atlsupdawg#2

Hey all, I have six Siemens 72lb injectors that were used briefly on my Supra. They are the domestic style o-ring type and I wanted to know how involved it would be to fit these as opposed to some of the other injectors sold. I know I would need custom fuel rails, which I would be able to manufacture myself if need be.
http://www.rossmachineracing.com/extrusion.html

overZealous1

iTrader: (27)

i am running the 60lb siemens injectors. the stock 350z injector clips are different than required to run the siemens so you will need to get the correct clips and splice them into the wiring. i used the stock fuel rails and just cut the ends off and welded fittings on them to make my return system. but i did run into a problem with the extra height of the 60# injectors. there is not much room at all where the rails fit and i had to take some material off of the bottom of the manifold to clear and make some special sized spacers to bolt the rails back down. not sure if you could even make or find fuel rails to fit injectors much bigger.but if you got'em, give it a trial fit and see.

atlsupdawg#2

Thanks OZ1 for the reply. If you're running the 60's, the 72's shouldn't be that much taller. I was mainly concerned with whether or not they'd fit the stock rail and if I needed to fabricate manifold adapters. But if all I'd be doing is reworking the stock pieces I'm good with that..

theking

iTrader: (3)

Do you know if the clips are the same as the RC 440's in the greddy kit. I am thinking on doing the same since 60lb equate to 630cc. Those injectors are half the price and are used on my high hp supras.

overZealous1

iTrader: (27)

from what i understand, the rc injectors are the siemens injectors. rc just puts a sticker over them, lol. so yes the clips should be the same.

overZealous1

iTrader: (27)

you will be limited to adjustment on the top of the injector as you still need to use tyhe stock fuel rail to injector clip. but you might be able to ge more clearance going into the manifold. try fitting them without the lower o rings and see if you can get the manifold on. then mark injector depth and then match that on final install, or you might need to drill the manifold out more. i had to spend about 2-3 hours removing material to fit the 660's, and it is pretty much maxed out. but if the injector is just larger around, you would be ok. good luck

overZealous1

iTrader: (27)

atlsupdog, i just looked at your ross machine link there, and that was the route i was hoping to go also. just get fuel rail stock and drill it out. no way that style will work on the Z though. they have them packed in pretty tight and, well , you will see once you get it apart, lol.

theking

iTrader: (3)

Seimens 60lb's here I come. Thanks for your help Overzealous1. When I was looking at the RC injectors I said to myself "These look like standard top feed domestic injectors" Half the price and same sprace pattern. Can't beat that.
Alan

atlsupdawg#2

Yeah, from what I remember rc eng. also matches the flow rates and spray patterns for each injector to a "tighter" tolerance, so to speak. That's where the higher price comes into play..

theking

iTrader: (3)

Double. Seems a little high to have put on a flow bench and matched.

theking

iTrader: (3)

I just picked up a set of 60lb high impedance injectors from seimens. I went to the closest Mustang shop and pick up a set for $65 each. I did confirm that Supras use low impedance injectors so unless you run dropping resistors or find a way to use a different set of drivers then those will not work. Seimens does not make high impedance 72lb injectors. At 3.5bar which most people run on our cars these 60lb injectors are the equivalent of 735cc for most horsepower calculation tables.

atlsupdawg#2

Yeah, my 72lb's are low imp. injectors but won't the emanage ultimate be able to run these or would I still need a resistor pack??..

theking

iTrader: (3)

Need to ask Sharif. Running it through the EU would be way better and more accurate than using resistor packs. I started turning the boost up tonight!!! 70% duty cycle at 12psi. Remember that I have cams and a ported head so that would be the flow of approximately 14-15psi without the cams or headwork. I know this cause I could max out the 440s(100% duty cycle) at 8psi. That right there tells me it's flowing alot more air than nonported/stock cams. Anyways I would think that their is simply a dipswitch or output table on the EU to change the output signal for the fuel injectors.

overZealous1

iTrader: (27)

you would still need a resistor pack even with the emanage ultimate so i have read. so king those injectors dropped right in with the aam fuel rails. good deal if they did! i am still trying to tune my car in so not driving it hard, but did some datalogging while driving last night and at only 5.5lbs boost i was at 38% duty cycle, 54% throttle, and hit 138% charge efficientcy. stock stock maf was reading 4.6v. can't wait to see what this thing will do when at full throttle and full boost. looks like it will really pass alot of air. i did cams and major ported heads and intake also.

theking

iTrader: (3)

They dropped right in. At first I didn't think they would because they are physically longer. I went ahead anyways and found out that they actually go further into the fuel rail and injector bosses.

I'm hitting stock maf limit in the neighborhood of 4800rpm at 12psi.