Vendors and Tuners please help!

[mercedestech]

My car: 2010 ls3, xs power 1 7/8 lt's, 3 inch exhaust, no cats, 60lb hr fic injectors, whipple with 4 inch pulley, Vengeance kaotic cam with full supporting mods (pushrods,springs,trunion upgrade, melling oil pump,katech chain,3 bolt conversion),rotofab intake,mgw shifter, kenne belle bap, prosport gauges,canton intercooler tank,Vengeance tune. All work performed by me.

My problem: car drives great, sounds great, but losing fuel pressure if I am cruising in first or second and stab the throttle to wot. The alarm on my prosport gauge is set to go off at 52psi, and just recently started going off while driving as mentioned above. I should note this combo was fine for the first 900 miles (drove it to the fest with no issues at all). A gradual roll into the throttle is fine, higway speeds at wot seem fine (11.0-12.0 afr @ 55 psi), just when i bring it to 3k rpm or so in 1st or second and hold it there for a minute then nail it to wot it sets the alarm off at 52psi. a/f when this happens is usually still falling from the 13-15 at cruise with little load and no boost to around 12.5-13. I lift as soon as the alarm goes off so the gauge really doesn't have time to stabalize and give me an accurate reading before I lift (this all happens in a second or two....stab the throttle, alarm goes off, try to lift and look at the a/f and fuel gauges while lifting, try not to wreck etc..etc..)

Vengeance says the BAP is good for 650rwhp and I should not be at that level with my combo. Although, I have not had it to the dyno because Mike at Vengeance has been dialing in my setup remotely. I figured once everything looked good in the logs, I would re dyno it. It did dyno at 415rwhp with the exhaust and intake mods prior to the cam and whipple.

Today I used a scan tool to verify the factory fuel pressure sensor matches my gauge..it does. backprobed the factory fuel pump control unit to check voltage input when all of this happens...17 volts. BAP seems to be doing its job and is installed correctly

This all leads me to beleive i'm running out of fuel, but why are so many others ok with this setup and a bap and i'm not? why did it take 900 miles for this to happen? is the 650 rwhp number Vengeance is giving me for safely running a bap accurate? What are the other shops recomendations to fix my issue?

Sory for the LONG post, and thanks in advance!

This thread is in no way meant to question Vengeance and their suggestions for parts on my build. Ron and Mike have been ABSOLUTELY FANTASTIC to work with in trying to figure this out, and I would and will buy from them again. I'm just looking for others insight.

[Whipped416]

DOnt short your build ... Fuel is one the the most important things!!! Get rid of the BAP and go to a dual pump setup and bigger injectors!!! For the time being stay off the gas until u get your fuel system corrected! That setup is for a stock motor wth a whipple once u add a cam and lt u need to look at dual pump setup and your injectors might still be fine, just need to check duty cycle.

[HufferSS]

I was just thinking about you today and wondering if you had sorted this out. Did you change anything between the time that it was working ok and now that it isn't working ok?

[mercedestech]

Nope didn't change a thing Bill. I may be driving it a little harder now than I did before since everything is broken in and I'm getting used to the new found power, but that's about it. I took it really easy when doing the first few logs/tunes with Mike and when going to the fest (had the cruise set at 75mph most of the way), and really just started driving it hard.

I just don't get why this setup works for most, and isn't for me. The last thing I want to do is hurt the engine because I spent $400 on a BAP instead of $1000 on a LPE setup...pretty sure that $600 wouldn't be much of a savings if I destroy the engine. Everything I have read and have been told said this BAP was good for 650rwhp....I shouldn't be anywhere near that. I just don't get it!

Did I mention Ron and Mike have been great at trying to help me with this? Just making sure!

[Oxtar41]

60lb injectors dont seem like enough injector for 650 rwhp. IMO a BAP and stock fuel pump is useless over 550 rwhp. I have the ZL1 pump and left my BAP hooked up with a set of id850's and im running 700 rwhp and my afr stays at 11.3 and just hits 11.5 at 6500 rpm. I really dont think you have enough fuel to run your set up.

I had 52lb injectors and a bap and was running out of fuel around 550 rwhp. This was supercharger only, I added a cam and more boost and had to up the fuel supply.

[mercedestech]

Originally Posted by Oxtar41

60lb injectors dont seem like enough injector for 650 rwhp. IMO a BAP and stock fuel pump is useless over 550 rwhp. I have the ZL1 pump and left my BAP hooked up with a set of id850's and im running 700 rwhp and my afr stays at 11.3 and just hits 11.5 at 6500 rpm. I really dont think you have enough fuel to run your set up.

I had 52lb injectors and a bap and was running out of fuel around 550 rwhp. This was supercharger only, I added a cam and more boost and had to up the fuel supply.

I guess that's the big question..how much power am I really making? Ron at Vengeance has this exact combo of parts running around in a few cars and thinks I should be in the 550rwhp-580rwhp range. It's a combo they know works, and we're really not sure why my car is having fueling issues. I kept the 4 inch pulley knowing full well my cam and LT's/no cats were going to have me at a lower boost level than a stock engine with a whipple. I did this to keep boost levels safe for my stock bottom end, and really did not expect this fueling issue especially given my boost level.

[Oxtar41]

With a cam you should be over 580 id assume. unless your boost is like 5lbs. Idk the specs on the cam but im sure its probably not much different then mine. I have the JRE rough idle blower cam and although i cant give specs out since its teds grind I will say its over a .600 lift on intake and exhaust. Its a bigger cam then most would expect.

[mercedestech]

From the logs I think Mike said I'm hitting 7.5 lbs. I decided to install an A/F and fuel pressure gauges instead of a boost gauge, so I don't know first hand what it's making. My Cam is a little variation of their stage 3 cam...pretty agressive. I've been told by some it's not a good blower cam, but it drives absolutely awesome with it and sounds better than most I've heard.(Thats a whole other thread...I like it, it drives good, and I'm not looking for a monster high hp dyno queen...just a quick street car)

[Oxtar41]

your over 580. My car with a e-force only made 540 rwhp on 7.5-8.0 lbs and your blower is bigger then mine. My car had stock exhaust and everything. That was just the blower only at 7.5-8.0 lbs. I personally think your fuel system is not enough. And I think many will agree.

[mercedestech]

Thanks for the help oxtar...I agree with you, now I just need to figure out which way to go. drop in a ZL1 pump and use my current BAP, LPE dual setup, ADM ZL1 pump and control unit with no BAP.....I got this wrong once appearantly, I don't want to get it wrong twice.

[Oxtar41]

IMO unless your going for high numbers, the ZL1 is cheap and with a bap it WILL support 700 rwhp i can tell you first hand. I already had the BAP installed so thats why i went with the ZL1. And its plug and play, I think most others are also. I did mine in the garage on my back, wasnt bad at all. Put a floor jack under the rear diff pull the sub frame bolts out and lower it down and pull the tank out. I think it took all of maybe an hour and a half. Hardest part was unhooking the parking brake lines.

[HufferSS]

Your car should be right around 580...trust me when I say that with the quantity of cars that Vengeance builds with FI they can accurately predict what a combination is going to make.

I had pretty much the same setup at 10psi putting out 630 to the wheel on pump gas so if you are 7.5psi then you should be around the 580 mark. IF you are going to replace your stock pump then I would drop in a simple ZL1 pump and keep the BAP for security. The LPE pump setup works awesome and is plug and play too though and would require no BAP, you could remove it and sell it for something.

[mercedestech]

Bill when you were at 630rwhp, did you just have the stock pump and BAP?

Oh and again, I don't doubt anything Ron has told me, and I'm sure the car will come in at the number he stated. That's why I can't figure out how the hell I'm running out of fuel. He was even nice enough to offer me a refund on the BAP so I could go another route for fuel, or ship me a ZL1 pump asap that I could use with the BAP. He really has been GREAT to work with. I just wish he wasn't 12 hours away so he could get a look at what is going on first hand.

If anyone has any other ideas on how to make what I already have work, or what else to check in my setup I'm all ears.

Being that there is 17 volts available under boost at the stock fuel pump control unit on pin 1 of the connector when the pressure drops to 52psi, I have to believe I have everything installed correctly, and it's doing what it should be. I even went so far as to verify my prosport gauges were reading accurately by reading the actual value from the ecm for fuel pressure when all of this happens...it is about 3psi lower than what my gauge shows, so I am in deed running out of fuel.

The kicker to all of this is initially the fuel pressure did not drop...it took 900 miles for this problem to happen. Right when Mike has 90% of the tune sorted out, we have to put the brakes on tuning because of this fuel issue.

[HufferSS]

Originally Posted by mercedestech

Bill when you were at 630rwhp, did you just have the stock pump and BAP?

Oh and again, I don't doubt anything Ron has told me, and I'm sure the car will come in at the number he stated. That's why I can't figure out how the hell I'm running out of fuel. He was even nice enough to offer me a refund on the BAP so I could go another route for fuel, or ship me a ZL1 pump asap that I could use with the BAP. He really has been GREAT to work with. I just wish he wasn't 12 hours away so he could get a look at what is going on first hand.

If anyone has any other ideas on how to make what I already have work, or what else to check in my setup I'm all ears.

Being that there is 17 volts available under boost at the stock fuel pump control unit on pin 1 of the connector when the pressure drops to 52psi, I have to believe I have everything installed correctly, and it's doing what it should be. I even went so far as to verify my prosport gauges were reading accurately by reading the actual value from the ecm for fuel pressure when all of this happens...it is about 3psi lower than what my gauge shows, so I am in deed running out of fuel.

The kicker to all of this is initially the fuel pressure did not drop...it took 900 miles for this problem to happen. Right when Mike has 90% of the tune sorted out, we have to put the brakes on tuning because of this fuel issue.

Ron doesn't post much on this board but he's an awesome guy to deal with. I had the LPE pumps in my car.....I knew I was planning on pushing my boost up into double digits so I wanted pumps that would handle it.

Little did I know that mild retardation would set in and I would end up where I am today. Sounds like maybe your stock pump is starting to give up...maybe it's a bad pump? It happens....I definitely would take the opportunity to upgrade though and not replace it with stock. The ZL1 pump and a BAP is good for a ton of power.