Hi all,

I need some guidence, again!

My car was recently remapped to 338BHP with a number of mods.

I've had to change my inlet manifold, and as its off, i'm having fuel rails and a fpr fitted. I know its overkill for the power i have, but i have the parts and the manifold is off, so i thought i might as well get it all put in and save the space its taking up in the house!

My question is, when i change from the pink 550cc to 650cc injectors, will i need a remap straight away? Or, will i be OK to drive the car around with the new injectors?

I know i wont be getting the most out of the injectors until i do a remap, but, since there is easy access to them now, i'm hopping i can fit them without causing damage to my car, and until i can get a remap again.


Thoughts guys?

 

I would've thought without a map you would get some borewash as the bigger injectors will still be using the smaller injector cycle, thus pumping more fuel in? Could be wrong though....

 

It will defo be running too rich, so remap is a must...

 

Speak to the mapper, i am sure you will need a map tweak to adjust the fueling.

 

Need remap ASAP. Most people fit the injectors just before the remap. Once rails are fitted only takes a few minutes to swap the injectors.

 

The issue is that injectors are stupid, and they only do what they are told to do by the ECU. Relative to sensor inputs, the ECU will control injector duty. This means they pulse at a specific rate at any one time, which results in a specific quantity of fuel flow. If you fit injectors that flow more fuel for a given duty setting, the engine will run rich, relative to the previous injectors, and your mapper must deal with this on the spot.
I'd say you need to leave the injectors until you have the mapper there with you.

 

Thanks guys, really appreciate the help :-) owe you all a beer!

I'm not going to fit the injectors now, i'll wait until i upgrade other parts that will make the best use of them.

Cheers again all!

 

Wouldn't the ECU be just about able to cope on Open loop......so drive it to the mapper like a granny off boost and light throttle ?

Shaun

 

Dont drive it buddy.........I did injectors without a remap it was pumping fuel out and running rough. Had to get a Si from Jolly green out just to set a base map so that I could move it.
Not worth causing damage mate

 

yes definately