replacing pintle cap w/ 4-nozzle on stock injectors

[packratbimmer]

Too many discrepancies! We should pay someone to run a set of M50 injectors at all three pressures. So far so good here with the 2.5 bar FPR, but I would not want to run lean.

[packratbimmer]

Update: Been driving for a few days with the M50/2.5 bar set-up. It runs fantastic around town and at idle. Honestly, the drive-ability is better than I have ever experienced with my E30's - been driving E30 cars for 21 years straight now! No indication of lean running, but I am still just a bit concerned. Anyone else running the set-up?

[digger]

not much wrong with a good condition stock set of injectors......only reason to run bigger injectors on a stock or basically stock engine is if you have a performance chip that is meant to use a bigger injector. why not simply get a get stock set

[jdusty4]

digger,

that makes sense to me, and would seem to override the benefit of having the 4-nozzle design, but I couldn't find a source for refreshed stock injectors and didn't have the time to have them out of my car long enough to have them refreshed.

I am getting the m50s in this week and am keeping the stock FPR, will update with how it goes

[MercyFlush]

digger,

that makes sense to me, and would seem to override the benefit of having the 4-nozzle design, but I couldn't find a source for refreshed stock injectors and didn't have the time to have them out of my car long enough to have them refreshed.

I am getting the m50s in this week and am keeping the stock FPR, will update with how it goes

Fwiw 'refreshed' injectors are a BS thing. Injectors are not a serviceable item, however you can replace the filter, pintle cap and O-Rings. I just recently picked up a set of Ford Falcon AU injectors (supposed 200cc/min or ~19Lb/Hr, but I hate Lb/Hr as it's stupid and useless for flow measurement) and they are a 0280 Bosch injector as well (4 hole injector, High Impedance).

Instead of going off the supposed flow rate (which is tested using a different fluid, hence not really accurate) I just built an injector flow bench and flow tested them myself. In the end using the fuel I will be using and testing at 3 bar, I got an average of 209cc/min with 98RON and all injectors were within a 2% variance.

Take note this was using injectors that cost me $50 AUD and had done over 500,000km (an old taxi). Btw the car runs no better than with the old injectors, except on cold starts where the better atomisation helps.

Just as Digger said there is not much point otherwise, bigger injectors are only useful if you're capping out your current ones i.e. >85% duty cycle. For reference in my 2.9L I was only hitting about 80% duty at peak with a set of 190cc/min injectors ;)

[TurboJake]

TurboJake, thanks for the info. I have been wondering if there was a way to get the pressure closer to stock with the m50 injectors. Are there any other issues associated with running the ETA FPR?

Also - I used the values found here: http://www.unofficialbmw.com/phpBB/v...452277310c401b

M50 injector is 0280150415 190.2 cc/min at 50.75psi (3.5 bar),

at 2.5 bar (36.25 psi) that would appear to give 15.2 lbs/hr, not 14.8? (I used this calculatorhttp://www.rceng.com/technical.aspx#Find_Fuel_Flow_After_Pressure_Chang e)

Nope. there aren't any other issues. The ECU only measures how rich or lean the engine runs, which adjusts the duty cycle. Running lower pressure will just flow less fuel through the inject, and not affect any other system. Allowing the ECU to adjust accordingly, while not initially flowing too much during startup.

As for conflicting data, it's everywhere. The fact of the matter is the stock injectors are PLENTY of fuel, even for a modded engine. You really don't need to go any bigger even with a stroker engine, unless you boost it.

The other thing to consider is that even IF the the m50 injectors flow less fuel, it has a much better atomization, allowing more fuel to be burned during ignition, which makes it more efficient, resulting in less fuel needed to begin with. So, upping efficiency, which would carry over to fuel milage and better MPG's.

No matter what though, M50's on a stock 3 BAR FPR have been known to cause rich issues, solve that with less pressure behind it and it works. As I stated earlier, I run the 0280155771 injectors with an E fpr and a maf, and it results in this.



Instant throttle response, nice and smooth, and I average 27mpg. Having the WAR chip to tune it if I needed to helped me do the purchase, but I run pretty much the miller stock injectors 87 octane MAF tune, only sightly changed. It isn't a very complicated tune from the get go.

[jdusty4]

Well, drove today with the "refreshed" or cleaned, whatever, (MEPEH) m50 injectors and the stock 3 bar regulator. I also have a new diff and moved the arm in the AFM to new track on the potentiometer, but overall slightly better throttle response, smoother idle, less engine ticking. The injectors I had were probably dirty - 135k, I've been running crappy gas and never used fuel system cleaner for 9 years and 50k, not sure about before. I'm sure the improvement came mostly from them being cleaner. But either way, at least so far, no problems with rich idle or cold starts. I am curious what will happen in the winter in Vermont and at 8k ft in Colorado.

[sandman_01]

As I stated earlier, I run the 0280155771 injectors with an E fpr and a maf, and it results in this.



Instant throttle response, nice and smooth, and I average 27mpg. Having the WAR chip to tune it if I needed to helped me do the purchase, but I run pretty much the miller stock injectors 87 octane MAF tune, only sightly changed. It isn't a very complicated tune from the get go.

What exhaust are you running in that video? Sounds great! Any chance you'd share what you changed on that tune for those that want to do a similar setup?