stee3 Member 194 Member For: 13y 5m Posted 09/01/13 10:09 AM Share Posted 09/01/13 10:09 AM I posted this reply in another thread but probably should of started my own thread. I have decided to put the old girl on E85 this time around, I have a Walbro 400lph feeding my surge tank and a Magnafuel MP-4303 fuel pump feeding the twin entry fuel rail. Due to the amount E85 flows I also have to modify the return line as well otherwise my fuel pressure will go through the roof. The fuel flow back into the return will back up and pressurise the return line due to the size of the return on the factory swirl pot. I’ve been told this can be done by drilling the return line pipe to larger dia. into the swirl pot or drill it out completely and tap it then screw a larger fitting into it. Has anyone done this or have any pictures of it modified? I’m sure I can figure it out but If I can see one done its easier.Fuel system consists of Magnafuel MP-4303, Walbro 400lph, Surgy, ID2000s, FPR2000, twin entry with -8AN line, -6AN return to surge tank. 1 Link to comment Share on other sites More sharing options...
IH8TOADS Silver Donating Members 3,618 Member For: 19y 4m 18d Gender: Male Location: OZ Posted 09/01/13 01:38 PM Share Posted 09/01/13 01:38 PM Do you have a problem on 98ron? Or have you not fitted the bigger pump yet?Actually are those magnafuel pumps voltage adjustable? You would need to drill and tap a larger return (but its plastic yeah?) if you wanted to do it properly, or make a custom replacement. Link to comment Share on other sites More sharing options...
shaun001 Member 16 Member For: 11y 10m 26d Posted 09/01/13 01:55 PM Share Posted 09/01/13 01:55 PM are you currently having problems getting pressure down?if you have a decent after market fuel pressure regulator you shouldn't have to mess with the factory return line,have used factory return lines on quite a few different combos and always been able to get rail pressure down to 4bar as it should be.Also not sure what line you plan on using to feed the surge,if you are using the factory line make sure you get rid of the factory filter and replace it with a stainless element filter. Link to comment Share on other sites More sharing options...
stee3 Member 194 Member For: 13y 5m Posted 09/01/13 11:14 PM Author Share Posted 09/01/13 11:14 PM The magnafuels pumps are not voltage adjustable and dont require any type of step down motor they have an internal bypass. Im not having any issues what so ever at the moment with 523RWKW using 100 octane fuel controlling fuel pressure. I run a base of 60psi and gets up to around 85PSI at full boost. I have set a few cars as well but nothing like what I have been building in this car, I do see this as being an issue.When I fit the 400lph into the swirl pot ill have a real close look at it and see if I can tap a fitting into it. I dont want to get on the dyno and try push it then have any issues.With 30-35PSI of boost its going to require alot of fuel especially when using E85 and when that fuel needs to return to the tank. The little hole on the factory swirl pot I dont think is not going to cut it. Link to comment Share on other sites More sharing options...
JETURBO ...JD TUNING ADELAIDE... Gold Donating Members 23,708 Member For: 16y 5m 25d Gender: Male Location: Adelaide Posted 09/01/13 11:58 PM Share Posted 09/01/13 11:58 PM See what ben xyz and john quik1 have done both over 600rwkw on e85 Almost say still std return It does look small the plastic 90 degree on top Link to comment Share on other sites More sharing options...
turbotrana Member 2,586 Member For: 21y 7m 26d Gender: Male Posted 10/01/13 12:27 AM Share Posted 10/01/13 12:27 AM You need to do some testing with pressure gauges hooked up in a couple of spots. Make an adaptor with a gauge that can fit on the return line plus your gauge on the FPR. Then apply power to the pumps to see the pressures. Then disconnect the return line and observe pressures. Its worth the time to experiment to see if its a worthwhile mod you intend doing Link to comment Share on other sites More sharing options...
IH8TOADS Silver Donating Members 3,618 Member For: 19y 4m 18d Gender: Male Location: OZ Posted 10/01/13 12:57 AM Share Posted 10/01/13 12:57 AM If its not a problem now, it will be less of a problem with e85. No need to worry IMO. The problems normally arise at low injector pulsewidths on non voltage regulated high flowing pumps. With e85 your INJ_PW will obviously lengthen and there will be less fuel returned. Link to comment Share on other sites More sharing options...
KITID New Member 10 Member For: 6y 6m 1d Posted 29/09/18 04:37 AM Share Posted 29/09/18 04:37 AM Hey guys same topic. I'm having issues with a bf barra turbo cutting. I've heard of the rebore but I'm not sure how big to go. Car is running standard boost. The fuel pump is a 255 walbro. Currently the return and breather are sitting around 4.5mm (roughly) 4mm slides in and 5 mm wont go in. Any advice appreciated Link to comment Share on other sites More sharing options...
adams355 Member 529 Member For: 7y 6m 24d Gender: Male Location: Brisbane Posted 29/09/18 06:26 AM Share Posted 29/09/18 06:26 AM I take it you took the pressure valve out Link to comment Share on other sites More sharing options...
KITID New Member 10 Member For: 6y 6m 1d Posted 29/09/18 08:36 PM Share Posted 29/09/18 08:36 PM No that's still in there. I dont have a fuel pot hooked up to it currently though which wouldnt be helping Link to comment Share on other sites More sharing options...
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