RobSheffield Posted December 26, 2006 Share Posted December 26, 2006 What is the real world difference (apart from colour) between PHR, Titan and HKS aftermarket fuel rails? I will be using Siemens 720 or 850cc Injectors, controlled by AEM Quote Link to comment Share on other sites More sharing options...
ajazyasin Posted December 26, 2006 Share Posted December 26, 2006 If they are all top feed then the main difference I guess is whether they are duel feed or single. Quote Link to comment Share on other sites More sharing options...
Wez Posted December 26, 2006 Share Posted December 26, 2006 Why not go with with PE 800cc direct drop ins? Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 Im running along the same lines as Michael, i dont know where, but i read that Drop ins are the cheap way of doing things Not that that is a bad thing of course Quote Link to comment Share on other sites More sharing options...
Wez Posted December 26, 2006 Share Posted December 26, 2006 Cheaper solution yes, but why is that a bad thing. The fuel rail is just a piece of metal with a hole through it, why pay for another one in a pretty colour????? I think it already been mentioned that the stock unit has a larger ID than some aftermarket units. Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 Like i said Wez, cheaper isnt a bad thing. Im not actually fond of Purple actually, but back on topic Quote Link to comment Share on other sites More sharing options...
ajazyasin Posted December 26, 2006 Share Posted December 26, 2006 Ive recently bought an aftermarket fuel rail. The stock rail doesnt have a larger ID than most aftermarkets. Apart from that, the fact that the oe rail is side feed is not such a great thing. If you think about it, the last injector is recieving fuel that has passed through the other 5 before. This is 5 injectors cycling the fuel and causing pulsations in the flow. The top feed system gives fuel to each injector that hasnt passed through the others. If your rail is duel feed then fuel enters from both sides giving an equal flow to both ends of the rail. On full throttle, which is when all of this really comes into play, you dont really want fluctuations in the fuel going to the cylinders. ps. These are conclusions I have logically come to and could be a steamy pile of shite:) Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 These are conclusions I have logically come to and could be a steamy pile of shite:) They are broadly similar to my own conclusions I like ya thinking Quote Link to comment Share on other sites More sharing options...
Wez Posted December 26, 2006 Share Posted December 26, 2006 Never thought of it like that Quote Link to comment Share on other sites More sharing options...
captainchaos Posted December 26, 2006 Share Posted December 26, 2006 dunno the dif but needed one for 1000cc injectors so i bought the purple one(HKS) to go with the injectors i ordered lol Quote Link to comment Share on other sites More sharing options...
Nic Posted December 26, 2006 Share Posted December 26, 2006 Some of CW's opinions on the subject. HERE and HERE Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 Some of CW's opinions on the subject. HERE and HERE Before i read them i knew it would be bad Interesting that CW suggests pretty much what ill be doing, a Bosch pump and Bosch FPR Quote Link to comment Share on other sites More sharing options...
Nic Posted December 26, 2006 Share Posted December 26, 2006 Interesting that CW suggests pretty much what ill be doing, a Bosch pump and Bosch FPR Which Bosch pump are you fitting Rob? What flow rate? Quote Link to comment Share on other sites More sharing options...
Wez Posted December 26, 2006 Share Posted December 26, 2006 A Bosch 044 maybe???? Quote Link to comment Share on other sites More sharing options...
ajazyasin Posted December 26, 2006 Share Posted December 26, 2006 Mr CW was talking about the skyline setup on fuel rails. Ive got a j-spec supra rail here and it is a small ID. I also agree with him in that most fpr are junk. The rail will only operate as well as the pressure of the fuel in it. A combo of good pump setup and fpr should ensure a constant pressure of fuel to the rail/injectors. Quote Link to comment Share on other sites More sharing options...
ajazyasin Posted December 26, 2006 Share Posted December 26, 2006 The selection of a single pump setup is ideal because if the pump fails you will just cut out. Whereas with the dual pump setup, if one pump goes you can run lean(top end) due to low fuel pressure. I reakon you can resolve this issue by just having a gauge with warning alarm in the car. Im running dual Walbro255's. Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 A Bosch 044 maybe???? Yeah, that one Quote Link to comment Share on other sites More sharing options...
Wez Posted December 26, 2006 Share Posted December 26, 2006 Yeah, that one Good choice, are you mounting it in the tank like the stock unit? Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 No, im going for a Walbro(or stock toyota) to Surge tank, then 044 from tank to filter Quote Link to comment Share on other sites More sharing options...
michael Posted December 26, 2006 Share Posted December 26, 2006 No, im going for a Walbro(or stock toyota) to Surge tank, then 044 from tank to filter I'm thinking about this too with a stock UK spec pump I have kicking around, will be interested to see how you get on (I suspect you'll get there long before I do ) Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted December 26, 2006 Author Share Posted December 26, 2006 I'm thinking about this too with a stock UK spec pump I have kicking around, will be interested to see how you get on (I suspect you'll get there long before I do ) I wouldnt suspect too hard I have a bizzare pump in at the moment, and was going to replace with a Walbro, but i guess i dont actually need to as it just needs to fill the swirl pot, and so doesnt matter about the pressure or flow rate. Quote Link to comment Share on other sites More sharing options...
Wez Posted December 26, 2006 Share Posted December 26, 2006 No, im going for a Walbro(or stock toyota) to Surge tank, then 044 from tank to filter Very nice indeed Quote Link to comment Share on other sites More sharing options...
Guest DaveH Posted December 27, 2006 Share Posted December 27, 2006 Have you seen flow charts for that bosch pump? I don't think they flow much (if any) more than the stock Supra pump? They are a good pump quality-wise, but the flow is lacking. Some good info here http://www.stealth316.com/2-fuelpumpguide.htm#j6 The fuel rail discussion is good, depending on your fuel flow requirements sometimes the larger diameter is needed. A too-small rail can actually have less pressure on the outlet end vs the inlet end. The stock rail is pretty good, but if you are putting in 800cc injectors or so, and plan to be using them to their fullest, I'd get a larger rail. The HKS is not terribly larger ID, I'd get the Titan, etc as they have the 17mm ID stock. DaveH '93 na-t SP73/AEM 9.46 @ 143mph Worlds quickest NA-T Supra Quote Link to comment Share on other sites More sharing options...
TLicense Posted December 27, 2006 Share Posted December 27, 2006 Some of CW's opinions on the subject. HERE and HERE On this occasion I couldn't disagree with Mr Wilson more. I don't know it he's actually seen the difference in diameter between the stock and say the PHR fuel rail, but let me enlighten you... Stock:- PHR:- The PHR fuel rail is 17mm I.D. (IIRC it's certainly something of that order, I'll try to find a pic with a scale in...) Also, if you are changing fuel injectors, due to the fact that there is no standard pressure that all injectors are flow rated for, it is very unlikely that the injectors that you buy will have been flow tested at the stock base pressure. If you run at a different pressure then your 700cc injectors will not be flowing 700cc's. It could be more, but it could be less. The only way of ensuring that they flow the amounts that they have been tested to is to fit an adjustable fuel pressure regulator and set it to whatever pressure the injectors have been tested at. If you're running the pressures at anything less than what they're tested at then you're robbing yourself. You might as well just buy much smaller injectors and ramp the pressures right up... (If people are happy to do that then I've got some 440cc, I mean 800cc injectors for sale that will fit a stock rail! ) Quote Link to comment Share on other sites More sharing options...
TLicense Posted December 27, 2006 Share Posted December 27, 2006 Whilst on the subject of fuel pumps, does anyone know what pressure the Walbro (Or any pump for that matter!) is tested to flow 255 l/hr at? Without knowing that figure is meaningless.... I mean say if it is 30 PSIG (I seriously don't think it is!) then it's supplying 255000cc per hour. Say your injectors on your single are rated to 800cc at 30 PSIG then they require 48000cc of fuel supplied. If that's the case would I be worried about losing 1 pump? Not with over a 5x factor of safety. No. However if the pump is rated at a much much higher pressure than the injectors then it could be a completely different story... See what I'm saying? Quote Link to comment Share on other sites More sharing options...
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