hans14914

I am *considering* swapping over to a fuel cell instead of the factory plastic tank. E85 is prevalent in the midwest, so I think I would like to give it a try. I know the factory tank doesnt like the stuff, and I have had leaks in my tank before in the past, so its probably a good idea to swap it out anyway.

I do have a spare plastic tank, and ready to go back with stock, so in advance, I would like to ask people to try and keep on topic, and not make this about "why do the switch."

On the 89+ cars, we have the wonderful digital dash, and it has a nice calibration utility for the tank. If the capacity for the tank is reduced, can the recalibration routine "learn" the new volume, or will it always assume the stock volume? I would guess that it has a built-in lookup table where it compares the sender signal to a list of volumes because the tank is oddly shaped, and the fuel level in the tank does not correlate simply to the fuel quantity in the tank.

In short, if I swap to a fuel cell, that say is a 15gallon unit, would I be able to get the digital readout to work properly with a scaled output from an aftermarket sender, or woudl i need to retain the stock sender, or is there a program in the dash that will fight it no matter what I do?

Thanks,
Hans

Vilhuer

You can get at least 15L level right by using stock sender and calibrating it same way as shown in WSM. But if tank shape is different all other reading will be off. How much is good question.

AO

Hans,

I could be wrong on this, but I beleive the the fuel level calibration is only to calculate distance till empty. I do not beleive it actually affects the fuel level indicator. And since you're going to be using different-sized injectors, the reading on the digital dash will be off no matter what, as it's based on the injector pulse rate for the stock 19# injectors.

hans14914

I already have a solution to fix the injector issue, so now have to make sure I can keep the tank level in check. I may just have to use that spare tank I have in the garage with some water for "dataloging" the output of a sensor. Anyone have a fuel level sender laying around? I am sure someone has already plotted this out, if so, anyone have the correction curve?

Thanks,
Hans

dprantl

Can you please share this solution?

Dan
'91 928GT S/C 475hp/460lb.ft

hans14914

You can feed the dash a dummy 19lb signal with a micro controller like an Arduino (see the MPGduino project for inspiration). It would require creating a custom correction table, but not too complicated. However, I would like to try and keep this thread about the fuel level only.

Thanks,
Hans

dprantl

Sorry about the off-topic post, but thanks for the info.

Dan
'91 928GT S/C 475hp/460lb.ft

Lizard928

So long as the depth of the tank is nearly the same as factory then the guage will work as normal.

I could however make you an aluminum tank that is nearly the same as factory. You would need to have it anodized after to ensure it was protected.
It wouldnt be cheap either. But neither is a good fuel cell....