No PI, no overdrive, no meth - How much power is available with only LPFP upgrade?

typedRew

Sergeant
Feb 25, 2019
404
213
0
Ride
2009 335i xDrive
I searched but couldnt find a definitive agreed upon answer.

Lets say I have increased air flow with larger twins, but not an upgraded fueling solution aside from a dual 450 low pressure upgrade.

Whats the number that can be chased with a limited amount of ethanol. i know with a decent sized single ive seen people get into the high 500s, but i doubt bottlenecked twins will do anywhere near that. So we would probably need ethanol, but with ethanol comes increased fuel system demand. So its going to be a fine line between fuel flow capability and knock threshold with limited ethanol content.

I feel like ive seen people do 550 wheel without issue with about E50 in the tank. Does that seem viable? Is more available with less ethanol content?

I don't think ive seen a lot of people go for a mid to high 500s number without more fuel, so i'm curious what people think about the stock DI capability with low side only upgrade.

I do plan on running meth injection, but i'd like two solid tunes without, 93 and E30/40/50. Just curious.
 

Torgus

Major
Nov 6, 2016
1,852
1,307
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Boston
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ACF 6466 E92 + METH
Not as much as you probably want ;)

Get a custom tune on 93 1st. Dyno and see where you are.

Then get a custom tune on E85. You will see your rail pressure dive when the HPFP can't keep up. You will have to play around with E content %s and it will depend on how healthy your HPFP is. I would start with a very low E content % and slowly increase it until you can see the HPFP not be able to keep up and then back it off a bit. Your tuner should do this all for you. Then dyno. Share dynos with the community.
 

typedRew

Sergeant
Feb 25, 2019
404
213
0
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2009 335i xDrive
Oh im well aware i'll want more power, thats why ill have meth in the end. Im just curious what can be done without.

I most likely wont dyno, i dont care about the numbers that much. I will however share my 1/4 and 60-130 times on all the finished tunes.
 
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Blaster3500

Sergeant
Nov 5, 2016
287
227
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SC
You probably could not find and answer because it varies a good bit between setups. Pump condition, turbo size, fuel, how far you are willing to push it rail pressure wise, weather etc all play factors. I would say on average 525 is around the limit, but the new HPFP tables may help some. It is a bit frustrating trying to push it to the edge and constantly watching logs to make sure rail pressure looks good.
 

zomski101

Lurker
Dec 28, 2019
24
4
0
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335i
According to virtual dyno, on dynojet setting, I made 484 whp on e50 with mmp stage 3 and single walbro 450. Rail pressure was around 1350 to 1450 and lpfp didn't dip below 62psi.
Maybe with a more aggressive/revised tune i'd probably get 500whp.
 

yuli8466

Specialist
Sep 6, 2018
79
12
0
you can shoot at 700WHP at racegas and very large single turbo at top end with some tuning. I saw somebody reach 765WHP in this forum . I ask the same question before years , you can make a seach
 

JohnDaviz

Sergeant
Jan 6, 2019
356
202
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335i E92 DCT
@martymil Is there a known psi limit for the hpfp? My understanding is the less psi you have the higher the dutycycle is for the injectors and the longer the injecting times get.

My understanding was that 1400psi was meant as a "safe" limit.

Can you elaborate on this?
 

martymil

Colonel
Sep 6, 2017
2,413
1,423
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Down Under @ madautodevelopments
madautodevelopments.com
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S65 1m
On hybrids 20psi to redline I've seen no issues and run down as low as 1000 psi as long as your injectors are healthy along side plugs and coils.

you will need a stage 2 pump and drill out your rail, pull filter out of di pump and modify the di lpfp stainless line to unlock full flow not to cavitate it
 
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twinturbos

Sergeant
Jan 1, 2019
269
66
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E92 335i MT
On hybrids 20psi to redline I've seen no issues and run down as low as 1000 psi as long as your injectors are healthy along side plugs and coils.

you will need a stage 2 pump and drill out your rail, pull filter out of di pump and modify the di lpfp stainless line to unlock full flow not to cavitate it

Is there a guide for all that somewhere ?
 

Dramat1ca

Lurker
Jul 10, 2018
10
3
0
Ride
n54 335i 6MT
I think my car might be relevant to this question, maybe not. I went and got a baseline dyno run yesterday before I try out port injection. I wasn't able to grab any logs because I was having issues with the wifi MHD for some reason. šŸ˜­ I can go get a couple though because I understand this info is useless without them...

100k miles
Fuel-it stg 2 fuel pump
GC lites
FBO
Wedge tuned
flex fuel kit
all maintenance done, new index 12's, new HPFP.
E25 mix

Drove 40 mins to the shop and immediately did 3 pulls. short clip at the end.
IMG_5095.jpg

"
 

langsbr

Captain
Apr 5, 2017
1,189
678
0
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07 335i 6MT e90
550whp should be easily reached on e40 - e50 with just a stage 2 LPFP. There's been at least a half dozen or so crack 600whp on hybrids with just a stage 2 LPFP (bucketless) on e40 - e50. Probably not in the 1300+ rail pressure but it'd doable. I've yet to dyno but my car traps 130 on E30 with just a bucketed stage 2 pump.