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914World.com _ 914World Garage _ Aftermarket Injectors ...

Posted by: SirAndy Feb 25 2005, 05:05 PM

i'm looking for Aftermarket Injectors that have a similar flow-rate as the stock 2.0L injectors.

they *don't* have to fit the 914!

i'm making my own runners and fuel-rails, so any brand goes ...

what's out there? cheap? flow-rate? quality? availability?

ideally, i want something that is in stock at your local FLAPS and fairly cheap ...
Andy

i see bosch injectors come in various ratings (lbs/hr),
19, 24, 30, 36, 42

Posted by: TimT Feb 25 2005, 05:11 PM

There are lots of options

find out what flow rate you need

http://www.injector.com/ I buy stuff form these guys

Besides Marren, Summit has good prices on injectors, find whether you need low impedance/high impedance your flow rate and go from there

Posted by: lapuwali Feb 25 2005, 05:48 PM

You may actually want to use some injectors that flow rather less than the stock 2.0 injectors, esp. if you're using Megasquirt to drive them. The all-analog D-Jet system appears to have a much easier time than most digital ECUs are varying the pulsewidth by very small increments. So, it can control the idle on even very large injectors, as its "resolution" is really a function of the physical limits of the injector, not the ECU. The Megasquirt system has some difficulty with handling variations in pulsewidth smaller than 0.1ms, and Dave Hunt has already noted he has some difficulty getting idle level fuel set perfectly on a 2.0. The MS resolution simply isn't good enough to injectors that oversized. There is some hi-res code available with 0.000001ms resolution, but that has some other limitations (can't do PWM injector control, useful for low impedance injectors). btw, this is being fixed in the MSv3.0 boards, which should be out this year.

SDS also has a simple flow rate to engine HP table:

http://www.sdsefi.com/techffhp.htm

I'd say something down near 28lbs/hr will be plenty for any Type IV. I believe the 2.0 injectors are up around 36lbs/hr, the 1.7 injectors are around 25lbs/hr, and should be suitable even for a 150hp 2270, let alone an 80hp 1.7, or a 100hp 2.0. The smaller the injectors you use, the easier it will be to control low-load mixture.

Posted by: airsix Feb 26 2005, 11:44 AM

I agree that if you're tuning digital EFI the smaller the injector the easier it is to tune because you have finer adjustment.
Andy, are you building a fuel rail that uses an O-ringed injector interface or hose-barbs (like the stock rail)? If you go with hose-barb injectors (getting less common) you might try injectors for a 1.8 Subaru turbo. These are the injectors I'm currently using on the 1.7 turbo. They are too small for my turbo motor but they would work for a stock 2.0. You can pull the collars off them, put the 914 collars on, and they drop right in.

Basically look for cars that have the similar per-cyl power as your engine.

-Ben M.

Posted by: Tom Perso Feb 26 2005, 01:28 PM

I calculated that 24lb/hr injectors would work with my 2270. Summit sells basic Bosch-type injectors (think Mustang 5.0/4.6) for $35 each or so. I went to the junkyard and picked up an injector off a 4.6L in a Crown Vic to see what it looked like. It fits the injector bung stock you can buy from most places. Just get that, DIY fuel rail, make a clamp-down, and you're set.

Andy - we are thinking on the same track, FYI.

Later,
Tom