jhm hpfp question

[KingKostas]

i believe my autotech internals are starting to fail, start up is becoming a bitch at times.

thinking of going jhm pump, anyone have good luck with them? or should i go apr

i know jhm ppl running it on their tunes, anyone running the hpfp with a gt30 or bigger?


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[mbruveris12]

I’ve been running JHM’s pump with their stage 2 tune for 15,000 miles now. Haven’t had a single issue. Can’t speak for APR’s pump but I’d say either is a solid choice.

[KingKostas]

I’ve been running JHM’s pump with their stage 2 tune for 15,000 miles now. Haven’t had a single issue. Can’t speak for APR’s pump but I’d say either is a solid choice.

thank u for the feedback


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[vce1232000]

check [o_o]your lpfp or vcds for codes

[KingKostas]

check [o_o]your lpfp or vcds for codes

no codes [emoji2361]

lpfp is new (walbro 525)
fuel filter is new too.


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[EvolutionArmory]

JHM’s fuel pump internals are GTG. 3 years/80,000 miles 😀 and going strong for me.

It’s the only JHM part I haven’t had issues with.

[vce1232000]

A [up] alternative is the IE hpfp or its internals also imo. I have a APR pump. it hasnt ever let me down. But if I needed a [wrench]. I would do a IE vs the APR this time around due to the low spring psi exerted on the cam lobe

[KingKostas]

JHM’s fuel pump internals are GTG. 3 years/80,000 miles [emoji3] and going strong for me.

It’s the only JHM part I haven’t had issues with.

sounds good thank u


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[KingKostas]

A [up] alternative is the IE hpfp or its internals also imo. I have a APR pump. it hasnt ever let me down. But if I needed a [wrench]. I would do a IE vs the APR this time around due to the low spring psi exerted on the cam lobe

cam lobe shouldnt be an issue for me rn or anytime soon, brand new intake cam , new cf , iabed cam roller conversion.

i was thinking IE internals and a new pump, but i dont mind buying a brand new one put together from jhm or apr


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[aluthman]

cam lobe shouldnt be an issue for me rn or anytime soon, brand new intake cam , new cf , iabed cam roller conversion.

i was thinking IE internals and a new pump, but i dont mind buying a brand new one put together from jhm or apr


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I’ve been running IE internals for about 3 years now with no issues. The last year and a half or so have been on the iABED roller follower conversion.

[Jayz691]

Have you logged your rail pressure to see if its even coming up short?? If its hard starting after a while. I would think more of an issue with pressure bleeding off, not hpfp. Like when I had an injector seal leak, but that ya vould smell, lol. Could be a # of things though.

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[vce1232000]

iabed cam roller conversion.


The last year and a half or so have been on the iABED roller follower conversion.

Gotta [o_o] into [wrench] 1 of these kits soon [up]

[vvenom800tt]

JHM internals for 14,000 miles now. No issues at all.

Super easy to install as well.

Fuck APR, If you wanna throw away money at their overpriced pump then go for it.

Buy a new OEM pump from ecs for $250 and get the JHM internals for $350. $600 and you're good to go.

I can even sell you a drilled out barb if you're running the revised low pressure line (no banjo bolt). It helped my low side immensely meeting requested.

Evolution Armory did my graphs for me. Hes seen it.

Here are the before and after graphs for proof.

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212413212414

[KingKostas]

Have you logged your rail pressure to see if its even coming up short?? If its hard starting after a while. I would think more of an issue with pressure bleeding off, not hpfp. Like when I had an injector seal leak, but that ya vould smell, lol. Could be a # of things though.

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with ur bad injector seal were u seeing any visible white smoke?


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[KingKostas]

JHM internals for 14,000 miles now. No issues at all.

Super easy to install as well.

Fuck APR, If you wanna throw away money at their overpriced pump then go for it.

Buy a new OEM pump from ecs for $250 and get the JHM internals for $350. $600 and you're good to go.

I can even sell you a drilled out barb if you're running the revised low pressure line (no banjo bolt). It helped my low side immensely meeting requested.

Evolution Armory did my graphs for me. Hes seen it.

Here are the before and after graphs for proof.

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212413212414

thank u for the feedback, im most likely leaning towards jhm


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[Brillo]

A [up] alternative is the IE hpfp or its internals also imo. I have a APR pump. it hasnt ever let me down. But if I needed a [wrench]. I would do a IE vs the APR this time around due to the low spring psi exerted on the cam lobe

vce I really don't have an opinion about after market HPFPs but your statement about springs is a bit perplexing. The force between the cam follower and the cam is primarily the result of the pressure in the fuel pump chamber, not the spring. In fact, the spring pressure results in an almost insignificant force. Here's why. At mid to high rpm where the ecu calls for max fuel rail pressure (I think stock is about 120 atm = 1800 psi) this results in a back pressure through the pump piston to the CF of about 150 pounds which is far greater than either spring will cause, and it is this pressure that keeps the pump piston from floating at higher rpm. The higher volume HPFPs are pushing about 33% greater fuel volume so the back pressure is about 200 pounds, which is why these pumps require more frequent CF change. Also, the pumps have a small pressure accumulatorn within them to help maintain pressure within the pump chamber. Clearly, the pressure does drop on the downstroke at which time is draws fuel from the low pressure feed side of the system. The springs really don't do much of anything except maybe at startup and low rpm. The roller followers have a lot more mass and likely need a heavier spring to overcome its inertial effects, but I've never examined a roller follower.

[vce1232000]

vce I really don't have an opinion about after market HPFPs but your statement about springs is a bit perplexing. The force between the cam follower and the cam is primarily the result of the pressure in the fuel pump chamber, not the spring. In fact, the spring pressure results in an almost insignificant force. Here's why. At mid to high rpm where the ecu calls for max fuel rail pressure (I think stock is about 120 atm = 1800 psi) this results in a back pressure through the pump piston to the CF of about 150 pounds which is far greater than either spring will cause, and it is this pressure that keeps the pump piston from floating at higher rpm. The higher volume HPFPs are pushing about 33% greater fuel volume so the back pressure is about 200 pounds, which is why these pumps require more frequent CF change. Also, the pumps have a small pressure accumulatorn within them to help maintain pressure within the pump chamber. Clearly, the pressure does drop on the downstroke at which time is draws fuel from the low pressure feed side of the system. The springs really don't do much of anything except maybe at startup and low rpm. The roller followers have a lot more mass and likely need a heavier spring to overcome its inertial effects, but I've never examined a roller follower.

APR from my understanding uses a heavier spring that will need your cf to be [wrench] about every 15k. I experienced a punch thru @ 22k. So now I [wrench] out every 15K until I get a roller cam follower [wrench]. The IE from what I was reading uses a stock psi spring that will not cause premature wear as I experienced from the APR pump

[aluthman]

I agree with Brillo. That’s also why some people experience different wear rates on the follower. Driving habits will dictate how often the pump is asked to generate those higher pressures and will subsequently affect the rate the follower wears.

[vce1232000]

vce I really don't have an opinion about after market HPFPs but your statement about springs is a bit perplexing. The force between the cam follower and the cam is primarily the result of the pressure in the fuel pump chamber, not the spring. In fact, the spring pressure results in an almost insignificant force. Here's why. At mid to high rpm where the ecu calls for max fuel rail pressure (I think stock is about 120 atm = 1800 psi) this results in a back pressure through the pump piston to the CF of about 150 pounds which is far greater than either spring will cause, and it is this pressure that keeps the pump piston from floating at higher rpm. The higher volume HPFPs are pushing about 33% greater fuel volume so the back pressure is about 200 pounds, which is why these pumps require more frequent CF change. Also, the pumps have a small pressure accumulatorn within them to help maintain pressure within the pump chamber. Clearly, the pressure does drop on the downstroke at which time is draws fuel from the low pressure feed side of the system. The springs really don't do much of anything except maybe at startup and low rpm. The roller followers have a lot more mass and likely need a heavier spring to overcome its inertial effects, but I've never examined a roller follower.


I agree with Brillo. That’s also why some people experience different wear rates on the follower. Driving habits will dictate how often the pump is asked to generate those higher pressures and will subsequently affect the rate the follower wears.

thank you gentleman for the insight on this [up]

[Jayz691]

with ur bad injector seal were u seeing any visible white smoke?


Sent from my iPhone using Audizine ForumNo smoke, mine was the o-ring, at the fuel rail that was leaking. So I could smell gas, and see it leak if I looked shortly after shutdown. But if you have any kind of leak, you'll lose pressure while not running. Which could cause it to be a little harder to start. Easiest way to find out is check your rail pressure(vcds or obdeleven) and see if it drops after you shut the car off. I could watch mine drop a few bar per second, it was leaking pretty good. If its small enough, ya "may" not see/smell it, but still lose pressure over an extended time.

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[KingKostas]

No smoke, mine was the o-ring, at the fuel rail that was leaking. So I could smell gas, and see it leak if I looked shortly after shutdown. But if you have any kind of leak, you'll lose pressure while not running. Which could cause it to be a little harder to start. Easiest way to find out is check your rail pressure(vcds or obdeleven) and see if it drops after you shut the car off. I could watch mine drop a few bar per second, it was leaking pretty good. If its small enough, ya "may" not see/smell it, but still lose pressure over an extended time.

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ill log on vcds later, group 106 right? i had logged not too long ago everything seemed fine.

my hpfp had gotten clogged by some debris recently, cleaned and all now but i believe it may have gotten slightly damaged.

i ordered a new pump and jhm internals just incase


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[KingKostas]

vce I really don't have an opinion about after market HPFPs but your statement about springs is a bit perplexing. The force between the cam follower and the cam is primarily the result of the pressure in the fuel pump chamber, not the spring. In fact, the spring pressure results in an almost insignificant force. Here's why. At mid to high rpm where the ecu calls for max fuel rail pressure (I think stock is about 120 atm = 1800 psi) this results in a back pressure through the pump piston to the CF of about 150 pounds which is far greater than either spring will cause, and it is this pressure that keeps the pump piston from floating at higher rpm. The higher volume HPFPs are pushing about 33% greater fuel volume so the back pressure is about 200 pounds, which is why these pumps require more frequent CF change. Also, the pumps have a small pressure accumulatorn within them to help maintain pressure within the pump chamber. Clearly, the pressure does drop on the downstroke at which time is draws fuel from the low pressure feed side of the system. The springs really don't do much of anything except maybe at startup and low rpm. The roller followers have a lot more mass and likely need a heavier spring to overcome its inertial effects, but I've never examined a roller follower.

good info thx


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[esandes]

Integrated engineering has a very nice kit. Look it up to find the advantages. I have experienced APRs pump too.

I prefer IE.

[EvolutionArmory]

I doubt anyone can actually tell the difference between 1 HPFP upgrade from the next in the drivers seat.....



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[aluthman]

I doubt anyone can actually tell the difference between 1 HPFP upgrade from the next in the drivers seat.....



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Nope, but there are certainly companies I would rather support over others...

[Jayz691]

IE is nice, if your pump had a lot of miles on it. Cuz it comes with a new retainer/seal. Also allows the piston to not have to be tapered, same size end to end. Other than that, prob all perform the same. Believe theyre all about 10mm.

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[esandes]

IE claims 10% more flowrate than competitors too. The lack of taper is a huge selling feature too. Original spring used.

[Brillo]

IE claims 10% more flowrate than competitors too. The lack of taper is a huge selling feature too. Original spring used.

Which taper are your referring to? The one at the CF end or the pressure chamber end? And do you know why this is claimed to be a selling feature? Also, I would be intertested in knowing the contact patch area of each piston where it abuts the bottom side of the CF for each of the stock, APR, IE, and JHM pistons.

[esandes]

https://performancebyie.com/products/ie-hpfp-vw-audi-20t-fsi

[Jayz691]

Which taper are your referring to? The one at the CF end or the pressure chamber end? And do you know why this is claimed to be a selling feature? Also, I would be intertested in knowing the contact patch area of each piston where it abuts the bottom side of the CF for each of the stock, APR, IE, and JHM pistons.At the pressure side. They're all 10mm(one may be 9.8mm), thats why they all flow 50% more fuel than stock(8mm iir). Not really sure the advantage, think they claim strength, idk. Just cuz other internals need to drop in size to fit through stock collar/seal. I know the Autotech have a small contact point, like a button. One(VIS I think) uses a stock style retainer, so think it has a bigger contact area. Pic of my Autotech when I installed.212973

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[Brillo]

I asked esandes about his comment regarding a taper
The lack of taper is a huge selling feature too. I get two responses that have nothing to do with tapers. Additionally, I'm well aware that the piston diameter controls the pumping volume, and also affects the force between the CF and the cam with a commensurate relationship to CF wear rate.

I've also thoroughly read the materials available from APR, IE, JHM and Autotech about their pump offerings. While they all seem to be well designed the ad materials contain some misleading and incorrect information. As one example, the IE info says their titanium retainer "eliminates valve float". I assume they mean piston/CF float but this claim is nonsense anyway. From the design point of view I like the non-stepped pistons (APR and IE) better than the JHM approach. DLC and nitrided piston surfaces has appeal to me from the wear resistance perspective so that would also enter into the buy decision. But AE is probably right that you'd be hard pressed to tell a difference. I have no practical experience with any of the products but there haven't been any negative reports either.

[Jayz691]

I asked esandes about his comment regarding a taper . I get two responses that have nothing to do with tapers. Additionally, I'm well aware that the piston diameter controls the pumping volume, and also affects the force between the CF and the cam with a commensurate relationship to CF wear rate.

I've also thoroughly read the materials available from APR, IE, JHM and Autotech about their pump offerings. While they all seem to be well designed the ad materials contain some misleading and incorrect information. As one example, the IE info says their titanium retainer "eliminates valve float". I assume they mean piston/CF float but this claim is nonsense anyway. From the design point of view I like the non-stepped pistons (APR and IE) better than the JHM approach. DLC and nitrided piston surfaces has appeal to me from the wear resistance perspective so that would also enter into the buy decision. But AE is probably right that you'd be hard pressed to tell a difference. I have no practical experience with any of the products but there haven't been any negative reports either.Well thats the taper that he was talking about. So if ya already know, why ask?? Taper meaning stepped, not same, consistent size. Thats what IE uses as on of their selling points. But seems you can do your own research, sorry for trying ta help...

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[Brillo]

A 'taper' and a 'step' are two distinctly different geometries. Words have meaning. The IE info says "...other upgrade kits available use a piston that steps down" - no mention of a taper. That was the reason for me asking esandes for clarification for his poor choice of words. Done with this discussion.

[Jayz691]

A 'taper' and a 'step' are two distinctly different geometries. Words have meaning. The IE info says "...other upgrade kits available use a piston that steps down" - no mention of a taper. That was the reason for me asking esandes for clarification for his poor choice of words. Done with this discussion.Omg, ok...

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[esandes]

Let's go back to the beginning gents.

How do you know your current HPFP is going bad? Logs?

Check the battery. Is an interior light in the back left on?

[aluthman]

Generally it goes bad by a CF getting eaten, which destroys the pump. You rarely see the hpfp truly fail outside of catastrophic engine damage (hydrolock, CF failure, valves hitting pistons, etc) or introduction of foreign debris. The N276 might go out, but that can be swapped from another pump easily enough. Lots of people like to inexplicably replace them while playing parts darts for some reason though.

[esandes]

I had two cam follower failures and each time there were no codes nor did the car drive/feel any different or start any differently.

A tell tale sign of a fuel system issue is a loss of duty at higher demands. Maybe the hog needs some onions and an Italian tune.

It couldn't hurt to pull the plugs to check for excess fouling.

[esandes]

Ethanol gas absorbs water in the air. I avoid that crap. When the ethanol fuel sits overnight it can draw a layer of water at the bottom of the tank where the pump is. Hard starts.

[Jayz691]

Ethanol gas absorbs water in the air. I avoid that crap. When the ethanol fuel sits overnight it can draw a layer of water at the bottom of the tank where the pump is. Hard starts.Yes it does, but not overnight...

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