Modified Injectors - Thoughts
 

Hi folks

As a followup to my wanted post I've spoken to Mark at Lateral about modifying my original hawkeye WRX injectors. Reasonable price, sure that he does an excellent job...however, still not 100% sure what to do.

Need some "expert" opinions on the subject. He reckons they'll end up at 800cc which is more than enough.

Any thoughts?

Many thanks in advance!

I modified my oem injectors on my newage car myself. Simple case of carefully grinding off the perforated end caps with a small hand file.

The blue oem newage wrx injectors do flow about 800cc once modded as Mark says. You can get them flow tested but I personally did not bother.

You will need to adjust the injector scaler and latencies on the ECU otherwise the car will be grossly overfuelling and will run very badly if at all.

Some professional tuning companies frown on this modification with claims of uneven idle and fueling problems at low loads but I have never had any problems in the 2 years following the mod.

how does this work?

Yeah, Bob R will be mapping my car again at the end of Jan (all being well). Really wanted some mappers opinions on the subject.

Thank you for your wisdom! :)

Api modify injectors so they are adjustable. The cc of them depends on the fuel pressure. So once you have an adjustable fuel reg, and a set of these injectors, you never need to change them again! They can follow your mods.

And how much does this modification cost?

I think he said they were £250 the set, on an exchange basis. Also, the injectors you exchange need to be 440's or more, they can't modify the 380's.

I would strongly recommend that if people modify their injectors, they do get them flow tested, because it's not uncommon to see up to a 10% flow disparity between the highest, and lowest.


Mark.

And what kind of range would be acceptable for mappers? 1%? 5%?

If I'm flow matching new injectors, I aim for 1.5% or better, with 1% or better being common.

With modified injectors it depends on how many I'm working on at the time. I always ask the owners if they are happy for me to mix their injectors with others, because the more I have to mix, and match, the closer the sets will be.

I wouldn't be happy unless I can get a set to within 2% or better, with the aim always 1% or better.

It also depends on the mapper, and if the ECU being used has individual cylinder fuel compensation.


Mark.

Got a set of Lateral modified injectors on mine, no probs here..:thumb:

how is the mod done and are they only adjustable by increasing the fpr?why cant 380's be done?

Does anyone know what the cc equivalency works out to be on these modded injectors, when still running the OEM FPR at normal 3bar pressure?

I find the adjustable comment highly amusing.. every injector is adjustable then as the higher the fuel pressure the more they flow... the lower the less they flow :)

the nearer match the flow of each injector is the better and as has been said I wouldn't go modifying injectors yourself without getting them flow matched.. when the car is mapped the wideband used to set up the fuelling takes a reading in the exhaust which is an average of all four cylinders.. you really don't want the fuelling to be that different between cylinders.

Simon

Quite. That's the whole point of an adjustable FPR - so you wouldn't have to keep upgrading to larger cc injectors - just up the FPR pressure (within limits), to achieve the same end goal of higher fuel-flow rates.

Simon,.do you know therefore what these so-called 'adjustable' injectors are/how are they modded? I'm confused by the 'concept' :wonder:

Simon, what are your thoughts on flow matched modified injectors?

Some specialists do this by enlarging the holes on the end cap for a corresponding increase in flow. Great care is needed ensure consistency of flow rate and spray pattern.

By doing this, the injectors are not really 'adjustable' in a true sense as once you have enlarged the holes there is no going back to the previous state.

"I find the adjustable comment highly amusing.. every injector is adjustable then as the higher the fuel pressure the more they flow... the lower the less they flow"

Also they are adjustable by the duration of the "on" time !

Martin

Laterals in mine, were fine until i took my old motor out and they'll be staying when the 2.5 goes in. :)

lol just a bit!

same as all the modded injhectors.. just being called something different..
I assume..

excellent.. work very well

Excellent. Thank you for the feedback, will give Mark a call on Monday!

that was my point simon, flow can be changed by fpr but there seemed be talk of a mod which would point towards enlarging hole(takes me back to 2 stroke jetting days!)something that shouldnt be done without flow testing as it would be hugely hit and miss as lateral says. Does anybody use the lm1 wideband o2 logger? Got 1 here for whenthe weather gets better and can be bothered to get the car out of the lock up!

Just for clarity here is a picture of the modification (before being polished up) on a newage wrx 380cc injector. It involves the removal of the perforated end cap of the injector which more or less doubles the capacity. I think we all agree that the exact flow rate post the mod can only be confirmed by flow testing the injectors.

The other approach is to leave the end cap on and enlarge the diameter of the holes - clearly something to leave to an injector specialists.

http://i468.photobucket.com/albums/r...ctormod005.jpg

Does this mod not upset the spray pattern and therefore bugger the atomisation ability?

So. if a 380cc injector had this mod and it effectively doubles the capacity, are we saying that it would now flow 760cc odd at normal 3bar pressure?

You end up with more of a fine disk pattern than a 'spray' following the mod. Some people claim this will result in rough running/idling issues due to the different spray pattern. This is not something I have experienced myself. In any case, it can be fixed relatively easily with the correct injector scaler, latency and tip in adjustments on the ECU.

I also uprated the fuel pump to walbro at the same time to keep up with the increased flow.

newage injectors only btw..