bastarddsm
20+ Year Contributor
- 5,774
- 1,703
- Aug 26, 2003
-
Mendota,
Illinois
Gofer -
I run a walbro 255hp, and I run my injectors to 100%. Yeah, I live dangerously, but I havn't puked a motor from it, and I made some good power. I'm not sure what power I'm actually making, but the car weighs 3400lbs, and I was on a 20cm T3 HX35 at 25psi, turning it 8000, when I made my timeslip numbers. I used to run about 13:1 AFR's too. My 255hp is really old and on stock wiring too.
With your 950's I see no reason you shouldn't be able to make 500whp on E85 with them with a n/t regulator and a good rewired 255hp. Might have to do an inline as the boost gets up there, the line pressure will get above the crack pressure on the 255.
Once again its not so much as the injectors sticking open, its that they don't have enough time for the magnetic field to collapse and the pintle to close, before its time to open. There is no "sticking" they just don't react fast enough. Playing with the circuitry in the ecu could help the magnetic field collapse faster possibly reducing deadtimes.
Anyway, you'll see it in a graph of flow vs dc for a given frequency, the flow will linearly increase with increases of dc, until about 90-95% and then flat line. Obviously the higher the frequency the earlier the flat line occurs. I remember seeing bosch 1600's curve, and on a 1000z wave ( thats like turning your engine 120000rpm), they flat lined at right around 90%.
Right now I'm on my HY35 at 22psi, and it holds its afr flat as hell all the way to 8500. I'm running a 2g maf, and I get to 96% idc's, and my afr's according to my lc1 are dead flat at 12.5 to 1 right now. They don't make any funny changes as the injectors cross 80%, 90% or even 95%. I have never noticed a rich spike, but maybe the 1g ecu logs too slowly to see it.
Also, stop paying so much attention to the AFR's. Tune it to run the most trap speed, without knocking and having decent timing, then give it just a little more fuel for a cushion. Learn to read plugs, and notice what the car does. Hell, up until just this summer all I had was a stock narrow band. I tuned my car on sd with it and ran really good. Who cares what the AFR's are if its making power and not self destructing.
for a while before I got my 750's I used a nitrous solenoid, and an old school fuel nozzle to inject fuel into the uicp under boost to keep from going lean when I installed the HX35.
Landspeed - Your right I didn't mention the pump issue, but I don't think its that big of an issue. On a 14b, your not going to get much of 22psi, so even with a n/t fpr or even stupid high bfp like I used to run, you won't hit the crack pressure. I just started to hit it with my new injector setup because the pressure drop across the oem filter is too great when your using some fuel.
I now run a dual fuel rail setup with 450's and 750's I put a relay in and it switches out the resistor pack for the second set of injectors when the boost hits. I have the ecu code switch the global comp too. I leave the deadtimes alone, but big for the primary 750's I run n/t regulators, and will be running 2 255hp's inline.
I should also say I never recommended running injectors on the super ragged edge 95% on up. I stated that I do it and do not have problems. If your consistently in the mid 90s, its time to look for something bigger, but buying bigger injectors because you had 81% idc's is just plain retarded.
I run a walbro 255hp, and I run my injectors to 100%. Yeah, I live dangerously, but I havn't puked a motor from it, and I made some good power. I'm not sure what power I'm actually making, but the car weighs 3400lbs, and I was on a 20cm T3 HX35 at 25psi, turning it 8000, when I made my timeslip numbers. I used to run about 13:1 AFR's too. My 255hp is really old and on stock wiring too.
With your 950's I see no reason you shouldn't be able to make 500whp on E85 with them with a n/t regulator and a good rewired 255hp. Might have to do an inline as the boost gets up there, the line pressure will get above the crack pressure on the 255.
Once again its not so much as the injectors sticking open, its that they don't have enough time for the magnetic field to collapse and the pintle to close, before its time to open. There is no "sticking" they just don't react fast enough. Playing with the circuitry in the ecu could help the magnetic field collapse faster possibly reducing deadtimes.
Anyway, you'll see it in a graph of flow vs dc for a given frequency, the flow will linearly increase with increases of dc, until about 90-95% and then flat line. Obviously the higher the frequency the earlier the flat line occurs. I remember seeing bosch 1600's curve, and on a 1000z wave ( thats like turning your engine 120000rpm), they flat lined at right around 90%.
Right now I'm on my HY35 at 22psi, and it holds its afr flat as hell all the way to 8500. I'm running a 2g maf, and I get to 96% idc's, and my afr's according to my lc1 are dead flat at 12.5 to 1 right now. They don't make any funny changes as the injectors cross 80%, 90% or even 95%. I have never noticed a rich spike, but maybe the 1g ecu logs too slowly to see it.
Also, stop paying so much attention to the AFR's. Tune it to run the most trap speed, without knocking and having decent timing, then give it just a little more fuel for a cushion. Learn to read plugs, and notice what the car does. Hell, up until just this summer all I had was a stock narrow band. I tuned my car on sd with it and ran really good. Who cares what the AFR's are if its making power and not self destructing.
for a while before I got my 750's I used a nitrous solenoid, and an old school fuel nozzle to inject fuel into the uicp under boost to keep from going lean when I installed the HX35. Landspeed - Your right I didn't mention the pump issue, but I don't think its that big of an issue. On a 14b, your not going to get much of 22psi, so even with a n/t fpr or even stupid high bfp like I used to run, you won't hit the crack pressure. I just started to hit it with my new injector setup because the pressure drop across the oem filter is too great when your using some fuel.
I now run a dual fuel rail setup with 450's and 750's I put a relay in and it switches out the resistor pack for the second set of injectors when the boost hits. I have the ecu code switch the global comp too. I leave the deadtimes alone, but big for the primary 750's I run n/t regulators, and will be running 2 255hp's inline.
I should also say I never recommended running injectors on the super ragged edge 95% on up. I stated that I do it and do not have problems. If your consistently in the mid 90s, its time to look for something bigger, but buying bigger injectors because you had 81% idc's is just plain retarded.
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