Larger fuel injectors without a tune?

[Olson1288]

Alright so I apologize ahead of time if this comes off as a dumb question


I'm about to install a supercharger kit in the BRZ, and I'm also throwing some larger injectors (most likely Deatschwerks 700cc's) in. Due to long hours at work and what not, I'd like to possibly install these injectors the day prior to my supercharger install. Would the vehicle be safe to run on the new injectors without the forced induction tune? In all reality I probably won't drive it anywhere, but I will need to start and drive it to the garage the next day which is only a few minutes down the road.


I don't anticipate there being any issues with such a short drive, but I'd rather be safe then sorry. Thanks for the help!

[Mr.ac]

Don't quote me on this, nor take anything i say as true, but as crazy as it sounds you should be ok. Will run rich and might shoot flames out the tail end, but who knows.
If anything it might just end up running in limp mode.

Take a video and post up if your car catches fire.

[tomm.brz]

i wouldn t drive it with 700cc while on tune it's written 228cc and the inj latency is totally screwed up... but well. Use stock map and drive super light

[steve99]

As above stock i jecgors 228 cc about 1/3 size of your 700 cc


Ie you will get triple the fuel its supposed to out of the port injectors wgich supply about 50% of the fueling at low rpm



Also cars starts on port only so it will inject 3 time the fuel at startup might not even start or could flood quite badly.


Get tuner to send you a stock tune with 700 cc injectpr scaling and cranking pulse widths reduced by at least 50%

[Irace86.2.0]

I doubt it will run at all on 700cc without a tune change.

[DarkPira7e]

I also share the opinion that you'll be lucky to have it start and idle with those injectors. See if your tuner can create some sort of a dummy map to limp you there. Anything will be better than trying to run on the stock map. If it's only a short drive, why not have it towed here? If you have AAA, it'll be free!!

[bfrank1972]

lol you'd probably be better off running the FI tune with the larger injectors and no supercharger than running a stock tune with just the larger injectors. Have it towed. Also you might also look at other things to save time instead - i.e. if your kit requires removing the bumper, you can do that ahead of time.

[Sriracha]

Good question, there are no dumb ones.

Firstly, Im super glad you asked before just trying it unlike some people I've come across. I agree as stated above. With injectors that much larger i would definetly NOT start it and personally either:

1. Install them and receive a base tune to drive it over
2. Wait to install them until you are at the shop
3. Install them and grab a buddy and a car trailer ( buddy can help push car up on it )

What can happen if you do not choose one of these could be anything from running rich af, clogging a cat ( if you have one ), or more likely just not starting or flooding. Basically nothing good can come out of it.

Also what are you using for tuning (ecutek / oft) ? You might be able to find a base map online to fulfill option 1 if your tuner wont send you anything.

[Strife26]

I wouldn't. Or I would consult with your tuner first. They will tell you yes or no, or send you a base tune that will get you to the shop (probably).

Also a newb here, but just sounds risky considering you're dealing with fuel... The combustible part of combustion aka the scary part, heh.

Sent from my HTC U11 life using Tapatalk

[Olson1288]

Thanks for the replies guys. Sounds like I'll wait and do it all together unless I can get a base tune on.

Originally Posted by Sriracha

Good question, there are no dumb ones.

Firstly, Im super glad you asked before just trying it unlike some people I've come across. I agree as stated above. With injectors that much larger i would definetly NOT start it and personally either:

1. Install them and receive a base tune to drive it over
2. Wait to install them until you are at the shop
3. Install them and grab a buddy and a car trailer ( buddy can help push car up on it )

What can happen if you do not choose one of these could be anything from running rich af, clogging a cat ( if you have one ), or more likely just not starting or flooding. Basically nothing good can come out of it.

Also what are you using for tuning (ecutek / oft) ? You might be able to find a base map online to fulfill option 1 if your tuner wont send you anything.

I'm currently using Ecutek with a flex fuel tune. I'm not too familiar with Ecutek yet, so I guess my next question would be if I flash back to the stock tune for whatever reason, can I freely switch back to the current flex fuel tune, or does that require another license? From what I understand, when I purchased the dongle it only came with one license, which was consumed after applying the flex fuel tune. If I can switch back and forth without having to spend more money that would be great, because I also need to unmarry my OFT so I can sell it, which I forgot to do before applying my flex fuel tune

[steve99]

Originally Posted by Olson1288

Thanks for the replies guys. Sounds like I'll wait and do it all together unless I can get a base tune on.






I'm currently using Ecutek with a flex fuel tune. I'm not too familiar with Ecutek yet, so I guess my next question would be if I flash back to the stock tune for whatever reason, can I freely switch back to the current flex fuel tune, or does that require another license? From what I understand, when I purchased the dongle it only came with one license, which was consumed after applying the flex fuel tune. If I can switch back and forth without having to spend more money that would be great, because I also need to unmarry my OFT so I can sell it, which I forgot to do before applying my flex fuel tune

The ecu licience stays in ecu


You can flash an ecutek licienced ecu as many times as you like


Jist make sure you have copies of all tunes you need


But answer is yes you can flash you tunes back and forth as much as you like.


http://www.ft86club.com/forums/showthread.php?t=117520




But you now have a drama with oft


If you flash stock tune back to ecu with ecutek that unlocks it from ecutek but ecutek licience still in ecu


You could then flash your stock tune back from oft ,but you will overwrite and delete your ecutek licience doing that and ecutek will want another licence before you can flash with ecutek again


But ecutek licences can be renewed by your tuner, but talk to them first as ecutek has to re issue the licience

[tomm.brz]

Going back to topic,
if you look at mapaccess in ecutek during crank, ecu uses during cold start 50% DI and 50% PI
then when cold start finish it uses for a minute or so 100% PI and then 100% DI on idle and start using the PI/DI maps as normal


supposing the engine cranks, wouldnt STFT/LTFT help fixing the enormous fuel amount the 700cc would put out ?

[churchx]

3 times more fuel then needed is not acceptable ratio of fueling change. Fuel trims affect more timings depending on detected amount of knock, not as much amount of fueling. ECU logic/safeguards in it more then probably cannot work with that bit of difference. Engine may not start up due flooding at all, or spark plugs may warrant soon replacement (PITA procedure in these cars), or other issues may creep up. One should stop finding optimistic arguments/theories that may falsely stengthen false overconfidence to try doing wrong things. It's not safe run this way. Better go proper way with doing whatever is required with getting proper hardware tune was modified for or getting tune modified to run with new upgraded hardware, if change is of that major extent. I see no other way out, and trying to selectively inventing or imagining arguments that would make seem it safe enough running something that off seems completely wrong state of action.

[tomm.brz]

i do not see the correlation about fuel trims and ign timings and knocks. fuel trims works adjusting lambda measured afr to target afr.
you are right about the cranking, it would probably be a bad idea but if it starts the stft and ltft would probably correct the fueling on closed loop.. IF IT STARTS