Stock w/ BAP vs Walbro

[fullboogie]

You misunderstand the meaning of my post. Most of us are aware of mass air flow, brake specific fuel consumption, injector duty cycle, etc. To the extent we are talking about these concepts, yes, the math can provide you with an answer.

What this thread appears to be about, in my opinion, is that the masses are looking for rules of thumb that give a safe margin for FP duty cycle, injector duty cycle, and a/f readings. For example - "you're safe with the bone stock fuel system up to 550 rwhp"; "you should invest in a BAP between 550 and 650 rwhp"; and "anything above 650 you must have a BAP and at least 72lb injectors."

I know there are 50 ways to skin a cat, but that's not what I'm getting at. What people are hearing is that Tuner #1 will say "oh, you're fine with just a BAP up to 700 rwhp" and the next Tuner will say "I hate BAP's, so you need to upgrade to 72's and a pair of 300lph pumps". It can be confusing to everyone - that's all.

 

[MRL Performance]

Gotcha.

Well, then again, that is where the "depends" comes in lol. If a certain tuner doesn't like BAP's, then that is his call. If you have a tuner you trust, then listen to their recommendations. I see where it can be confusing, but the tuner is the lifeline, if you can't trust him then you are screwed from the get go. I work with Lund a lot, he knows what I do, and I know what he does, so there are never any surprises when it comes to the fuel system.

I listed above what works for me and my builds. For instance.....(assuming Dynojet numbers here as well, pump or race gas, and again, just how I work my builds)
Stock-600rwhp, the 100% stock fuel system is fine.
600rw-650(675 maybe), stock pumps, no BAP, 72lb injectors (or 80's but they are crap)
675rw-800rw stock pumps w/BAP, 72lb injectors for the bottom half, ID1000 for the upper half ie: above 750rw.
Anything projected to be above 800rwhp will get a full return setup designed accordingly (although I have run close to 900rwhp on the stock returnless setup).

Some tuners will run the stock injectors up to 650rw with a BAP. I don't like to, so this is one of those cases where it depends. Injector technology has also come a long way. Not so long ago, sizing the injector was important because "big" injectors did not work so well at low PW and drivability suffered. Now you can run a 2000cc injector off a stock ECM and maintain stock like drivability.

And again, I have dozens of graphs and logs showing these various combinations. Also, back to the OP's original question, the FRPP hat setup only outflows the stock setup by like 3-5% (as Van also stated), so what is the point? There is nothing wrong with using a BAP, there are literally thousands of them installed and I'll bet the actual failure rate of a BAP is less than 1%.

 

[Illtaketwlight]

The BAP isn't the problem. Its running the shit out of stock fuel pumps that have a high failure rate with out a BAP. This is why you will have a very hard time finding someone that races for a living or as a hobby running a BAP. A good fuel system is one of the most important system on fast or race cars. Just google F150 fuel pump failure. Welcome to 20 pages of failures with out a BAP. Now take that same pump and run it on 18 volts for a 10/20 second pull and if only one gets just a little weak. It can and most likely will cost you an engine. The bad part is, it may test and work fine once it cools off. Until next time, Good Luck...

 

[MRL Performance]

The BAP isn't the problem. Its running the shit out of stock fuel pumps that have a high failure rate with out a BAP. This is why you will have a very hard time finding someone that races for a living or as a hobby running a BAP. A good fuel system is one of the most important system on fast or race cars. Just google F150 fuel pump failure. Welcome to 20 pages of failures with out a BAP. Now take that same pump and run it on 18 volts for a 10/20 second pull and if only one gets just a little weak. It can and most likely will cost you an engine. The bad part is, it may test and work fine once it cools off. Until next time, Good Luck...

Really.........
I'm not saying fuel pumps don't fail, but I think your a bit off on this one. I have yet to see a stock GT500 fuel pump setup fail, with or without a BAP. I also spent 13 years with Ford before I opened my own shop, and fuel pump failures accross the entire lineup were very few and far between. The ONLY reason we ever changed fuel pumps on the gas trucks was due to the EVAP system injesting dirt/dust at the canister and recirculating that back into the fuel tank.

I will agree that the fuel system is very very important, but it's silly to think the failure rate on aftermarket pumps is lower than stock pumps. In the end you could have tripple 400lph pumps, if one fails (and you rely on that pump), you are still in the same boat.

 

[Illtaketwlight]

Really, Ive replaced an alternator and the tank unit on my car and it only has 10K now. I worked as a tech for 30 years and Ive replaced 100's of in tank fuel pumps. Our gas buggy was one of our most used tools. The trucks i just lifted one side of the bed. So i didn't need to pull or drain the tank.

 

[jchristena]

So, lot of debate here. Is it worth it to stick the stock hat back in and add a dual BAP? Why not just add a BAP to the Walbro setup? Sorry, I come from the non F/I world where fuel system isn't nearly as important..

 

[Blackmax]

You misunderstand the meaning of my post. Most of us are aware of mass air flow, brake specific fuel consumption, injector duty cycle, etc. To the extent we are talking about these concepts, yes, the math can provide you with an answer.

What this thread appears to be about, in my opinion, is that the masses are looking for rules of thumb that give a safe margin for FP duty cycle, injector duty cycle, and a/f readings. For example - "you're safe with the bone stock fuel system up to 550 rwhp"; "you should invest in a BAP between 550 and 650 rwhp"; and "anything above 650 you must have a BAP and at least 72lb injectors."

I know there are 50 ways to skin a cat, but that's not what I'm getting at. What people are hearing is that Tuner #1 will say "oh, you're fine with just a BAP up to 700 rwhp" and the next Tuner will say "I hate BAP's, so you need to upgrade to 72's and a pair of 300lph pumps". It can be confusing to everyone - that's all.

Fullboogie pretty much hits it on the head here and thanks to MRL for responding to our posts. I have to add that not all dyno's read the same and of course different air comes into play. It really becomes an individual car and conditions type of thing. When I blew my motor I had 680hp with no BAP only 72 injectors and hadn't changed fuel filter in 2 years plus I hot lapped the car. My 7&8 cylinders burned up in a matter of maybe a sec during which time I could almost feel the fuel starvation.

 

[19COBRA93]

Why not just add a BAP to the Walbro setup?

I'd like to hear thoughts about this as well.

 

[MRL Performance]

Fullboogie pretty much hits it on the head here and thanks to MRL for responding to our posts. I have to add that not all dyno's read the same and of course different air comes into play. It really becomes an individual car and conditions type of thing. When I blew my motor I had 680hp with no BAP only 72 injectors and hadn't changed fuel filter in 2 years plus I hot lapped the car. My 7&8 cylinders burned up in a matter of maybe a sec during which time I could almost feel the fuel starvation.

Yeah, you were probably one of those cases where the pumps were good on the dyno, but just not enough wiggle room in the real world. This is where the 20% extra comes in handy (lack of fuel filter changes probably didn't help either). I really don't like to see much more than 85% FPDC on the dyno during a full 4th gear pull especially on a car that is going to get tracked hard.

No reason not to run a BAP with the Walbro setup. The initial question was is the Walbro setup by itself any better than the stock setup, and the answer is no. Either setup with a BAP will work just fine for 700rwhp, the pumps by themselves will not be enough.

 

[19COBRA93]

No reason not to run a BAP with the Walbro setup. The initial question was is the Walbro setup by itself any better than the stock setup, and the answer is no. Either setup with a BAP will work just fine for 700rwhp, the pumps by themselves will not be enough.

Why then are people pulling them out to install a BAP?

 

[jchristena]

Why then are people pulling them out to install a BAP?

That's what I was wondering. It seems like Walbro vs stock is a wash for all intents and purposes. So, assuming they aren't just trying to make labor, why do they want to swap the stockers back in and then add a BAP.

 

[Blackmax]

I spoke to Paul's Hi Performance last year trying to get pumps he supplied to Tasca and was told no longer available. From what I was told regardless of pumps the rest of the fuel system can only handle so much anyway. Line size, fuel rails etc.

 

[me32]

Imo I would not go with the 255 walbo pumps unless you do sometime of return setup. When I set mine up with a 17.5 bap on full time I had some issues..I ended up going to a return system an still run the dual fpdm an the fuel pressure sensor on the rail. No issues since.

 

[Illtaketwlight]

The biggest problem with the stock system is the very small fuel filter. If it plugs just little it would cause many issues. Also by design cylinders 7 and 8 can run lean. 7 and 8 are the end of the line for the returnless system. Its where all the dirt collects and with no real fuel flow for cooling the fuel rail. Injectors 7 and 8 do run the hottest and it can cause a vapor lock.

The stock system does have two regulators built into the tank unit. So if the filter plugs at all, like just a little. It'll start to bypass to much fuel through the regulators and will fill the passenger side of the saddle tank. Instead of siphoning fuel from the passenger side like its designed to do. Regulators in the tank are nothing more that an orifice tube and non adjustable. It would also cause back pressure on the pumps and they would most likely fail over time. All of this could happen if too big of pumps were installed also.

If the filter plugs you have no way of telling ether. Pressure would be fine and just the fuel flow would be affected. If your running more hp than around 700 you should start thinking about a return system. With 10AN lines and good quality filters, pumps, regulator. If not your running on the ragged edge.

Most dont want to hear this because they dont have or want to spend the money. Well its cheaper than being a member of the famous BMC. :lol1:

 

[fullboogie]

I asked this in another thread but didn't get an answer - is there a good quality replacement fuel filter we can use? A non-stock design that will fit in the factory spot?

 

[thgt500]

I asked this in another thread but didn't get an answer - is there a good quality replacement fuel filter we can use? A non-stock design that will fit in the factory spot?

Not that I could find. Went searching after you asked in the other thread.

 

[fullboogie]

Sure would be nice if Aeromotive, Magnafuel, or someone else would make a setup that adapts into the factory spot. I'm starting to hate that factory-style filer after reading these threads.

 

[racerat]

My performance shop is recommending I ditch the Walbros that came with my FR750 kit and reinstall the stockers with a dual BAP. I'd like to hear some opinions from you guys on this.

Much thanks.

The Walbro pumps are a rotary style pump and work fine in return style systems. I have no idea why Ford offers this.

The kit pumps are return style pumps and your tuner strongly prefers the stock returnless pumps and a BAP.

 

[fullboogie]

Looks like Steeda sells a replacement filter, but it looks like a Fram without the lettering:

Steeda High Flow Fuel Filters for Ford Mustang

 

[Illtaketwlight]

Replacing the filter can be done. Two adapters and cut the stock fuel line. You can make your own quick connect lines or modifi your stock lines with this tool. Ive made many lines with out any problem.

Aeromotive | 15118 - 3/8'' Female Quick Connect to ORB-08 Port

Great deal on Mastercool - 71475-SUPREME at ToolTopia.com