2.8 stroker questions

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Yeti
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Tue Jul 12, 2016 10:04 pm

what can you use for an upgrade for the injectors on the 325?

can i get a ecu chip for the 2.8 for my ecu?

thanks
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reggid
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Wed Jul 13, 2016 12:32 am

m30 injectors
E30 325is with M20B31
Kedge
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Sat Jul 16, 2016 11:00 pm

reggid wrote:m30 injectors
Do you think the standard M20 ones flow too little?

Mine is overfueling a lot, wondering whether that's down to the unknown B25 performance chip in it. Been reluctant to get the proper mapping done until I've sussed that out.
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reggid
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Sun Jul 17, 2016 12:11 am

ive seen where they do run at 100% duty with a good cylinder head, mild cam and good induction on a 2.8L running stock injectors. if you use bone stock head, cam and induction stock injectors are probably fine with a tune as you wont make much more peak hp than stock.

17lb injectors also work and probably work better with the stock tune as its it roughly prorata e.g.

17lb/15lb = approx 2.8/2.5

so pulse width will be roughly same motronic might have an easier time
E30 325is with M20B31
Kedge
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Sun Jul 17, 2016 6:02 am

Bare with me here as this is the first I've really looked into how injectors work. So 100% duty, does that mean that the injector is open constantly, and so effectively flooding the system?
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reggid
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Mon Jul 18, 2016 11:11 pm

its open continuously at WOT at the topend so if anything you cant add enough fuel to keep the mixtures in the sweet spot often it goes a bit lean. the injectors dont behave nicely (consistently) either and its not a good practice.

the best bet is if your getting a chip have a chat to the guy who does the chip and see what the most compatible injector flow is.

There is a 2.8L on r3V with about 250bhp that maxes out even the 19lb units and had to source 24lb but tthats with ported head, cam and ITB. Its a track car
E30 325is with M20B31
Kedge
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Tue Jul 26, 2016 10:11 am

Had the car on a dyno yesterday, it's lean throughout the range, apart from a brief hit of richness high in the revs, before going lean again. Been advised to go for injectors in the range of 180-220 cc.
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