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I am installing a 9 PSI Kenne Bell 2.1L on my stock engine 2003 GT. When I got the kit from KB, I found the literature that warned not to drop below quarter of a tank (they state this over and over) or risk cavitation and lean out. Reading the forums, I found the way around that is to install a sumpped tank from an 03/04 terminator Cobra. So I picked one up out of a 2003. Since this is the best time to replace the 15 year old pumps, I went ahead and picked up a set of 265LPH pumps.

So the KB kit came with a BAP for the lower flowing 2V pump so that it could keep up with the fuel demand and not lean out under boost. The new pumps that I bought will flow significantly more than the stock 2V.

Should I still install the BAP? Is there any reason not to?
 

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my combo made 458 at the wheels with one high pressure 255. That leads me to believe the bap would be overkill.
 

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I am installing a 9 PSI Kenne Bell 2.1L on my stock engine 2003 GT. When I got the kit from KB, I found the literature that warned not to drop below quarter of a tank (they state this over and over) or risk cavitation and lean out. Reading the forums, I found the way around that is to install a sumpped tank from an 03/04 terminator Cobra. So I picked one up out of a 2003. Since this is the best time to replace the 15 year old pumps, I went ahead and picked up a set of 265LPH pumps.

So the KB kit came with a BAP for the lower flowing 2V pump so that it could keep up with the fuel demand and not lean out under boost. The new pumps that I bought will flow significantly more than the stock 2V.

Should I still install the BAP? Is there any reason not to?

What were the numbers you came with when you did the required fuel calculation?

Pumps, lines, injectors have a limit to what they support
 

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Discussion Starter #4
What were the numbers you came with when you did the required fuel calculation?

Pumps, lines, injectors have a limit to what they support
I haven't calculated it and honestly I do not know how to calculate it. I would be very happy to learn how. I just ordered the kit from Kenne Bell and have what they supplied.

The pumps are 265LPH each (my understanding of the Cobra fuel system is that one pump is slave to the other so it is not 265+265)
The injectors are 36#
I have the intercooled, 9 PSI, 2.1L kit that is supposed to produce right about 400HP @ 5500 rpm.
Fuel supply system other than the pumps is stock
Intake is JLT CAI (through fender)
MAF is SCT BA-2400
Gearing is 3.73
 

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there are many fuel calculators out there, you should be able to find one without issue

you can try the eec analyzer free trial software

or you can do exactly what KB suggests as they designed it for your car

you have your tuning options taken care of?
 

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Discussion Starter #6
there are many fuel calculators out there, you should be able to find one without issue

you can try the eec analyzer free trial software

or you can do exactly what KB suggests as they designed it for your car

you have your tuning options taken care of?
Thanks. I'll check it out.

KB has not been very helpful. Once I found out that there was the 1/4 tank issue (which, by the way, is not printed or disclosed anywhere before you get the kit. Then it is all over the literature included with the kit), I contacted them with what I was planning on doing with the new tank and fuel pumps. This threw them. They typically just send you a chip that they burn.
1) they wouldn't modify for the fuel pumps
2) they wouldn't modify for the BA-2400 and JLT (stock intake only or buy their Big Air CAI, which by almost all accounts is no good due to the flexible hose and location to MAF)
3) when asked about using the BAP with the new fuel pumps, they would not commit (statements like, you SHOULD be ok. You MIGHT want to run the BAP. You COULD be OK with out it. You MIGHT not need it... never anything definitive even when pressed)
4) I ended up getting my base tune from JMS Automotive Products (via TPS Motorsports who I bought the KB system from). It was supposed to come from Don LaSota but they were shutdown 1/19 - 2/4.

I am sure that that had I kept the stock tank and stock intake the 2.1L would have done exactly what KB states. But for my peace of mind and for performance, I had to make these changes.
 

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KB has nothing but helpful with me.

but, your situation is different you are asking them things that are not proven to them.

I can understand why they are not going to give concrete answers, I wouldn't as well

its not right for you to ask them to commit to things that they do not endorse

they spend a lot of r and d on there own setups

by you saying that their big air is no good because of internet reviews, well what do you expect

like i said, do it on your own, or stick with what they sell and endorse

since you have decided to do it on your own, no point to ask them any further

regarding the tuning, you are doing it after this 'base tune'?
 

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I bet they were reluctant to say because, not all pumps are created equal. Fuel pumps have different lph ratings at different psi. Where your pumps may be rated at 265 lph at say 30 psi, at a higher psi, that rating may fall off the chart. Where-as a name brand pump with data flow charts available on google, may only drop to 250 lph.

also, I don't understand the slave pump Ford uses. Some cars, like a Lincoln ls, uses two pumps but, that is to pump from one side of the tank to the other. Your pumps are stacked in one assembly.
 

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Discussion Starter #10
For what it is worth, and if anyone is ever looking for the flow datasheet of the QFS-344FT-1033, here it is. I should have loads of headroom with the 2.1L @ 400HP.
 

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Discussion Starter #12
Thank you for pointing that out. Absolutely makes a difference. What I am not 100% sure of is the fuel pressure under boost. For the 2003 2V, am I correct that even under boost it will be regulated to just about 40psi? With the 36lb injectors, 9psi boost producing about 400rwhp, I should have plenty of fuel even if goes to about 45psi.

Sound right?
 

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tip pressure will be held at the recom press

usually 40psig

therefore if manifold pressure is 10psig, the fuel pressure must be 50psig to maintain 40psig tip pressure

therefore flow from the pump must determined by what your fuel pressure will be.
 
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