So...I've changed my views on stock injectors and FMUs
 

Well...I was always one to recommend an FMU over an AFC anyday...still am. But I only recommended FMU's up to about 5 psi, and then after that I say chipped ECU all the way.

However, I had an opportunity to sell my DSM 450s for a good price, and needed to go in for NJ State Inspection anyway, so I threw the stock 240cc Low Impedence injectors back in and started to tune.

I thought throwing in stock P75 maps would do me nicely...however, with whatever mods this engine had before I got it...---- ran pretty lean at about 42 psi of fuel pressure. So I upped the pressure until the idle AFRs leveled out to about 15.3 and hit that at about 58 psi of rail pressure...nice!

Well, I added boost to the ROM and started tuning...I have a red Tial spring (whatever PSI that it) and when I hook my wastegate up directly to that little port on the compressor of the turbo, I only see about 4 psi of Manifold pressure max...AND MY STOCK INJECTORS ARE HOLDING JUST FINE!!!

Pulls nice for 4 psi...stock injectors arent even really close to being maxxed out with that much rail pressure!

So the new recommendation is, get an adjustable FPR, jack up the base fuel pressure to 55-60psi, leave the stock injectors and have at it to 4-6 psi on a chipped ECU!

8)

Re: So...I've changed my views on stock injectors and FMUs
 

that's just ghey :P

Re: So...I've changed my views on stock injectors and FMUs
 

No need to get pissy because you keep blowing your car up and it never runs... :P

Re: So...I've changed my views on stock injectors and FMUs
 

this is actually really good to know. and coming from u i highly think people are gonna do this over fmu. stock injectors hold nice up to 4-6 psi on a chipped ecu by jus uppin the fuel pressure? thats awesome.

Re: So...I've changed my views on stock injectors and FMUs
 

I'm at maybe 85% duty cycle at 6500 rpms at 4 psi of boost...and I am using a fairly conservative 1 degree linear retard as well.

Re: So...I've changed my views on stock injectors and FMUs
 

my car's built and has been running, wanna compare time slips and dyno charts? :D and if you want to get technical, i ran 5 psi for a few weeks with no fuel management at all back in the day and it held find, i've tuned quite a few cars on stock injectors with chipped ecu up to about 5-6 psi, it's not really a big discovery, just kind of pointless when dsm 450's are only 50-70 bucks and you already have a chipped ecu if you.

Re: So...I've changed my views on stock injectors and FMUs
 

I think any B series vtec car will no doubt be maxed out on the stockers. I am sure you could get away with it on a D series or an LS.

Re: So...I've changed my views on stock injectors and FMUs
 

:-X

Re: So...I've changed my views on stock injectors and FMUs
 

:-X

Re: So...I've changed my views on stock injectors and FMUs
 

And xenocron has converted to the darkside!!!!!

I main support for ECU tuning will never be the same, whats next, China made FPR, FMUs and 240cc Boostable Injectors on his website? J/K