j_jza80 Posted February 11, 2015 Share Posted February 11, 2015 When installing a Bosch 044 on a BPU car, does the external (outside of the fuel tank) wiring from the hanger to the battery need to be upgraded? I know on single setups, people run uprated wiring, with a 30a fuse and a relay, but I can't find a definitive answer for BPU. Thanks Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 11, 2015 Share Posted February 11, 2015 They can draw quite a lot of current, and in my opinion the stock plug and socket on the tank top fitting isn't really up to the job. I used to make turned alloy caps for the Skylines and drilled them for motorsport wire feed throughs and Aeroquip style fittings. Certainly twin 044 pumps will overheat / melt the plastic sealing the stock terminals into the socket. There are two easy options to feed wire out of a fuel tank without leaks. Both from ATL. One cheap, the other very costly. But to answer your question more directly, if you keep the stock connector I would replace the in tank wiring with something more substantially rated. Beware cheap Ebay cable, the latest trick is copper coated aluminium strands. Looks like copper, will solder, but has terrible current carrying ability. The cable to the controller / relay or whatever you are using could also usefully be upgraded, voltage drop costs flow. Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 I might get a spare fuel hangar, and attempt to make a bulkhead fitting for the wiring using some bolts and some nylon/teflon. I've found several ready made solutions, but don't fancy spending £100 on a bulkhead fitting! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 11, 2015 Share Posted February 11, 2015 http://www.atlltd.com/C/Products/Motorsport/In-Tank/Fuel%20Pump%20and%20In-Tank%20Hosing%20and%20Electrical%20Accessories 2 pin Clubman = Cheap. Demon Tweeks used to keep them Mil Spec = very expensive and needs special crimp tooling (also very expensive) to crimp the pins on the wire. If you did want the MIL spec I could crimp the pins for you, I have many Deutsch crimp tools these days. Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 http://www.atlltd.com/C/Products/Motorsport/In-Tank/Fuel%20Pump%20and%20In-Tank%20Hosing%20and%20Electrical%20Accessories 2 pin Clubman = Cheap. Demon Tweeks used to keep them Mil Spec = very expensive and needs special crimp tooling (also very expensive) to crimp the pins on the wire. If you did want the MIL spec I could crimp the pins for you, I have many Deutsch crimp tools these days. I think the MIL spec one might be overkill Wouldn't I need a 4 pin one though if removing the stock plug? As presumably the wires for the level sender are also in that? Quote Link to comment Share on other sites More sharing options...
TheTurtleshead Posted February 11, 2015 Share Posted February 11, 2015 I think the MIL spec one might be overkill Wouldn't I need a 4 pin one though if removing the stock plug? As presumably the wires for the level sender are also in that? I think there are 3 wires on the sender unit. Two for the level sensor and one for the low level indicator? I'd leave the stock plug in for the level sensor etc.. and drill a new hole for your new bulkhead connector. I'm using a single 044. I am going to re-use the stock connector but upgrade all wiring, including a new high amp feed from the fuse box, utilising a spre fuse slot in the box.(You'll need connector t82998-12140 x2 for a new fuse box feed) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 11, 2015 Share Posted February 11, 2015 (edited) The fittings are merely sealed feed throughs, the wire from the pump is continuous through the fittings, and they supply a two pin plug and socket to connect externally to the tank. Work well, the fittings compress when tightened, sealing the insulation on the cables against fuel and fumes leakage. Each of the Clubmen ones takes two insulated wires, so you need two of them. they are quite cheap: http://www.demon-tweeks.co.uk/motorsport/fuel-pump-accessories/atl-clubman-electrical-connector-set-bulkhead-and-quick-release-fittings Edited February 11, 2015 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 The fittings are merely sealed feed throughs, the wire from the pump is continuous through the fittings, and they supply a two pin plug and socket to connect externally to the tank. Work well, the fittings compress when tightened, sealing the insulation on the cables against fuel and fumes leakage. Each of the Clubmen ones takes two insulated wires, so you need two of them. they are quite cheap: http://www.demon-tweeks.co.uk/motorsport/fuel-pump-accessories/atl-clubman-electrical-connector-set-bulkhead-and-quick-release-fittings Thanks Chris It says the bulkhead fitting will accept 2x 14 gauge wires, are these substantial enough to run this pump? I think there are 3 wires on the sender unit. Two for the level sensor and one for the low level indicator? I'd leave the stock plug in for the level sensor etc.. and drill a new hole for your new bulkhead connector. I'm using a single 044. I am going to re-use the stock connector but upgrade all wiring, including a new high amp feed from the fuse box, utilising a spre fuse slot in the box.(You'll need connector t82998-12140 x2 for a new fuse box feed) I might buy a few of those, and mount my heated seat fuses in the factory fusebox. Where are you ordering yours from? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 11, 2015 Share Posted February 11, 2015 14G (assuming proper copper strands) multistrand will easily run an 044 with no significant voltage drop, no worries. If paranoid you can go thicker once out of the tank, after the two pin connector, so you will then only have 15 inches or so of it. Quote Link to comment Share on other sites More sharing options...
TheTurtleshead Posted February 11, 2015 Share Posted February 11, 2015 Thanks Chris It says the bulkhead fitting will accept 2x 14 gauge wires, are these substantial enough to run this pump? I might buy a few of those, and mount my heated seat fuses in the factory fusebox. Where are you ordering yours from? Toyota. £4.50 ea Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 Brilliant stuff, cheers Chris Quote Link to comment Share on other sites More sharing options...
Andy Blyth Posted February 11, 2015 Share Posted February 11, 2015 I can certainly recommend these harness kits: http://www.racetronix.biz/itemdesc.asp?ic=BCWS-001&eq=&Tp= Cheap as chips and only needs a 10mm (approx.) hole giving you 4 x 14ga cables in your tank. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 11, 2015 Share Posted February 11, 2015 Out of curiosity, what difference does it make to whether you are BPU or Single? Surely the pump is running full pelt on WOT regardless of turbo variant? The difference is the single will use more of the fuel and the BPU will send more back down the return line? Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 Out of curiosity, what difference does it make to whether you are BPU or Single? Surely the pump is running full pelt on WOT regardless of turbo variant? The difference is the single will use more of the fuel and the BPU will send more back down the return line? Probably none at all. I just wanted to relay as much info about my setup as possible. During my research, I have found people who are going BPU to be less inclined to run new wiring from the battery to the pump, though that is probably because they are being cheapskates! I want to do it properly, first time. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 11, 2015 Share Posted February 11, 2015 That's a tricky little gizmo Andy. Bookmarked, cheers! Scott: The current draw will vary with boost pressure. The FPR will demand more pressure in a direct ratio with boost pressure above atmospheric, with a normal regulator. Creating more pressure uses more energy (electrical current in this case). Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 I can certainly recommend these harness kits: http://www.racetronix.biz/itemdesc.asp?ic=BCWS-001&eq=&Tp= Cheap as chips and only needs a 10mm (approx.) hole giving you 4 x 14ga cables in your tank. That looks like a nice, neat solution. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 11, 2015 Share Posted February 11, 2015 That's a tricky little gizmo Andy. Bookmarked, cheers! Scott: The current draw will vary with boost pressure. The FPR will demand more pressure in a direct ratio with boost pressure above atmospheric, with a normal regulator. Creating more pressure uses more energy (electrical current in this case). I understand that Chris, but I mean with regards to the pump itself. As I understood it the fuel controller had 2 states of draw, low and high. When below a certain RPM/Load it was in "low" mode, when on WOT it was in "High". People did the fuel pump 12v mod to bypass the fuel controller and just have a constant 12v feed. When in this mode the pump is constantly running at full capacity. During idle most of the fuel goes down the return line thanks to the FPR. As the boost increases the fuel use increases and the FPR controls the fuel going to the rail. My understanding was that at no point did the pump's current draw change. What would control the current draw with a constant and direct 12v feed? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 11, 2015 Share Posted February 11, 2015 Probably none at all. I just wanted to relay as much info about my setup as possible. During my research, I have found people who are going BPU to be less inclined to run new wiring from the battery to the pump, though that is probably because they are being cheapskates! I want to do it properly, first time. Don't forget to document how you run the wire to the pump. Always interesting to see what route is best. It's something I haven't even considered going single. I was told by numerous people that the stock setup is fine for 1 pump. When you move onto 2 it's a whole new configuration required though. Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 11, 2015 Author Share Posted February 11, 2015 Don't forget to document how you run the wire to the pump. Always interesting to see what route is best. It's something I haven't even considered going single. I was told by numerous people that the stock setup is fine for 1 pump. When you move onto 2 it's a whole new configuration required though. I've got some new seats to fit and loads of other wiring to do, so one weekend I'll have all the carpet out of the car. I'll probably run it down the passenger side sill, as that *should* be the path of least resistance, as hydrologists say. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 11, 2015 Share Posted February 11, 2015 (edited) I can certainly recommend these harness kits: http://www.racetronix.biz/itemdesc.asp?ic=BCWS-001&eq=&Tp= Cheap as chips and only needs a 10mm (approx.) hole giving you 4 x 14ga cables in your tank. That looks brilliant. Am I right in thinking that due to the angle it comes out at, it won't require any modifications to the cover? Just checked the price of one of them posted and it's the same money for the post. I quite fancy getting one, might be worth looking at a group buy if anyone else is interested? Much cheaper buying multiples and getting them shipped Edited February 11, 2015 by Scott (see edit history) Quote Link to comment Share on other sites More sharing options...
Andy Blyth Posted February 11, 2015 Share Posted February 11, 2015 That looks brilliant. Am I right in thinking that due to the angle it comes out at, it won't require any modifications to the cover? I'm not sure; I'm not using it with the stock hanger. When the connector is installed into the hole, you need clearance around the hole for the o-ring and also to the side the connector comes out. If you zoom in on the picture, you can see a support moulded in to the yellow piece. I guess you could trim it off with a knife if it got in the way. Quote Link to comment Share on other sites More sharing options...
Andy Blyth Posted February 11, 2015 Share Posted February 11, 2015 During idle most of the fuel goes down the return line thanks to the FPR. As the boost increases the fuel use increases and the FPR controls the fuel going to the rail. My understanding was that at no point did the pump's current draw change. What would control the current draw with a constant and direct 12v feed? The easiest way to look at it is the pump provides hydraulic power. Hydraulic power is simply pressure x flow; in the same way that electrical power is voltage x current. The pump can be considered as a constant flow source (OK, it's not really as the flow drops off a bit with load) for a given voltage. When the FPR raises the line pressure with this fixed flow, the hydraulic power the pump is delivering is increased. This must be linked with an increased electrical power entering the pump; we're not going to be breaking the laws of physics here! As the voltage supplied to the pump is constant (ignoring supply cable voltage drop) then the current drawn by the pump must increase to give the increased electrical power. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 11, 2015 Share Posted February 11, 2015 (edited) I understand that Chris, but I mean with regards to the pump itself. As I understood it the fuel controller had 2 states of draw, low and high. When below a certain RPM/Load it was in "low" mode, when on WOT it was in "High". People did the fuel pump 12v mod to bypass the fuel controller and just have a constant 12v feed. When in this mode the pump is constantly running at full capacity. During idle most of the fuel goes down the return line thanks to the FPR. As the boost increases the fuel use increases and the FPR controls the fuel going to the rail. My understanding was that at no point did the pump's current draw change. What would control the current draw with a constant and direct 12v feed? I think you are confusing flow and pressure and volts and amperes. The pump will most definitely draw a lot more current when asked to supply more pressure. Block the output so it makes as much pressure as it is able to and see what the current draw is then. It will be a LOT more than when just making 1PSI or whatever. The fuel controller ecu is actually a very sophisticated and complex bit of kit, I looked inside one and it seems to have two microprocessors. Far more complicated that I expected and it *MAY* use pulse width modulation to feed the fuel pump. Andy is infinitely more capable than I to comment, if he's still about. This sort of stuff is kids play compared to his day job EDIT: Andy put this a lot more clearly and authoritatively, what Mr. Blyth said Edited February 11, 2015 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted February 11, 2015 Share Posted February 11, 2015 (edited) I think you are confusing flow and pressure and volts and amperes. The pump will most definitely draw a lot more current when asked to supply more pressure. Block the output so it makes as much pressure as it is able to and see what the current draw is then. It will be a LOT more than when just making 1PSI or whatever. The fuel controller ecu is actually a very sophisticated and complex bit of kit, I looked inside one and it seems to have two microprocessors. Far more complicated that I expected and it *MAY* use pulse width modulation to feed the fuel pump. Andy is infinitely more capable than I to comment, if he's still about. This sort of stuff is kids play compared to his day job I must be confusing myself here as I understand all of that. Ok, I'm going to simplify my thinking so don't take offence at my ridiculously simple understanding here...... Car idling, not very much fuel being used, fuel pressure on my FPR is set to 3bar. With the pump producing more than 3 bar the excess is allowed to exit via the return line. Car on WOT, lots of fuel being used. This leads to a pressure drop in the line which the FPR regulates by allowing less fuel down the return line. During both instances above the pump should be working at the same rate. In fact, if it's assumed that the return line puts more of a resistance on the fuel system than the fuel rail does.... the pump will actually be working harder at idle when the fuel is harder to pump through due to back pressure, than it is when on wot and the fuel is freely flowing through the line. Why would there be more pressure on WOT than there is at idle? The pressure at the rail should remain constant thanks to the FPR bypassing less fuel. The pressure prior to the FPR should also be constant, as the rate of fuel down the return line is regulated to keep the pressure constant. I have an aeromotive FPR. I've set the pressure at 3 bar. It makes no odds what I do, the pressure is constant. Blocking off the return line would increase the pressure and thus increase the load on the pump. I understand that, but I don't see why driving would increase/decrease the pressure prior to the FPR. Edit: Just thinking about a hose with a y-pipe with one side regulated. If you turn the flow onto max, the flow out of both lines will be equal if the hoses are equal, adjust the regulator to restrict one and the other will increase. Close the regulator and all of the flow will come out of the other, at the maximum rate the water comes out. The pressure before the split doesn't change at any point during any of this, it's simply the "bypass" that is adjusted to increase/decrease the flow out of the other end. Edited February 11, 2015 by Scott (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted February 11, 2015 Share Posted February 11, 2015 (edited) The easiest way to look at it is the pump provides hydraulic power. Hydraulic power is simply pressure x flow; in the same way that electrical power is voltage x current. The pump can be considered as a constant flow source (OK, it's not really as the flow drops off a bit with load) for a given voltage. When the FPR raises the line pressure with this fixed flow, the hydraulic power the pump is delivering is increased. This must be linked with an increased electrical power entering the pump; we're not going to be breaking the laws of physics here! As the voltage supplied to the pump is constant (ignoring supply cable voltage drop) then the current drawn by the pump must increase to give the increased electrical power. Again, I understand this. What I don't get is why the pressure increases in the line. The pressure should decrease as the fuel is being used. To combat this less fuel is re-directed into the fuel return and more is put into the injector rail to bump up the pressure post FPR. The pressure is regulated using a bypass (fuel return), not by increasing/decreasing the back pressure to the pump. Edit: Adding to this, once you have reached the limit of a single pump.... the pressure in the line drops as more fuel is being used. At this point surely the pump is working less than it is when there is a higher back pressure. Edited February 11, 2015 by Scott (see edit history) Quote Link to comment Share on other sites More sharing options...
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