Having taken my 2014 ST to 302whp & I am now out of fuel. I know there are bigger high pressure pumps available for the Ford eco boost range but cannot find any info on anyone upgrading the pump. Stratifled have shown a possible solution but is massively complicated to MAP correctly and not the route I want to go. Anyone done anything different here?? Looking for 380-400whp..
-
Sign Up! To view all forums and unlock additional cool features
Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!
Fiesta ST200 (UK ST180) High Pressure Fuel Pump
- Thread starter McGee-01
- Start date
Thread Starter
#3
My car is an evolvement and over time I have and do work with AET Motorsport, my build and modifications have taken the car as far as it can go without meth/nitro. There is no-one in the UK that has any solution without fitting secondary fuelling solutions. You guys in the USA always lead the way with this sort of stuff and I did find once a company that seemingly were trying to develop something but I lost the link and cant find it again. I wasnt sure if one of the other pumps from one of the other cars might just plug and play or adapt so that the internal from say the 3.5lt F150 might swap across? I am sure it is more complicated than this example or is it??
Currently, we don’t have an HPFP upgrade options. A company (I think Livernoise ) is or was working on a HPFI for the 3.5L ecoboost and the 2.0L ecoboost. But no one gives the 1.6L any love. The stratified MPFI aux fuel ( $1500~ ) is the best way to go for 400+ whp. But really, despite what “marketing info” was put out about the throttle body system ($900), it good for 500whp with the correct injector. ZZP performance builds a single injector system similar to straified, but it’s for the cobalt SS turbo. Those car make between 500-750whp pretty regularly with just a single 5th injector.
Why are you so against the Aux fuel setups ?
Your other option would be to upgrade to a better turbo and make 300whp for more of the powerband. Even if you cap out at 300whp at 7,000rpm, you can still have a goal of making 300whp from 5,000-7000rpm. Enter.... Garrett G-25-550 turbo.
But really, I don’t see the issue with using a Stratfied aux fuel. I just installed the single injector TB style system last week, and the fitment and parts were high quality and I have no worries about it.
What is the setup on the car currently to get you to 300whp ? (Don’t say X47 lol. In that case, we’d be talking about BHP)
Why are you so against the Aux fuel setups ?
Your other option would be to upgrade to a better turbo and make 300whp for more of the powerband. Even if you cap out at 300whp at 7,000rpm, you can still have a goal of making 300whp from 5,000-7000rpm. Enter.... Garrett G-25-550 turbo.
But really, I don’t see the issue with using a Stratfied aux fuel. I just installed the single injector TB style system last week, and the fitment and parts were high quality and I have no worries about it.
What is the setup on the car currently to get you to 300whp ? (Don’t say X47 lol. In that case, we’d be talking about BHP)
Also... dispite what we were told by people that were marketing aux fuel systems, in my research, I’ve found other platforms that said, “if your running out of fuel at peak torque, that is the HPFP. If your running out of fuel at higher rpm, that is the flow of the intank fuel pump (LPFP).”.
That is coming from real deal LT4/LT5 tuners. Guys making 700-1000whp. And also from Cummings diesel forums. And also from 40 year experienced CAT tech’s.
I have 2 questions.
#1 who has race tuner software and has actually installed a walbro 340lph fuel pump ? (No one has )
#2 what do you guys think there is more money in? $1500/$900 aux fuel systems ? Or $120 fuel pumps?
Bonus question. What are people more than likely going to install? A spacer plate on the intake? Or dropping the entire fuel tank out of the car to install a fuel pump ?
To my knowledge, not a single person yet has been in the 340-350whp area and swapped in a walbro 340 to see if it could help.
That being said... I don’t think it will help to the point of 400whp lol.
That is coming from real deal LT4/LT5 tuners. Guys making 700-1000whp. And also from Cummings diesel forums. And also from 40 year experienced CAT tech’s.
I have 2 questions.
#1 who has race tuner software and has actually installed a walbro 340lph fuel pump ? (No one has )
#2 what do you guys think there is more money in? $1500/$900 aux fuel systems ? Or $120 fuel pumps?
Bonus question. What are people more than likely going to install? A spacer plate on the intake? Or dropping the entire fuel tank out of the car to install a fuel pump ?
To my knowledge, not a single person yet has been in the 340-350whp area and swapped in a walbro 340 to see if it could help.
That being said... I don’t think it will help to the point of 400whp lol.
Thread Starter
#7
Thanks for the response Jamie. I am trying to do the job 100% right and understand that given the time/money involved that few if any thus far will take my route. Maximising/improving the factory fuelling was/is my preferred route. I wasnt sure if the other pumps were the same output or indeed if there wasn't a bolt on swap option that hasn't made it across the pond yet, seemingly not! So I will take a further look at all the other options but might face issues with mapping as again I am unsure who in the UK has experience with ST200 5th injector mapping. AET Motorsport Hybrid Turbo fitted with full stage 3 set-up is what I run and for some reason have the most powerful version that AET have produced although my car is only 11000 miles still. Link here to take a look hope this is allowed? https://www.aet-motorsport.co.uk/project/mike-mcgee-fiesta-st-track-car/
This statement is incorrect because the throttle body injector system can not distribute fuel evenly between the cylinders. Around 430-450whp, you are putting a cylinder at risk (likely cyl 3) of leaning out and causing catastrophic danger.
Is it your opinion that HPFPs are not being tapped out and that companies just want to sell aux fuel systems? You’re likely correct that no FiST owner has upgraded the in-tank, but also, VERY few FoST owners have. I’d wager 5-10 max. To be clear, I’m not saying you’re wrong because an engine is just a big air pump and we can always determine fuel delivery needs, so it’s not completely wrong to bring LT4s into the conversation. But it does bring me to my next point... 1.6L. We’re not necessarily hitting the limits of the fuel pumps...we’re hitting the limits of what a 1.6L can produce on a certain fuel.
On 100% stock fuel system with 93, we’re tapping out the HPFP at the top end (not the LPFP) around 310-320whp because of the amount of fuel needed at RPM to make power on a 1.6L.
This is important to note because even on TBI, 93oct will only make 310-320whp. With TBI we just add more fuel and can back off the DI.
Then we add E85. With TBI and up to E50 mixtures can see 380whp - 430whp. Again, it’s not the HPFP or LPFP that is the limiting factor... It’s fuel distribution. A couple engines, including my stock engine, have been lost to poor fuel distribution around 430whp+. Cyl 3 runs leans, and things just cascade into catastrophic failure.
So, where we are right now with fuel delivery is 430whp with E50 and TBI is safe (on a built engine, 380 on stock engine). As a side note: above E50, the LPFP does start tapping out (not HPFP). I have the Strat 4-port in hand, and will have my head built. I’m considering an LPFP or surge tank set-up but life is changing fast in other areas. Either way, we’ll soon see what the 4-port can take us to before we need to consider LPFP upgrades.
Sent from my iPhone using Tapatalk
Is it your opinion that HPFPs are not being tapped out and that companies just want to sell aux fuel systems? You’re likely correct that no FiST owner has upgraded the in-tank, but also, VERY few FoST owners have. I’d wager 5-10 max. To be clear, I’m not saying you’re wrong because an engine is just a big air pump and we can always determine fuel delivery needs, so it’s not completely wrong to bring LT4s into the conversation. But it does bring me to my next point... 1.6L. We’re not necessarily hitting the limits of the fuel pumps...we’re hitting the limits of what a 1.6L can produce on a certain fuel.
On 100% stock fuel system with 93, we’re tapping out the HPFP at the top end (not the LPFP) around 310-320whp because of the amount of fuel needed at RPM to make power on a 1.6L.
This is important to note because even on TBI, 93oct will only make 310-320whp. With TBI we just add more fuel and can back off the DI.
Then we add E85. With TBI and up to E50 mixtures can see 380whp - 430whp. Again, it’s not the HPFP or LPFP that is the limiting factor... It’s fuel distribution. A couple engines, including my stock engine, have been lost to poor fuel distribution around 430whp+. Cyl 3 runs leans, and things just cascade into catastrophic failure.
So, where we are right now with fuel delivery is 430whp with E50 and TBI is safe (on a built engine, 380 on stock engine). As a side note: above E50, the LPFP does start tapping out (not HPFP). I have the Strat 4-port in hand, and will have my head built. I’m considering an LPFP or surge tank set-up but life is changing fast in other areas. Either way, we’ll soon see what the 4-port can take us to before we need to consider LPFP upgrades.
Sent from my iPhone using Tapatalk
McGee thanks for posting here. Sure wish we could get more guys from the UK and other places to hang out with us, and compare lots of things. But your right, the tuning situation will be different since you guys don’t have the Cobb access port support we have due to your car being MAF based and our cars being MAP based. Funny side story about that. People used to compare MAF numbers (flow) per given turbo setup to try and say one was better than the other. Ironically, the Fiesta ST (USDM) don’t look at the MAF even the remote most small bit AT ALL. It does look at the intake air temp sensor in the MAF, but it doesn’t look at MAF air flow AT ALL. If you remove your MAF sensor from the car, then go do a datalog, you will oddly find that the car some how has logged mass air flow, even while the sensor is just sitting in the engine bay. The USDM fiesta uses the MAF for 100% NOTHING. It does figure the iat, but it’s almost pointless because the ecu is much more concerned with the charge air temp.
Anyway. Just want to say I respect the info you bring to the forum Isaac. I know who you are and where you have been. But yes. That is what I’m saying. I’m saying these 100’s of guys with X47, C39, and Mcgee’s Type hybrid turbo update could likely be by-passing a soluation that would address THEIR situation, but what never offered. It wasn’t offered #1 because DHM never really had a use for a 330whp-340whp fuel system. Every turbo setup they ever fully marketed really did need 350+whp of fuel. And did they REALLY actually truely 100% test the idea of taking a real life car making 310whp with a commanded AFR of 11.1 that is seeing 12.5 AFR at 5800+ rpm and then slap in a $120 walbro 340lph? No.... they had a theory that it would not help, and moved on to $900 solutions that would support 350+ whp. A $900 soluation with a profit margin, vs a $120 soluation that could be bought from pretty much any vendor anywhere with not much profit margin ( but you do have to make sure you don’t get a China knock off, which has been an issue ).
I didn’t want to turn this into a debate or tech conversation. Mostly because honestly, it’s $120, and someone should just spend $300 at a local shop to have a walbro installed on there C39/X-47 and see what it will do on E30 before running out of fuel. But... in my research, this is what I found. Basically.
The LT1/LT4/LT5 guys actually do have HPFI upgrades and options. They have cam lobe upgrades etc. but what applies more to us and is more of a direct comparison is... the LT1 guys that add superchargers etc. what they found is... when they needed more fuel, they could buy the expensive LT4/LT5 HPFP and bolt it onto their LT1 system. But... they were disappointed to find, the peak torque was no longer an issue with fueling ( mid range RPM peak torque ), but the higher rpms, was still not getting enough fuel.
This is how this was explained. We ( fiesta ST etc ) look at pressure. “Is your fuel rail pressure dropping?” “Is your LPFP pressure dropping?”. But no one talks about the flow.
The HPFP is just a translator. Flow is flow. Pressure is pressure. The HPFP will FLOW about as much as you can throw at it ( ok, it surely has a limit at some point, but let’s not focus on that for now ). The HPFP simply takes what ever is “flowed” to it and translates it to higher pressure. If you FLOW 100hp of fuel in, it will take 100hp of fuel and jack up it’s pressure to requested (2900-ish psi on a hard tuned ST ). The HPFP doesn’t really “flow” anything. It does not dictate how much fuel is flowed or moved or supplied. It simply translates the fuel flowed to it from 90psi/200hp to 2150psi/200hp (in stock form). So you can flow 90-100psi/400hp to 2900psi/400hp.
This has been proven is LT1/LT4/LT5, as well as countless diesels. Let’s face it. This engine ( like all DFI engines ) is basically a Diesel engine that runs on gasoline.
Now don’t take me the wrong way. I’m not saying that if have a 400whp fiesta ST with an Aux fuel, that you could remove the aux fuel and just swap in a LPFP. I’m just saying 80% of the people with these cars want to make 300whp on e30 or 320whp on a hybrid turbo. Maybe 320-330whp on 108octane gasoline. Because 300whp on pump gas fuel on a hybrid turbo just isn’t going to happen ( aka, 93oct ).
Another, simpler option that a vendor could offer, would be a booster in-line pump. No removing the fuel tank. Little more room for profit. And it would really make a difference for those 80% looking to supplement their fuel system for another 30-40hp. Of course for customers like Mcgee, and myself the 5th injector is the way to go.
Isaac I’vd read the same debates over on the cobalt forums. “You can’t run just one 5th injector” etc etc etc. those threads are years and years old telling ZZP that it would not work correctly and fuel would not be evenly distributed etc etc. and years and years later, ZZP is basically the only name in that game and have countless 500whp builds on 1 single 5th injector. They even did tech posts about the difference cylinder to cylinder being equal to 11.100 or 11.095 AFR. And lots and plenty of “online experts” argued that ZZP wrong and all this, yet.... send me a link to a bolt on 4 port aux fuel for a cobalt SS. There isn’t one because the 5th injector is $500 and the MPFI would cost $1500 for .01 difference in cylinder fuel distribution.
Another thing we can learn from the cobalt SS crowd. They had modified HPFP’s. And it seems all of them ended up having issues with those upgraded HPFP’s, and currently, it seems they just skip the expensive and sometimes problem prone HPFP and just to the 5th injector.
That being said.... We have a MPFI setup. It’s expensive, but reasonably priced for what it is. And it def works ( my focus friends are happy with it ). But for less than 425whp, or even 400whp, Nothing wrong with the TB based 5th injector. And that’s about 97% of fiesta guys. And again.... if you upgrade the LPFP the entire system will be happier.
Do we really think ford built a 170whp car and put a 500whp fuel pump in it ?
The only real way to test this truely ? Take a guy with a car running Out of fuel ( non-aux fuel car ), and swap in a booster walbro or walbro 340lph ( or higher ) and see what happens. From all the research I’ve done, that wasn’t based with core in DHM knowledge/theory, says a LPFP upgrade could surprise us all. And it could do only a little bit, or it could shock us all. But it really
Just needs to be done by someone without a horse in the race ( and that excludes guys with AUX fuel system ). Tons and tons of guys running X37’s that could maybe use E50 instead of E30. Tons of guys running X47’s that could be fueling 300whp on E30. Tons of guys that could be fueling 300whp on C39’s on E30.
So really, the question is why hasn’t someone done this already ( ok, we know why, we were told it wasn’t going to help by a company that sells a solution that is 10times more expensive ). But with the research I’ve done ( before I installed the AUX fuel ), it’s a little more than interesting that no one has dared to upgrade the LPFP.
Then again.... I could be wrong lol. But unlike other sources, I don’t have a reason talk anyone into skipping the fuel pump upgrade. I don’t work for a vendor. I don’t work for Walbro. But it is rather interesting.
Anyway. Just want to say I respect the info you bring to the forum Isaac. I know who you are and where you have been. But yes. That is what I’m saying. I’m saying these 100’s of guys with X47, C39, and Mcgee’s Type hybrid turbo update could likely be by-passing a soluation that would address THEIR situation, but what never offered. It wasn’t offered #1 because DHM never really had a use for a 330whp-340whp fuel system. Every turbo setup they ever fully marketed really did need 350+whp of fuel. And did they REALLY actually truely 100% test the idea of taking a real life car making 310whp with a commanded AFR of 11.1 that is seeing 12.5 AFR at 5800+ rpm and then slap in a $120 walbro 340lph? No.... they had a theory that it would not help, and moved on to $900 solutions that would support 350+ whp. A $900 soluation with a profit margin, vs a $120 soluation that could be bought from pretty much any vendor anywhere with not much profit margin ( but you do have to make sure you don’t get a China knock off, which has been an issue ).
I didn’t want to turn this into a debate or tech conversation. Mostly because honestly, it’s $120, and someone should just spend $300 at a local shop to have a walbro installed on there C39/X-47 and see what it will do on E30 before running out of fuel. But... in my research, this is what I found. Basically.
The LT1/LT4/LT5 guys actually do have HPFI upgrades and options. They have cam lobe upgrades etc. but what applies more to us and is more of a direct comparison is... the LT1 guys that add superchargers etc. what they found is... when they needed more fuel, they could buy the expensive LT4/LT5 HPFP and bolt it onto their LT1 system. But... they were disappointed to find, the peak torque was no longer an issue with fueling ( mid range RPM peak torque ), but the higher rpms, was still not getting enough fuel.
This is how this was explained. We ( fiesta ST etc ) look at pressure. “Is your fuel rail pressure dropping?” “Is your LPFP pressure dropping?”. But no one talks about the flow.
The HPFP is just a translator. Flow is flow. Pressure is pressure. The HPFP will FLOW about as much as you can throw at it ( ok, it surely has a limit at some point, but let’s not focus on that for now ). The HPFP simply takes what ever is “flowed” to it and translates it to higher pressure. If you FLOW 100hp of fuel in, it will take 100hp of fuel and jack up it’s pressure to requested (2900-ish psi on a hard tuned ST ). The HPFP doesn’t really “flow” anything. It does not dictate how much fuel is flowed or moved or supplied. It simply translates the fuel flowed to it from 90psi/200hp to 2150psi/200hp (in stock form). So you can flow 90-100psi/400hp to 2900psi/400hp.
This has been proven is LT1/LT4/LT5, as well as countless diesels. Let’s face it. This engine ( like all DFI engines ) is basically a Diesel engine that runs on gasoline.
Now don’t take me the wrong way. I’m not saying that if have a 400whp fiesta ST with an Aux fuel, that you could remove the aux fuel and just swap in a LPFP. I’m just saying 80% of the people with these cars want to make 300whp on e30 or 320whp on a hybrid turbo. Maybe 320-330whp on 108octane gasoline. Because 300whp on pump gas fuel on a hybrid turbo just isn’t going to happen ( aka, 93oct ).
Another, simpler option that a vendor could offer, would be a booster in-line pump. No removing the fuel tank. Little more room for profit. And it would really make a difference for those 80% looking to supplement their fuel system for another 30-40hp. Of course for customers like Mcgee, and myself the 5th injector is the way to go.
Isaac I’vd read the same debates over on the cobalt forums. “You can’t run just one 5th injector” etc etc etc. those threads are years and years old telling ZZP that it would not work correctly and fuel would not be evenly distributed etc etc. and years and years later, ZZP is basically the only name in that game and have countless 500whp builds on 1 single 5th injector. They even did tech posts about the difference cylinder to cylinder being equal to 11.100 or 11.095 AFR. And lots and plenty of “online experts” argued that ZZP wrong and all this, yet.... send me a link to a bolt on 4 port aux fuel for a cobalt SS. There isn’t one because the 5th injector is $500 and the MPFI would cost $1500 for .01 difference in cylinder fuel distribution.
Another thing we can learn from the cobalt SS crowd. They had modified HPFP’s. And it seems all of them ended up having issues with those upgraded HPFP’s, and currently, it seems they just skip the expensive and sometimes problem prone HPFP and just to the 5th injector.
That being said.... We have a MPFI setup. It’s expensive, but reasonably priced for what it is. And it def works ( my focus friends are happy with it ). But for less than 425whp, or even 400whp, Nothing wrong with the TB based 5th injector. And that’s about 97% of fiesta guys. And again.... if you upgrade the LPFP the entire system will be happier.
Do we really think ford built a 170whp car and put a 500whp fuel pump in it ?
The only real way to test this truely ? Take a guy with a car running Out of fuel ( non-aux fuel car ), and swap in a booster walbro or walbro 340lph ( or higher ) and see what happens. From all the research I’ve done, that wasn’t based with core in DHM knowledge/theory, says a LPFP upgrade could surprise us all. And it could do only a little bit, or it could shock us all. But it really
Just needs to be done by someone without a horse in the race ( and that excludes guys with AUX fuel system ). Tons and tons of guys running X37’s that could maybe use E50 instead of E30. Tons of guys running X47’s that could be fueling 300whp on E30. Tons of guys that could be fueling 300whp on C39’s on E30.
So really, the question is why hasn’t someone done this already ( ok, we know why, we were told it wasn’t going to help by a company that sells a solution that is 10times more expensive ). But with the research I’ve done ( before I installed the AUX fuel ), it’s a little more than interesting that no one has dared to upgrade the LPFP.
Then again.... I could be wrong lol. But unlike other sources, I don’t have a reason talk anyone into skipping the fuel pump upgrade. I don’t work for a vendor. I don’t work for Walbro. But it is rather interesting.
Mcgee is there a place we can read more about your specific hybrid ? I don’t want to loop it in with the X47/C39 stock rebuild type hybrids we have here if it’s a different sort of hybrid. Like... a new compressor housing and new bearing housing on a stock turbine housing or something.
Edit:
https://www.aetmotorsportshop.co.uk...rt-vt330-hybrid-turbo-kit-ford-fiesta-st-1-6t
Wow. That looks awesome. Why have we never seen or heard of this ?
Edit:
https://www.aetmotorsportshop.co.uk...rt-vt330-hybrid-turbo-kit-ford-fiesta-st-1-6t
Wow. That looks awesome. Why have we never seen or heard of this ?
![[offtopic]](/images/smilies/icon_smile_offtopic.gif "Off Topic [offtopic]"){kind=icon}
I know (maybe you should start a car/build thread on here?), but;Any pics with the red Cossie wheels on it?
On which gearbox/internals is AET going to base the sequential they are developing for you?
Factory case, or one of the aftermarket deals (X-Trac, Quaife, FFD, Sadev, Saenz, etc.) with an adapter plate setup?
![[dunno]](/images/smilies/icon_smile_dunno.gif "Dunno [dunno]"){kind=icon}
Thread Starter
#13
Merry Christmas to all you guys/gals over the pond !!! I will get back to this topic straight after new year and thank the big contributions. Seems a $150-300 solution might be there.. I will also upload a load of pics to FB and list the link.... This is only the beginning ;-)
Well, no one has verified yet, but there’s a possibility that we have the same LPFP as the FoST. With E45-50, and the supporting mods, they can see 500whp on the LPFP. My car is near maxing out the LPFP on E50. Even so, there was power left on the table at 425whp because of the TBI issues. I think it’s reasonable to expect 430-450whp with port injection. 460-470 with a built head. The reasoning is as follows: a built bottom end FoST w/ port Injection will make 420-460whp on E45-E50 (externally gated 2971r); built bottom end FiST on TBI will make 400-430whp on E45-50 (ext gated 2867r). They’re so close because the FoST has that stupid headfold holding it back. But a built head on a FoST will do anywhere from 470-550whp.
The TBI injector issue...well, both cars that failed at power failed in the same exact way. Both ran lean on the same cylinder and the ringland went bye bye in the same spot. While it’s only two cars, do we want to keep testing that? Once you start pushing higher power on the TBI a cylinder starts to run lean. It’s been seen on multiple cars and two engines have been lost to it. Another thing to take in account is engine size... Cobalts are 2.0L? I think the 1.6L is doing great for ~430whp on a TBI set up.
Anyway, I do understand the meat of the conversation. On our platform, looking back at the HPFP, the FRP begins to drop (at high RPM) and the AFRs go lean, while the LPFP is fine. This is where Aux fuel systems come in. They do the majority of their work on the top end. Pressure is pulled off of the stock system and the aux fuel shares the work load. This brings me back to the TBI system: when you’re really pushing it, the TBI is doing a LOT of the work. The HPFP is really the problem, and why we need aux fuel. Once my car is up and running, the port Injection will actually be doing the majority of fueling... Anyway on E85, the LPFP can’t flow as much past E50 (because of the amount of fuel needed) and pressure starts dropping.
At the end of the day, I can’t deny that it would be interesting to see a hybrid turbo with an upgraded LPFP. For the reasons above, I don’t believe the LPFP is an issue on fuels E50 and below, but someone trying it would close the question definitely. Now, around 500whp, like I brought up before, there definitely needs to be an upgrade...but that’s number crunching. It could actually be 450whp in real life...we haven’t been there yet.
No worries about a debate... I’ve enjoyed digging through my mind, though. Lots of typing on a phone, so I hope I hit all the points.
Sent from my iPhone using Tapatalk
The TBI injector issue...well, both cars that failed at power failed in the same exact way. Both ran lean on the same cylinder and the ringland went bye bye in the same spot. While it’s only two cars, do we want to keep testing that? Once you start pushing higher power on the TBI a cylinder starts to run lean. It’s been seen on multiple cars and two engines have been lost to it. Another thing to take in account is engine size... Cobalts are 2.0L? I think the 1.6L is doing great for ~430whp on a TBI set up.
Anyway, I do understand the meat of the conversation. On our platform, looking back at the HPFP, the FRP begins to drop (at high RPM) and the AFRs go lean, while the LPFP is fine. This is where Aux fuel systems come in. They do the majority of their work on the top end. Pressure is pulled off of the stock system and the aux fuel shares the work load. This brings me back to the TBI system: when you’re really pushing it, the TBI is doing a LOT of the work. The HPFP is really the problem, and why we need aux fuel. Once my car is up and running, the port Injection will actually be doing the majority of fueling... Anyway on E85, the LPFP can’t flow as much past E50 (because of the amount of fuel needed) and pressure starts dropping.
At the end of the day, I can’t deny that it would be interesting to see a hybrid turbo with an upgraded LPFP. For the reasons above, I don’t believe the LPFP is an issue on fuels E50 and below, but someone trying it would close the question definitely. Now, around 500whp, like I brought up before, there definitely needs to be an upgrade...but that’s number crunching. It could actually be 450whp in real life...we haven’t been there yet.
No worries about a debate... I’ve enjoyed digging through my mind, though. Lots of typing on a phone, so I hope I hit all the points.
Sent from my iPhone using Tapatalk
Interesting theory regarding the low and high pressure fuel system. You need to look at this system as a low side and a high side that work together.
Pressure and flow are directly related. Pressure is created by resistance, no resistance, no pressure. Increase pressure and you will increase flow. The high pressure side varies pressure between around 750psi to 2900psi depending on engine speed/load and boost of course. More pressure, more flow (flow from the injectors) verse time. As engine speed increases there is less time for the combustion cycle to occur. As we increase the boost level and air flow into the engine then naturally we need more fuel flow to compensate as well so the HPFP increases pressure. Opening the injectors and holding them open longer increases flow, increasing supply pressure to the injectors increases flow verse time. Remember the injectors really just open and close verse time, duty cycle.
The way the system works is basically the low pressure pump charges the inlet of the high pressure pump with fuel. The high side of the system creates the resistance and therefore pressure of the low side. Increasing flow to the high side by upgrading the LPFP will do nothing unless the low side of the system is failing to keep up with demand. Easily to check, run the vehicle on a dyno and max it out, measure low side pressure, is it dropping? Do you think any of the companies/Tuners marketing auxiliary fuel systems bothered to check this to find out which side of the system is running out of fuel first.
If the low side of the system is running out of fuel flow first then upgrades to the high side like adding auxiliary TB and now MP injection systems are not going work.
Pressure and flow are directly related. Pressure is created by resistance, no resistance, no pressure. Increase pressure and you will increase flow. The high pressure side varies pressure between around 750psi to 2900psi depending on engine speed/load and boost of course. More pressure, more flow (flow from the injectors) verse time. As engine speed increases there is less time for the combustion cycle to occur. As we increase the boost level and air flow into the engine then naturally we need more fuel flow to compensate as well so the HPFP increases pressure. Opening the injectors and holding them open longer increases flow, increasing supply pressure to the injectors increases flow verse time. Remember the injectors really just open and close verse time, duty cycle.
The way the system works is basically the low pressure pump charges the inlet of the high pressure pump with fuel. The high side of the system creates the resistance and therefore pressure of the low side. Increasing flow to the high side by upgrading the LPFP will do nothing unless the low side of the system is failing to keep up with demand. Easily to check, run the vehicle on a dyno and max it out, measure low side pressure, is it dropping? Do you think any of the companies/Tuners marketing auxiliary fuel systems bothered to check this to find out which side of the system is running out of fuel first.
If the low side of the system is running out of fuel flow first then upgrades to the high side like adding auxiliary TB and now MP injection systems are not going work.
I don’t need a dyno. At 285-290whp on 93oct, I can watch my LPFP drop from 100psi to 90psi on the high end. I can watch HPFP become less consistent as well.
You are more pressure will help flow to a point. But a walbro that flows 40% more at 90psi vs the stock pump pretty much means 40% more fuel dispite pressure. But really theory’s aside. Other platforms know what we are trying to “theorize” already ( and prove it ).
Isaac something to think about. What is your feeling of “what would have happened?” If your LPFP was already upgraded, and your commanded AFR was 10.5 instead of 12.5 ? Even if you saw an entire point shift from cylinder to cylinder AFR, you’d still be safe. Even you said already your LPFP was running out. Prob means your AFR target wasn’t 10.5. And I know with what you guys were doing with the car at the time was trying to squeeze every whp out of a maxed out setup, so leaning the car out sort of made sense. But.... running 10.5 AFR from 6,000-7400rpm wouldn’t be the end of the world for power. Def not “optimized” but if your using a 600whp to make 450whp, it’s not going to be a big deal to run a little rich. Just food for thought. Currently, on pump gas my car leans out to 12.5 above 5800rpm. Little leaner when it’s cold ( like 12.8 for 500rpm ). I guess I’d be the perfect person to test my own theory lol. But I’m fixing to switch to E50 and turn the aux on.
Maybe feel free to troll some diesel forums, old cobalt forum posts and newer LT-1/LT4 forums.
You are more pressure will help flow to a point. But a walbro that flows 40% more at 90psi vs the stock pump pretty much means 40% more fuel dispite pressure. But really theory’s aside. Other platforms know what we are trying to “theorize” already ( and prove it ).
Isaac something to think about. What is your feeling of “what would have happened?” If your LPFP was already upgraded, and your commanded AFR was 10.5 instead of 12.5 ? Even if you saw an entire point shift from cylinder to cylinder AFR, you’d still be safe. Even you said already your LPFP was running out. Prob means your AFR target wasn’t 10.5. And I know with what you guys were doing with the car at the time was trying to squeeze every whp out of a maxed out setup, so leaning the car out sort of made sense. But.... running 10.5 AFR from 6,000-7400rpm wouldn’t be the end of the world for power. Def not “optimized” but if your using a 600whp to make 450whp, it’s not going to be a big deal to run a little rich. Just food for thought. Currently, on pump gas my car leans out to 12.5 above 5800rpm. Little leaner when it’s cold ( like 12.8 for 500rpm ). I guess I’d be the perfect person to test my own theory lol. But I’m fixing to switch to E50 and turn the aux on.
Maybe feel free to troll some diesel forums, old cobalt forum posts and newer LT-1/LT4 forums.
I don't really need to troll diesel forums, my background is diesel truck engines and plant machinery. A 10 psi drop in the low pressure side is not going to make any difference when your talking about 2900psi from the high pressure pump.
Anyway you are free to think what you like, stick your Walbro pump on but this system is closed loop, no return line. (that's a hint)
Anyway you are free to think what you like, stick your Walbro pump on but this system is closed loop, no return line. (that's a hint)
My gut feeling is that it’d be a waste of money/time, but could be worth the certainty. I’d say I’m 99% sure it wouldn’t help much. Other platforms may have their stuff figured out, but I think it’s still comparing Fuji apples to Honey Crisp apples. Slightly different technologies, fueling strategies, cam profiles, ECU architectures, etc etc etc...
Plain and simple, the HPFP becomes a problem before the LPFP becomes a problem. But, maybe the community has just been traveling down the road of a mistake made long ago?
I have questions for you, though. If you’re convinced, why don’t you do it? If you knew all of this why did you buy aux fuel?
Sent from my iPhone using Tapatalk
Plain and simple, the HPFP becomes a problem before the LPFP becomes a problem. But, maybe the community has just been traveling down the road of a mistake made long ago?
I have questions for you, though. If you’re convinced, why don’t you do it? If you knew all of this why did you buy aux fuel?
Sent from my iPhone using Tapatalk
Similar threads
-
-
-
-
-
Ford Fiesta ST200 on The Grand Tour "Eboladrome" lap time board- Started by OffTheWall503
- Replies: 12
-
-
-
-
-
Ford Community Posts
-
Tail lights stuck on full brake light- Latest: TyphoonFiST
-
-
-
Finally test drove a FiST and FoRS and I finally get it…
- Latest: SpeedandPower