404cc

You don't want to add an additional injector right after the throttle body. Either you add it at least 6" before th throttle body, or add an additional injector in each of the runners in the manifold. Adding it after the throttle body wil result in poor dostribution of fuel. You do want to keep the distance between the injector and the cylinders as small as possuible, but if you are looking to keep costs down by using less injectors, adding it before the throttle body is a viable and effective option. It will waste a small amount more fuel, but since it's not going to be on until you reach a certain amount of boost/airflow, it won't be a huge difference. It is certainly an effective option though.

[C-Kwik]

Anyways whats the max power I could run if I had 2 extra 1000cc injectors? I think 1000's the max.

270 x 4 = 1080

1080 + 1000 + 1000 = 3080

3080/10.5 = 293.33

293.33/.5 = 586.66 HP.

Keep in mind I am also ignoring the 90% injector duty cycle that Orion used in his calculations. Injectors will fail open at some point so the actual fuel delivery will be 100% of the injector's capability. So you can actually safely run boost up to the 100% duty cycle. Between the max controllable duty cycle and 100%, you will not longer be able to control how much fuel, but it will still run as it will just stay open.

[turbotruck]

Wow I have a T-3 t-4 that will support 530 h/p And i am running stock EVERYTHING, NO INTERCOOLER, and its fine running 7 lbs A/F looks fine at 7 lbs!!!!! Damn and mine is even in the truck so its not even as much power as the 240.. and my stock injectors are fine by the way.

[WDRacing]

What T3/TO4 are you using that will support over 500HP without becoming a heat pump. In a trim that big I would think you'd have serious compressor surge at only 7 psi...Not that I doubt you, I'm just curious by nature.

WD

[Jookmasta]

so then if i want to run 8 psi from my t3 turbo, my factory injectors are fine to use since i have a vortech 8:1 FMU?

[C-Kwik]

Wow I have a T-3 t-4 that will support 530 h/p And i am running stock EVERYTHING, NO INTERCOOLER, and its fine running 7 lbs A/F looks fine at 7 lbs!!!!! Damn and mine is even in the truck so its not even as much power as the 240.. and my stock injectors are fine by the way.

This sounds suspect. Unless the truck's stock injectors are much larger. I'd be curious to see what kind of power you make as well.

[C-Kwik]

so then if i want to run 8 psi from my t3 turbo, my factory injectors are fine to use since i have a vortech 8:1 FMU?

8 psi may be pushing it. It can depend on the condition of your fuel pump.

[Jookmasta]

300zx fuel pump

[Jookmasta]

ya i would be using a 300zx fuel pump, 8:1 Vortech FMU and stock injectors to push the 8 psi from the t3?

[turbotruck]

This sounds suspect. Unless the truck's stock injectors are much larger. I'd be curious to see what kind of power you make as well.

It made 160 on a mustang dyno, Everything is stock except the turbo... Now i have a problem though the rings wouldnt hold up!!!

A friend of mine that builds turbo's and injectin pumps for a living built the turbo for me! I dont know alot about turbo's but it is like a H ? trim and the exhuast is .48 and compressor side is .70 and the wheel is like a 58mm.... he said it should support 530 horse

Ohh and no surge yet, a guy from turbonetics even said that it should be good and efficient at 18----20 lbs

[C-Kwik]

160 HP? At 7 pounds you should be over 200 HP easy. The rings won't hold up? Could be the result of detonation. Not enough fuel can do that.

The turbine sounds like a T3. That's fine. Not sure what compressor that might be. You probably have the number wrong. 63 mm is about 2.5 inches. No T4 compressor has any blade dimensions in or around that size. The smallest major diameter is 2.75 inches and the largest minor is 2.29 inches.

And I would not expect any surge on a KA with a T3/T4. And if it doesn't surge now, it should not surge later. Surge is a product of airflow. Without any changes to the motor, the airflow shouldn't change any. So given the same motor and same turbo, surge should not be an issue. Unless you run no BOV, there may be some surge when lifting off the throttle.

[turbotruck]

my a/f was fine on the dyno it acually ran rich till 6 pounds then it leaned out alittle to 12.0 12.5 at 7 so we didnt push our luck anymore and left it there. As for the motor making more power than that, i thought so too but appearanly it was weak and tired or something... At 7 lbs it made a huge difference... I am going to figure out weather its the head gasket or the rings, Fix it and ad a inline pump that i already have and an fmu, small intercooler and just drive it tell it says no more!!