Fueling

[lofty]

right,

after reading the bit on fueling in this months CCC i was thinking of calculating the max BHP that the williams/16v injectors are capable of,

to do this you need to know the figures for the injectors, does anyone know what they are?

its amazing how similar the fueling system is to a one pipe heating system, dead simple really,

also where does a Power boost valve go?

does it go in the place of the fuel pressure regulating valve?just befor the rail?

 

[BenR]

PBV.........replaces the regulator as far as i know.....but why pay over the odds for a glorified fuel pressure regualtor?

as for teh injectors.....who knows.......youll have to test them....

But why bother, they wont be up for much more as they are probably running about 75% already.......

 

[lofty]

i wondered if they might a bit light at the moment, they are the same as the 16v, say thye are running at 90&% it would take much tuning or a blockage for them to lean off a bit, how difficult is ot to measure flow at the return? its just a rubber hose i assume, not even high pressure

 

[BenR]

sorry mate,

not sure i know what you want to do.......

what would be the point of measuring them......and you have no means of measuring them safely without the right equipement. And the flow would change depending what presure you ran......

give yourself a goal first otherwise the results will mean nothing, unless you find out you are running at 90% where you them have to get higher flow injectors......

if you were to measure fuel at the return, you would need to measure how much was actually getting throught to the rail so you can then divide the number by 4...and that line is also high pressure.

 

[Nick Read]

Well you could remove the rail and injectors and then aim them into 4 jam jars and fire them...measure how much fuel they deliver in half a minute to give you an idea of max flow rate? Obviously depressurise the fuel system before you start messing around with it just to be on the safe side - an eye full of pressurised fuel is not much fun.

Ben - PBV a glorified fuel pressure regulator? Its not even that - just a normal adjustable regulator (and no I dont think it should be called a PBV). I wouldnt say you pay over the odds for it though...if you think that it does come with the pipework and joiners you need, mounting bracket, adjustable regulator itself, fuel rail adapter etc, its not really that expensive. OK if you know where to go and you could machine up your own rail adapter etc youd save a few quid. Hardly worth it for the hassle that most people would have to go to to get the parts and be sure they would work, when your power boost valve kit has everything in it. On top of which for a lot of people, itll be the first time theyve messed around with their fuel system, and it comes with all the instructions you need.

Just as long as you dont expect power from it! The handy thing is the adjustability really.

 

[lofty]

im not into the PBV, its adds one more variable, and if it goes better it just means your crudely overcoming a problem elsewhere, but if you had a mixture gaugein car you could roughly adjust the pressure to suit, and i bet "Cliocup" could make one dead easy

im not going to take it all off and test it, i just wondered if anyone new,

the obvious thing would be to use the cold start injector all the time, would be cheap and easy to do, and i know its probably nothing but im sure my car goes that little bit better when cold (i know you shouldnt do it) but then there are many other things that could cause this, and its probably not faster anyway its probably just psycological,

If you want overfureling i have been running my 1800 lump on a hillpower williams chip for the last few days, it must pushing way to much mixture through, but then it only miss fires when cold (cold start injector must make a significant differnce)

isnt Jimbo running the 5th injector from the cold start?

 

[cliocup]

Funny you should mention that mate, i have just the gauge you are talking about right here infront of me!

Its almost finished, just needs putting in a box and testing (not in that order! its bound to need some playing with!)

Just got 10 LEDs and a bar graph display chip and took the output from the lambda and fed it into the input of the chip, bit of adjustment and calibration and there you have it! More flashing lights!!!

yeah, i have also heard about putting a switch on the cold start injector, never done it and not really convinced you would notice a differenc, but hey, who knows.

Anyway, cold weather just around the corner, that means lots of lovely dense, cool air for our engines!!! Oh and just as i get the thing set up for the dry it pisses with rain for a week and it wont turn in too well...! More playing with dampers needed.

 

[Captain Slarty]

a pbv is more than a normal reg, as it has a non linear output curve controlled by manifold vacuum, the normal reg is far more linear, this is to avoid overfueling at lower revs / load.

as for measuring flow rate, Nick is spot on.. I have done this many times using a calibrated jar, however, As Ben says, what is the point ??.. with my turbo conversion, fine, I already know the injectors cannot flow the required amount for 300 + bhp, so no contest.. add another bank..

Unless you go to tbs, I am confident that the existing setup will offer all you need. Dont forget most mods add little of anything (normal IK, Exhaust etc etc)

Playing with the cold start injector is brutally primitive and a non starter really.

re the mixture meter.. forget it for full load or WOT.. it will not work effectively. The normal lambda is out of range at the mixture settings required at WOT. You could always buy a modifyed lambda that is centered on 13:1, but I wouldnt bother.. a 5000 quid analyser at the RR is your best bet..

Joe.

 

[cliocup]

You lot went through this the other day, narrow band sensors which more than likely have a 10% tolerance on them from the factory anyway. Not much use, still tells you if there is a drastic problem and you can stop quick smart and sort it.

 

[Captain Slarty]

it will only tell you something if you go MASSIVELY lean.. ie - back into its registering range, at that point you will have done the damage.

Look at is as a gimic, pure n simple, not, as a diagnostic tool, and you will be fine.

Joe.

 

[BenR]

as measuring the injectors teh idea of measuring all 4 is fine, you can see if they are balanced too. BUT

My mate does it on his Gti.....with K-Jetronic which had the air flap and constant injection......fair enough......

But, is the clio injection sequential and beased on crank angle?

i.e. does the engine have to turnover for the nijectors to fire? i mean, you cant just put the injector into a jap and push teh throttle and the fuel will come out......Will it? never tried or looked at a F7 setup.