Hesitation in boost and high rpm

[polskifacet]

Hey Guys,
I'm on the list for the next batch of pumps. I'm going into this without full confidence but feel like I'm too far in to back out. Of course there is no guarantee that the pump will magically fix the issue. I'm hoping that even if the issue exists, I'll never reach the point where the LMS pump would exhibit the issue. LMS also said that if the pump doesn't fix the issue, they would need the car for an extended period and fix the issue for an additional charge. I'm pretty gung hoe about buying the pump but would like your guys opinion.

[StealBlueSho]

They give you a time frame? I am supposed to get a call as well when they are available..

[polskifacet]

They give you a time frame? I am supposed to get a call as well when they are available..

told me a few weeks

[StealBlueSho]

They give you a time frame? I am supposed to get a call as well when they are available..

told me a few weeks

Ha! I was told 2 weeks 3 weeks ago... lol don't hold your breath..

[polskifacet]

yea that was the first batch, im talking about the second lol

[StealBlueSho]

yea that was the first batch, im talking about the second lol

Interesting... I would have figured someone on this forum would have gotten one if there was a batch available...

I asked Anthony yesterday and he told me he was unaware of any HPFP being sold yet for the SHO... I have the email... lol

Oh well...

[polskifacet]

Just an observation, using the Torque app, with it being 75 degrees with some humidity it doesn't go below 1950 psi. I would have to log to get exact numbers but there is no hesitation etc.

Could any of you guys gauge how much fuel is missing? Is it 10% or is it 40%? That could help be make a better educated guess on the pump purchase.

[polskifacet]

Logged what I felt, seems to be true. fuel pressure is on par with commanded. This is the 93 octane tune.

[AJP turbo]

Just an observation, using the Torque app, with it being 75 degrees with some humidity it doesn't go below 1950 psi. I would have to log to get exact numbers but there is no hesitation etc.

Could any of you guys gauge how much fuel is missing? Is it 10% or is it 40%? That could help be make a better educated guess on the pump purchase.

What do you mean how much fuel is missing?

[polskifacet]

A guesstimate on how much more room the stock pump should have. I'm assuming that I'm on the bleeding edge right now.

[StealBlueSho]

A guesstimate on how much more room the stock pump should have. I'm assuming that I'm on the bleeding edge right now.

Rule of thumb from the tuners I have worked with is 1500 psi is the lowest you want to go.

[TopherSho]

A guesstimate on how much more room the stock pump should have. I'm assuming that I'm on the bleeding edge right now.

Rule of thumb from the tuners I have worked with is 1500 psi is the lowest you want to go.

for my education is that for sustained,  or at all costs?   I have seen mine dip into the 1400's on shift but had assumed that happens since there is reduced load and reduced rpm driving things.

[StealBlueSho]

A guesstimate on how much more room the stock pump should have. I'm assuming that I'm on the bleeding edge right now.

Rule of thumb from the tuners I have worked with is 1500 psi is the lowest you want to go.

for my education is that for sustained,  or at all costs?   I have seen mine dip into the 1400's on shift but had assumed that happens since there is reduced load and reduced rpm driving things.

I can just say from my experience is that Brad and Torrie were not happy with a sustained pressure of 1500 or less...

That being said... more of the issue is the dips after a shift around 4K RPMs... usually that's when a boost spike is evident...due to the increase in boost from the spike along with the drop is fuel pressure you are more prone for knock/heat issues....

I have never had a tune besides an E blend on a non-e tune that would not recover the fuel pressure...

I have had pressure as low as 800 psi while playing around... the ECU closes the throttle to prevent damage at that level...

[TopherSho]

A guesstimate on how much more room the stock pump should have. I'm assuming that I'm on the bleeding edge right now.

Rule of thumb from the tuners I have worked with is 1500 psi is the lowest you want to go.

for my education is that for sustained,  or at all costs?   I have seen mine dip into the 1400's on shift but had assumed that happens since there is reduced load and reduced rpm driving things.

I can just say from my experience is that Brad and Torrie were not happy with a sustained pressure of 1500 or less...

That being said... more of the issue is the dips after a shift around 4K RPMs... usually that's when a boost spike is evident...due to the increase in boost from the spike along with the drop is fuel pressure you are more prone for knock/heat issues....

I have never had a tune besides an E blend on a non-e tune that would not recover the fuel pressure...

I have had pressure as low as 800 psi while playing around... the ECU closes the throttle to prevent damage at that level...

ok no worries for me then ty sir..

[StealBlueSho]

You don't want fuel pressure drops, even momentarily, below 1500 psi... but that's really up to your tuner and how comfortable he is with your car...