I've got mechanical fuel injection on my engine and am wondering if I can activate some of the external controls (barometric, temp and cold start) via computer controlled solenoids instead of heated tubes,temp sensors and timers. Any comments?
I've got mechanical fuel injection on my engine and am wondering if I can activate some of the external controls (barometric, temp and cold start) via computer controlled solenoids instead of heated tubes,temp sensors and timers. Any comments?
NC Region
1980 ITS Triumph TR8
Well, now, not so fast.
That is a fuel pump. Fuel pumps are free. Some common fuel pumps have the ability to govern themselves and so on. I can control my fuel pump with a switch, or even a rheostat.....
(I credit that definition to a couple CRB guys, who, when we were classing a Porsche 911, on an ITAC con call, told me that it could make oodles of power, when I was telling them that it was pretty much maxed from the factory (headers, port sizes, air cooling mechanical fuel injection with s largely unadjustable space cam). They insisted it is a fuel pump and you can 'do anything you want with it'.)'
So, ......
Jake Gulick
CarriageHouse Motorsports
for sale: 2003 Audi A4 Quattro, clean, serviced, dark green, auto, sunroof, tan leather with 75K miles.
IT-7 #57 RX-7 race car
Porsche 1973 911E street/fun car
BMW 2003 M3 cab, sun car.
GMC Sierra Tow Vehicle
New England Region
lateapex911(at)gmail(dot)com
Wow, that is a good one -- I don't remember that one Jake....did that one really get put out there?
I guess under that theory a fuel injector would be a fuel pump too???
NC Region
1980 ITS Triumph TR8
Not sure if you're familiar with the MFi system in a 911, Jeff. it's like a little inline 6 cylinder engine. There's a low pressure pump that feeds a main galley, then the pistons pump up and down, pressurizing the fuel down 6 lines to the ports.
Where the EFi systems use a crank trigger and electronics to trigger the solenoid injectors, this uses a belt off the cam to drive it, and adjusts with internal widgets for rpm, load, temperature, baro pressure, etc.
But, fundamentally, it's a pump. And it pumps fuel to the cylinders in a 911.
Yes, the members of the CRB (at the time) who said it were quite impassioned. I certainly see the logic.
The injectors are the injectors in either car, and can not be changed.
But the pump itself is free by todays ITCS, and it's common for people to add supplementary switches, and i'd opine, legal as well.
Last edited by lateapex911; 08-22-2011 at 06:32 PM.
Jake Gulick
CarriageHouse Motorsports
for sale: 2003 Audi A4 Quattro, clean, serviced, dark green, auto, sunroof, tan leather with 75K miles.
IT-7 #57 RX-7 race car
Porsche 1973 911E street/fun car
BMW 2003 M3 cab, sun car.
GMC Sierra Tow Vehicle
New England Region
lateapex911(at)gmail(dot)com
As Jake points out, the rack under the MFI pistons has multiple control inputs and we'd like to smooth out the fule flow at the lower RPMs. On EFI this is easily doable with a MegaSquirt system. We're working on a MechaniSquirt (TM ) way to achieve the same results from the pump.
Can't speak to the CRB thing, but yup, MFI is the same general technology as a diesel injection pump: in the end, it's the fuel pump.
Negative. A fuel injector is typically a solenoid valve; it does not pump fuel, it meters and atomizes it. In the case of MFI, it's just a pop-off valve.I guess under that theory a fuel injector would be a fuel pump too???
Last edited by Greg Amy; 08-23-2011 at 08:59 AM.
Interesting. Well, I learned something today and will defer to you guys who know far more about mechanical injection than me.
Thanks for the explanations.
NC Region
1980 ITS Triumph TR8
Yeah..carbs and a dizzy (w/points) for me too.
Fear not, the area we are working on helps us get the car in and out of the trailer and around the paddock. I just wanted to get some clarification so that the other mid-pack IT-S drivers won't panic and run to the stewards when they see wires going to my mechanical fuel injection.
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