Supercharger install 9+lb boost! Full build

[94Eddie]

Its funny I thought the same and then reminded him
So I'm not sure what he is up to but whatever it is its definitely showing

I think he is trying to get to a safe tune and work out the bugs before the meth is introduced. It is one less parameter to be concerned with for now. This will be the base line to start from before adding another fuel source. Then he will add timing and adjust fuel to dial things in under boost with the meth included.

 

[Blown]

I don't get it. I tuned with the meth/water from the start, as soon as I added the smaller pulley. I felt it needed the cooling with 10lbs of boost. I already had my injectors dialed-in. I think he is trying to get your injectors dialed-in first and maybe some fine tuning with the MAF curve. I would stay out of high load and high boost till you get the meth running. It the cooling effect of the meth/water that will allow more timing, higher boost and therefore more power.

 

[donalds]

I installed the snow performance injection kit today I still have to wire up the tank float and light
I couldn't find a key power source that could handle a extra 15 amp load
So I used a key power source to power up a relay put it under the dash
30a relay and socket 20a fuse of course

 

[donalds]

This morning we did 2 meth runs passed a mustang at 90 lmao

 

[donalds]

im being told im running out of fuel pump

lasoda
Those do not look too bad early on in the run. However it goes quickly dead lean at the top of the run. I’d guess you are running out of fuel pump. If there is some way to monitor fuel pressure during a run from a gauge inside the car than do that. If you do not have a gauge, we have connected one to the rail and had the gauge peeking out the rear of the hood and taped it down so we could watch it during a run. The fuel pressure should be base pressure (you said it was 69) PLUS boost pressure. So if you run 10# of boost, the FP should get to 79# and stay there throughout the run. If it drops, then you are out of fuel pump. No way to fix this in the tune, it is a mechanical limitation. I would immediately get out of it if it drops and limit future runs to max at 4100 RPMs – after that it is dead lean.



I also enclosed a file that uses a ‘fuel adder’ starting at 4000 RPMs – if it does not help, you ARE out of FP.



There is hardly any timing in it as the IAT temp is 150ish, so the PCM is pulling timing to save the motor the IAT is not getting cooling from the meth, which means the engine is not either.

me

Should I put a bigger nozzle for the meth?
It has a number four on it. I also have a number 6.
I do have a fuel pressure gauge.
I am using walbro 255 fuel pump.


lasoda

Try the larger nozzle -can’t hurt. Watch FP at WOT like I said.

me


just did a run fuel pressure stays at 67 rock solid no matter the rpm
the fuel pressure regulator is in the tank
af said 12 . 3

lasoda

It should go UP as boost hits. Is there any way to boost reference the fuel pump? A vac line or something like that? As boost is in the intake, the injectors have to ‘fight’ the boost, so their output gets lower unless fuel pressure is increased.

But try the file we sent, maybe the fuel adder will keep it from going lean.

 

[94Eddie]

Are you still using stock fuel lines from the tank to the engine? Just a guess but maybe the headloss in the line is causing an issue with pressure. Look at the fuel pump curve and see how much flow volume you lose running at higher fuel pressure versus stock plus boost pressures. I think there is a bottleneck between the pump and injectors.

Also, I wouldn't rely on the meth injection to heavily supplement fuel delivery. If anything goes wrong with the water/alcohol system it could be catastrophic.

I used a very fine mist nozzle because running straight water doesn't require much volume to cool IAT. I can't remember the size of nozzle I ran.

 

[donalds]

67 is stock
Return less
Regular in the tank
Could I just use a bigger pump

 

[donalds]

Any pumps and pump lph do you suggest

 

[Blown]

I was able to run 10lbs with the stock fuel pump and lines, no problem. I had to upgrade the pump in my more recent 5.0 build.

Have you changed the fuel filter?

I wish I could see his tune. I still have my working Tweecer tune.

 

[donalds]

I changed the fuel filter today
It was fine
I'm running a walbro 255

 

[donalds]

It seems to go lean when she starts to lift her foot
But I don't know much about reading them
I thought the 255lph pump would be fine

 

[CDW6212R]

How old is the fuel pump, age and mileage? The 255lthr pump should be enough for a 4.0 and the 10psi boost level. I would ask John how his boosted SOHC was with milder boost, the pump he used. He's got 16-18psi now, but I doubt he has a huge pump versus the 255.

But the pressure I wonder how that's supposed to work without being raised with vacuum, I never thought of that. It's natural in a return system, the boost affects those FPR's.

You showed no loss of pressure, at 67psi, if you had I'd wonder if the pump hoses could have a crack in them. Those should be the same age as the pump.

 

[donalds]

How old is the fuel pump, age and mileage? The 255lthr pump should be enough for a 4.0 and the 10psi boost level. I would ask John how his boosted SOHC was with milder boost, the pump he used. He's got 16-18psi now, but I doubt he has a huge pump versus the 255.

But the pressure I wonder how that's supposed to work without being raised with vacuum, I never thought of that. It's natural in a return system, the boost affects those FPR's.

You showed no loss of pressure, at 67psi, if you had I'd wonder if the pump hoses could have a crack in them. Those should be the same age as the pump.

Pump is 2years old had new hoses

 

[CDW6212R]

See what John thinks, unless something in the fuel system is different and restrictive, I'd lean to what Lasota said, the pump. But I'd be inclined to think the pump is weak, not too small.

 

[donalds]

Its gonna suck to pay for a tune again just over a weak pump

I'm not even sure what pump to buy

 

[94Eddie]

67 is stock
Return less
Regular in the tank
Could I just use a bigger pump

I wouldn't just assume it is the pump. A properly operating Walbro 255 should be enough. Do you know the model number of the pump? Fuel pump volume goes down fast as fuel pressure rises. You might have a pump that is intended for lower fuel pressure demands. Knowing the model will let you look at the flow vs. pressure curve for the pump.

 

[donalds]

Walbro GSS342 Intank Fuel Pump 255LPH High Pressure (Universal)​

Sorry for the caps

 

[94Eddie]

This should be the chart for your pump. At about 77 psi (67+10) your pump is delivering about 43 -53 gph depending on voltage the pump sees. Can you or Lasota tell, or estimate, your the fuel demand in gph at near WOT? My gut is telling me if the pump is working properly then it should be enough. Is there any estimate on how much hp you are making?

 

[donalds]

Is there any estimate on how much hp you are making?

I have no idea

FAQs - ModdBox

What is the hp potential? Is a tune required? -Joe The hp potentials for an engine with stock internals are listed below (based on dynos performed at 400m elevation and tunes). Note that all drive-by-wire (electronic throttle models) require tuning at all boost levels. ~Est.Crank HP RWHP Torque...

modd.me

 

[CDW6212R]

Yes, give him the pump model and let him know it's two years old, plus the returnless detail(no FPR vacuum referenced).