E30 Zone

hi guys ive searched and got more confused.
ive got a s50b32 in my m3, its got a fuel pump in the tank and a external.
i know the b32 uses a 5 bar pump and my stock one isnt up to the task.
i was gonna replace it with a walbro 255 or bosch 040 in tank and remove the external, just leave a filter there.
can i do that or do i need to keep both? should i replace internal pump or external or both
thanks

Do you have any issues with the pump? or running issues?

I know some guys with M3's running Alpha-N on S14's running with 5bar but can't remember if they used the M3 pump or another.

Keep in mind, it's not the pump which is rated at 5 bar, it's the pressure regulator.
As long as a pump can supply the AMOUNT of fuel required at a certain pressure, it will be fine.

Keep in mind, it's not the pump which is rated at 5 bar, it's the pressure regulator.
As long as a pump can supply the AMOUNT of fuel required at a certain pressure, it will be fine.

Exactly.

But if you do need to upgrade, I have a walbro 255 fitted in tank and it works well and fits fine.

I would recommend keeping the intank pickup pump and fitting an upgraded external, it would also be a good idea to fit a small swirl pot next to the external pump.

I used a walbro pump in the tank before and had terrible fuel starvation at anything under 1/2 tank of fuel. The original pickup is an important part of the tank/pump design so its best to keep it.

thanks guys it doesn't go as well in the top end of the rev range, just trying to eliminate the 20 year old pump. plus i have future mods im thinking ahead for..
so if i were to change just the external, would this effect the performance of the internal? (would it keep up)
what do you recommend for external walbro? bosch? /(best/easiest fit)
is the swirl pot necessary?

An upgraded external and swirl pot is the best bet. The swirl pot will more or less garauntee you wont have fuel starvation during cornering or on a low tank.

Bear in mind though: I used an M3 (M-Coupé to be precise) pump cut off an E36/7 cage and fitted to an E30 one. I then bought a sock filter very similar to the E30 one with a push on brass connector for the pump from FSE. Never had any issue with fuel starvation at all on my S50B32...

HTH

Jai

What external pump do you guys recommend for upgrading the stock one?

i used a walbro 255 intank, bracket needed to be modified a little. (shorten supply line on bracket, cut mounting bracket for old pump off, secure with steel cable ties.) this was because the walbro pump was taller than the original unit.
i removed external pump, replaced with a 12mm to 8mm reducer and a length of fuel line.(new filter)
runs much better i think my old ones were on their way out

Out of curiosity I was looking at E36 M3 fuel pumps on Ebay because some people use these in their conversions. Seems like there are several versions, 1 pipe and 2 pipes. I know the E30 intank has 2 pipes so that's probably what we can use. But can the 1 pipe version be used as well? How does it work?

on the intank pump bracket (e30) one is for a feed to engine and the other is a return. i dont know about the e36 pump/bracket.

Never mind my ignorance. I took apart the feeder unit last Sat and found out the motor itself had only 1 outlet which connected to one of the pipes. The other pipe was the return pipe. So I recon if I am to retrofit the M3 fuel pump, either one would work, as long as it can build enough pressure.

update on walbro.
it didnt generate enough pressure on its own so i had to use the stock inline pump aswell.
need to find a better solution for the pump

In answer to your origional question, Yes, you can run with the E36 EVO pump in the tank on a modified E30 cradle out to the standard filter. Mine has been running like that for 8 years and never a problem.