Posted by ferguson777 on 03-03-2004 01:43 PM: in the fuel injection forum .

Copied over to here, hoping for more responses -

flow matched injectors ?

Where can I get 19 lb. flow matched injectors?

These are for a mild SD-EFI 1990 F150 302. Summit carry two brands - Ford Motorsports (which are clearly stated - must be used with modified MAF-EFI) & the Venom brand.

Are the venom brand o.k.?

Accel also offer them but they seem pricey.

Need to buy new injectors anyway, and just want to ensure I squeeze every last ounce of efficiency out of this engine.

Thanks,



__________________
RMF



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Posted by EPNCSU2006 on 03-03-2004 01:46 PM:

I don't see why the FMS 19lb/hr injectors won't work. I think that comment is to make sure people know that maf vehicles must have an air meter calibrated for the injectors. As long as they have the same resistances as stock injectors, there shouldn't be any trouble running them.

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'87 F150 302 manual 4sp od 4x2



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Posted by ferguson777 on 03-04-2004 06:11 PM:

Thanks but does anyone know anything about the Venom brand or know of a place to get flow matched 19 lb. injectors?



__________________
RMF

 

19# injectors are 19# injectors. You won't get any more performance out of the FMS "flow-matched" ones than you will out of stock ones. The flow-matched ones might be marginally useful on a full-race engine where minor differences in injectors could cause minor imbalances in cylinder pressures and temps and rob a couple of HP from max. On a street engine you'll never know the difference. If you can't get your injectors cleaned and re-fitted, just buy a set of 19# Bosch brand injectors at the parts store, that's who Ford buys them from.

 

If you want them matched, whichever ones you use check with apexmotorsports, I think they have that service available.

 

Thanks guys. I'm afraid Strange may be right. Even if I got flow matched injectors, it's pretty much guaranteed I'd never, ever feel any difference whatsoever from non-matched units. Guess I got a little carried away there in my quest for maximizing power/efficiency within my well publicized budget and induction restrictions...Oh well, back to reality.....

Thanks,

 

Yeah, I'd have to agree with strange too, the difference in a street engine would be negligable. I'm sure it wouldent be worth the $$, but I wasent sure what your quest was, just that $$ can get you whatever parts your heart desires!

 

An interesting wrinkle -

Normal , average, everyday 19 lb. injectors run $115. EACH at my local autoparts store. (Remember, this is Canada). And I get garage price.

I can get the Venoms from Summit for approx. $210. USD for a set of 8. That's about $300. Cdn with exchange and UPS.

Unless someone can point me to Bosch via on line ordering, I'll likely be going with Venoms.

Later,

 

Can someone please explain why the MAF must be calibrated to the injectors. I thought the PCM measured the air intake (from the MAF & IAT), then calculated the fuel pulse rate for the injectors based upon the injector size and fuel tables programmed into it. Seems the MAF should just be calibrated to accurately measure the airflow.

 

There is a company in Indiana that will rebuild(?) your injectors. Supposedly flow tests them. I think that he can do 'matched' sets also. If you need me to look it up, let me know.
tom

 

Tom,

If you wouldn't mind......

Anybody ever bought injectors (or anything) from Fiveo Motorsports? They seem to have really prices on genuine Bosch injectors...

Anybody?

 

You've got the second part right there. The computer calculates the pulse rate for the injectors and is calibrated for a certain size injector. A reprogrammed mass air meter will account for the different pulse width required by the different injectors without having to hack into the computer program to change it there.

 

Linder Technical services
gasoline alley,
indianapolis, In
317 487 9460
888 809 3835
http://www.lindertech.com/

Never used them, but they have a good reference.
from: http://www.samsgarage.com/ quick contact links Sam has TV & radio shows...
tom

 

I've looked at some of the PCM data logs from EEC Tuner and they have a value for the injector size. If you have a custom chip, they should know the address to reprogram for different injector sizes.

Just seems ***-backwards to monkey with an input sensor to compensate for injector output (smells too much like the IAT resistor/chip mod). BUT, since it seems to be the accepted way to adjust for them, how is it done?

 

The maf meter is calibrated for high flow and idle flow, and just outputs a different voltage for each. I don't know how they do it, since idle voltage should always be near .7V. The high voltage is more of a potential air flow measurement, and so I think they just lower that when calibrating, so that the full airflow voltage is lower than it would be for stock size injectors. I don't know a lot about chips, but don't they just piggyback the computer or do they actually plug into the service port on the back of them? Anytime you change the programmed fuel and ignition maps in the computer, you are venturing into a lot of unknown territory to most people. I'm sure people who program these computers can do it in short time, but it will likely cost a lot, and possibly involve dyno time.

 

StockRanger:
I read over one of my book marked pages and found this: http://www.offroad.com/ford/bigbronc...h/massair.html . Calibrating the mass air meter is a backwards way to account for larger injectors indeed, and can cause problems. After reading what this guy had to say, I would wager that a recalibrated mass air meter was the source of my part throttle pinging condition. Maybe the calibrations are hit or miss, I don't know.

Edit: just found this on pro-flow's website - for larger injectors, the same voltage corresponds to a higher airflow than original.

http://www.pro-flow.com/flow%20sheets/37ptflow.htm

 

I've used a couple sets of injectors from five0 motorsports. Both sets worked flawless. Bruce's customer service was also very good.