F4i Fuel Pump

[wtpLXfox]

I searched and saw some threads from 4 years ago on this, but who is running the stock F4i fuel pump? We're looking at going with this and I'm curious to see what issues people ran into with running the in-tank pump. Was the biggest issue in the tank design or any running issues and starving the car?

-David

[wtpLXfox]

I searched and saw some threads from 4 years ago on this, but who is running the stock F4i fuel pump? We're looking at going with this and I'm curious to see what issues people ran into with running the in-tank pump. Was the biggest issue in the tank design or any running issues and starving the car?

-David

[Diablo_niterider]

hey,

we have been running the stock pump for 2 years now with no problem whatsoever ,this year we are changing to an external pump for making the fuel tank of complex shapes for packaging reasons

the problems i see would be

1 - the size of the pump which will increase the size of the tank, hence packaging could be an issue

2 -leakage issues - we had to cnc the mounting plate and use sealants to ensure that it doesnt leak , it didnot for us

3- more time consuming to service than an external pump

advantages are that its perfect for starters , you dnt have to worry about pressure regulation etc

[Marshall.Hagen]

In addition to the above points, do not run an internal pump if you plan on using E85 (conductive!).

[Poe]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">do not run an internal pump if you plan on using E85 (conductive!) </div></BLOCKQUOTE>
do what?

Our dyno fuel tank was a stock F4i bike tank and pump. It ran just fine on E85. I don't see why E85 would be any more or less conductive than regular gasoline, or why it would even matter. What am I missing?

[VFR750R]

ethanol is electrically conductive but gasoline is not. i don't know about E85 but i'm assuming since part of the mix is conductive it will be conductive as E85.

Most internal pumps let the gasoline cool the rotor of the electric motor directly, running with alcohol can short the pump. Now, I've heard of many people running internal pumps with alcohol and claiming to be unaffected, no doubt the pumps will continue to work, but I think you'll see more amperage draw compared to gasoline, with that extra amperage just shorting through the E85.

[Poe]

Doesn't the fuel run directly through the windings of an external pump as well? What is the difference, the electric hookup isn't submerged?

[VFR750R]

not all external, not even all internal pumps for that matter. its almost model specific, but most aren't compatible with alcohol fuels.

[Poe]

I always figured the alcohol compatibility thing was more whether or not the pump would last when exposed to alcohol. Oh well, I learn something new every day.