High flow fuel injectors

[Pisobiker]

Hi all.

I'm in te process of needing higher flow fuel injectors, but more urgently I need advice about them for my friend (the one who owns an RS2) who has already the car by his tuner for fitting a Garrett GT3071R + some other goodies.

I was looking at aftermarket injectors like RC, which rate them @ 550-650-750 cc/min @3 bar fuel pressure. I didn't want to go too big and was thinking that if the Bosch "greens" are capable of up to 420-430 Hp on our engines (~440 cc/min each @ 4 bar) the 550 cc/min @ 3 bar (therefore giving over 630 cc/min @ 4 bar) could exceed even 600 hp....

But the supplyer sayed the 550 cc/min are not a big improvement over the "Bosch greens" therefore suggesting the 750 cc/min ones !!!!

don't know what to think, but for sure I don't want mega-big injectors I then might not be able to tune at idle or low loads.

Any advice or feedback appreciated.


Ciao

Marco

[Mihnea]

550cc/min ARE an improvement over the green ones, definitely!!!! I would run them at 4 Bar however, better flow pattern.

Getting the car to start and idle when warm is going to be an issue with either 550/650cc or more injectors. If the tuner doesn't know real hidden functions of the M2.3.2, he'll be fooked, as there are lots of undocumented (for everyone I mean) parameters that need changed. With those parameters carefully adapted, I got a friend's car to start, run and idle just as a stock engine with 1000cc/min injectors, but it hasn't been easy and I don't know of anyone else, bar a tuner friend from germany who could do that.


Cheers,

Mihnea

[Pisobiker]

550cc/min ARE an improvement over the green ones, definitely!!!!

........

Mihnea

That's exactly what I thought looking at numbers, so I really don't understand theyr statements unless:

a) Theyr 550 cc/min @ 3 bar are way over theyr REAL flow;
b) Bosch "greens" flow MUCH MORE than what we think.....

Anyway a reason they might suggest much bigger injectors is aftermarket ones maybe don't like going much over the 80% max duty cycle for relatively long perieds, while, on this respect, the Bosch ones might be more reliable....


What about the Bosch "orange" ones? what is the exact % increase in flow with the "greens"?


Thanks

Marco

[Mihnea]

Marco, any injector won't run very well over 80% duty cycle, BTDT.

[Billman]

@mihnea

who is this friend of yours from germany? Tom oder Peter?

MFG

[Mihnea]

Billman: Peter is a good guy but I don't know much more about him, he knows his stuff but what exactly???

Tom? damn, I pissed myself laughing. Ask Tom to tune a car on a dyno for you, you'll see. His 90 quattro with supposedly 530 PS or something never made more than 370 when it was dynoed in köln after he sold it.

My friend, who really knows his ****, is erdal, he is really good and he can do whatever you want.

Mihnea

[Pisobiker]

So Mihnea, are you confirming the 550cc/min @ 3 bar ones, run @ 4 bar should be able to flow up to 500/550 hp on our applications?


Marco

[S2central.net]

Surely 550cc injectors at 3bar are enough for ~550bhp by the usual rule of thumb. Running them at 4bar would give plenty of margin in my opinion !


Paul

[Pisobiker]

I was pretty sure about that too Paul, but then the supplyer, with the story the 550 ones are no big improvement over the "greens", just messed all my assumptions up....

Think will go for the 550 ones.
No need to go any bigger.


Thanks


Marco

[RustyNut]

Is the conclusion here that the green injectors will easily handle a 400 - 450 hp set up?

[Mihnea]

No.

Is the conclusion here that the green injectors will easily handle a 400 - 450 hp set up?

[s2dude]

No.

Informative..........!

[twoqu]

Is the conclusion here that the green injectors will easily handle a 400 - 450 hp set up?

I think what he is trying to say is what is the power limit of the RS2 injectors at say 4bar.

[RustyNut]

No.

you would recommend? You will be getting a call when the car is ready.

[corrado]

If you are running stock ecu than it might be wise to get someone who knows the ecu well like mineha is saying, howerver I would rather run a bigger injector at 3 bar than a smaller at 4 bar.

550cc injectors at 43.7 psi would be good for 450hp

For 550hp I would go 680-780cc, this is at 3 bar and 85% duty cycle a safe place.

Rule of thumb to get a good iddle is to not exced 1.5 times displacment of the cylinder.

Myself run 1000cc on standalone with no issues, duty cycle on iddle is 1%