injector size

#1
just for info :)

standard injectors are 252 cc or 24 lb, ideal for 163 bhp

2.0 sc injectors are 357cc or 34 lb, ideal for 231 bhp

I originally thought the sc injectors were 310cc, so surprised they work in a 2.2 na :?

Ideally I should have 336cc or 32 lb :roll:

2.0 sc injector part number = 12790827
 
#2
vocky said:
just for info :)

standard injectors are 252 cc or 24 lb, ideal for 163 bhp
Is that all!? I thought you had yours running almost 200bhp on the standard ones, and hit 220 with the LSJ's?

If i were to get installed on my VX220, would you say new injectors required? At which point is it worth upgrading?:
2.4 Inlet Manifold + K&N + Vocky FPR Mod
Piper 270 Degree Cam Regrinds
Patriot Stg 2 Head Assy With +1mm Valves, Ti Retainers, Springs etc
De Pre-Cat
De Baffle
 
#3
it doesn't mean they won't be any good above that figure, just that is the power they were designed to work at :)

certainly they max out at 200 bhp

80% duty cycle = 160

100% duty cycle = 200
 
#4
edbutler said:
If i were to get installed on my VX220, would you say new injectors required? At which point is it worth upgrading?:
2.4 Inlet Manifold + K&N + Vocky FPR Mod
Piper 270 Degree Cam Regrinds
Patriot Stg 2 Head Assy With +1mm Valves, Ti Retainers, Springs etc
De Pre-Cat
De Baffle
really over 190bhp you should upgrade the injectors dunno..
 

markv

Regular Member
#7
There seem to be more ways to "guestimate" the horsepower you can achief with injectors. If you look on the Emerald homepage you see:

http://www.emeraldm3d.com/em_how.html

As a rough guide to power output, take the injector flow in cc/min and divide by 5 then multiply by the number of injectors.
So basically, with the 252cc/min injectors you would get:

252/5*4 = 201bhp

So that seems to be closer to Vocky's experience and also what you see with other tuners (Vmax raise the fuel pressure with 1 bar when doing their 190 kit).

Which brings me to a question. I understand the 252cc/min. The cc/min seems to be the normal way injectors are sized. However, the amount of fuel you are going to feed through an injector depends on how high the fuel pressure is. So, is there a standard pressure when measuring the flow of an injector? Seems a bit weird :)

Mark
 

markv

Regular Member
#9
Yup, I've seen that calculation too. Don't know which one is right. But it seems to me there are more variables involved here, mainly the fuel pressure. That can skew the results big time..

Mark
 
#11
OK, so once the 2.4 manifold is fitted I'll have itg induction, shrick cams, ported head and a Milltek. The ECU was mapped for the existing mods aswell. I'm hoping that this will give somewhere near 200 bhp. If I managed to find some bigger injectors, would simply fitting them bump the power or would a remap be necessary? Also, I'm not to sure which injetors I should be looking for if I want to upgrade?
 
#12
the ecu will not adjust to the 2.0 sc injectors, so a tms remap is a must

Some 280cc injectors (I wonder what the 2.4 has notsure.gif ) might work on a standard ecu dunno..
 
#13
vocky said:
the ecu will not adjust to the 2.0 sc injectors, so a tms remap is a must
With his mods... it should, BUT I Wonder what TMS/courtenay and co do to the autolearn feature when flashing for the higher rev limiter on the Schricks
 

markv

Regular Member
#15
Hmmm, interesting. So when connecting an OBD reader to a remapped car we should never see a long term fuel trim change coming by. Is there anybody who has been able to test this?

Mark
 
#17
As mentioned above, and I think I pointed it out on another thread before, an alternative to bigger injectors is to up the fuel pressure and instead of fitting an expensive FSB valve or the likes there is a slightly cheaper and invisable way of doing it. :) You can swap the fuel pressure regulator found in the end of your fuel rail (only two small screws) with one from a vauxhall diesel, Its the same size and fits straight in to give you 6bar pressure. 8) The part number is 93176029, but I cant remeber which engine its off notsure.gif Personally I dont know If id go that route myself having read a little of the link posted above on injector sizing as they recomend you stay below 60psi or so or the injectors may not open and close properly, and with 4 bar being 58 psi and 6bar is more like 88 psi its way over. Perhaps worth a try though as I know someone who's running the 6bar regulator on a full dbilas settup 2.2 and its fine.
 
#18
what happens if you increase the fuel pressure too much is the injector will leak - not close fully

as you say 60 psi is quite high, to get the same fuelling as my sc injectors the standard injectors would need almost double the fuel pressure :?

I choose to replace the injectors with some designed for the power I expected from the engine, playing with an already high fuel pressure isn't the best method really dunno..
 
#19
Your proabably right vocky, thats why I decided to go down the same route as you and got some injectors off ebay.com a while back for £25 deliverd from canada! :D flipping bargin! The us boys have a stage two remap for the 2.0sc engine that replaces the charger pully for a smaller one and they change to even bigger injectors, so they sell there "take off parts" as they call it on ebay. Ive seen loads of sets on there, quite easy to get hold of really.

The only problem I can see with these is the idle tuning as again described on that site. I'm having serious idle problems with the cams and manifold as it is. In fact i'm getting a little worried.
 
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