Being that those with the LNF are utilizing a fairly new technology with Direct Injection, it seems that the traditional fuel injection limits and rating system are no longer valid.

Since many of us will eventually be pushing the limits of what this motor can take, has a concensus been reached as to what the max hp on the factory injectors could be assuming sufficent air is being delivered to the cylinder's?

If anybody has been able to extrapolate this from duty cycle info or other flow rate information, I (and I am sure many others) would be interested to know how much hp we can theorectically get out of them.

 

i beleive 80% duty cycle is limit to turbo cars.Anything over that is pushing them past there limit,and car startst to knock after couple runs...so my guess would be 320whp before they go nuts..just a thought

 

i thought i read on here somewhere the max for injectors was 400

 

I've seen 400 HP talked about too, but I personally don't know for sure.

 

It is the injection time that is really limiting us here. The injectors are 122 lb/hr, but they have very little time to inject the fuel they could support well over 500 HP but they will not if the motor has to be reved over 6K to acheive that. Injection window becomes too short and injection time becomes too long above 6500 or so with most setups so the injection cycle carries over to the compression stroke which messes things up pretty badly. That is why no matter what setup people are running the power drops off above 6300-6500 RPMs.

 

Well there are two ways to make horse power you can either work to increase torque or try to reach higher revs, I guess the choice is to make more torque as pushing the torque curve up won't accomplish much as the injectors won't handle it. So the amount of potential horse power becomes a function of max torque. What is the most torque the engine can produce without lowering the torque curve in the rpm range becomes the pertinent question.

 

that doesn't make any sense

 

X2.
The car is knocking becasue it is heatsoaked and your IAT2s are high probably 120*+. Unless your A/F is rediculously lean.

 

Crazy Steve has WHP and WTQ in the upper 300 and no change in injectors.

 

We just need to modify the stock injectors to flow more at the stock pressures and we need tuning support from HP tuners to tune for the new injector setup. Once we get that we will see 500+ whp LNF cars that rev to 8K RPMs.

 

Does anyone know when the injection starts @ 6300 rpm (Degrees before TDC)?

 

No, But injection window is approx 5 milliseconds at 6300.

 

Has anybody played around with fuel pressure yet? I don't know for sure, but I would assume that the computer controls the fuel pressure by pulse width modulation on the fuel pump(the one in the tank). By increasing the intermediate pressure you could increase the pressure in the rail, depending on what types of mechanical limits there are on it, ie pressure relief valves, etc.

 

The bosch gdi papers say 5ms but going to 6-6.5 is still doable without any side effect.
Either way with the stock turbo you shouldn't have any problems with fuel, once you get into the gt30 territory is when you might start to have fuel issues in high rpm/boost situations.

I dont think anyone wants to play around with fuel pressure, its already at 2200psi and its controlled by the ecm.