I currently have a perfect (Pro) tune on my AEM F/IC for 550cc injectors. I was planning on purchasing 700cc's possibly and was curious about the upgrading process.
If I load my tune on my laptop and simply change the injector sizing from 550 to 700, would that be all that'd be required? It would seem that way, however something seems too simple, too.

Thanks for your advice.

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I think you will still have to adjust your pulse width for the injectors.

 

not so familiar with fic but if it has that adjustment for injector size that changes the pulse width of your fuel map when you enter your new injector size then you will be very close assuming you you have entered the the injector latency of your old and new injectors correctly. If you didnt have the correct lag time you will have a different afr on boost and vacuum but still its a faster way to redo the fuel you would just need to adjust and smoother out the afr

 

no it will not be enough it only gets you in a ball park area so that u can drive to tuners easier...

IMO the injector size change is a giant POS i was tuned for 440cc injectors and then i put 550, i then did the injector size change and after i loaded the tune it ended up that it was pulling too much fuel in vac, the ecu did compensate by adding fuel and giving a perfect AFR in closed loop but in doing so gave me a system too lean code and was running a + 35 fuel trim


long story short march 9th im going back to ptuning to get uned =P woot woot

 

^^ happened to me too leaner vacuum but richer boost, several times when i changed from 550 to E85 then to fuel return then to 900cc, whats worst I have 32x32 resolution lol but like i said your injector lag time for both injectors are entered correct they will be close

 

yeppers...

I would take your map your running on now and copy it by clicking on save as and renaming it..close out fic program and reopen. open your map copy and click on your fuel map. right click anyplace on your fuel map and do the injector size change. input old injectors and imput new injectors.

like whats said above it will only get you in the ballpark, more tuning will be needed.

 

That's is correct. the injector rescaling feature will only give you a rough rescaling of the injector pulse width. It will give you a rough ball park change to inj. pulse width so you can start and idle your car. I would not try driving for an extended period or getting into boost after the rescaling prior to getting a another tune. I highly recommend you get a retune after upgrading the injectors. There's no point going from your current injector to a larger injector unless you're planning to up the boost.

Mrc

 

Well duh.

Haha I would be upping the boost (not before a tune though). I also don't have the 550s anymore and plan to add some more power, so I figured why buy another set of 550s just to need more fuel in the near future.

But, alas, I suppose I'll just buy 550s and then upgrade when the time is right.

 

or keep the 550s and upgrade the fuel system to a return.. the 550 will go a long way with a return setup

 

Ding ding ding we have a winner. That's probably what I'll do. Thanks for the responses guys. I appreciate it!!

 

What i was getting at was that if you're going to upgrade your injectors because you want to up the boost, you're going to need to get it retune and your tuner can take care of the rescaling process.

Upgrading from 550 to 700 injectors will not gain you anything once you start approaching the 10psi mark because the factory return-less fuel. You're better off investing in a return-style fuel system before going to larger injectors. you can still get more out of the 550 with a return-style fuel system than swapping to 700cc without it.

MrC

 

Didn't see the post. we're on the same page

MrC

 

Gotcha. Don't worry, Toan is the only tuner to touch my car.

Any clue what installation/labor rate is on the return system?

 

PM Sent.

MrC