low fuel pressure
#22
04-20-2014, 10:03 AM
Wait... so you're saying... all these guys that I meet like, almost every day, who are pushing 1000HP with stock head studs and twins, chewing up ZR1 Corvettes and spitting them out on the highway are... lying?
I'm glad we're on the same page here.
As for locking the rack (again, really whinging it on this) isn't that more or less likely to happen based on the model year p-pump in question? I'm not super clear on the differences, but I thought there was more to it than DV's.
I'm glad we're on the same page here.
As for locking the rack (again, really whinging it on this) isn't that more or less likely to happen based on the model year p-pump in question? I'm not super clear on the differences, but I thought there was more to it than DV's.
#23
04-20-2014, 10:13 AM
Wait... so you're saying... all these guys that I meet like, almost every day, who are pushing 1000HP with stock head studs and twins, chewing up ZR1 Corvettes and spitting them out on the highway are... lying?
I'm glad we're on the same page here.
As for locking the rack (again, really whinging it on this) isn't that more or less likely to happen based on the model year p-pump in question? I'm not super clear on the differences, but I thought there was more to it than DV's.
I'm glad we're on the same page here.
As for locking the rack (again, really whinging it on this) isn't that more or less likely to happen based on the model year p-pump in question? I'm not super clear on the differences, but I thought there was more to it than DV's.
His explanation was they had a pump on a puller that was running a very high fuel pressure with no return (80-100psi). Mid track the pump ran away. They then benched the pump and found the rack "hydrostaticaly" (sp?) Locked. I'm not sure how you would determine that, What it is or how high fuel pressure would relate to that.
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#24
04-20-2014, 10:27 AM
Diesel Bomber
If you really crank down on it the LP will make over 80. (Don't ask me how I know 
) I've never measured how much is returned but it seems like a good bit would still be returned at 35-50. Years ago I had a discussion with the guys up at enterprise and he mentioned that anything over 50 there was a chance of actually locking the rack up. I've never heard of or seen that happen but I'd rather not take that chance. The real benefit I'm guessing is fill time is reduced so all trucks benefit, big power trucks benefit more.
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) I've never measured how much is returned but it seems like a good bit would still be returned at 35-50. Years ago I had a discussion with the guys up at enterprise and he mentioned that anything over 50 there was a chance of actually locking the rack up. I've never heard of or seen that happen but I'd rather not take that chance. The real benefit I'm guessing is fill time is reduced so all trucks benefit, big power trucks benefit more. Sent from my SCH-I605 using Tapatalk 2
You are correct on the fill time comment making power at higher rpm will require more fuel pressure to a point. Like it has been stated in this thread most trucks will be fine with 30-40 psi of pressure .
---AutoMerged DoublePost---
Oh you have those guys too!?!?!? Are they the same ones who tow 25k at 700rwhp too? Lol
His explanation was they had a pump on a puller that was running a very high fuel pressure with no return (80-100psi). Mid track the pump ran away. They then benched the pump and found the rack "hydrostaticaly" (sp?) Locked. I'm not sure how you would determine that, What it is or how high fuel pressure would relate to that.
Sent from my SCH-I605 using Tapatalk 2
His explanation was they had a pump on a puller that was running a very high fuel pressure with no return (80-100psi). Mid track the pump ran away. They then benched the pump and found the rack "hydrostaticaly" (sp?) Locked. I'm not sure how you would determine that, What it is or how high fuel pressure would relate to that.
Sent from my SCH-I605 using Tapatalk 2
Last edited by 94 12valve; 04-20-2014 at 10:27 AM. Reason: Automerged Doublepost
#25
04-20-2014, 10:27 AM
Oh you have those guys too!?!?!? Are they the same ones who tow 25k at 700rwhp too? Lol
His explanation was they had a pump on a puller that was running a very high fuel pressure with no return (80-100psi). Mid track the pump ran away. They then benched the pump and found the rack "hydrostaticaly" (sp?) Locked. I'm not sure how you would determine that, What it is or how high fuel pressure would relate to that.
Sent from my SCH-I605 using Tapatalk 2
His explanation was they had a pump on a puller that was running a very high fuel pressure with no return (80-100psi). Mid track the pump ran away. They then benched the pump and found the rack "hydrostaticaly" (sp?) Locked. I'm not sure how you would determine that, What it is or how high fuel pressure would relate to that.
Sent from my SCH-I605 using Tapatalk 2
Regardless, my best guess of what they were trying to say is- (since hydrostatics is essentially the science of liquid pressure at rest) that they somehow determined that more fuel was crammed into the pump than the rack had travel to move out the other side.
That isn't the way I'd have put it, but I'm sure they know more about it than I do...
#26
04-20-2014, 10:31 AM
I've scaled 25K with a lot less than 700HP, but that said, over 7K of it was the truck.
Regardless, my best guess of what they were trying to say is- (since hydrostatics is essentially the science of liquid pressure at rest) that they somehow determined that more fuel was crammed into the pump than the rack had travel to move out the other side.
That isn't the way I'd have put it, but I'm sure they know more about it than I do...
Regardless, my best guess of what they were trying to say is- (since hydrostatics is essentially the science of liquid pressure at rest) that they somehow determined that more fuel was crammed into the pump than the rack had travel to move out the other side.
That isn't the way I'd have put it, but I'm sure they know more about it than I do...
Sent from my SCH-I605 using Tapatalk 2
#27
04-20-2014, 01:49 PM
Well, I know mine has nowhere near 500, never mind 700. Hell, I'd be shocked if the average working power was half that. I do think it's a whole lot more reliable towing as it sits than it ever was from the factory, but most of that's the tranny. It just so happens that a tranny like this on a factory 12V is, well... sort of stupid.
Regardless, towing is a whole other ball of wax than running down the drag strip for sure, even if your venue means running down the drag strip with a sled behind you. It seems like anyone who knows their stuff should be able to make something hold together for under a minute of abuse, whereas pulling twice your weight across the state is a little more demanding on the reliability scale than it is on the dyno.
That all being said, most of the newer trucks in our fleet claim more power right off the showroom floor than mine optimistically has turned up as it is, but they all go out to work every day, and mine has proven to be far more reliable than these "factory supertrucks", out-performing them in every way but brakes, and cheaper to fix when it hits the fan. I certainly wouldn't say they are more reliable, modded or otherwise, and mine works circles around them to boot. But I may be missing your point.
Regardless, towing is a whole other ball of wax than running down the drag strip for sure, even if your venue means running down the drag strip with a sled behind you. It seems like anyone who knows their stuff should be able to make something hold together for under a minute of abuse, whereas pulling twice your weight across the state is a little more demanding on the reliability scale than it is on the dyno.
That all being said, most of the newer trucks in our fleet claim more power right off the showroom floor than mine optimistically has turned up as it is, but they all go out to work every day, and mine has proven to be far more reliable than these "factory supertrucks", out-performing them in every way but brakes, and cheaper to fix when it hits the fan. I certainly wouldn't say they are more reliable, modded or otherwise, and mine works circles around them to boot. But I may be missing your point.
#28
04-20-2014, 02:47 PM
Well, I know mine has nowhere near 500, never mind 700. Hell, I'd be shocked if the average working power was half that. I do think it's a whole lot more reliable towing as it sits than it ever was from the factory, but most of that's the tranny. It just so happens that a tranny like this on a factory 12V is, well... sort of stupid.
Regardless, towing is a whole other ball of wax than running down the drag strip for sure, even if your venue means running down the drag strip with a sled behind you. It seems like anyone who knows their stuff should be able to make something hold together for under a minute of abuse, whereas pulling twice your weight across the state is a little more demanding on the reliability scale than it is on the dyno.
That all being said, most of the newer trucks in our fleet claim more power right off the showroom floor than mine optimistically has turned up as it is, but they all go out to work every day, and mine has proven to be far more reliable than these "factory supertrucks", out-performing them in every way but brakes, and cheaper to fix when it hits the fan. I certainly wouldn't say they are more reliable, modded or otherwise, and mine works circles around them to boot. But I may be missing your point.
Regardless, towing is a whole other ball of wax than running down the drag strip for sure, even if your venue means running down the drag strip with a sled behind you. It seems like anyone who knows their stuff should be able to make something hold together for under a minute of abuse, whereas pulling twice your weight across the state is a little more demanding on the reliability scale than it is on the dyno.
That all being said, most of the newer trucks in our fleet claim more power right off the showroom floor than mine optimistically has turned up as it is, but they all go out to work every day, and mine has proven to be far more reliable than these "factory supertrucks", out-performing them in every way but brakes, and cheaper to fix when it hits the fan. I certainly wouldn't say they are more reliable, modded or otherwise, and mine works circles around them to boot. But I may be missing your point.
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