Need to get a HPFP

[A4B7Avant]

Need to get a uprated HPFP (innards). Who has the best deal for one?

[dalmation53]

Wolfautoparts.com

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[A4B7Avant]

Ok I meant an aftermarket upgrade

[vce1232000]

I prefer IE. I believe they have the upgrade[wrench] internals that doesnt exert psi on the cam lobe like APR and some other's do [:)]

[A4B7Avant]

Thanks for the info. Just picked one up at 30% off.

[DownhillA4]

Pucked up from where? Link?

[Brillo]

Perhaps a point of confusion on my part. When you say 'upgraded' HPFP I assume you really mean higher volume HPFP. There is really nothing 'upgraded' about them with regard to quality. As far as I can tell all the aftermarket higher volume pumps advertise a treated piston shaft, but even the stock shaft is treated. Besides, the shaft and seal area of the pump is not really the problem area. As most know it is the cam follower. I notice that some aftermarket folks advertise higher pressure. But this is not exactly true as the pressure is controlled by the pressure regulator solenoid and the tune, not the piston, though it is true that the higher volume HPFP can maintain the pressure at the highest demand point on a stage tuned setup where the stock HPFP would run out of capacity. I'm not aware that this will happen on a stock setup.
vce1232000 (post #4) makes a confusing statement. Any higher volume pump piston arrangement will necessarily place higher pressure on the follower-cam lobe. It can't be any other way. So if the higher volume pump is advertising 40% higher fuel flow volume, the pressure on the cam lobe-follower will also increase by 40%. Pressure in excess of the fuel pressure demand will be controlled by the fuel pressure solenoid and the particular fuel pressure relief valve installed in your setup.
So, to avoid confusion, just suggesting more descriptive terminology - higher capacity or higher volume HPFP instead of 'upgraded' HPFP. The term upgraded might give the less informed the impression that the cam follower issue has been resolved.

[vce1232000]

vce1232000 (post #4) makes a confusing statement. Any higher volume pump piston arrangement will necessarily place higher pressure on the follower-cam lobe. It can't be any other way. So if the higher volume pump is advertising 40% higher fuel flow volume, the pressure on the cam lobe-follower will also increase by 40%. Pressure in excess of the fuel pressure demand will be controlled by the fuel pressure solenoid and the particular fuel pressure relief valve installed in your setup.
So, to avoid confusion, just suggesting more descriptive terminology - higher capacity or higher volume HPFP instead of 'upgraded' HPFP. The term upgraded might give the less informed the impression that the cam follower issue has been resolved.

I was [o_o]ing this https://www.performancebyie.com/ie-high-pressure-fuel-pump-hpfp-upgrade-kit-for-2-0t-fsi-engines As IE claims to use the stock spring instead of a spring that has more tension to exert more psi on he follower. Their claim is 50% more flow and still utilize the stock spring unlike APR and some other upgrade HPFP's. HTH to avoid any [confused] from my above statement. If my upgrade APR HPFP goes. The IE would be my 1st choice just because it uses the stock spring[:)]

[Brillo]

The spring is not responsible for the pressure against the follower and cam, or at least only a very small fraction of the pressure. The back pressure of the fuel in the pressure chamber is the main factor. All higher capacity HPFPs work by increasing the diameter of the piston (the displacement of the piston) as the pump stroke is controlled by the cam height. For example, IE advertises a piston/shaft diameter of 9.8 mm. At a max pressure of 115 bar, which equals about 1700 psi, times the piston area (0.117 square inches) equals about 200 pounds. So the fuel pressure in the pump chamber is pushing the piston down against the cam (with the beloved cam follower in between) with a force of 200 pounds. Add to that about 20 pounds of spring tension giving a grand total of 220 pounds between the cam and follower. No wonder they wear out! The force on a stock HPFP is about 150 pounds. Those with higher volume HPFPs need to check/change the cam follower more often because if will wear out faster.

[vce1232000]

The spring is not responsible for the pressure against the follower and cam, or at least only a very small fraction of the pressure. The back pressure of the fuel in the pressure chamber is the main factor. All higher capacity HPFPs work by increasing the diameter of the piston (the displacement of the piston) as the pump stroke is controlled by the cam height. For example, IE advertises a piston/shaft diameter of 9.8 mm. At a max pressure of 115 bar, which equals about 1700 psi, times the piston area (0.117 square inches) equals about 200 pounds. So the fuel pressure in the pump chamber is pushing the piston down against the cam (with the beloved cam follower in between) with a force of 200 pounds. Add to that about 20 pounds of spring tension giving a grand total of 220 pounds between the cam and follower. No wonder they wear out! The force on a stock HPFP is about 150 pounds. Those with higher volume HPFPs need to check/change the cam follower more often because if will wear out faster.

I follow what your saying with the math you have seem to back it up [up]. But for the average consumer such as I would [o_o] that statement from IE would get [confused]. How would they be able to make a claim like that and not be fraud to the general consumer. There statement says " Retains OE spring to greatly reduce cam follower wear". Is there any truth to to their statement [confused].

I [wrench] my cam follower out every 15k miles to be on the safe side. I already suffered a cam follower failure with a APR pump. I had to [wrench] cam, follower,& another APR HPFP [mad]

[Ashtonts]

From what both of you are saying, it seems like neither of you are wrong. Even if the stock spring has a slightly lower spring rate (ie, exerts less force on the cam), it will slow down wear pretty significantly over an upgraded pump that pushes more fuel through AND has a higher spring rate. Even if it’s a relatively small force difference, over the life of the follower it definitely adds up.

I don’t think VCE is ever trying to claim that the pumps that retain the stock spring wear the follower as slowly as the stock pump, just significantly slower than a higher flow pump that also has a stiffer spring.

In my experience, my auto tech HPFP (I believe stock spring) wears the follower a lot slower than others. Some people [wrench] their followers at 5k miles with upgraded components, and I changed mine at 10k and it had a lot of life left in it.

[vce1232000]

I don’t think VCE is ever trying to claim that the pumps that retain the stock spring wear the follower as slowly as the stock pump, just significantly slower than a higher flow pump that also has a stiffer spring.

[hail]... Thanks. I sometimes have a [down] way of explaining whats on my mind [:p].

[Brillo]

Here is what I think IE is saying. They have reduced the mass of the spring-spring retainer-follower composite by greatly reducing the mass of the retaining clips. By doing so they are able to retain the stock spring and still avoid floating the follower at high RPM. This says to me that other providers of high capacity HPFPs pumps increase the spring rate (and spring tension) to compensate for the heavier piston/spring/retainer mass in order to avoid floating of the follower. I personally do not know if this is true but have no reason to doubt IE's implication. At high rpm the dynamic stress on a floating follower would would have a dramatic adverse effect on its wear performance - a very undesirable situation. It would be much higher than the static stress calculation of 220 pounds I made in my post #9. Technically, this makes sense. The way vce1232000 stated it was confusing to me until I studied the IE link he provided. Did not mean to impugn him in any way.

[vce1232000]

Here is what I think IE is saying. They have reduced the mass of the spring-spring retainer-follower composite by greatly reducing the mass of the retaining clips. By doing so they are able to retain the stock spring and still avoid floating the follower at high RPM. This says to me that other providers of high capacity HPFPs pumps increase the spring rate (and spring tension) to compensate for the heavier piston/spring/retainer mass in order to avoid floating of the follower. I personally do not know if this is true but have no reason to doubt IE's implication. At high rpm the dynamic stress on a floating follower would would have a dramatic adverse effect on its wear performance - a very undesirable situation. It would be much higher than the static stress calculation of 220 pounds I made in my post #9. Technically, this makes sense. The way vce1232000 stated it was confusing to me until I studied the IE link he provided. Did not mean to impugn him in any way.

I can follow what your saying now[up]. Since IE didnt go into more details on being how it was being accomplished. I just needed further explanation. I didnt get insulted or catch feelings. Thank you for your insight and explanation. It was a very [up] [o_o] and answered everything I wanted to know. [up]