nismo.capri Posted June 5, 2008 Share Posted June 5, 2008 Here's a pic of an FPR !! the arrows for flow are the wrong way. The fuel pressure pushes against the spring, say it's a 45 psi spring once the pressure goes over 45 psi the spring will compress allowing the fuel to go out the return. This FPR doesn't have a pressure port, if it did it would put manifold pressure behind the diaphram with the spring You can see the diaphram and spring of the built in FPR on the throttle body injection unit I'm running Quote Link to comment Share on other sites More sharing options...
Steelies Posted June 5, 2008 Share Posted June 5, 2008 chair bowl, .. When it reaches the set pressure the FPR cracks open to relieve the excess pressure. i think thats what i was getting at. can you control the pressure being fed to the FPR in order to stop overloading the pump? or should the pump just be grunty enough to keep running at maximum cracking pressure (incl. boost), so its always running through the relief.. albeit at low flow rate if the motors chugging gas hardout just seems wierd that a system with inbuilt relief would still stall the pump at the high end, just when you need megatron performance levels Quote Link to comment Share on other sites More sharing options...
Guest vvega Posted June 5, 2008 Share Posted June 5, 2008 why the fuck would the pump stall? at max boost the motor will be using shit loads of fuel You are right, it won't stall under most conditions, but it's flow will be heavily reduced. In the event that you have a batch fire system it WILL stall if no injector is open at some given time and pressure has been pushed up too high. Same goes if you have sufficient pressure and sequential injection with short pulsewidths that don't overlap. Not good for the pump to be stopping and starting like that... Also, do you really expect your injectors to open predictably at 75psi tip cross pressure? I wouldnt. At the VERY LEAST they are opening a LOT slower quite possibly reducing fuel flow overall because of the linear rate of flow reduction with opening time and the non linear rate of flow increase with pressure. Obviously some higher pressure will net gains, but if you have a standalone you are just shooting your foot to use rising rate. sure, run 60psi base pressure to get a little more flow from the injectors, but don't use rising rate... Fred that's just scare mongering if hes dead set on running rising rate let him if he finds he has issues he will change in good time...and its hardly a big job i used to use a pair of boash injectors with 100 psi poked up the bum of them form a jetronics fuel pump in a centrifugal jet engine i built years ago and they were fine i went though far more turbines and shafts than i did injectors v Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 5, 2008 Share Posted June 5, 2008 can you control the pressure being fed to the FPR in order to stop overloading the pump? Yep lower the boost. or should the pump just be grunty enough to keep running at maximum cracking pressure (incl. boost), so its always running through the relief.. albeit at low flow rate if the motors chugging gas hardout That's exactly right, size your pump for a wee bit more than the max PSI it will need to flow. A rising rate FPR will run at a higher pressure, all things being equal. just seems wierd that a system with inbuilt relief would still stall the pump at the high end, just when you need megatron performance levels The trick is not to think of it as a relief valve (even tho that's sort of what it does). It's a pressure valve and it's job is to make sure the injectors are getting the correct pressure. As boost increases it needs to increase the pressure. If the pump doesn't have the balls to push that pressure it will stall. Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 5, 2008 Share Posted June 5, 2008 Fred that's just scare mongering I don't think so it's relevant info. if hes dead set on running rising rate let him if he finds he has issues he will change in good time...and its hardly a big job True, but there is a possibility that the pump wont have the balls right when it needs it and then the engine will lean out. I'm not saying don't use the RRFPR just be aware of what issues you are up against and monitor them. I always run an O2 just to keep an eye on the AFR. Basicly just to see that the AFR hasn't leaned out for what ever reason and turned my engine in to a gas axe. i used to use a pair of boash injectors with 100 psi poked up the bum of them form a jetronics fuel pump in a centrifugal jet engine i built years ago and they were fine i went though far more turbines and shafts than i did injectors v Compairing a jet turbine to a piston engine isn't really fair as the injector could have been dribbling becase of the 100 PSI and the jet would still be running fine. Jet engines generally don't have to deal with the load changes that a car engine does. Quote Link to comment Share on other sites More sharing options...
Guest vvega Posted June 6, 2008 Share Posted June 6, 2008 if the pump don't have the balls he will find out when there tuning it so hes hardly gunna kill anything unless hes got a shit tuner from my understanding its getting tuned before anything happens and no if the injectors were dribbling i would have known i would have ended up with a explosion in the burner can .....aside from the fact i checked them every time under full pressure only a dumbarse plays with something that can turn into a shrapnel explosion with making all the checks first assumption is a bad thing making calls on his fuel pump is stupid when we don't know what hes running yet....i think at last check...it's a 910 calling assumptions no matter how educated relevant just confuses the issues Quote Link to comment Share on other sites More sharing options...
fishtailfred Posted June 7, 2008 Share Posted June 7, 2008 Good posts nismo.capri! The main point is that the vast majority of pumps do NOT flow well at very high pressures which an RR WILL generate. He may shoot himself in the foot if he wishes, but he should just size his parts appropriately... How much power, how many litres, how much boost, how many rpm, what sized injectors, which pumps are you planning on using? Just design a good fuel system one way or another and leave RR regs out of it. They are a hack for OEM ecu use. Fred. Quote Link to comment Share on other sites More sharing options...
Guest vvega Posted June 7, 2008 Share Posted June 7, 2008 No the main point is you cunts are big noting telling him what to do when you have no idea what parts hes useing Quote Link to comment Share on other sites More sharing options...
fishtailfred Posted June 7, 2008 Share Posted June 7, 2008 http://www.google.com/search?hl=en&q=ri ... tors&meta= Third link : http://www.cartech.net/fmu2020.htm In other words, it's cheaper than a standalone. Fred. Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 8, 2008 Share Posted June 8, 2008 if the pump don't have the balls he will find out when there tuning it so hes hardly gunna kill anything unless hes got a shit tunerfrom my understanding its getting tuned before anything happens. Read my post again all I said was there is a possibility it will stall due to pressure and to watch the AFR for lean out. assumption is a bad thing making calls on his fuel pump is stupid when we don't know what hes running yet....i think at last check...it's a 910 I'm assuming the pump might have an issue as it's not designed to run with an RRFPR and he should be ready for it. Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 8, 2008 Share Posted June 8, 2008 No the main point is you cunts are big noting telling him what to do when you have no idea what parts hes useing Me and Fred have been telling him the safe way to set it up and why. RRFPR work when running with the right pump, run the wrong pump and you loose flow right where you need it. Quote Link to comment Share on other sites More sharing options...
forced Posted June 8, 2008 Share Posted June 8, 2008 The only real use for a rising rate regulator is as a band aid for injectors that are too small. Quote Link to comment Share on other sites More sharing options...
Guest vvega Posted June 8, 2008 Share Posted June 8, 2008 bunch of shit show me the pump hes using your talking about his pump this and his pump that...but you dont know what pump so how can you work off anything' ive already said a while back its the wrong reg to use and that i think the fuel curcuit's shit perhaps reading a thread though before you start digging into to people will stop you from looking like a complete fuckwit and right now you do Why do you think fred asked what pump hes useing....Perhaps hes just realised he dosent know i fault find all day ...and as a professional at it THE FIRST THING YOU DO IS ESTABLISH FACTS not just make up senarious and tri to aplly them to something as i said last time i heard he said he was GUNNA LOOK AT A 910 PUMP so all your pump will stall blaa blaa is pointless bushit that dose not apply to his situation .....and forced yes your right but its what hes got and he wants to tri it Quote Link to comment Share on other sites More sharing options...
durty Posted June 9, 2008 Share Posted June 9, 2008 whats with all the hate guys??? cant we all just get along??? Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 9, 2008 Share Posted June 9, 2008 whats with all the hate guys???cant we all just get along??? Pissining and moaning removed Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 9, 2008 Share Posted June 9, 2008 show me the pump hes using your talking about his pump this and his pump that...but you dont know what pump so how can you work off anything' You are absolutly right I don't know pump he's using. Now you show me where I've said that his pump and or that RRFPR's wont work? Quote Link to comment Share on other sites More sharing options...
forced Posted June 18, 2008 Share Posted June 18, 2008 Just to bring this one back from the dead,plus I've got time to kill, it's also wind up day. The arrows look like they're the correct way to me. Does everyone else here believe EVERYTHING they read? Here's a pic of an FPR !! the arrows for flow are the wrong way. The fuel pressure pushes against the spring, say it's a 45 psi spring once the pressure goes over 45 psi the spring will compress allowing the fuel to go out the return. This FPR doesn't have a pressure port, if it did it would put manifold pressure behind the diaphram with the spring Quote Link to comment Share on other sites More sharing options...
nismo.capri Posted June 18, 2008 Share Posted June 18, 2008 Just to bring this one back from the dead,plus I've got time to kill, it's also wind up day. Did you get sick of wanking? The arrows look like they're the correct way to me. Does everyone else here believe EVERYTHING they read? Obviously not Quote Link to comment Share on other sites More sharing options...
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