ideal number injector for e30 conversion ?

[e30gumball]

i am wondering what number is the ideal one for the e30 injector swap ?

#19 or #20 or different ?

also what part number ?
i have loads of 415`s here.

[nando]

17# (M50) or 19# (mustang 5.0) work fine. I wouldn't go above 19#.

search on ebay.. they go for about $50-$100 for a set.

[Saul325is]

What mods are you doing under your hood? If you rich it out like that you as might as well put in an M30AFM or convert to MAF. Other than that you will just be running rich and your OBC will be screwed up (hence larger injectors). I say just stay with the stock injectors.

-Saul

[nando]

your car will NOT run rich with bigger injectors! that is a lie. I get ~22.5mpg in my slushbox ix, which is what it got when it was new from the factory!

the fuel economy meter is off, but how accurate is the OBC at calculating mileage anyway? It's not worth worrying about either way, it's a worthless gimmick.

besides that, e30gumball has a built to hell M20, so he might actually gain a little power by having more fuel. :P

[rwh11385]

the fuel economy meter is off, but how accurate is the OBC at calculating mileage anyway? It's not worth worrying about either way, it's a worthless gimmick.

Lies. On my most recent tank the OBC said 18.2 mpg and my calculated mpg was 18.19! 8)

I am going to swap to 19# + hopefully your AFM though. Clicking injectors are gay.

[Tangent]

My OBC also calculates mileage within a couple of tenths of reality. I understand that running bigger injectors won't make you run rich under normal conditions since the O2 sensor would read any rich condition and the ECU would compensate, but what about at WOT, doesn't the ECU go into open loop and use a fixed fuel map?

[SlammedE30]

I have 21.5# in my 3.0L, they work great.
-Ted

[nando]

My OBC also calculates mileage within a couple of tenths of reality. I understand that running bigger injectors won't make you run rich under normal conditions since the O2 sensor would read any rich condition and the ECU would compensate, but what about at WOT, doesn't the ECU go into open loop and use a fixed fuel map?

probably, but so what? there's more than enough air going through the engine at WOT, especially near the redline where the stock injectors are running too closely to their efficiency peak and begin to drop off.

trust me, I go WOT plenty, and my gas mileage is always the same! It actually went up recently though, which might be related to that can of seafoam I dumped into the engine :)

maybe if your ECU is crap, or your engine runs like shit, then maybe it would make your engine run worse. otherwise, it will run better.

[e30gumball]

i will be using a full emerald and maf conversion on the car.

[Tangent]

I'm just thinking that they would have set the fuel map to give you a good A/F mixture at WOT with stock injectors. I'd assume that using that same map with higher flow injectors would result in running rich and consequently losing a bit of power. Naturally unless you drive like a complete maniac the few times you go WOT and run rich would make only the most miniscule impact on mileage.

I'm still pretty new to E30s so please help me out, I'm not just trying to argue. Do the stock injectors start to lean out near redline at WOT? I know that you want a little richer than stoich when you're floored, is that what you end up with when using bigger ones while the stock flow rate injectors tends to lean out a bit? Does anyone have a dyno run with A/F mapped with stock or bigger injectors that we can use to see what really happens?

[e30gumball]

We had a recent rolling road day for a bmw club in the UK and EVERY car had fuel leaning out at the top of the rev range.

[Tangent]

We had a recent rolling road day for a bmw club in the UK and EVERY car had fuel leaning out at the top of the rev range.

Good to know... What's the rating of the stock injectors anyway?

[e30gumball]

i am unsure to be honest but when i spoke to hartge in germany they told me that on the e30 the injectors were "at there limit"

[E30/M30]

i will be using a full emerald and maf conversion on the car.

Jay,if you're going to get an Emerald stand alone like mine then you don't need an AFM or a MAF.It's uses a throtle potentiometer(SP ?)as it's main load sensor input.

Are you going to try to map it your self or are you taking it to Dave Walker ?

Cheer's

Andy

[e30gumball]

i am sure that if i loked into it i could map it myself but will take it to dave for the initial setting up.

you seen this on an m20 before ?
what are your thoughts ?

cheers.