injector upgrade

Hey guys

I was wondering what kind of gains could be expected from upgrading the std injectors to
650cc. has anyone done this?

Nothing unless you are maxing your injectors out now.

How much can you get them for??

Well it'll flow more, correct? but you need other mods in place before you do the injectors or can you do it on the standard setup?

It will flow more so he can flood the car cause he doesnt have the supporting mods.

well - he hasnt given us much info to work with.

so if everything else is stock and he installs 650cc, his car wont run nicely and he'll be pissing fuel out the exhaust everywhere he drives!

Yeah!!! 3kms/l @ R147.43 per liter means u r f@kd.

No seriously - big injectors = big power (if you have the right motor of course).

Another thing to bear in mind is that if the injectors are too big you won't get proper fuel atomisation as injection occurs - this will lead to erratic ignition, heavy fuel consumption and no power.

well currently i have a

- 63mm exhaust
- diktator
- and i recently rebuilt the std T25 turbo (don't know the terminology but something was done to it so i can safely boost at least 1.2 bar and it is still under guarentee from turbo exchange )

i made 150kw on ferrolli's dyno on 0.8 bar boost.
but cylinder 3 was running a bit lean after checking the spark plugs we turned the boost down to 0.6 again for reliability.

So i am thinking if i get 650cc injectors i should safely be able to up the boost more and make more power. I have asked around and found quite a few std 18det (and by std i mean stock block ) running on at least 1 bar boost.
Are any of you guys doing it?
Is it reliable?
What kinda power are you guys making?

Gary57 wrote:

Nothing unless you are maxing your injectors out now.

How much can you get them for??

650cc injectors well my mech can get them for R650 but neva asked what brand .
Otherwise I can get RC injector R3600 for a set of 4.

Can you get it for a better price?

650cc's are probably too big for a stock engine, t25 and stock management...

i'm not sure though so you should probably expect a better informed statement from the likes of gary or pinkfluff.

just noticed you running dictator - so you could manage the extra fuel capacity. so getting them shouldnt really be a problem, but with that T25 dont expect big gains!

a t25 is out of its efficiency range at around 0.9 bar - so boost much more than that and you will only be blowing hot air into the motor, and overspinning the turbo shaft!!!

0.9 bar mmmm.....
Is anyone running a sx with a smiliar setup to mine exhaust etc
boosting 1 bar reliably on a stock block? Wat kind of power gains can be expected guys?

At the end of the day i just wanna know if its worth it upgrading the injectors.
Cos its prolly gonna set me back about 4-5k just to do this with injectors , fuel rail and tuning.

Also keep in mind that I only wanna do generic mods at this stage so that when i do my motor swap its one less thing i have to buy.

mono wrote:

0.9 bar mmmm.....
Is anyone running a sx with a smiliar setup to mine exhaust etc
boosting 1 bar reliably on a stock block? Wat kind of power gains can be expected guys?

At the end of the day i just wanna know if its worth it upgrading the injectors.
Cos its prolly gonna set me back about 4-5k just to do this with injectors , fuel rail and tuning.

Also keep in mind that I only wanna do generic mods at this stage so that when i do my motor swap its one less thing i have to buy.

In my opinion just go for a T28 turbo and larger intercooler for now. cause you already have the management system and exhuast. thats what I'm gonna do. Will do the injectors eventually but only when I max them out...

There's something weird about the stock injectors. It's rated at 375cc or whatever. Last weekend I decided to try to get a replacement for my leaky ones. Had my injector tested on a jig with a known 388cc brand-new injector. At the same fuel pressure and duty cycle, the stock injector flowed almost DOUBLE the amount that the 388cc injector flowed! The mac claims that the stock ones are more like 550cc or something.

This would explain why, when I got injectors custom-made to 375cc, my car wouldn't even idle with them.

I'm really confused about the injector capacity. Is it possible that there are different standards for measuring injector flow rate? For example, the japs maybe use a different duty cycle or pulse duration or fuel pressure, etc. when testing flow?

its possible... i mean they measure power in PS. its almost the same as HP, but a lot different to Kw.

anyway i have the opposite story. i got an injector leak on my first set of injectors with the ca18. i pulled those out and noticed that they had different part numbers to what i thought was stock.

i had them sonically cleaned and flow tested. they measured in at about 200cc, not the stock 370cc. but my car was running perfectly fine on those injectors???? i changed to the stock ones immediately after that, and there was no change in the engine performance!!!??? 😕 😕 😕

Save that R3600 and fit a bigger turbo or FMIC if you are after more power.

Im doing a RB swap later in the year and then i will probably invest in a new turbo.

For now im just trying to buy strengthen everything round the motor to reduce costs when i do the actual swap.

You will not get close to maxing them with your current mod list.
Also what type of RC injector’s high or low impendence? (Peek and hold vs Saturated)

Its normally tested at 3bar what was the brand of injector toby?

I don't know what make the other injector was, or whether it was peak-and-hold or saturated (I don't even know what that means). Nevertheless, he guaranteed me it is 388cc. Mine was the stock injector off an import motor, which currently works perfectly in my engine with stock ecu. I wish someone would get to the bottom of this issue and find a Bosch equivalent injector for our stock injectors.