Running out of fuel
05-16-2006, 08:01 PM
#13
Originally Posted by TIM Z
damn! tell us more 
The truck is a '72 Chevy 3/4 ton longbed 4x4 my dad bought new in 72
. The motor will stay mostly stock, with a Master Power T-70 front mount intercooled turbo. Should be fun! Its also going to be getting 4 links and air bags front and rear. keeping the stock ride height, but getting rid of the tank like ride 
Sorry for the Highjack
05-16-2006, 09:03 PM
#14
Originally Posted by Quik
when you say your running out of fuel, does the truck just shut off then runs again when you let off the pedal for a second or so? im betting this is happening in 3rd?
i mean as shut off all guages start to act wierd and if you let off the pedal time passes and it regains its position?
i mean as shut off all guages start to act wierd and if you let off the pedal time passes and it regains its position?
NO! Nothing like that, It drives great. When we had the truck on the dyno we where monitoring the o2's and as soon as we hit 4500rpm (wot) it started to get extremely lean. Not just a little but like if you where to draw a vertical line, thats how it looked
From 10.9 to 12.0 in less than a second. I don't know for shure but it seamed like fuel preasure drop. I want to just be able to finish the run and see when the torque and hp start to fall with that intake, It looks like it was still climbing but we had to take our foot out at 4700rpm. I think I am going to do it in stages and see if I can get away without changing the the injectors and tune. I know I am being hard headed. I did talk to julio at alkycontrol and he said to add the 255 intank and the 3 bar for the meth and an extra nosel. What fuel system is parish running? I think I read that he is useing a two 255's intake, one on a presure switch. Thanks for the input, I need lots... I don't mind lossing the motor if it just can't take anymore but I would be mad at my self if I let it go lean and I blow it up. If this does not work the next step will be the 60's. Thanks again.
05-16-2006, 09:31 PM
#15
TURBO8,
I believe Parish is running 2 in-tank 255 like you said, but he is also running 96lbs injectors I believe or something like that. In my opinion, a stock fuel pump with a 255 in-line will flow more fuel that a single in-tank 255 (which is what I have now, but would do if dirently if i had to do it again) The reason being it that fuel pumps are flow rated at their operating pressure. So when you have 2 pumps in series like that, they are spliting the pressure duty between them and they will flow MORE then there rated flow at LOWER pressure. So if your stocker can't maintain the flow at 58 psi, then the in-line will pickup the slack for the pressure allowing the stocker to flow the required volume with the in-line maintaining the pressure.
The reason you have been able to get as far as you have with the 43 lbs injectors is because you have a vac refinances fuel pressure reg. As you boost increases, your fuel pressure is also being increases and is squirting more fuel with the same open time. I'm sure if you had a scanner on it when you were on the dyno, it would show your injector where MAX out at over 100% DC. Hell my 43 pounders are at 80% at 7-8lbs of boost on a 4.8. You need bigger injectors to be safe. More meth would only really be a bandaid.
I believe Parish is running 2 in-tank 255 like you said, but he is also running 96lbs injectors I believe or something like that. In my opinion, a stock fuel pump with a 255 in-line will flow more fuel that a single in-tank 255 (which is what I have now, but would do if dirently if i had to do it again) The reason being it that fuel pumps are flow rated at their operating pressure. So when you have 2 pumps in series like that, they are spliting the pressure duty between them and they will flow MORE then there rated flow at LOWER pressure. So if your stocker can't maintain the flow at 58 psi, then the in-line will pickup the slack for the pressure allowing the stocker to flow the required volume with the in-line maintaining the pressure.
The reason you have been able to get as far as you have with the 43 lbs injectors is because you have a vac refinances fuel pressure reg. As you boost increases, your fuel pressure is also being increases and is squirting more fuel with the same open time. I'm sure if you had a scanner on it when you were on the dyno, it would show your injector where MAX out at over 100% DC. Hell my 43 pounders are at 80% at 7-8lbs of boost on a 4.8. You need bigger injectors to be safe. More meth would only really be a bandaid.
05-16-2006, 10:36 PM
#19
I think a stock intake pump is rated some where around 160lph, and I think you would lose a little off the max flow of the 2. I would conservatory put this type of setup at around 350lph. That should support a 700 hp setup. These number are off the top of my head, would really need to do some more research to get a more exact figure.
05-16-2006, 11:10 PM
#20
5 year bitches!
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^^^^^^^hey KBracing what would you do in my situation. im running svo30s which they say are about 36# injectors on a LS1 psi but i run a stock pump. would it be better to upgrade to a 255intank or get an inline pump but if i get inline which should i get?
sorry ot hijack
sorry ot hijack