Converting to e85 on the returnless system.

Have been digging for awhile trying to figure out everything I need to convert to e85 on the returnless fuel system and still have questions. The set up I’m going to run. Is -4 lower, 2.76 upper, ported Eaton, full exhaust etc.

So far I’ve gathered 80lb injectors, walbro dual gss340 pumps, lethals -8 fuel line upgrade kit.

My questions are, flex fuel sensor(will it be a restriction since it would be placed in the feed line? Or can I not use one? Yes I understand each station is going to vary on ethanol content but I don’t plan to run anything besides e.
, fpdms,
will I need a BAP?
what about the factory maf?
will I have to modify my stock fuel hat to support the pumps.
I know most recommendations are to just do it all once and go returnless the proper way. But I’m just trying to touch 550whp and leave the car alone for a few years. Thanks for any advice.

I am not sure if anyone uses as flex Fuel Sensor on our year cars. It is something I have looked at in the past but could not find anyone making one for us. Most use the ole water and fuel tube to check.
You can use your factory MAF with a MAFia or you can upgrade to an aftermarket one. You probably should make sure you have upgrade FPDM(s). One of the biggest restrictions in the fuel system is the stock hat so yes you should upgrade the hat. Also the pumps are different sizes so make sure you have the correct depth and they are held in there correctly. In the end if you go return style you will end up paying for it twice.

Braydon kahl said:

Have been digging for awhile trying to figure out everything I need to convert to e85 on the returnless fuel system and still have questions. The set up I’m going to run. Is -4 lower, 2.76 upper, ported Eaton, full exhaust etc.

So far I’ve gathered 80lb injectors, walbro dual gss340 pumps, lethals -8 fuel line upgrade kit.

My questions are, flex fuel sensor(will it be a restriction since it would be placed in the feed line? Or can I not use one? Yes I understand each station is going to vary on ethanol content but I don’t plan to run anything besides e.
, fpdms,
will I need a BAP?
what about the factory maf?
will I have to modify my stock fuel hat to support the pumps.
I know most recommendations are to just do it all once and go returnless the proper way. But I’m just trying to touch 550whp and leave the car alone for a few years. Thanks for any advice.

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GodStang said:

In the end if you go return style you will end up paying for it twice.

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I'd really look into this option hard. You can make the returnless system work, but it won't be any cheaper really. I priced out a returnless system when I found a NIB Fore hat for sale. I was $400 away from a whole new L2 system when all was said and done. So I have a return style system waiting to go in.

I understand what everyone is saying. But let’s just continue on the topic of a ported eaton e85 cobra on the returnless system for the sake of this topic. (I may end up going to return style after all) I have -8 feed line, walbro gss342 pumps, and 80lb injectors, what fpdms do I need? Or what do people buy? Will I need a BAP? With the MAFia, would I still need say an hptuners license or sctx4 for a tuner to custom tune on?

If you want to put the sensor in line. Just "Y" the line so the main line won't be restricted.

Braydon kahl said:

I understand what everyone is saying. But let’s just continue on the topic of a ported eaton e85 cobra on the returnless system for the sake of this topic. (I may end up going to return style after all) I have -8 feed line, walbro gss342 pumps, and 80lb injectors, what fpdms do I need? Or what do people buy? Will I need a BAP? With the MAFia, would I still need say an hptuners license or sctx4 for a tuner to custom tune on?

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Will the Walbros work in a returnless set up? My guess is you'll either need dual stock FPDM's with the matching harness or an upgraded FPDM. Both of which you can get from Black306. Don't forget the needed wire upgrade to power everything. I can't answer the need for a BAP, but personally I'd stay away from it.

Whether you go with an upgraded MAF or a MAFia you'll need a tune. If you have the choice go with the upgraded MAF. If you decide to tune it yourself you'll need some sort of software like the HP license.

slo984now said:

Will the Walbros work in a returnless set up? My guess is you'll either need dual stock FPDM's with the matching harness or an upgraded FPDM. Both of which you can get from Black306. Don't forget the needed wire upgrade to power everything. I can't answer the need for a BAP, but personally I'd stay away from it.

Whether you go with an upgraded MAF or a MAFia you'll need a tune. If you have the choice go with the upgraded MAF. If you decide to tune it yourself you'll need some sort of software like the HP license.

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This! You should not use GSS342s in a returnless. You can either go dual fpdms or upgraded. Yes upgrade the wires. Probably won't need a BAP at this point but every setup is different. Yes you will still need a tune to get the MAF to work.

Thanks for everyone’s replies. I ended up buying a fore returnless set up that has a configuration to be ran as return style.

get the aem a/f gauge with the flex fuel sensor in it already

If you're using the factory computer....the flex fuel sensor will only be for reading the content in the tank....the factory computer will not change the tune on the fly. So, if the ethanol content changes enough from your current tunes assumption of what it is....you're gong to need to manually drop in a new tune.

I'd rather just test pump side before product goes into the tank so you could swap tunes immediately before the car even fires back up. Fortunately for me, that's never an issue because the station I use is 85% or slightly greater year round, and year after year.

Regarding the pumps....I do not believe they are for returnless use, only return.

I have seen the gss342s work just fine in ethanol.....but they are not rated for ethanol whatsoever. So keep that in mind. Fore's website will tell you this as well.

You probably want to go with the improved supercar GT pumps (302s). They are rated for ethanol use. And they are specifically designed for returnless use and should work perfectly in your new Fore hat.

Thanks for the reply. The hat I bought came with the supercar pumps. I’ve decided to stay away from e for now and just buy a different blower to achieve the numbers I want on the returnless fuel system.

Braydon kahl said:

Thanks for the reply. The hat I bought came with the supercar pumps. I’ve decided to stay away from e for now and just buy a different blower to achieve the numbers I want on the returnless fuel system.

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Smart idea.