how much boost can I run on 440 injectors and if i'm looking to boost 30lbs do I need 750 or 1000cc's?

 

It really goes by hp and not psi, what hp will you be running?

 

I have heard this over and over again and still dont understand. Cause If I open a the intake valve and the combustion chamber is open the intake pressure which is read by your boost gauge then it dosent matter about cfm's on how fast it gets there the area of the clyinder is still only pressurized to the set PSI regulated by the wastegate. CFM's would only affect actual boost peak time or how fast it can get to the regulated psi. so to me it only makes sense to mesure the air just like the gauge in psi. but for a answer to the question 30psi would require some 1000cc injectors, 780cc might work but the duty cycle would be high and you would end up getting bigger injectors anyway. its always easier to shorten pulse width then it is to make it longer.

 

thank you

 

not sure yet,

board to 84mm, darton sleeves, crower rods good to 50lbs of boost, je turbo pistons, balanced, springs retainers skunk2 valves, skunk2 turbo 2 cams,skunk2 intake manifold I baord out to 70 mms, 70 mm DH throttle body, t70, 3inch exhaust all the way, no cat, 255 lph holley fuel pump, adjustable fuel pressure regulator, external msd, 9mm wires,gsp axles.

running old tune, from old motor that was rich and now is dead on at 10to 12lbs, wideband tells me. finally at 1000 miles and getting ready to tune,for 30lbs.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsrhatch2356 &raquo;</TD></TR><TR><TD CLASS="quote">I have heard this over and over again and still dont understand. Cause If I open a the intake valve and the combustion chamber is open the intake pressure which is read by your boost gauge then it dosent matter about cfm's on how fast it gets there the area of the clyinder is still only pressurized to the set PSI regulated by the wastegate. CFM's would only affect actual boost peak time or how fast it can get to the regulated psi. so to me it only makes sense to mesure the air just like the gauge in psi. but for a answer to the question 30psi would require some 1000cc injectors, 780cc might work but the duty cycle would be high and you would end up getting bigger injectors anyway. its always easier to shorten pulse width then it is to make it longer.</TD></TR></TABLE>

you don't understand how cfm's are involved? Say that again?

A t25 at 7psi doesn't flow near the CFM of a t3/t4 at 7psi. Less cfm=less volume, as CFM = VOLUME. Therefore, a t3/t4 at 7psi will make more power than a t25 at 7psi because there's more CFM! More cfm requires more fuel. More air and more fuel=more power.

PSI doesn't matter a damn if you don't define the VOLUME of air. PSI isn't volume, psi is simply pressure of the molecules against a surface.. There's a big difference between the two.

so, again. I can't answer your question as to what injectors you need unless you tell me what your power goal is and what turbo you have.

Just off the top of my head, you'd have to be running a big ol honkin turbo to push 30psi and it not be simply a super-hot air pump at that pressure. And my guess is, if you're running 440cc injectors now, you don't have a motor capable of running 30psi on a large turbo.

So, assuming you have a t3/t4, and you want about 400whp (with forged pistons and rods) you might need something along the lines of of 880cc injectors.

But lets not talk PSI because there again, it all depends on your motor, mods, tune, etc. to see what power you make at a given psi.

 

I see what your talking about but volume can not exceed that of the area of the clyinder combustion chamber. think about it like this, if I had a 12x12x12 box and filled it up to 10psi then I still have that area full of 10psi it cant change depending on cfms cause the valve still closes the box and the wastegate still regulates the psi so the same amount of air space is the same everytime. more cfms only means the box fills up faster and before the valve closes and then the wastegate takes over to regulate the air before it closes. meaning that all you can count on is the boost gauge to tell psi. but whatever point is regardless that with certain setups you can except to have to have certain fuel requirments like 30psi and big a$$ fuel injectors go hand in hand regardless of cfms or anything else.

 

the way I'm telling you is the way it works. I understand your thinking on this, but if your thinking were true, turbo size wouldn't matter, only PSI would, meaning a t25 at 10 psi would make the same power as a t4 at 10psi.

Compressing the air means you're fitting more air into the given volume of space. So, say a t25 makes 10cfm, and you're compressing that 10cfm by 7psi, you're fitting more volume of air into the cylinder....while a t4 may make, say, 30cfm, and you compress that to 7psi, you're fitting WAY more air into the cylinder that way.

You're thinking is correct, I believe, except for the fact that you're not considering the compression of the charge increasing the actual amount of air in a given space increasing.

 

OP, why the hell do you want to run 30psi?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gibsanez &raquo;</TD></TR><TR><TD CLASS="quote">OP, why the hell do you want to run 30psi?</TD></TR></TABLE>

cuz it sounds cool to tell to other people?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chimmike &raquo;</TD></TR><TR><TD CLASS="quote">

cuz it sounds cool to tell to other people? </TD></TR></TABLE>

I guess. A lot of people realize that over 300WHP on the street is borderline useless, but everyone wants a 450whp DD now a days.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gibsanez &raquo;</TD></TR><TR><TD CLASS="quote">

I guess. A lot of people realize that over 300WHP on the street is borderline useless, but everyone wants a 450whp DD now a days.</TD></TR></TABLE>


Here's a formula/calc to answer the OP. They use hp as the gauge and not turbo psi. I'm no physics guy but I agree with chimmike based on what ive seen.
http://www.rceng.com/technical...VLDbr

 

man, anything above like 230whp is useless in 1st gear and maybe even 2nd gear on the street. 400whp is insanity, and 500+whp is suicidal


but I like it so I'm gonna do 300whp for a while, then 450whp after some pistons and rods :D

 

300 whp is not enough for the street. 450 is good if you have dr's......like i do

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gibsanez &raquo;</TD></TR><TR><TD CLASS="quote">

I guess. A lot of people realize that over 300WHP on the street is borderline useless, but everyone wants a 450whp DD now a days.</TD></TR></TABLE>

How is 300whp on the street borderline useless? Unless your running some crappy suspension and tiny all season tires, then yes it would be.

When you make the power, it common sense to have the proper tire/suspension to put it down.

I personally make 380whp and i dont think it all that amazing, i personally think it could make more and be fine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StolenTeg &raquo;</TD></TR><TR><TD CLASS="quote">I personally make 380whp and i dont think it all that amazing, i personally think it could make more and be fine.
</TD></TR></TABLE>

x2

 

I've been in a few car's that were even sub 300, and low gears were useless on the street for trying to play around.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chimmike &raquo;</TD></TR><TR><TD CLASS="quote">the way I'm telling you is the way it works. I understand your thinking on this, but if your thinking were true, turbo size wouldn't matter, only PSI would, meaning a t25 at 10 psi would make the same power as a t4 at 10psi.

Compressing the air means you're fitting more air into the given volume of space. So, say a t25 makes 10cfm, and you're compressing that 10cfm by 7psi, you're fitting more volume of air into the cylinder....while a t4 may make, say, 30cfm, and you compress that to 7psi, you're fitting WAY more air into the cylinder that way.

You're thinking is correct, I believe, except for the fact that you're not considering the compression of the charge increasing the actual amount of air in a given space increasing.</TD></TR></TABLE>


Well I have to say that you have made the most since out of everybody I have talked to everybody else just says it cause that's what everybody else says and my own knowledge and theory of engine dynamics didn't allow me to fall into it without a good explanation and although I am not completely there you make a good point.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chimmike &raquo;</TD></TR><TR><TD CLASS="quote">the way I'm telling you is the way it works. I understand your thinking on this, but if your thinking were true, turbo size wouldn't matter, only PSI would, meaning a t25 at 10 psi would make the same power as a t4 at 10psi.

Compressing the air means you're fitting more air into the given volume of space. So, say a t25 makes 10cfm, and you're compressing that 10cfm by 7psi, you're fitting more volume of air into the cylinder....while a t4 may make, say, 30cfm, and you compress that to 7psi, you're fitting WAY more air into the cylinder that way.</TD></TR></TABLE>

PV=nRT; Ideal Gas Law, read up on it. It makes the way you wrote look foolish. With a motor, you have a fixed space into which you are pushing air. If you're at sea level and push 30 cfm of atmoshere into a fixed space and get 7psi/120f, you get 30x7=nRT. If you push 25cfm of sea level atmosphere into that same space at same ending temp, you would get 3.38psi. This is butchering the Law for sake of an example, but it shows there's "no free lunch" concerning CFM or PSI.

It has to do with the efficiency of the turbo (amount of heat it dumps into the air to compress it) and how it can increase the volumetric efficiency of the motor, essentially the other side of the equation. There are actually a large amount dynamics that allow a GT40 to make twice the HP as a smaller turbo at the same PSI, and virtually every part of the motor tweaks that equation.


To answer the OP's question given a 2.0L with a T70 - 30psi is probably going to get you &gt;600whp, well over that actually. Try it at 20psi first, because that 255lhp pump will only supply about 600whp at 73psi of fuel pressure (43+30 due to FPR).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">

PV=nRT; Ideal Gas Law, read up on it. It makes the way you wrote look foolish.</TD></TR></TABLE>

I'm no engineer and I faintly remember high school physics stuff. I'm in insurance, and I tried my best

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">

PV=nRT; Ideal Gas Law, read up on it. It makes the way you wrote look foolish. With a motor, you have a fixed space into which you are pushing air. If you're at sea level and push 30 cfm of atmoshere into a fixed space and get 7psi/120f, you get 30x7=nRT. If you push 25cfm of sea level atmosphere into that same space at same ending temp, you would get 3.38psi. This is butchering the Law for sake of an example, but it shows there's "no free lunch" concerning CFM or PSI.

It has to do with the efficiency of the turbo (amount of heat it dumps into the air to compress it) and how it can increase the volumetric efficiency of the motor, essentially the other side of the equation. There are actually a large amount dynamics that allow a GT40 to make twice the HP as a smaller turbo at the same PSI, and virtually every part of the motor tweaks that equation.


To answer the OP's question given a 2.0L with a T70 - 30psi is probably going to get you &gt;600whp, well over that actually. Try it at 20psi first, because that 255lhp pump will only supply about 600whp at 73psi of fuel pressure (43+30 due to FPR).</TD></TR></TABLE>

holy **** lmao, I would be suprised if anyone on this forum could comprehend what the hell you just said in that post. Just reading some of that gave me a headache.

 

hopeing to shead light for myself in the midst of very intelligent men and women if there are any in this forum,

I was running 270hp at the wheels on a stock motor pushing 10lbs on a t4oe hybrid and that was cool.

threw in my rebuilt motor, built for 40lbs of boost, still running the same tune, felt even better.

But guys, when I took out my t4oe and moved my radiator and put the t70 in.,
big difference, same tune, feeling more power-torque, sorry havent got the print out yet, and boost gauge is hitting 12lbs easy on the same spring.

I think who ever was making the statement of bigger turbo more volume, I would have to side with them on that note even if the numbers were all inclusive.

 

thank you for your insight and i'm glad there is experienced individuals around!

I just looked on holley the other day and they said the 255lph is good to 750 hp at 60psi.

and I think I am going to go with 20 or 24lbs,hearing from most it's good to gradually than wam-be there and miss the enjoyment of scaling.

I wasnt sure what the hp would be on this set up-thanks HiProfile

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sevenj &raquo;</TD></TR><TR><TD CLASS="quote">

I was running 270hp at the wheels on a stock motor pushing 10lbs on a t4oe hybrid and that was cool.

threw in my rebuilt motor, built for 40lbs of boost, still running the same tune, felt even better.

But guys, when I took out my t4oe and moved my radiator and put the t70 in.,
big difference, same tune, feeling more power-torque, sorry havent got the print out yet, and boost gauge is hitting 12lbs easy on the same spring.

I think who ever was making the statement of bigger turbo more volume, I would have to side with them on that note even if the numbers were all inclusive.


</TD></TR></TABLE>


Please get it tuned!

 

k