What is your opinion? If I want to make sure my fuel pressure stays up, should I install a Racetronix harness, a BAP, or both? I own both, but don't know if I have to install the BAP. Mine is the MSD BAP.

Will the Racetronix harness suffice?

 

I just ordered the same harness and will put that on first to see if it ups the voltage any (they say it will about 10-15% more psi). im sure ill have to do the BAP also though.

 

Thanks. I am going to install new fuel rails next week with a man ual pressure gage and a pressure transmitter, to monitor from inside. So, After I do that, and learn the pressure curve, I will install the Racetronix harness, and test again. I have 60# injectors...

What kind of pressure should I maintain as a normal, and what is the minumum pressure that should be monitored for?

 

i had a problem with pressure at 5500rpm and above.....
my tuner/installer (Fran - Race Proven Motorsports) had already installed the LPE Fuel Pump for me. He then added a KB BAP and the RaceTronix Harness.... i am now anywhere between 61-65 psi all of the time, no drop off in Fuel Pressure...

 

For 2 years I had LPE intank pump, Racetronix harness, KB BAP and 60lb injectors. I had enough fuel for 700rwhp without any issues on stock bottom end. I recently went forged and added A&A fuel system (boost referenced) on top of all the above. I wanted a bullet proof fuel system for 900 plus rwhp

 

Right now and apparently when my car was tuned I had low pressure with 60 lb injectors:
60 lbs rock steady at idle and cruising/light throttle
52-58 going through the gears "normal" driving shifting at 3500-5500 out of boost

Once in boost the pressure begins dropping FAST
50-40 WOT from 2-4 psi
40-30 WOT from 4-9 psi

AFR's are fine so I guess even having low pressure can be tuned for. I'm at 60 psi idle and cruising and drops to 30 psi WOT at 8-9 psi and 550 rwhp and have been for the past 3500 hard driven miles. Kinda baffling it can work like that and I don't like it so im gonna get the pressure where most peoples are and re-tune.

 

That's a pretty big drop. Do you have a wideband to log the AFR? I use a stock pump, KB BAP, and Racetronix hot wire harness. If it helps any, mine varies alot by temperature and I thought the pressure drop was normal. In my case the tuner compensates and the AFR is steady. Here's what I see in my last races at the track:

Early morning run, first run of the day about 10am in cool air: started the run at 61psi, finish about 51, ambient temp 65 degrees F.

Afternoon run, after a few passes and temps getting hot outside: started the run at 52psi, finish about 46, ambient temp 79 degrees F.

 

Hey Chris.
You're going fairly fast and making good power.Why don't you have an after market pump?

 

Wideband is next on the list.

 

ECS Fuel System

 

Simply because I haven't needed one.

 

Doing my BAP this weekend. I loose pressure approve 5500

 

My MSD boost a pump caught fire after 1-1/2 years of use. So I will never put any boost a pump back on the car. Dont get me wrong it helped with fuel delivery but the risk for me now far out weights the rewards. Dual intank going in.

 

Had MSD BAP,Racetronix harness,and Racetronix injectors @ 600rwhp without any problems. Now have Racetronixs/Lonnie performance double pumper and 95# with Racetronixs AEM injector driver with harness @ 950+ rwhp.

 

I would say if your concern is enough fuel and pressure then do the HARNESS with a BAP!

The harness will up the voltage but under BOOST the BAP will make sure it gets the extra voltage while sustaining BOOST!

IMHO! Only

Thanks,Matt

 

So did this system start to show its weaknesses at 700 rwhp Nouman, or did you stop because you didnt want to push the stock block anymore?

Im only asking because this is what I have, and Im getting tired of the Nitrous stuff and was thinking about going FI.

 

It did NOT show any weakness at 700rwhp. I started showing weakness because of the stock block Now with the forged motor, and all the above (without the A&A fuel system) I was running out of fuel in mid 700s. After adding A&A fuel system (boost referenced) along with LPE Intank pump, KB BAP and Racetronix harness, I have enough fuel for 1000+ rwhp.

 

Gotcha....thanks brotha

 

I have modded the C5 fuel system in many ways and in gradual steps, and finally ended up also with the A&A style set-up. It's such an easy route to take. Even though mine is home brewed, and made right about the time Andy came out with his, it has cured all of my problems. It is activated with an RPM switch and comes on only when the N2O system is activated and at 3500rpm. I carry this kit and give my forum buddies a nice % discount off of list pricing. We can set the kit up for spray easy enough and currently comes plug and play ready for the boost guys. Those that use this kit with spray just tie it into the nitrous activation switch so the pump comes on when ever your ready to spray.

So my system currently has the Racetronics pump/hot wire, return and reg at the rails, then a complete "Parallel" Andy style aux fuel system. My Racetronics system started running out of fuel around the 550/600hp area and thus the reason for going Parallel system. We absolutely do not want pressure drop at high demand when spraying, as we all know what lean and spraying can do.

The one thing that can be done to stop the pressure drop in high load conditions is to get the regulator/return at the rails (which Andy's kit does). Some guys fudge the tune to compensate, however the correct fix is getting the reg and return at the rails and having adequate supply.

Here's a picture of one of the A&A kits I carry, and couple more are being added. Watch for the new billet dual pump hanger/kits from RSI to be added in a few days. Also a full line of stand alone fuel systems are coming. The link is a write up on our fuel systems and modding them, and it should offer some good insight into what you may want to do (Andy's kit has a great how-to step by step install manual).

Csdunaway, the write up covers my early mods and limits and why and when I upgraded from there. So you may be able to map out your needs and contains some math for sizing your system. If you have any questions I am always available. The parts you have may be enough, though watching your fuel pressure and a/f ratio will be your best indicators.
Fuel System Up-Grading

 

That can't be true, tell us you were kidding, lol?
Robert