Stevie Boy Posted October 25, 2004 Share Posted October 25, 2004 Whats the advantage of side feed then Ian? Should i be after some of these then and don't stocks feed from the top (i haven't really looked that closely yet!!! ) Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 25, 2004 Share Posted October 25, 2004 Side feed injectors are a straight swap for the stock ones (they fit into the stock fuel rail. Ian's top feed injectors required a purple anodised "uprated" fuel rail with the correct fitting. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted October 25, 2004 Share Posted October 25, 2004 Every Days a School Day as they say! I've seen the HKS Purple Fuel Rail Looks quite fancy!! Having read some of this thread for my near future plans of reasonale boost increase from stock turbo's (is 1.4 - 1.6bar feasable with J-Spec ceramic turbo's?) would i be fine running 800cc injectors, would i need upgrade fuel pressure regulator? E-manage should be able to adjust duty down enough for the size increase i would ahve thought??? When the J-Spec TT's give the ghost looks like the price of Single kits is making Hybrid Twins not seem worth while..... So a decent enough Single kit good for say 1.8- 2bar max, cams lighter valve gear and depending on lottery results, another engine upgrade parts i can afford!! YOU MUST UNDERSTAND I MUSY BEAT MY MATES' RX7 AND SKYLINE AT ALL COSTS!! THEY MUST DIE I MUST WIN!!! Well 1/4mile and V-Max runs anyway!!! Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted October 25, 2004 Share Posted October 25, 2004 Where do i get these side feed uprated injectors from then??? Ar'nt PowerEnterprise jobbies direct replacement for Stock Jap Spec ie Therefore Sidefeed and High impedance so no need for faffing with resistors??? Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 25, 2004 Share Posted October 25, 2004 Yes Stevie Boy, no resistor, and we have 650cc and 800cc in stock. Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted October 25, 2004 Share Posted October 25, 2004 Now were talking, I'm thinking after yesterday evenings Injector discussion antics it's not a good idea to talk business in the forum....? Are there prices on your website and what kinda discount can i get for being such a fine upstanding member of the Owners Group??? Quote Link to comment Share on other sites More sharing options...
TLicense Posted October 25, 2004 Share Posted October 25, 2004 Originally posted by Ian C Isn't there something to do with pressure as well? The fuel system needs a certain pressure at the injectors and if there is a bottleneck at the entrance to the fuel rail it may drop pressure there before it gets to the injectors. Probably not a big factor though unless you go for daft power. I got a HKS rail as I had top feed injectors. The side feed ones only came into our circulation just after I'd forked out. But it looks nice -Ian Hmmm yes I believe so. That's why I thought you would run at the maximum pressure the injectors can handle when you're at idle, (assuming you have a 1:1 reg. of course, but they're a whole'nother already done to death thread) That way when the revs/load rise, the injectors will be getting the maximum amount of fuel pressure possible. Then you can run a much lower duty, than say having the pressure at 50% of what the injectors can handle and then running longer duties? Does that make sense? Am I talking rubbish, I don't know. Dude, you spent quite an amount of time building your fuel system (I saw the pics), how did you go about specc'ing the components? (I know how to work out injector sizing, but don't know how you decided on fuel pressure and rail spec's etc...) Cheers Tony Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 25, 2004 Share Posted October 25, 2004 Originally posted by TLicense Hmmm yes I believe so. That's why I thought you would run at the maximum pressure the injectors can handle when you're at idle, (assuming you have a 1:1 reg. of course, but they're a whole'nother already done to death thread) That way when the revs/load rise, the injectors will be getting the maximum amount of fuel pressure possible. Then you can run a much lower duty, than say having the pressure at 50% of what the injectors can handle and then running longer duties? Does that make sense? Am I talking rubbish, I don't know. Dude, you spent quite an amount of time building your fuel system (I saw the pics), how did you go about specc'ing the components? (I know how to work out injector sizing, but don't know how you decided on fuel pressure and rail spec's etc...) Cheers Tony Agreed Tony. I set my static pressure to 36psi, and then upped it to 40psi and noticed a marked increase in the fuelling, so having a lower duty cycle and a higher pressure (providing you start off that way and you keep the pressure sensible) is a good thing. As for speccing a fuel system, you start off with what maximum power you think you'll be delivering, select beefy enough injectors, and refer to known examples for pumps/line sizes/rails etc.. Finding out what little bits join everything up is the fun/expensive part - mucho trial and error, especially when different parts use different fitting standards -Ian Quote Link to comment Share on other sites More sharing options...
Jake Posted October 25, 2004 Share Posted October 25, 2004 Originally posted by Stevie Boy is 1.4 - 1.6bar feasable with J-Spec ceramic turbo's? No! You'd blow them up in a very short time. Besides, I seem to recall reading on here that J-spec turbos are past their peak efficiency by 1.3 bar, so you'd not be gaining anything anyway. Quote Link to comment Share on other sites More sharing options...
SimonB Posted October 25, 2004 Share Posted October 25, 2004 The formula for the relative amount of fuel you get with changing pressures is this:- sqrt((new pressure)/(old pressure)) * 100 So for 40psi over 36psi that would be sqrt(40/36)*100 = 105%. So that's like having 5% bigger injectors. If you rearrange you can find out what pressure you need for a given increase in fueling:- new pressure = (desired increase%/100)^2 * old pressure For example if you wanted to make 440cc injectors look like 550cc ones you would need to raise the fuel pressure from 36 to 56psi, as 550/440 is a 125% increase in fuel and (125/100)^2 * 36 is 56.25. Fairly sure that's right anyway... Quote Link to comment Share on other sites More sharing options...
b_have Posted October 25, 2004 Share Posted October 25, 2004 Thats an interesting formula Simon, I am running 52psi through 550's will that compromise low speed fueling? I have always had a lumpy idle but put that down to 264 cams. Can't seem to dial it out with the SAFC. what do you think? Quote Link to comment Share on other sites More sharing options...
Alex Posted October 25, 2004 Share Posted October 25, 2004 What's the max adjustment on the S-AFC? Thought it's range wasn't that massive, or am I making that up? Quote Link to comment Share on other sites More sharing options...
SimonB Posted October 25, 2004 Share Posted October 25, 2004 Originally posted by b'have Thats an interesting formula Simon, I am running 52psi through 550's will that compromise low speed fueling? I have always had a lumpy idle but put that down to 264 cams. Can't seem to dial it out with the SAFC. what do you think? Errrrr, dunno. you've reached my limit of knowledge on the subject! I don't see why it should affect low speed fueling as long as you have compensated for all that extra fuel with your SAFC (you'll be getting the same fuel as if you had 680cc injectors at the stock pressure). I take it you've had it on a dyno or have a wideband to see what the fueling is doing? On the Emanage you'd put a correction factor in to reduce the fueling everywhere, then add fuel where you want it with the additional injector doobrie. I don't know much about the SAFC. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 26, 2004 Share Posted October 26, 2004 Charlie, at low speeds or TP, the ecu should go into Closed Loop and adjust the fuelling accordingly. However there is only so much it can adjust. Have you not got an AFR gauge in there??? Quote Link to comment Share on other sites More sharing options...
eyefi Posted October 26, 2004 Share Posted October 26, 2004 does the SAFC make adjustments in closed loop? Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 26, 2004 Share Posted October 26, 2004 I doubt it, but the stock ECU should still. Quote Link to comment Share on other sites More sharing options...
dandan Posted October 26, 2004 Share Posted October 26, 2004 The stock ecu cannot adjust enough in closed loop to compensate for the overfuelling produced by 550's (replacing 440's) at idle. If I remeber correctly, Ian C should be able to comment on that! Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 26, 2004 Share Posted October 26, 2004 That may be correct Dan, although I have got 650's to idle at stoich on a very rich map just this weekend. Quote Link to comment Share on other sites More sharing options...
dandan Posted October 26, 2004 Share Posted October 26, 2004 On a Jap spec with stock ecu and no piggy backs? Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 26, 2004 Share Posted October 26, 2004 Originally posted by dandan On a Jap spec with stock ecu and no piggy backs? No with piggy back, BUT the piggy back was running a Map at lest 10% rich ( off the lamba scale) Quote Link to comment Share on other sites More sharing options...
dandan Posted October 26, 2004 Share Posted October 26, 2004 Aha, I knew there must've been some correction in there somewhere. The stock ecu can obviously trim a certain amount, but no way trim back 550's or 650's to a stoich idle. I think we were talking cross purposes a bit there mate. Quote Link to comment Share on other sites More sharing options...
LeeT Posted October 26, 2004 Share Posted October 26, 2004 Originally posted by eyefi does the SAFC make adjustments in closed loop? at what point is the ecu in closed loop? i know its in low revs but up to what rpm. the US guys dont recommend tuning below 4000rpm Quote Link to comment Share on other sites More sharing options...
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