[carolina03svt]

I have my cobra set up using a triple hat with only 2 pumps currently. I ordered another pump since i will be going e-85 sometime in the near future. Can i add the new pump without tuning the car again on the current setup? If not i will just hold onto it untill im ready for e-85 tune to go in. Also do i need to change the Driver module with 3 pumps instead of 2, or is the original ok. Thanks

 

[keith89]

I have my cobra set up using a triple hat with only 2 pumps currently. I ordered another pump since i will be going e-85 sometime in the near future. Can i add the new pump without tuning the car again on the current setup? If not i will just hold onto it untill im ready for e-85 tune to go in. Also do i need to change the Driver module with 3 pumps instead of 2, or is the original ok. Thanks

I have a similar question. I have dual external walbros and am thinking of replacing them both with a single magnafuel. Wondering if I would need a retune.
My thought is that as long as the return line isn't restrictive with the extra flow of adding that 3rd pump, the fuel pressure regulator should still hold the same pressure at the rails so you would not need a retune if that is the only change. Is this incorrect? I'm hoping to be able to replace my pump setup and relocate it to a better position(closer to the sump outlet) without having to get a retune.

 

[carolina03svt]

This is what i was thinking, that no matter how many/strong the pumps are that the regulator should keep the pressure the same, and the fuel injectors will only pump what the tune tells it? But i wanted to ask first.

 

[keith89]

This is what i was thinking, that no matter how many/strong the pumps are that the regulator should keep the pressure the same, and the fuel injectors will only pump what the tune tells it? But i wanted to ask first.

Agreed. Lets see if anyone else can confirm this. especially a tuner.

 

[RussZTT]

If you're going to run E-85 most likely you will gain more HP. Between that, playing with fuel pressure, timing and checking inj duty cycle I would check the tune.

 

[keith89]

If you're going to run E-85 most likely you will gain more HP. Between that, playing with fuel pressure, timing and checking inj duty cycle I would check the tune.

he's not going e85 yet. He's wondering if adding that 3rd fuel pump to his current setup with no other changes would require a retune.

 

[carolina03svt]

he's not going e85 yet. He's wondering if adding that 3rd fuel pump to his current setup with no other changes would require a retune.

This, I plan to go e-85 in the near future but i already have the 3rd pump and will put it in if i dont need to re-tune my current setup just from adding the pump. If i do have to re-tune then i just will wait.

 

[4vMn12]

a retune is not required, but it is a good idea to have a wideband hooked up, in addtion to an FP gauge to verify during some WOT runs that all is well for a before/after assessment. i.e. in case anything that is changed had a negative affect.

 

[keith89]

a retune is not required, but it is a good idea to have a wideband hooked up, in addtion to an FP gauge to verify during some WOT runs that all is well for a before/after assessment. i.e. in case anything that is changed had a negative affect.

makes sense. Thanks