W3bb3r04
Slow 3v Member
I remember Jason "Jodade" Had some drivability issues with his with twin 405's in a GT500 hat running returnless. I guess the only issue is when you are flowing too much for the factory components to compensate for.
Return VS. Returnless Fuel System...Which way to go?
- Thread starter BadPiggy
- Start date
I wonder how far Dual Deatschwerks DW200 Fuel Pumps In Stock Hat, S&H Performance Hat To Rail Fuel Line Kit With FORE Fuel Filter, FORE Fuel Rails and ID1000's will take me without a BAP on E85 returnless? LOL, I might find that out next week.
Yup. The pcm had a hard time dealing with the rapid change in flow when it modulated those pumps. I have had two people test the dual 405 pump in a gt500 hat setup in returnless. First Greg and then Jason. Both tuners Mike at Mid Atlantic Performance and Adam at rev auto for each car respectively had a hard time and spent a lot of time getting them to work well. Greg's setup was seeing some pretty wild spikes, some up to 90-100psi iirc. He had every returnless supporting mod in the book, other than stock rails still. I had full 10 gauge wiring to the fpdms and from fpdms to the pumps, pprv deleted, 8an line and fore filter upgrade. We even tried adding a bap to help stabilize the voltage to keep the pressure under control. Safe to say 800-900lph was too much for the returnless setup to handle.
To guess, around 600rwhp on your turbo setup with e85. A pd blower setup would see a bit less. A single 40amp bap would make me feel a little more comfortable on that setup depending on your power goal.
A safe rule of thumb that I'm starting to see work pretty often for e85 is that max power potential is around 10% (give or take) more than the total lph of your pumps.
So if you have a twin 255lph pump setup or around over 510-520lph of flow 600rwhp is a safe estimate. If you want 1,000 rwhp on e85 a pump flow of around 900lph is a safe goal. etc
Again things like bsfc for your setup, line/rail upgrades, injector size etc, all play a role in this.
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BruceH
BBB Big Bore Boss 322
First I'd look at the manufacturers data. I haven't found an aftermarket pump that was recommended for a returnless system other than Walbro. With that said I know that they are being used successfully in some applications so there is a disconnect of some kind in the manufacturers specs.
I've used GT500 pumps without a bap and with E85. The pumps were maxed at around 575rwhp. Changing from the gt500 power wire (14 gauge?) to an 8 gauge wire allowed for a safe 599rwhp.
Adding a single 40 amp bap allowed for 699rwhp and a duty cycle of 86% with e85. That was with Bosch Racing 970cc injectors and a delta of 39.15psi.
I would think that two 255 walbros would give you the same results only a little more because you aren't driving a supercharger.
I've used GT500 pumps without a bap and with E85. The pumps were maxed at around 575rwhp. Changing from the gt500 power wire (14 gauge?) to an 8 gauge wire allowed for a safe 599rwhp.
Adding a single 40 amp bap allowed for 699rwhp and a duty cycle of 86% with e85. That was with Bosch Racing 970cc injectors and a delta of 39.15psi.
I would think that two 255 walbros would give you the same results only a little more because you aren't driving a supercharger.
Considering DeatschWerks DW300m in the GT500 setup for ~ 650whp on e85. Anyone have any thoughts?
http://www.deatschwerks.com/resources/fuel-pump-tech/dw300m-fuel-pump-tech1
http://www.deatschwerks.com/resources/fuel-pump-tech/dw300m-fuel-pump-tech1
Dubstep Shep
WUB WUB VROOM VROOM
I did it and was making 17 lbs without any issues on e85 with the M122. Getting the pumps to fit in the GT500 hat is a BITCH though.
My setup. No issues at 707 HP. Builder thought I could make 800-850 before maxing.
Dual Deatschwerks DW200 Fuel Pumps In Stock Hat, S&H Performance Hat To Rail Fuel Line Kit With FORE Fuel Filter, FORE Fuel Rails, Kenne Bell KB89063 KIT DUAL BOOST-A-PUMP 40 AMP/20V "COMPETITION"
Dubstep Shep
WUB WUB VROOM VROOM
Welp, guess they finally fixed that issue lol. I had the 200s, I figured bigger ones would be even harder. Good job on their part
They are a good choice, I have used the standard ones modified to fit, they work very well and dw's 3 year warranty is legit. But like mentioned it was a lot of work to get them in. I am currently testing the more compact dw300's that fit the gt500 hat right now and plan to add them to my lineup of offerings. I want to make sure they have the same range of performance first and I have a few different setups being tested.
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You can always push more fuel through stock stuff with enough pump. But at 600rwhp on e85 is where I would upgrade it. On Dysan's car he saw a 26% drop in duty cycle with the 8an line and filter upgrade and pprv delete. This was a gt500 fuel system with a bap at around 600rwhp.
Does someone have a kit with bigger lines to stay returnless?
PM Jeremy.
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