twin fuel pump conversion - Page 4

adem.csl · 09-04-2013, 11:38 PM

Cantfind1 honestly what did you do in the end?after all the discussion you followed the gorilla?

**shimmy** · 09-04-2013, 11:54 PM

Quote:

Originally Posted by adem.csl

The Gorilla.Yes well put, however the fundamental floor in your plan is that the crap oem pump is not strong enough to suck fuel through lengths of hose around the tank hence why you install a second pump in place of the sender unit on the left hand side to push fuel to the right hand pump.

Hardly any extra weight as you are replacing the other unit with the same thing any way, it just has a pump in it which weighs grams!

The oem pump degrades over time and does not produce enough flow anyway, hence why i am going with the walbro conversion for piece of mind.
d1

So what would be the difference between a CSL with a new pump with full flow and a CSL with a tired pump with degrading flow.(I'm assuming you are on about flow and not pressure)?

Tbh that does sound like a quote from a whole load of US forums all rolled into one!

northernjim · 10-04-2013, 12:14 AM

Quote:

Originally Posted by adem.csl

The Gorilla.
Yes well put, however the fundamental flaw ( sorry had to correct that) in your plan is that the crap oem pump is not strong enough to suck fuel through lengths of hose around the tank, hence why you install a second pump in place of the sender unit on the left hand side to push fuel to the right hand pump.

Hardly any extra weight as you are replacing the other unit with the same thing any way, it just has a pump in it which weighs a kilogram!

you seem to be heading in your direction Adem no matter what......

a fuel pump will suck fuel thru a single length just as ( near as dammit) easily as a t piece....... have you flow tested a pump to see how much pressure and flow is affected?

adem.csl · 10-04-2013, 01:30 AM

That's not my post that was cantfind1 reply to gorilla post.the one that Neil m has added about making up the t pipe system.lol..sorry should have put it as a quote.read from Neil m post and it wil make sense.sorry im tryin to do this on a phone

adem.csl · 10-04-2013, 01:32 AM

Quote:

Originally Posted by northernjim

you seem to be heading in your direction Adem no matter what......

a fuel pump will suck fuel thru a single length just as ( near as dammmit) easily as a t piece....... have you flow tested a pump to see how much pressure and flow is affected?

Sorry I'm not disputing just gathering info before i open my tank.measure twice cut once kinda thing.lol

adem.csl · 10-04-2013, 01:43 AM

http://www.cslregister.com/forum/sho...uel+Starvation
This link is where I'm finding the info.all I'm asking is did twin pump work on csl and how did it plumb in.got the answers to both questions.I was just asking cantfind1 if he was bein honest about using a walbro pump and t piece after discussing wid gorilla that it was cheap route that wouldn't work.

**cantfind1** · 10-04-2013, 02:05 AM

Ah...yeah ok...little confused....To be honest I have only made this change over this winter...have not read that other thread for a while.

TBH now that I have changed the OEM pump for the walbro one and added an extra length of fuel hose to suck from the left hand side of the tank, it seems to have made no difference to flow or pressure. Dyno results confirm AFR is thet same as before the mod.

However I did not add the walbro and the extra suck from the left at the same time.

I originally fitted two pumps...replaced the sender on the pax side with an oem pump and the oem pump on drivers side with walbro, this led to drop in power due to increased flow and rich running hence the change in fuel trim in ecu map...this also buggered up fuel guage reading but i lived with it.

I eventually wasn't happy with this solution....

I then spoke to various people I know and discussed ditching the second pump and just running a second feed from left side to the walbro pump on the right....so far it works, fuel guage is back to normal and AFR seems to be unchanged...I have not tested on track yet....I only used to get fuel starvation at Spa(this was with OEM pump as well)....seemed to not happen on other tracks i have used...

However my walbro pump is fairly new so I will be keeping an eye on this mod to make sure the walbro is coping wih sucking fuel from the other side of the tank...so far so good as i can hear a lot of fuel returning to the tank when idling, not sure whats happening at high rpm though....

I would not suggest doing this mod with your old OEM pump as they are crap. At a later date I will be running a swirl pot....

So what's the question?? lol

**alexk** · 10-04-2013, 10:41 AM

Why do you say OEM pump is crap ?

adem.csl · 10-04-2013, 04:04 PM

Quote:

Originally Posted by cantfind1

Ah...yeah ok...little confused....To be honest I have only made this change over this winter...have not read that other thread for a while.

TBH now that I have changed the OEM pump for the walbro one and added an extra length of fuel hose to suck from the left hand side of the tank, it seems to have made no difference to flow or pressure. Dyno results confirm AFR is thet same as before the mod.

However I did not add the walbro and the extra suck from the left at the same time.

I originally fitted two pumps...replaced the sender on the pax side with an oem pump and the oem pump on drivers side with walbro, this led to drop in power due to increased flow and rich running hence the change in fuel trim in ecu map...this also buggered up fuel guage reading but i lived with it.

I eventually wasn't happy with this solution....

I then spoke to various people I know and discussed ditching the second pump and just running a second feed from left side to the walbro pump on the right....so far it works, fuel guage is back to normal and AFR seems to be unchanged...I have not tested on track yet....I only used to get fuel starvation at Spa(this was with OEM pump as well)....seemed to not happen on other tracks i have used...

However my walbro pump is fairly new so I will be keeping an eye on this mod to make sure the walbro is coping wih sucking fuel from the other side of the tank...so far so good as i can hear a lot of fuel returning to the tank when idling, not sure whats happening at high rpm though....

I would not suggest doing this mod with your old OEM pump as they are crap. At a later date I will be running a swirl pot....

So what's the question?? lol

Question answered thank you cantfind1.that's all I was after because the other thread left no conclusion.thanx again.

Which pump did you use?255lph or 450lph?thanx

**cantfind1** · 10-04-2013, 04:38 PM

Walbro 255, a little noisey but once you're running you can t hear it! You get a lot of flow with this pump way more than OEM, pressure obviously is the same due to regulator....

It seems more than able to handle the extra pipe to the left side of the tank.

However as I said you may find your car will run rich so best to get dyno run before and after to get a rough idea of AFR's

09-04-2013, 11:38 PM	#31
adem.csl S5, Sport On, DSC M-track Join Date: Sep 2012 Location: north london Posts: 1,012 Casino cash: $7218	Cantfind1 honestly what did you do in the end?after all the discussion you followed the gorilla? __________________ Bmw in the blood!!

10-04-2013, 01:30 AM	#34
adem.csl S5, Sport On, DSC M-track Join Date: Sep 2012 Location: north london Posts: 1,012 Casino cash: $7218	That's not my post that was cantfind1 reply to gorilla post.the one that Neil m has added about making up the t pipe system.lol..sorry should have put it as a quote.read from Neil m post and it wil make sense.sorry im tryin to do this on a phone __________________ Bmw in the blood!!

10-04-2013, 01:43 AM	#36
adem.csl S5, Sport On, DSC M-track Join Date: Sep 2012 Location: north london Posts: 1,012 Casino cash: $7218	http://www.cslregister.com/forum/sho...uel+Starvation This link is where I'm finding the info.all I'm asking is did twin pump work on csl and how did it plumb in.got the answers to both questions.I was just asking cantfind1 if he was bein honest about using a walbro pump and t piece after discussing wid gorilla that it was cheap route that wouldn't work. __________________ Bmw in the blood!!

10-04-2013, 02:05 AM	#37
cantfind1 S5, Sport Off, DSC M-track Join Date: Oct 2009 Location: Sydney Australia Posts: 675 Casino cash: $6490	Ah...yeah ok...little confused....To be honest I have only made this change over this winter...have not read that other thread for a while. TBH now that I have changed the OEM pump for the walbro one and added an extra length of fuel hose to suck from the left hand side of the tank, it seems to have made no difference to flow or pressure. Dyno results confirm AFR is thet same as before the mod. However I did not add the walbro and the extra suck from the left at the same time. I originally fitted two pumps...replaced the sender on the pax side with an oem pump and the oem pump on drivers side with walbro, this led to drop in power due to increased flow and rich running hence the change in fuel trim in ecu map...this also buggered up fuel guage reading but i lived with it. I eventually wasn't happy with this solution.... I then spoke to various people I know and discussed ditching the second pump and just running a second feed from left side to the walbro pump on the right....so far it works, fuel guage is back to normal and AFR seems to be unchanged...I have not tested on track yet....I only used to get fuel starvation at Spa(this was with OEM pump as well)....seemed to not happen on other tracks i have used... However my walbro pump is fairly new so I will be keeping an eye on this mod to make sure the walbro is coping wih sucking fuel from the other side of the tank...so far so good as i can hear a lot of fuel returning to the tank when idling, not sure whats happening at high rpm though.... I would not suggest doing this mod with your old OEM pump as they are crap. At a later date I will be running a swirl pot.... So what's the question?? lol Last edited by cantfind1; 10-04-2013 at 02:25 AM.

10-04-2013, 10:41 AM	#38
alexk Driving it like I nicked it Join Date: Mar 2009 Posts: 2,785 Casino cash: $29970	Why do you say OEM pump is crap ? __________________ www.clubcsl.com - I am a BMW Motorsport fan ! My youtube channel is here

10-04-2013, 04:38 PM	#40
cantfind1 S5, Sport Off, DSC M-track Join Date: Oct 2009 Location: Sydney Australia Posts: 675 Casino cash: $6490	Walbro 255, a little noisey but once you're running you can t hear it! You get a lot of flow with this pump way more than OEM, pressure obviously is the same due to regulator.... It seems more than able to handle the extra pipe to the left side of the tank. However as I said you may find your car will run rich so best to get dyno run before and after to get a rough idea of AFR's