olie05 Posted November 28, 2007 Share Posted November 28, 2007 I'm going to be running a 12 injector setup, using my stock injectors and the stock injectors from 1-1/2 suzuki throttle bodies. Here is the first logical way that I can think of to run the fuel system, and maintain equal pressure at all injectors (while using the stock FPR) With the way the injectors will be firing, all 12 will be firing simultaneously for a very limited time, and the flow rates are 180cc/min (nissan stock) and 240cc/min (gsxr stock). Is there anything wrong with this setup? would any of you do it any other way? If so, why? <-don't you hate that question on tests? Quote Link to comment Share on other sites More sharing options...
veritech-z Posted November 28, 2007 Share Posted November 28, 2007 I'm not to up to speed on how that stuff works either, but without either a dedicated pump for the supplemental injectors or at least a higher output pump, wouldn't you get a significant drop in pressure when they open? Would that be enough to cause a problem, or would you not notice it, do you suppose? Quote Link to comment Share on other sites More sharing options...
240hoke Posted November 28, 2007 Share Posted November 28, 2007 I would think you would need to run them like any dual rail setup, a large supply line with a splitter to run the rails in series and then run the outlets to each side of the regulator which then dumps out the bottom. That is if you are running a after market regulator which I would recommend. If not you would just need to y them back before the regulator I wouldn't run it as a dead head setup like you have drawn there. Quote Link to comment Share on other sites More sharing options...
jerryb Posted November 28, 2007 Share Posted November 28, 2007 Other than increasing injector flow...why? Quote Link to comment Share on other sites More sharing options...
frank280zx Posted November 28, 2007 Share Posted November 28, 2007 Other than increasing injector flow...why? because he can!! (helps with fuel economy aswel btw) Quote Link to comment Share on other sites More sharing options...
Thumper Posted November 28, 2007 Share Posted November 28, 2007 BTW make sure they are indidy bitty injectors or you won't be able to get it idleto idle but you knew that so i'm just doing comentary for the audience. Good luck Olie! Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 28, 2007 Share Posted November 28, 2007 Olie how you doing on your ITB setup?! How were you planning on attaching the runners to the throttle bodies?! I was going to use a silicone coupler.. dont have enough time to weld up a flange and o-ring it. I wanted to run supplemental injectors.. but due to my spacing.. the stock GSXR throttle body fuel rail wont fit.. so i would need to machine a new one. Quote Link to comment Share on other sites More sharing options...
olie05 Posted November 28, 2007 Author Share Posted November 28, 2007 I would think you would need to run them like any dual rail setup, a large supply line with a splitter to run the rails in series and then run the outlets to each side of the regulator which then dumps out the bottom. That is if you are running a after market regulator which I would recommend. If not you would just need to y them back before the regulator I wouldn't run it as a dead head setup like you have drawn there. If i run the rails in series it would be end to end, I'm guessing you mean parallel? I'm hoping the stock size metal fuel pipe will supply enough fuel for these injectors. Other than increasing injector flow...why? Well, the throttle bodies come with an injector in each one, so I would either have to fill the hole, or run an injector in there. Also, the throttle bodies will be roughly 6 inches from the head, and that gives the fuel a little more time to mix thoroughly with the air. (helps with fuel economy aswel btw) yep! I think i got 28mpg ONCE after installing the megasquirt, and then after that my right foot just got too heavy BTW make sure they are indidy bitty injectors or you won't be able to get it idleto idle but you knew that so i'm just doing comentary for the audience. Good luck Olie! The plan is to maintain basically the same map for the lower load region, since it will be the same injectors, just different way of getting air in there. I plan on running it on speed density at first, and I'm crossing my fingers that I won't have to do a whole lot of re-tuning because my car runs amazingly right now. The second table will control the second set of injectors, (dual table) and won't affect anything until 4000rpm and above 70kpa. prox, you can cut up the little pipes that connect the injectors in half and connect fuel injection hose in between the two halves (after you space the throttle bodies) to keep the fuel in the rail... easiest way to get the job done until you can fab up a fuel rail. Are you going to be running 12 injectors as well? i don't think the stock gsxr injectors will handle the needs of a L6 turbo. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 28, 2007 Share Posted November 28, 2007 Well I do have 440cc injectors right now.. my plan was to use the secondary injectors for..methanol...*cough* Quote Link to comment Share on other sites More sharing options...
jerryb Posted November 28, 2007 Share Posted November 28, 2007 Thanx....haha!! Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted November 29, 2007 Share Posted November 29, 2007 Well I do have 440cc injectors right now.. my plan was to use the secondary injectors for..methanol...*cough* I thought methanol eats through normal injector bodies... If not i have 2 spare new 4runner injectors that I want to do the same to... Mario Quote Link to comment Share on other sites More sharing options...
Careless Posted November 29, 2007 Share Posted November 29, 2007 rofl @ vat of fuel gotta have a return line with a good regulator up ahead, though. Quote Link to comment Share on other sites More sharing options...
olie05 Posted November 29, 2007 Author Share Posted November 29, 2007 I made revision... honestly though, it seems like a hybrid dead headed/inlet-outlet setup would work the same. also, I think i might have a 2 inlet zx FPR i can use to set the system up at first. Questions, comments, concerns? Quote Link to comment Share on other sites More sharing options...
speeder Posted November 29, 2007 Share Posted November 29, 2007 The above setup should work, but may not provide equal fuel pressure in the two sets of injectors. A larger capacity regulaor than stock may be required, or maybe a second regulator just for the additional injector set. That said, you can tune around any irregularities with the Megasuirt. Try Megasquirt's Staged Injection to control the additional injectors. It will decrease the primaries at the point (rpm & boost) that the secondaries start to operate, making a smooth transition. In the one case I used staged injectors, it worked perfectly. Quote Link to comment Share on other sites More sharing options...
Thumper Posted November 29, 2007 Share Posted November 29, 2007 Also another way of keeping the pressure more consistent would be running higher fuel pressure. You could run up 45-50 since its n/a. I was running 40 base with 23lbs of boost ontop so about 70psi at full throttle (remember 7 for vacuum so actually 47 at idle with no vacuum) I just looked at your diagram more closely yeah speeder is correct a 2nd FPR would probably be in order. And I would upgrade to a 3/8" supply line. Then run the stock 5/16" supply line as your return line. Thats what most turbo guys do. Quote Link to comment Share on other sites More sharing options...
olie05 Posted November 29, 2007 Author Share Posted November 29, 2007 ...And I would upgrade to a 3/8" supply line. Then run the stock 5/16" supply line as your return line. Thats what most turbo guys do. wouldn't that require a fuel cell, or at least a sump? Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted November 29, 2007 Administrators Share Posted November 29, 2007 And I would upgrade to a 3/8" supply line. Then run the stock 5/16" supply line as your return line. Thats what most turbo guys do. The supply should be sized for HP and the return should be sized for the pump... the return should never be smaller than the supply. Quote Link to comment Share on other sites More sharing options...
Thumper Posted November 29, 2007 Share Posted November 29, 2007 The supply should be sized for HP and the return should be sized for the pump... the return should never be smaller than the supply. Really i've never run it that way. I've figured that you use up the fuel so not as much returns to the tank. But now that I think of it (in theory) the larger fuel line should continusey (sp) flow more fuel than the return line can handle so fuel presssure will keep going up. But i've never had this problem. And I know I've read to run a 3/8ths feed and a 5/16ths return from people on here. Any other thoughts about this? Sorry to kindof hijack the thread. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted November 29, 2007 Administrators Share Posted November 29, 2007 Sorry to kindof hijack the thread. You're not jacking a thread. Its entirely appropriate. I'd be happy to entertain alternate thoughts. Anyone see this different? Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 30, 2007 Share Posted November 30, 2007 There is a fuel pulsation dampener available (JeffP installed one on his car after installing the 720cc injectors) and for the price it really eases the job of the fuel pressure regulator. With that little accumulator/bladder arrangement the pulsations are evened out quite a bit meaning the FPR is not slamming open and closed to try and maintain the same line pressure---if you have smallish supply lines that will be an issue. Quote Link to comment Share on other sites More sharing options...
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