[Wedge1967]

I have the same issue now. I removed my booster pump before taking my car to get new turbos so I'm running 100% stock now and with Stage 1 + Sport OTS my LPFP is dropping into the 50's. So before I put all my mods back on and crank up the power again (without the PROcede this time) I'll be replacing my LPFP... Did I mention I have an AP now?

[matty088]

Installed cobb. Definitely a nice gain. Seems like it has some lag though. Will that improve as it learns the car. Only drove for twenty mins.also how much vacuum u guys seeing at idle. I have 9-10

[Jnat]

When you flash, the vehicle has to adaptive learn, the tune feel will improve over time.

[VNeBLOB42]

Originally Posted by matty088

Installed cobb. Definitely a nice gain. Seems like it has some lag though. Will that improve as it learns the car. Only drove for twenty mins.also how much vacuum u guys seeing at idle. I have 9-10

A few +1 WOT and you'll be good.

[VNeBLOB42]

Originally Posted by enrita

just log lpfp pressure, afr and stft. if pressure drops below 50-40 and you lean out than your lpfp cannot push enough fuel to the hpfp . All this things should be known BEFORE starting to experiment...

OK @enrita, help me understand something. I was aware of the LPFP issues before I went E50. not sure if this is all speculation but, this talk about running E40 is max without a lpfp solution is a grey area to me.

my WOT logs with stock LPFP logged 4 line items in the 50's (all rest in 60/70's) but never dropped below 52. Was told its normal to drop below requested PSI @ 72.48.

So does this mean my LPFP is good (for now?). There is just too many problems i have seen/read with a booster pump solution. If my LPFP is running fine, why should i go with a booster pump? Is it just a matter of time before my LPFP takes a dump? Just trying to fully understand the risks involved with my setup.

thanks,

Vince

Log Attached...

[135Pats]

Originally Posted by VNeBLOB42

OK @enrita, help me understand something. I was aware of the LPFP issues before I went E50. not sure if this is all speculation but, this talk about running E40 is max without a lpfp solution is a grey area to me.

my WOT logs with stock LPFP logged 4 line items in the 50's (all rest in 60/70's) but never dropped below 52. Was told its normal to drop below requested PSI @ 72.48.

So does this mean my LPFP is good (for now?). There is just too many problems i have seen/read with a booster pump solution. If my LPFP is running fine, why should i go with a booster pump? Is it just a matter of time before my LPFP takes a dump? Just trying to fully understand the risks involved with my setup.

thanks,

Vince

Log Attached...

IMO if your LPFP is meeting 50psi minimum it's not getting its ass kicked. If it falls below that it'll start to drag HPFP PSI down with it. So if your not running tight on fuel trim, and AFRs look good, I think 50PSI as a minimum LPFP PSI is OK. I've only recently started to mess with E85, but that's what my experience has been.

[VNeBLOB42]

Originally Posted by 135Pats

IMO if your LPFP is meeting 50psi minimum it's not getting its ass kicked. If it falls below that it'll start to drag HPFP PSI down with it. So if your not running tight on fuel trim, and AFRs look good, I think 50PSI as a minimum LPFP PSI is OK. I've only recently started to mess with E85, but that's what my experience has been.

Thanks,

yeah my trims and AFRs are good.

[matty088]

Originally Posted by VNeBLOB42

A few +1 WOT and you'll be good.

Tks for reply. What does +1 mean

[enrita]

Originally Posted by VNeBLOB42

OK @enrita, help me understand something. I was aware of the LPFP issues before I went E50. not sure if this is all speculation but, this talk about running E40 is max without a lpfp solution is a grey area to me.

my WOT logs with stock LPFP logged 4 line items in the 50's (all rest in 60/70's) but never dropped below 52. Was told its normal to drop below requested PSI @ 72.48.

So does this mean my LPFP is good (for now?). There is just too many problems i have seen/read with a booster pump solution. If my LPFP is running fine, why should i go with a booster pump? Is it just a matter of time before my LPFP takes a dump? Just trying to fully understand the risks involved with my setup.

thanks,

Vince

Log Attached...

as long as afr are stable and you dont lean out you are fine , of course you are making the lpfp work much harder. Depends as well how much power you are putting down. on E50 with stock lpfp i was leaning out after 6k .

[VNeBLOB42]

Originally Posted by matty088

Tks for reply. What does +1 mean

And another / 1 more

[VNeBLOB42]

Originally Posted by enrita

as long as afr are stable and you dont lean out you are fine , of course you are making the lpfp work much harder. Depends as well how much power you are putting down. on E50 with stock lpfp i was leaning out after 6k .

Thanks, ill take a look st my trims around 6k.

[matty088]

How much boost u guys seeing on stage one aggressive?

[VNeBLOB42]

Originally Posted by matty088

How much boost u guys seeing on stage one aggressive?

I think it's ~18.5 to about ~12. Ill have to double check.

[135Pats]

Normal stg1 agg? No way it boosts 18.5psi, i think it tops out at closer to 14-15.

[matty088]

Yeah I M seeing 14-15.

[VNeBLOB42]

Originally Posted by 135Pats

Normal stg1 agg? No way it boosts 18.5psi, i think it tops out at closer to 14-15.

Yeah I thought it didn't sound right when typing it I'll double check my logs I thought for sure it was, This sounds like more for down pipes. Anyway, what do I know..

[quattr0]

I have Stage1+FMIC installed. I was reading the NCS DIY guide under BMW Coding sub-forum http://www.e90post.com/forums/showthread.php?t=451145 .

One of the steps is to reset the ECU. I assume I need to uninstall Cobb first? Do the coding step and re-install stage1+FMIC? Or, the ECU reset will wipe out Cobb and cause me further trouble when trying to re-install/loading stage1+FMIC?

Thanks for any input.

[Jeffman]

Originally Posted by matty088

Yeah I M seeing 14-15.

Remember, max boost will depend on intake temp. Cooler temps mean denser air mass which means being able to hit the required load targets / afr at lower boost. Hot air temps require higher boost to hit targets.

[Florida650iGC]

Originally Posted by 135Pats

Normal stg1 agg? No way it boosts 18.5psi, i think it tops out at closer to 14-15.

I have hit 18.24 PSI on Stg 1+ FMIC SPORT map at about 4k rpm

[Florida650iGC]

Originally Posted by Jeffman

Remember, max boost will depend on intake temp. Cooler temps mean denser air mass which means being able to hit the required load targets / afr at lower boost. Hot air temps require higher boost to hit targets.

+1

This is probably why mine boosts so high, IAT in excess of 100*

[marv85]

Originally Posted by matty088

How much boost u guys seeing on stage one aggressive?

Originally Posted by 335XI///M

I have hit 18.24 PSI on Stg 1+ FMIC SPORT map at about 4k rpm

Originally Posted by 335XI///M

+1

This is probably why mine boosts so high, IAT in excess of 100*

stage1+ is very different from stage1 though. much more aggressive. It's more close to stage2+ than it is to stage 1.

18psi is impossible on stage1. if you see could be overboost, or when you let off your throttle. but it's not something you'll target

stage1+ agg, I can see it target 18 depending on various conditions (as mentioned a couple of posts above)

[VNeBLOB42]

^^ Thanks @marv85 for clarifying, I knew I wasn't crazy.

Just checked my logs with S1+ Agg w/ 20% E85 pump blend.

I was getting ~18.5 psi - ~12 psi (at redline) when CAT's are under 100°