mrgee2jz Posted October 29, 2009 Share Posted October 29, 2009 Hi everybody, i have what may be a small issue with my car. It was dyno'd a few weeks back: Its running a Power FC 800CC sard Injectors 3 bar sensor 350lph pump As it hit 1.5 bar 500whp and over it would go lean. And couldnt get it any richer. What is the stock fuel system minus pump capable of flowing?? I forgot to change the filter so will do that but its going to be pointless if the system cant physically flow it.. Is it capable of flowing 600-650hp? Thanks in advance, Gary Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 29, 2009 Share Posted October 29, 2009 Whats the duty cycle at? you are on a stock fuel pump at 500rwhp? Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 29, 2009 Author Share Posted October 29, 2009 Whats the duty cycle at? you are on a stock fuel pump at 500rwhp? Im not sure of duty cycle as i didnt try tuning it personally. 345lph pump. But my main question is, how much can our stock fuel lines/regulators run/?? Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 29, 2009 Share Posted October 29, 2009 Start with removing the fuel pulsation damper and see what happens to the duty cycle, im upgrading my fuel system as it started restricting my car at 630bhp. Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 29, 2009 Share Posted October 29, 2009 Check your fuel pressure as well. If it doesn't rise with the boost near the top end or tails off as revs rise, the pump is running out of capacity. -Ian Quote Link to comment Share on other sites More sharing options...
Pig Posted October 29, 2009 Share Posted October 29, 2009 I would say pump. I was running 1 walbro it that ran out of puff on a T61 @ 1.4 bar. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 29, 2009 Share Posted October 29, 2009 Without knowing the duty cycle your injectors are reaching and also what the fuel map is set to, you have no reference to determine what is causing the problem. Could be pump, FPR, filter, pipework etc related but could equally be bad mapping, restricted injectors, it would also help if you stated what turbo your running at 1.5 bar and achieving 500WHP? Basically not enough information to diagnose really. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 29, 2009 Author Share Posted October 29, 2009 Without knowing the duty cycle your injectors are reaching and also what the fuel map is set to, you have no reference to determine what is causing the problem. Could be pump, FPR, filter, pipework etc related but could equally be bad mapping, restricted injectors, it would also help if you stated what turbo your running at 1.5 bar and achieving 500WHP? Basically not enough information to diagnose really. It is running a Garrett GT35R. i have used the same turbocharger and its produced 630hp in a 2jz and 650hp in an rb26. But if the fuel lines are capable of more flow i will check all the other bits and proceed to change the filter Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 29, 2009 Share Posted October 29, 2009 It is running a Garrett GT35R. i have used the same turbocharger and its produced 630hp in a 2jz and 650hp in an rb26. But if the fuel lines are capable of more flow i will check all the other bits and proceed to change the filter Seems rather a lot on a GT35R, they are only rated at 600 BHP which i would think is crankHP, if you're making 600WHP then i would also think that you are pushing the turbo beyond its efficiency, which won't help things. However presumably you have been running this setup for some time and it has suddenly started running lean at high boost? In which case i would suspect the FPR, injectors, and fuel pump. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 29, 2009 Author Share Posted October 29, 2009 Seems rather a lot on a GT35R, they are only rated at 600 BHP which i would think is crankHP, if you're making 600WHP then i would also think that you are pushing the turbo beyond its efficiency, which won't help things. However presumably you have been running this setup for some time and it has suddenly started running lean at high boost? In which case i would suspect the FPR, injectors, and fuel pump. It was on my 2jz e30 with aaromotive fuel setup for 1100hp Hence my question Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 29, 2009 Share Posted October 29, 2009 Going back to your original question, as the last post has left me a little confused. Is the std Supra fuel system capable of flowing 500WHP? Some say the limit is 500- 550BHP some say more, if its WHP then you will be pushing around 580BHP at the crank so i would say its possibly not quite up to it, but i would still investigate the FPR and have the injectors and pump tested if its only just started doing this? I am running a lot smaller injectors with a Walbro pump on a completely std fuel system with a GT4088 and making 450-500 BHP dependant on boost, without a problem. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 30, 2009 Author Share Posted October 30, 2009 this supra i am having trouble with was a bpu supra and i went big single. so its never ran more than 1.5 bar before. i upgraded pump and injectors only Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 30, 2009 Share Posted October 30, 2009 this supra i am having trouble with was a bpu supra and i went big single. so its never ran more than 1.5 bar before. i upgraded pump and injectors only I do hope that you also mean its mapped to 1.5 bar (you mention a Power FC in another post) along with your pump and injector upgrade? Because if not then you have just answered your own question. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 30, 2009 Author Share Posted October 30, 2009 yes, it was on the dyno being mapped when this was happening Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted October 30, 2009 Share Posted October 30, 2009 What make of fuel pump is it? Sounds like its not getting enough fuel to me. Fuel pressure gauge will tell you straight away. Quote Link to comment Share on other sites More sharing options...
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