[steelheadrob]

Drsag, I am sitting right about where you were at, 11psi boost, E55 and seeing a low of 41psi on my lowside fuel pressure during a 1/4 mile run. KingLt1 has me thinking about adding a BAP.

I am curious what you were seeing in your Highside fuel pressure and pulse width at 43 psi and what if any improvements you saw in either of these after adding the BAP.

[KingLT1]

I was playing around with E mixtures today. I mixed 7 gallon of E85 with 3 gallons of E20(the pumps are side by side and E20 was only 2.55 a gal.) and ended up around E65. Injectors we're in the mid 5's, rail pressure was 28-3000psi, low side 70-75psi, 20-21 degrees timing. LT4 injectors, LPE DI pump, ZL1 in-tank with JMS, @ 9 psi. I could easily pulley down on this mixture.

Rob, one thing you can try if you have not yet is bump up your fuel pump voltage in the FSCM. Stock is like 14.7, move it up to 15.5. I bumped mine up as a fail safe just in case the JMS was ever to fail. I have seen guys set the table upwards of 16.5 volts.

[steelheadrob]

Joe, thanks I was just reading that and updated my tune to the 15.5 voltage, I will test it out tomorrow.

Most of my 10.44 1/4 mile run lowside was 45 to 46 psi, it temporarily drops to 41psi at the shift points when rpms drop. Pulse width was 5.2 to 5.3, it ticked to 5.4 for a split second. High side was 2,800 to 3,000 most of the run but again temporarily drops to 2,650 on the shifts as rpms drop. I dont think the drops would be picked up on the dyno as it only drops on the shift then builds back up as rpms increase. I am interested to see with the higher voltage if it will get rid of the drops I am seeing on the shifts.

When I drop pulleys and increased the boost I went from 9psi to 11psi, I decreased the timing, so I am current at 18 on timing. Keep in mind I am also spraying windshield wiper fuild.

[Drsagacity]

Originally Posted by steelheadrob

Drsag, I am sitting right about where you were at, 11psi boost, E55 and seeing a low of 41psi on my lowside fuel pressure during a 1/4 mile run. KingLt1 has me thinking about adding a BAP.

I am curious what you were seeing in your Highside fuel pressure and pulse width at 43 psi and what if any improvements you saw in either of these after adding the BAP.

715whp
@9psi Before the BAP
E60
fuel pressure was dropping from 70psi to 42psi.
Fuel rail pressure 2800-3000
Pulse width 5.8-5.9

Once we saw the Low pressure falling off at 9psi I added the BAP:
715whp
@9psi after BAP
E60
Fuel pressure 70psi start to finish
Fuel rail pressure 2800-3000
Pulse width 5.7-5.9

800whp
@12 psi After BAP
E70
Fuel pressure 70psi start to finish
Fuel rail pressure 2800-3000
Pulse width was 6.2-6.6

After the 800whp pull, E dropped for winter mix so my final pull was the 776whp on e60. I didn’t get to make a quarter mile pass last year. I actually have dialed back to 10-11psi now and am planning to drop back to 8psi tomorrow. Until I get better tires there is simply no point in running 800whp.

[steelheadrob]

Thanks. It seems even at 42psi it was enough to support the high side and pulse width for you at 9psi. But the BAP gave you the additional low side as you added boost. Not sure I need it now but will probably do it to support the pistons and cams that I will be doing next winter.

[Joshinator99]

Originally Posted by steelheadrob

Thanks. It seems even at 42psi it was enough to support the high side and pulse width for you at 9psi. But the BAP gave you the additional low side as you added boost. Not sure I need it now but will probably do it to support the pistons and cams that I will be doing next winter.

I just ordered up a Whipple too, and have to say I think I’m going to give the FSCM reprogram a try first before resorting to the BAP. Looks like we can get the vast majority of the benefit of a BAP with a simple reflash?

[Drsagacity]

Originally Posted by steelheadrob

Thanks. It seems even at 42psi it was enough to support the high side and pulse width for you at 9psi. But the BAP gave you the additional low side as you added boost. Not sure I need it now but will probably do it to support the pistons and cams that I will be doing next winter.

I would have stayed where I was without the BAP. The BAP allowed me to find the next bottleneck...which was the injectors in the 820whp range at 14psi.

[KingLT1]

I bumped the Fuel Pump Voltage via the FSCM on my brothers C7Z today and low side pressure went from 55 to holding 75psi. The pic I posted earlier was the tune for his car . We are going to hook up a Flex sensor and see how much E it will take. This car has a Kong ported charger, upper pulley, cordes 5" intake, ported LT5 tb, catless borla x, with Billy boat axle back.

[Drsagacity]

Originally Posted by KingLT1

I bumped the Fuel Pump Voltage via the FSCM on my brothers C7Z today and low side pressure went from 55 to holding 75psi. The pic I posted earlier was the tune for his car . We are going to hook up a Flex sensor and see how much E it will take. This car has a Kong ported charger, upper pulley, cordes 5" intake, ported LT5 tb, catless borla x, with Billy boat axle back.

Funny, I am doing something similar on my Vette. I have a Jokerz ported blower sitting in my office and I will check on this setting because Vettes apparently don’t take as kindly to the BAP as the Camaro. The Vette has a different in-tank pump, so I am hoping I see the same thing on my Vette.

[VAZL1]

[KingLT1]

Originally Posted by steelheadrob

Joe, thanks I was just reading that and updated my tune to the 15.5 voltage, I will test it out tomorrow.

Most of my 10.44 1/4 mile run lowside was 45 to 46 psi, it temporarily drops to 41psi at the shift points when rpms drop. Pulse width was 5.2 to 5.3, it ticked to 5.4 for a split second. High side was 2,800 to 3,000 most of the run but again temporarily drops to 2,650 on the shifts as rpms drop. I dont think the drops would be picked up on the dyno as it only drops on the shift then builds back up as rpms increase. I am interested to see with the higher voltage if it will get rid of the drops I am seeing on the shifts.

When I drop pulleys and increased the boost I went from 9psi to 11psi, I decreased the timing, so I am current at 18 on timing. Keep in mind I am also spraying windshield wiper fuild.

Also you might need to change those switches highlighted in red(refer to the pic) if you have voltage/fuel pressure fluctuations due to the variable rate charging system. changing those will keep the voltage to the FSCM more consistent. Factory is set to 11.6v minimum, I bumped my Camaro and the Vette to 12.5, maximum voltage is 14.0, but you can do 14.6.

Credit to BlueCamaro6!!

[Drsagacity]

Originally Posted by KingLT1

Also you might need to change those switches highlighted in red(refer to the pic) if you have voltage/fuel pressure fluctuations due to the variable rate charging system. changing those will keep the voltage to the FSCM more consistent. Factory is set to 11.6v minimum, I bumped my Camaro and the Vette to 12.5, maximum voltage is 14.0, but you can do 14.6.

Credit to BlueCamaro6!!

I just checked and I already had 15.5 in my tune and it didn’t hold fuel pressure at the level of power I was running. After BaP pressure was perfect.

Still, I like this for my other car as I won’t be pushing it nearly as hard. Wicked SS and Wicked C7

[KingLT1]

Nice....I believe you can go higher then 15.5. that table will allow you to add up to 32 volts. I know Parish had his at 16.5volts. The BAP may still hold an advantage either way.

[ZEE0HSIX]

Originally Posted by KingLT1

I bumped the Fuel Pump Voltage via the FSCM on my brothers C7Z today and low side pressure went from 55 to holding 75psi. The pic I posted earlier was the tune for his car . We are going to hook up a Flex sensor and see how much E it will take. This car has a Kong ported charger, upper pulley, cordes 5" intake, ported LT5 tb, catless borla x, with Billy boat axle back.

I have a very similar set of mods, very curious how far you get with the E and a stock pump.