Am I running out of LPFP?

[DeTh]

Hey guys, technical question here.

LOG: https://bootmod3.net/log?id=668dcb8780350f446af008c3
This is revision 1 following my hpfp upgrade, so not finalized.

Relevant mods:
PS2+
Nostrum 180bar hpfps
PR Stage 3 Brushless LPFP
M5 EU5 Injectors
Currently tuning on E50

I'm going through the tuning process, and am getting inconsistent pulls. For 4 pulls the car can be running great and making all the power, then I can get 3 back to back where the car will start to pull, then buck hard. Upon looking at one of my recent datalogs, I'm noticing that my LPFP psi is around 70 off of the hit, then gradually pulls down until it hits low 50's (and sometimes 47-49).
I'm at around 30 psi (700ish WHP), and am not really close to approaching the claimed limit of the brushless LPFP (850whp claimed on E85, 900 on 93).

I talked with a few of my friends who are much more knowledgeable than I am regarding tuning (albeit they are not involved with BMWs: turbo k24 elise @600whp, and a tt gallardo friend) and both of them said that it is probably LPFP related.

Posting here just to try to confirm that. I am not super confident in their response only from the standpoint that there are lots of other people running this LPFP at this power level without issue. Could this be something else? All opinions wanted! Thanks

[DeTh]

Update - called Precision and they said the LPFP PSI was not normal. They want a log with the fuel cut and told me to send them the LPFP for internal inspection.

[Jaizero]

Your wastegate duty cycle is awfully high, and you are well below load target. Something is definitely up.

[Wanted_M]

For giggles, check you EKP module voltage.

[Schemxr]

this happened to me with precisions stage 4.5 lpfp after 2 years of use. the secondary pump gave up and my lpfp act psi went down to 58-60psig during WOT which was making my hpfp pressure drop causing fuel cuts.

sent them the lpfp back to diagnose and they fixed it with a new secondary pump and car is back to normal now.

i highkey recommend running a fuel regulator as well, i know the stage 4 and 4.5 kits come with an external regulator from precision raceworks, the fuel regulator must be set to 72 psi with ONLY the secondary pump activated since the main pump is controlled by the car and the secondary must be controlled by the regulator.

[-Eidos]

Originally Posted by DeTh

Update - called Precision and they said the LPFP PSI was not normal. They want a log with the fuel cut and told me to send them the LPFP for internal inspection.

Let me know if they say the LPFP is healthy and you reach a dead end. This may likely be the stock EKP not liking the upgraded brushless pump. If this is the case, then I may have a solution for it.

[NoorSinghJohal]

Originally Posted by -Eidos

Let me know if they say the LPFP is healthy and you reach a dead end. This may likely be the stock EKP not liking the upgraded brushless pump. If this is the case, then I may have a solution for it.

Is the solution an ekp cooler ?

[DeTh]

Originally Posted by Schemxr

this happened to me with precisions stage 4.5 lpfp after 2 years of use. the secondary pump gave up and my lpfp act psi went down to 58-60psig during WOT which was making my hpfp pressure drop causing fuel cuts.

sent them the lpfp back to diagnose and they fixed it with a new secondary pump and car is back to normal now.

i highkey recommend running a fuel regulator as well, i know the stage 4 and 4.5 kits come with an external regulator from precision raceworks, the fuel regulator must be set to 72 psi with ONLY the secondary pump activated since the main pump is controlled by the car and the secondary must be controlled by the regulator.

Did they fix it for you for free? They hadn't mentioned anything to me about pricing even though I am outside of their 1-year warranty. Talking to them on the phone their customer service was amazing. Steven took the time to look over a datalog I sent him and came to the same conclusion as me.
Would a regulator be necessary with the stage 3 brushless, since there is no secondary external Walboro?

Originally Posted by -Eidos

Let me know if they say the LPFP is healthy and you reach a dead end. This may likely be the stock EKP not liking the upgraded brushless pump. If this is the case, then I may have a solution for it.

I'll definitely update this thread. Someone else mentioned an EKP cooler which I see turner sells on their website (for cheap, $45) and the description mentions something about a 'Pro-Tool Voltage Fix Coding' which I haven't heard anything about previously. Does anyone has experience with this?

[Schemxr]

Originally Posted by DeTh

I'll definitely update this thread. Someone else mentioned an EKP cooler which I see turner sells on their website (for cheap, $45) and the description mentions something about a 'Pro-Tool Voltage Fix Coding' which I haven't heard anything about previously. Does anyone has experience with this?

no not for free, price of the part. around 230$ total including shipping. since i was outside their warranty time frame.

oh a brushless pump since it’s stage 3 then probably not. regulator is only if you have an additional secondary pump.

precision raceworks always has great customer service and their technicians are very knowledgeable and persistent to solve any problems. highkey recommend any of their products.

[-Eidos]

Originally Posted by NoorSinghJohal

Is the solution an ekp cooler ?

It's an upgraded brushless pump controller/EKP upgrade custom tailored to the Protec pump that's utilized in the Precision upgrade.

If the stock EKP is overheating, then an EKP cooler might be a temporary bandaid. If the stock EKP just isn't controlling the upgraded brushless pump properly, which is entirely possible and varies from car to car, then the cooler won't do a thing. Brushless pumps are very different than the two wire brushed pumps and are generally paired with a properly calibrated controller. When this isn't adhered to, pump life, controller life, or the controllers ability to accurately control the pump can be diminished.

[DeTh]

Update to this

So I purchased the brushless LPFP from someone here on the forum. Turns out it was a stock pump. I didn't realize when I installed because the brushless is supposed to be the same housing. PR called me and said they had no idea how I was able to get a single good pull in on the stock LPFP at 30psi of boost.

I got in contact with the dude that sold me the LPFP and he refunded me, not his fault. Shop removed his and mixed it up for the stock one.

If anyone has one for sale, let me know!

[Schemxr]

Originally Posted by DeTh

Update to this

So I purchased the brushless LPFP from someone here on the forum. Turns out it was a stock pump. I didn't realize when I installed because the brushless is supposed to be the same housing. PR called me and said they had no idea how I was able to get a single good pull in on the stock LPFP at 30psi of boost.

I got in contact with the dude that sold me the LPFP and he refunded me, not his fault. Shop removed his and mixed it up for the stock one.

If anyone has one for sale, let me know!

i would get a brand new one from precision raceworks, 2 years warranty and amazing customer and technicians thag will help you fix any problems. one thing to never skimp out on is proper fueling.

[DeTh]

Ok updated on this. Help would be greatly appreciated. This is a brand new LPFP. LPFP pressure now looks rock solid. I am still getting super aggressive misfires on WOT. Is this possibly an EKP problem? I have the BM3 top hat flex fuel sensor location.

https://bootmod3.net/log?id=66aabaf5afc0e52b4e9941a0

https://bootmod3.net/log?id=66aabe69607eb30daf5d0d26

I havent heard back from my tuner yet but my HPFP values looked super low on the second log.

[prisco]

HPFP is crashing really bad.

For reference my car with stock LPFP runs around 88psi. PS2+, EU5, stock HPFP and meth.

[DeTh]

Originally Posted by prisco

HPFP is crashing really bad.

For reference my car with stock LPFP runs around 88psi. PS2+, EU5, stock HPFP and meth.

These are the nostrum 180bar HPFPs. They shouldn't be at their limit. Maybe I just need a revision, Ill see what my tuner says

[prisco]

Originally Posted by DeTh

These are the nostrum 180bar HPFPs. They shouldn't be at their limit. Maybe I just need a revision, Ill see what my tuner says

They should hold 180 bar or 2600 psi but is crashing to 750 psi on the 2nd log.
Even my stock HPFP/LPFP on 30psi of boost same turbo never go lower than 2700.

[DeTh]

Originally Posted by prisco

They should hold 180 bar or 2600 psi but is crashing to 750 psi on the 2nd log.
Even my stock HPFP/LPFP on 30psi of boost same turbo never go lower than 2700.

I'm trying to look at the big picture here. Previously I never had any HPFP crashing until the LPFP values dropped. Now, we know that the LPFP are good values and not the cause here.
I see that the psi is crashing, but I see no reason to immediately point fingers at the HPFP being the problem here because I have had no issues with it previously.

[NoorSinghJohal]

Originally Posted by -Eidos

It's an upgraded brushless pump controller/EKP upgrade custom tailored to the Protec pump that's utilized in the Precision upgrade.

If the stock EKP is overheating, then an EKP cooler might be a temporary bandaid. If the stock EKP just isn't controlling the upgraded brushless pump properly, which is entirely possible and varies from car to car, then the cooler won't do a thing. Brushless pumps are very different than the two wire brushed pumps and are generally paired with a properly calibrated controller. When this isn't adhered to, pump life, controller life, or the controllers ability to accurately control the pump can be diminished.

I had my pr stage 3 brushless installed a couple days ago along with the dorch and eu5s.

Getting a shadow code of 11B210 Low fuel pressure sensor: Sensor value implausible.

Should this be any concern ?

[DeTh]

Originally Posted by NoorSinghJohal

I had my pr stage 3 brushless installed a couple days ago along with the dorch and eu5s.

Getting a shadow code of 11B210 Low fuel pressure sensor: Sensor value implausible.

Should this be any concern ?

I was just about to update this thread. I have the same code. I was going to email them. Are you getting fuel cuts?

[NoorSinghJohal]

Originally Posted by DeTh

I was just about to update this thread. I have the same code. I was going to email them. Are you getting fuel cuts?

I emailed them earlier today about it.

Can’t say anything about fuel cuts yet cause I’m still on my base tune just making sure everything is good.

Who is your tuner btw? Did you have your car on a dyno at 30psi for 700 whp cause that seems like a lot of boost for that.

[DeTh]

Originally Posted by NoorSinghJohal

I emailed them earlier today about it.

Can’t say anything about fuel cuts yet cause I’m still on my base tune just making sure everything is good.

Who is your tuner btw? Did you have your car on a dyno at 30psi for 700 whp cause that seems like a lot of boost for that.

Please update when you receive a response, Ill wait to email them then.

I'm tuned with RKTunes. I don't recommend.
Haven't actually dynod, just estimating based on a few comparable DI-only setups. It could be a bit more.

[NoorSinghJohal]

Originally Posted by DeTh

Please update when you receive a response, Ill wait to email them then.

I'm tuned with RKTunes. I don't recommend.
Haven't actually dynod, just estimating based on a few comparable DI-only setups. It could be a bit more.

I’ll let you know.

I had a hard time deciding tuners since there have been a lot of rough stories with some of the big tuners, I think I may have read about your story on the forum before too. Eventually decided to go with Chet Rickerman.