gmagnus7

Specialist
Dec 3, 2018
71
Question: Does a normal walbro (if installed with a Hobbs for example) run at 12v ? Does this allow us to bump it up to 13.5v and essentially add another 10gal/hr at our given fuel pressures? Like if someone was at the upper limit of their setup with a 450 for example.
 

matreyia

Captain
Apr 19, 2017
1,105
Question: Does a normal walbro (if installed with a Hobbs for example) run at 12v ? Does this allow us to bump it up to 13.5v and essentially add another 10gal/hr at our given fuel pressures? Like if someone was at the upper limit of their setup with a 450 for example.
A single 450 Walbro would not require a Hobbs switch. It would run directly off the stock controller...which will intermittently go over peak limit, ever so slightly. I had a single Walbro on the stock controller and it ran fine as long as my tune did not cause the fuel demand to exceed limit... each time it exceeded limit, there would be a slight, "wao wao wao" oscillation when accelerating under certain conditions...like going 60mph then half slam pedal to pass someone.

After installing this upgraded unit...there has never once been any oscillation of any kind under any conditions or loads. Just works flawlessly and STRONG.
 
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gmagnus7

Specialist
Dec 3, 2018
71
A single 450 Walbro would not require a Hobbs switch. It would run directly off the stock controller...which will intermittently go over peak limit, ever so slightly. I had a single Walbro on the stock controller and it ran fine as long as my tune did not cause the fuel demand to exceed limit... each time it exceeded limit, there would be a slight, "wao wao wao" oscillation when accelerating under certain conditions...like going 60mph then half slam pedal to pass someone.

After installing this upgraded unit...there has never once been any oscillation of any kind under any conditions or loads. Just works flawlessly and STRONG.
Yes I know, I meant if you have a second pump. I guess if you hooked up it to the stock EKP I assume it would be 12V then.
 

matreyia

Captain
Apr 19, 2017
1,105
Yes I know, I meant if you have a second pump. I guess if you hooked up it to the stock EKP I assume it would be 12V then.
If you have a second pump, then that is considered a stage 3 set up (two pumps) stage 4 set up is 3 pumps. Stage 2 set up is just one upgraded 450 Walbro pump. I have never heard of anyone adding a walbro pump to their stock pump. If you have more than on pump, you necessarily need the upgraded controller for sure.
 

gmagnus7

Specialist
Dec 3, 2018
71
If you have a second pump, then that is considered a stage 3 set up (two pumps) stage 4 set up is 3 pumps. Stage 2 set up is just one upgraded 450 Walbro pump. I have never heard of anyone adding a walbro pump to their stock pump. If you have more than on pump, you necessarily need the upgraded controller for sure.
The fuel it FI-650hp kit uses a stock pump as the first, then a walbro 450 as the second pump and is rated to 650 hp on E85. I guess I'm wondering if this can push the voltages higher since it's not directly off the stock EKP, and get more out of the pumps.
 

matreyia

Captain
Apr 19, 2017
1,105
The fuel it FI-650hp kit uses a stock pump as the first, then a walbro 450 as the second pump and is rated to 650 hp on E85. I guess I'm wondering if this can push the voltages higher since it's not directly off the stock EKP, and get more out of the pumps.
This is created to control voltage. So yes, it is exactly what you need.
 
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EOSpeed

Specialist
Platinum Vendor
Nov 7, 2016
94
Chicago, IL
Question: Does a normal walbro (if installed with a Hobbs for example) run at 12v ? Does this allow us to bump it up to 13.5v and essentially add another 10gal/hr at our given fuel pressures? Like if someone was at the upper limit of their setup with a 450 for example.
The BPM4 does not output a higher voltage then available in your system. That being said y
The fuel it FI-650hp kit uses a stock pump as the first, then a walbro 450 as the second pump and is rated to 650 hp on E85. I guess I'm wondering if this can push the voltages higher since it's not directly off the stock EKP, and get more out of the pumps.

The unit is made to control your pumps from the DME, and give you flexibility on how much fuel you get and when.(the slope changes that you can make to respond for the duty cycle the DME is asking for) The voltage in is the voltage out on the unit. The BPM4 is not a voltage increasing unit. It is a pump control unit.
 

rac

Specialist
Nov 14, 2016
98
Australia
Your voltage fluctuates depending on what's going on with other loads on the electrical system and the charge voltage. It's less than 12 cranking and should probably be more than 13.5 when running. The flow charts give examples of flow rates at 13.5v because a lot of vehicles will be supplying around that type of voltage when running. The controllers, this one and the dme control what proportion of that voltage is getting to the pump by switching off and on the voltage supply extremely rapidly but ultimately the system supply voltage is what it is.
 

scrllock

Specialist
Dec 17, 2018
74
  1. Get Oem connector
  2. Get Copper top hat screws
  3. Profit
Has anyone actually done this with a stage 3 yet? Found some bronze screws that fit but debating just going stage 2 until I get a billet tophat. I know it "should" work but looking for some reassurance.
 

doublespaces

Administrator
Oct 18, 2016
7,334
AZ
Has anyone actually done this with a stage 3 yet? Found some bronze screws that fit but debating just going stage 2 until I get a billet tophat. I know it "should" work but looking for some reassurance.
I still haven't paid for mine yet so I can't give too much insight. Hopefully will have it this month or next.
 

Jeffman

Captain
Jan 7, 2017
1,073
I’m almost as bad. I bought it 3-4 weeks ago but haven’t installed it yet. It’ll be at least another 2 weeks before I can work on the car again. :/
 
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buster84

Corporal
Mar 24, 2018
231
Wait do people actually get throttle fluctuations because of hobb switches? How does that work? I though just the LPFP fluctuates in logs? I just received my fuel it 650 package with the hobbs switch so now I'm curious. Since my ekp stays only with the stock fuel pump it shouldnt give codes or anything.
No they get throttle issues becuase the fuel has no where to go once it's in the rails. This is where the ekg module helps by only sending the exact amount of fuel needed for those conditions.

If you dont want to buy an ekg like most (expensive) and you have a stage 3 setup, upgrade your fuel lines and get a FPR with a return. I have the full fuelit fuel system that on my car with a stage 3 (dual walbros) setup with my PI and FPR and my fuel pressure is stable, without any throttle fluctuations, flutterong or issues at all and I also use a hobs switch to turn on my other pump.

It's more about what direction you plan to go. If you keep the stock system go EKG. If you redo all your lines to -6an then it's easy to add an e85 sensor, FPR and a return line at the same time.
 
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