question about injectors sizing....

[rossi46numberone]

Hi everybody,
I need some opinions about injectors size and pressure regulator.
I have recently installed a IHI VF48 turbo,and now at 1.35 bar of boost I hit 95~97% of duty-cycle to keep a correct AFR(+/- 0.75).
But the target is minimum 1.5 bar of boost !
I'm running a 3 bar pressure regulator with 440 cc injectors and I'm wondering if it's a good idea to swap it for a 4 bar?
Or,do I have to buy big injectors like the siemens 630 cc ?

Thanks.....

Michele

[gunni]

Play around here.

http://www.rceng.com/technical.aspx?UserID=11388880&SessionID=oG3ef7SqBdxPZVa4FjPN

[GintsK]

V48? I suppose it should flow somewhere around 350hp?
It is always good to chose injector size basing on given turbo maximal flow. OEM usually do so.

[rossi46numberone]

Thanks guys....
I suppose It will supply something like 330 HP but it's hard to define it exactly,and I didn't found any flow charts for this turbo(too recent).
With the 4 bar regulator they will supply about 510 cc ( 300 hp)at 87% duty (theorical),I think it 's too much near from the limit because my target is to pass the 300 hp wall.....
And if I keep in mind to stay under or egal at 80 %,what would be the better solution:
630 cc at 4 bar (58 psi) or 750 cc at 3 bar?
Does the pressure will affect the way the injectors spray or the idle operation?
It is so important to keep a good and smooth idle like i'm running today with my Lucas injectors....
What injectors do you recommend?
What is their voltage compensation(8v,10v,12v,14v,16v)?
Thanks.....

Michele.

[GintsK]

I have extremely good experience with new BOSCH ones. It was 970cc and 1000cc. EV14 kind. Idling extremely smooth. Can keep even 1.05 lambda without misfiring at idle. So I suppose smaller ones can't be worse. http://www.mksautobusiness.fi/page_injectors.html

[rossi46numberone]

what do you think about the Siemens deka IV ?

[jrussell]

Both the Siemens and Bosch are very good choices. The VEMS webshop keeps the Siemens in stock at 630cc and 850cc (727 and 980 @ 4bar). You could email them and ask about Bosch ev14 1000's too. There were some available, but not sure if they sold out yet or not.

[Ascona 400]

I would go for the new Bosch EV14 injectors.
I know that is one BMW M5 here in Sweden that passed the emission test with the 2200cc variant of this injectors on regular petrol. I think he said that he had only 0.6ms opening time at idle.. This is not with a Vems (he uses a ViPec) but anyway that is really good.

If you go with the Siemens injectors, the 630cc version is far better then the 850cc version.

So if 630cc is enough go for the Siemens because they are cheap,  if you need bigger ones or are willing to pay more use the EV14 injectors.