csun213

Hi guys, just doing some home work before getting the LS2 1593 Edlebrock E-force supercharger.

I plan on installing the KB boost a pump with Racetronix Harness along with 3.50 in pulley instead of the 3.875 pulley.

I know that a lot of guys had no problem with KB BAP with Vortech, ECS, etc and set the BAP to come on at 4 psi or so however since the PD type supercharger would come on at lower RPM, I would probably be getting into boost without giving it a lot of gas and therefore would have the BAP turn on most of the time which would be hard on the stock fuel pump.

My question is that since I will probably be about 6-7 psi max with the 3.50 in pulley, if I set the BAP to come on at 4 psi, do you guys think it would hard on the stock pump?

Since I have an A6 and don't want to replace the stock pump since it would be expensive, do you guys think I would be OK using the BAP and setting it at 4 psi or would you just recommend forgetting about the BAP and just install the 3.875 in pulley that comes with the 1593 kit and just live with less HP? Thanks

wallyj

I have just that setup, 3.50" pulley, A6, and BAP w/ Racetronix harness. No problems so far. I'm using the hobbs switch that came with the BAP to activate it. Don't recall if it is 3 or 4 lbs.

If I break the trans or diff I'll replace the pump while I have it apart.

I've only got maybe 2000 miles on the setup, and all is well. Fuel pressure does not sag and my AFR looks good all the way up the RPM/Boost curve.

Motorhead-47

My two cents worth…

How do you use your car? Street car only or ????
Run flat tires or something stickier? If you are sticking with run flats you won’t want more power than the base kit
Are you doing the work yourself or paying someone to do the install?

-Install the 1593 kit as-built. Drive it for a month or two and then see if you “need more”
-Decision point…the 3.5” pulley is going to give you about 50 flywheel horsepower…about 40-ish at the wheels…not a lot
-Why not skip the 3.5” and go to the 3.25”? Add the BAP and Racetronix harness and a set of 65lb FAST injectors

62Jeff

Howdy,
As a point of reference, I have the 1593 kit on my otherwise bone stock 2007 6 speed. I also have the 3.5" pulley. I still run the stock fuel pump and NO BAP. The tuning showed the BAP was not necessary for my car.

You can see from my dyno chart that I'm getting anywhere from 3.5 to 8 PSI of boost.




Ken (Motorhead) makes a good point too - I still have the stock runflats on my car and drive the car back and forth to work for the most part. I'm thinking of going back to the 3.875 pulley in order to make 1st and 2nd gear a little more useful.

Jeff

j_digi454

I just talked to ECS about an LS2 install on my 07 A6 a couple of days ago. They actually do an install using a BAP (I don't know which) and the 3.5" pulley with the 1593 kit as an alternative to using the 1594 kit that uses a ZO6 fuel pump. These guys are well recognized experts in FI and if they're using this method, I'd have to say it's a safe way to go that does save some substantial money.

I'm making the same decision for my Spring install whether to just go with the full blown 1594 kit, use the BAP with the 1593 kit or just do a 1593 kit install and maybe later add the 3.5" pulley and BAP if necessary.

Note that I don't have any plans to race or track my Vette and am looking more to maintaining the Vette's reliability but would like to get the maximum hp under those conditions at the same time.

Motorhead-47

I’m still on stock run flats with a 3.25” pulley and 65lb injectors (Z06 fuel pump). There is no way I can use all of the horsepower and torque as-is. I’m not at all interested in going to “R” compound tires (short wear life, poor wet weather performance and crappy handling) so until I can cough up the $8k or so it will take me to go widebody, I just chuckle when the car breaks the tires loose in 3rd. I manage traction the old fashioned way…with my right foot.

ghostrunner

Very good post

csun213

I will be using it for street only, maybe track once a year.

Running PS2

Friend doing the install.

I had a Vortech with a 4.50 in pulley at 6 psi, putting down 521 rwhp and would hope that by going to a 3.50 pulley, I would be around the same HP.

Not looking for more than 500-520 rwhp because I can't put the power to the ground.

I am just worried about the over stressing the stock fuel pump because with the Vortech, the boost doesn't come on until 3500 rpm or so, the BAP will not come on much. However with the E-Force, I was told that the boost will come on about 2K rpm therefore will put stress on the stock fuel pump even if I am not really getting into it.

Motorhead-47

FWIW there is at least one guy on this forum who says you can do the fuel pump swap on an A6 without dropping the rear cradle...says he's done it several times.

csun213

Thanks for the quick response. Since I don't plan on going much over 500rwhp, I am hoping that the BAP would be enough. I just don't want to burn up my stock fuel pump and then have to replace it.

Just trying to gauge how much stress a BAP would have on my stock fuel pump on an E-Force in everyday driving.

Motorhead-47

Two thoughts to extending your pump’s life
-The Kenne Bell Boost-A-Pump is not an all or nothing device. You might consider dialing in something less than 100% of the voltage increase
-Your fuel pump’s life is at least somewhat dependent on cooling from the fuel in the tank/s. More fuel equal more cool…try to keep the tank far away from ¼ full

csun213

Thanks, that is great information. I am planning on having the BAP come on at 4 psi to prevent it from coming on all the time.

I will remember to keep my fuel at half of better just to be safe.

Thanks again for the information.

j_digi454

Good advice.

Motorhead-47

I don't think you are getting my point. The pressure switch only opens and closes the circuit that activates the BAP. There is also a variable controller that comes with the KB BAP that allows you to adjust the voltage. I'm suggesting that you might want to set the variable voltage adjustment to something less than 100%.

csun213

OK, so you are saying that I should have the BAP set so it would never be at 100%. Would you mind telling me where I should have it set at like 90% or so? I don't know much about BAP. Thanks

Motorhead-47

You fuel pump normally operates at about 13 volts. The BAP, when powered up by the pressure switch circuit closing, amplifies the voltage to as much as about 18 volts which in turn spins the pump faster. This allows the pump to move more fuel which in turns allows you to maintain the 58psi under higher volume demand. A lot of guys just cut the adjustable switch off and wire the the two leads together so you get the full voltage all of the time when the pressure switch closes. I'm suggesting that you might want to try a 50% setting, watch your fuel pressure and if eveything is ok, leave it alone at 50%. This puts less wear and tear on the stock C6 pump.

csun213

Thanks for the info. Can I get my tuner to monitor this when he is tuning my car? I figure I would get him to start at 50% to see if it is enough, if not then he can increase it by 10% each time and see the fuel flow. I figure if I am paying him to tune my car, he might as well adjust my BAP at the same time. What do you think of this idea? I am just worried that I won't be able to watch my fuel pressure gauge and drive at the same time. I can monitor it after it has been adjusted but would feel better if my tuner adjust it first.

Motorhead-47

Absolutely he can and should do that. Once he has matched your fuel pressure to his tune be sure and make note of where that adjustment is set at and don't ever screw with it again....unless he's retuning your car.

csun213

Thanks, I will do that.

tlove32

Hey Charlie - glad to see you're getting something done to the C6. I was afraid you left us for the Ferrari crowd