At what size injectors is a BAP required? Looking at going FI soon, and not sure if the 47 lb need a BAP. How about the ID1000s, do they require a BAP also, or can they be run on the stock pump? My goal is ~600 rwhp; I know a BAP is recommended, but is it actually required for the 47s/1000s?
Injectors
- Thread starter achamb7
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Its not required for any size injectors. It is an alternative to buying an aftermarket fuel pump/set up. All it does is increase the voltage to a fuel pump(think of it as an amplifier for your pump) to make it supply more fuel to the injectors.
It's actually a combination of both. It's not one or the other. First off, there is a big difference between the 47's and 1000's
If you get the 1000's it will help offset that fact that your fuel pressure is dropping and might help you get away with not having a bap.
A larger injector will deliver more fuel than a smaller injector at the same pressure at a given pulsewidth.(obviously).
Buy the ID's, your tuner will thank you for it and it will cause you less grief possibly. I've spent a lot of time and money retuning and buying new injectors because I had shitty FRPP 80's that idled like shit. And you would never know it unless you looked at datalogs. And it wasn't for a lack of tuning or the know how but because of poor low pulsewidth stability that can't be tuned out. SOme understand this and some don't and think anything can be tuned. They think because their large injectors idle ok they think they are good but the logs would show otherwise.
I put an electric fuel pressure gauge and ran the signal wire into live link and set up the equation, it's a .5v-4.5 v sensor.
The car has a 55psi in tank pressure regulator. I have my Bap set at 70. At 8 psi the fuel pressure starts to fall at about 5000 rpm and by 7000rpm my pressure is about 46 psi. There are tables in the tune to compensate for fuel pressure drop across the injector but most don't know what it is because the new mustangs don't have a fuel rail pressure sensor like the old stangs did.
So you kinda need both...Consistent and better fuel pressure will come from the BAP and adequate fuel volume without having to high of an injector duty cycle will come from larger injectors...In theory I guess you could have 100psi fuel pressure and a small injector because it wouldn't need a high duty cycle because the pressure is there.
But even with large injectos you still need good pressure...I don't think tuners are comfortable with fuel pressure at 18psi when running boost, it becomes unreliable for fuel delivery.
I'm not a tuner.....Maybe the tuners can tell me how I did.
If you get the 1000's it will help offset that fact that your fuel pressure is dropping and might help you get away with not having a bap.
A larger injector will deliver more fuel than a smaller injector at the same pressure at a given pulsewidth.(obviously).
Buy the ID's, your tuner will thank you for it and it will cause you less grief possibly. I've spent a lot of time and money retuning and buying new injectors because I had shitty FRPP 80's that idled like shit. And you would never know it unless you looked at datalogs. And it wasn't for a lack of tuning or the know how but because of poor low pulsewidth stability that can't be tuned out. SOme understand this and some don't and think anything can be tuned. They think because their large injectors idle ok they think they are good but the logs would show otherwise.
I put an electric fuel pressure gauge and ran the signal wire into live link and set up the equation, it's a .5v-4.5 v sensor.
The car has a 55psi in tank pressure regulator. I have my Bap set at 70. At 8 psi the fuel pressure starts to fall at about 5000 rpm and by 7000rpm my pressure is about 46 psi. There are tables in the tune to compensate for fuel pressure drop across the injector but most don't know what it is because the new mustangs don't have a fuel rail pressure sensor like the old stangs did.
So you kinda need both...Consistent and better fuel pressure will come from the BAP and adequate fuel volume without having to high of an injector duty cycle will come from larger injectors...In theory I guess you could have 100psi fuel pressure and a small injector because it wouldn't need a high duty cycle because the pressure is there.
But even with large injectos you still need good pressure...I don't think tuners are comfortable with fuel pressure at 18psi when running boost, it becomes unreliable for fuel delivery.
I'm not a tuner.....Maybe the tuners can tell me how I did.
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Some people love the BAP and some hate on it. Good and bad possibly
Kenne bell will tell you that it acts as a voltage regulator and smooths voltage spikes which will make your fuel pump live longer and lower the duty cycle of the pump because the voltage is higher
Some say spend the money on a real fuel system and go with dual or triple pumps. But if one pump goes out you may not know at part throttle and low load cruising but then you step on it and the fuel isn't there and you lean out and something bad happens....With a BAP on one pump if the pump goes out you will know something is wrong before you step on it.
Some people really hate the BAP. For me it's hard to believe some of the big companies would jeopardize their reputation if it wasn't a tried and true method
Kenne bell will tell you that it acts as a voltage regulator and smooths voltage spikes which will make your fuel pump live longer and lower the duty cycle of the pump because the voltage is higher
Some say spend the money on a real fuel system and go with dual or triple pumps. But if one pump goes out you may not know at part throttle and low load cruising but then you step on it and the fuel isn't there and you lean out and something bad happens....With a BAP on one pump if the pump goes out you will know something is wrong before you step on it.
Some people really hate the BAP. For me it's hard to believe some of the big companies would jeopardize their reputation if it wasn't a tried and true method
654/600 @ 15# on id725s with no BAP. Justin said I'm fine. If you go with one, I'd get VMPs plug n play one. I believe it's $299.
Awesome, thanks for the responses. Zach, I forgot you didn't have one!
good post
scary..... lol
if you have the money, in general, i try to put guys onto at least a stage 1 fuel system, the difference between that and a good bap is not even 1k. very good insurance and gives you room to grow
So far so good Terry! Justin tuned mine at MIR last May and has done numerous tune revisions for me and he says I'm getting enough fuel. I was one of those who had the new fuel pump (2 actually) due to the check valve issues in early models. So I wonder if the revised pump is any different. Probably not but I wonder. Once I build the motor, I plan to up the boost so I will have to explore my fuel options at that point!
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