Sorry to point out the obvious Nigel but they are called 540cc for a reason
flow rate, 100% duty is 540cc/min
Approximately derate the flow from there with duty cycle. i.e
50% duty = 270 cc/min
25% duty = 135 cc/min
etc etc
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| ST205 Injector Flow Rate/Cycle/Duty http://www.gt4dc.co.uk/forum/viewtopic.php?f=13&t=3108 |
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| Author: | Muddy Water [ Mon Jul 27, 2009 10:41 pm ] |
| Post subject: | ST205 Injector Flow Rate/Cycle/Duty |
Does anyone happen to know what the technical details on flow rate, cycle, duty are on the standard ST205 540cc injectors? 205 standard Low impedance injector 540cc 2.8Ω This site looks interesting: http://www.rceng.com/technical.aspx |
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| Author: | TrackToyFour [ Tue Jul 28, 2009 12:21 am ] |
| Post subject: | |
I am running 1000cc RC injectors on the Track Toy. They are very popular with the Ford guys too. |
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| Author: | two_OH_five [ Tue Jul 28, 2009 12:22 am ] |
| Post subject: | |
Sorry to point out the obvious Nigel but they are called 540cc for a reason
flow rate, 100% duty is 540cc/min Approximately derate the flow from there with duty cycle. i.e 50% duty = 270 cc/min 25% duty = 135 cc/min etc etc |
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| Author: | Muddy Water [ Tue Jul 28, 2009 9:46 am ] |
| Post subject: | |
Thanks Steve I sometimes get a little carried away and miss the obvious 
What I'm trying to ascertain is... Would it be beneficial to replace the standard 540cc injectors with something like SARD 550cc injectors while maintaining the standard ECU. |
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| Author: | two_OH_five [ Tue Jul 28, 2009 10:11 am ] |
| Post subject: | |
no! Do not monkey with the stock components unless you're upgrading the ECU to cope with it |
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| Author: | Muddy Water [ Tue Jul 28, 2009 10:22 am ] |
| Post subject: | |
OK. Similar question... Would it be beneficial to replace the standard 540cc injectors with something like SARD 550cc injectors with say a Blitz Access ECU? |
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| Author: | Diceman [ Tue Jul 28, 2009 11:27 am ] |
| Post subject: | |
Nigel, A few basics (sorry if I am trying to teach you to suck eggs! The injectors are essentially a tap with a very fast acting open & close valve. When always open they will flow 540cc/min. The ecu controls how long the tap is held open for each "bang" of the engine. It is not clever and does not detect you are running lean or rich at any other point than when you are at idle or cruising. (that is the O2 feedback mechanism for emissions). The ECU basiucally has a pre set map from the factory that says "at 5000rpm and 1 bar I will open the injectors for 20 milliseconds because that is what Toyota told me to do". as a guide 20 milliseconds is the time taken for a full engine cycle at 6000rpm. At 3000rpm an engine cycle takes 40 milliseconds (twice as long). If your 540cc/min injectors are opened for 20 milliseconds at 6000rpm and you are running lean... you can't open them any longer as they are being held open constantly anyway. This is called 100% duty cycle. i.e. they can't be held open any longer to flow any more fuel. now a 540cc injector at 20 milliseconds opening will provide 10.8cc of fuel (540x20/1000) Change to a 800cc injector and you will get 800*20/1000 = 16cc of fuel. So you have an extra 48% of fuel capability. If the standard ECU is used with the larger injectors it will still open the injectors for roughly 20 milliseconds and hence overfuel by 48% which will kill your engine. The standard injectors flow 540cc/min = roughly good for 1.2 bar and hybrid turbo at 100% duty cycle with a relatively safe AFR. (the only issue really is that if the injectors are held open constantly they can over heat and jam open - flooding your engine and washing away all the oil... babboom!) To answer your question.. 1) SARD 550cc injectors - no point as almost idntical as standard (they probably are the same) 2) Blitz access will not cntrol bigger injectors properly - you need a programmable ECU like the Power Fc (oh wait - you aready have one!) Stick with PFC & SARd 800s m8 |
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| Author: | Muddy Water [ Tue Jul 28, 2009 11:56 am ] |
| Post subject: | |
Thanks JP. Quote: A few basics (sorry if I am trying to teach you to suck eggs!) Not at all mate...I'm here to learn and understand. You have hit the nail on the head with regards my concerns: Quote: The standard injectors flow 540cc/min = roughly good for 1.2 bar and hybrid turbo at 100% duty cycle with a relatively safe AFR. (the only issue really is that if the injectors are held open constantly they can over heat and jam open - flooding your engine and washing away all the oil... babboom!)
Hence my question with regards the possibility of uprating the injectors so they are not running at 100% duty cycle. I was kinda hoping that uprating the injectors, not by much - may be the same size but with a better nozzle/hole flow rate than standard, would not necessitate an ECU upgrade and ensure that the injector duty cycle doesn't max out (aiming at a max. 80% duty cycle). I have another question with regards ECUs. I assume that things like the Blitz Access ECU has a different fuel map. Does this mean it alters the amount of milliseconds that the injectors are held open? |
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| Author: | Diceman [ Tue Jul 28, 2009 12:53 pm ] |
| Post subject: | |
The Blitz is likely to reduce the duty cycle slightly (maybe 5-10% from some of the reported dyno plots - maybe bugger all from others). The issue is that you still don't actually have any control on what it is doing. It may reduce fuel at one rpm/load point but increase it another and you can do bugger all about it. Changing injectors to ones of the same size is very unlikely to improve things from a "spray pattern" only aspect. Most "drop in" injectors are the same spray pattern as standard. The newer types of injector I don't believe are available in the same 540cc size. TBH my view is either leave the standard ECU and injectors or do the job properly and take control via a programmable ECU and if you need to change injectors you can then). Strap-ons, piggy-backs, FCDs, AFR tweakers, pre-programmed ECUs need not apply. In the absence of Steve or I being available to map your PFC you coudl try Ryan at 2bartuning http://www.2bartuning.com/# he seems relatively cost effective. I haven't seen enough of his work to personally recommend (or otherwise) him but he has worked on many 3sgte and PFC equipped cars and carries out a dyno run at SRR if you ask and pay! |
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| Author: | two_OH_five [ Tue Jul 28, 2009 12:54 pm ] |
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yes it does. Unfortunately you cannot program it. This makes it plug and play but if your car doesn't like it there's nothing you can do If you remember the Surrey rolling road day, there was a 205 that DNF'd due to excessive detonation. That was running a Blitz that clearly disagreed with the car for some reason. Stop trying to buy stuff you don't need lol If you're going to do it fit the Pfc and a proper set of upgraded injectors. Other than that it might be worth getting a spare set of stock 540s flow tested and installing them just for piece of mind |
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| Author: | two_OH_five [ Tue Jul 28, 2009 12:55 pm ] |
| Post subject: | |
lol, Great/diseased minds think alike |
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| Author: | Muddy Water [ Tue Jul 28, 2009 1:19 pm ] |
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Thanks for your help guys. Quote: Stop trying to buy stuff you don't need lol
I can't help it...I have an BIN addiction
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| Author: | emicen [ Tue Jul 28, 2009 4:06 pm ] |
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Ryan should be mapping my mate's supra imminently. I'll post up results/feedback when he does. He is certainly well thought of in MR2 and Supra circles. |
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| Author: | Muddy Water [ Tue Jul 28, 2009 6:44 pm ] |
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Quote: Ryan should be mapping my mate's supra imminently. I'll post up results/feedback when he does. He is certainly well thought of in MR2 and Supra circles.
He's also highly thought of on the another GT4 forum as well. The only issue I have is that I would like to know how to map as there may be the need to tweek a map depending upon atmospheric conditions when racing. I've already had the datalogit software explained to me  but really need a lot of time to use and understand it.
There are a couple of people on this forum that I would trust to map and explain it to me. |
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| Author: | emicen [ Wed Jul 29, 2009 10:47 am ] |
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Pretty sure he'd take you through the basics or enough to allow you to make mild alterations. He guided my mate through removing the aem's closed loop idle on his supra to get it idling better over the phone. |
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