Rob Day

iTrader: (78)

Although im currently Subaruless, I was for some strange reason thinking is there a logical bhp for each cc on injectors?

It appears there is the way I have worked it out, stand to be corrected of course

78% of the CC is the Max output of BHP at 3.5bar pressure running full duty, does this seem right?

3.5 Bar


3.0 Bar


Remember im only asying there is a logical explanation for each table, im not saying this is the Power you will get from using the said injectors, also each table would mean that you would be running close to full duty.

Rob

PS Im ready for the stones to be thrown at me

madmerlin

iTrader: (14)

so for 420 i didnt need to buy 650's then --- Doh!!!!!!

JdcTypeR

iTrader: (19)

I was actually just searching for something like this
I'm looking at getting 550s but heard they struggle to get to 400 bhp but looking at the chart its saying different

addi monster

iTrader: (6)

hmm my 440`s were at 98% duty and could only manage 336bhp all other mods were more than capable,.,

JdcTypeR

iTrader: (19)

Same mate, mine were maxed at 320bhp

prodriverules

iTrader: (52)

I made 347 at 91% on 440's a while back but I did have a fuel reg fitted with 0.5 bar more fuel pressure.

jura11

iTrader: (7)

This can be truth,but with FPR and parallel rails and depends on fuel used,boost etc.


Jura

JdcTypeR

iTrader: (19)

I have a fpr so i should see what i want with about 0.5 bar pressure increase?

JdcTypeR

iTrader: (19)

To be fair though i was running standard pressure when i had it mapped.
I would of probably seen more with 3.5 bar then

prodriverules

iTrader: (52)

General rule of thumb is every 0.5 bar increase gives 10% flow so a 440 becomes 480ish cc.

chrisdicko

iTrader: (21)

Is there any disadvantage of increasing fuel pressure?? Why not just increase it as a matter of course when you map it?

53

iTrader: (41)

It's a nice table but the bhp figures in reality are perhaps a little optimistic

prodriverules

iTrader: (52)

As long as the fuel lines are all in good condition then no disadvantage at all.

bmposer

iTrader: (3)

I found this a while ago not sure if its correct tho
http://www.scoobypedia.co.uk/index.p...rFromInjectors

madmerlin

iTrader: (14)

yes lets go with this cos it makes me feel better about buying 650's

MattyB1983

iTrader: (51)

My RCM 550's were getting very close to their limit at 390. I now use a FPR to help them out a bit and currently set at 3.5 bar.
Don't think 432 would be achievable with 550's and no FPR to be honest.

JdcTypeR

iTrader: (19)

That looks more realistic, 440s at what i acheived at 3 bar.
sorry just re read Robs 1st post and he does state 3.5bar so 346bhp is possible then

Rob Day

iTrader: (78)

Guys I was only experimenting with the a simple formular

The % I was stating isnt duty cycle, its the % of the CC that creates seems to follow a pattern of bhp.

78% of 100cc works out at 78bhp
78% of 1000cc works out at 780bhp simples.

Im not syaing this is anywhere near right, but it does seem to be somewhere near after doing a little home work.

Also its worth pointng out that I know 440's will do 340bhp with a 3.5Bar FPR, also 550's will make well over 400bhp with a FPR. With this in mind the table although adventurous isnt a millions miles away.

I'll re-jig it for 3 bar

Rob

DisoDisp

iTrader: (1)

I use the following as a rule of thumb.

(CCs / 5) x 4

I.e 565cc injectors in theory should give 565bhp in a 5cyl car at 100% inj duty at 3.0 bar.

Hence in a 4 cyl = 452. Run at about 80% duty for 361bhp.

MartynJ

Or you could use this

http://www.rceng.com/technical.aspx

Martyn

chrisdicko

iTrader: (21)

Can you up the fuel pressure without a map, or only when mapping?

MartynJ

Only when mapping as it will alter the mixture.

Martyn

chrisdicko

iTrader: (21)

cheers

andy00v7

On a newage STD injectors (550 pinks) running at 100 % duty will max out at 384 bhp

Andy

Rob Day

iTrader: (78)

Maybe yes maybe no. All cars will vary, you can only offer a guide. Mine with a FPR got close to the stated on post1.

andy97

iTrader: (1)

My car runs 740 injectors, it has 500bhp, there is still room for more power from 740's

mickywrx

iTrader: (29)

Mine did that down there



<<

On standard fuel pressure and 380cc injectors.

GC8

Rule of thumb: 550cc x 4cyl = 2,200 / 5 = 440bhp (100% and 3BAR fuel pressure). Safe / 80% duty = 350bhp.