can i drive with 740cc injectors without remap?
 

getting the 740cc injectors fitted next week and was wondering if i can drive with them in, obviously off boost until i get remap?
im not planning on driving it daily,just from garage and back and maybe to the place where its getting mapped,it has alot more mods than just the injectors and dont want anything going wrong on way home
thanks

Technically yes, but you shouldnt and dont expect it to be smooth, fuelling will be out and you could encounter the odd misfire

Me personally I wouldent, what was/is the size of your current injectors?

If they were 380's or 440's the 740's will be putting wayyyy to much fuel into your system.

Just my opinion

Running open loop on idle and light throttle the ECU should just be able to cope as it tries to run stoic.....as soon as you start to boost and run off the map on the ECU it will be like turning on a tap LOL

Shaun

i currently have 440's in.soon as the headers/up-pipe and injectors are in,which is next week,im leaving my car parked up until i arrange a remap with jgm

i would be intrested to find out if you can too as i want to change my injectors

The answer is no, surely? Even if you had 500+cc injectors before youll still be over-fuelling by 50%! You cant possibly think that this will be 'alright'?

Id be concerned with bore wash tbh. Not recommended

JUST A QUESTION ON THIS.
I thought there was an optimum fuel/air ratio for each revolution of the engine controlled by the ECU, injection system, MAF etc.When they designed the engine do they not put in injectors that will cope with the maximum fuel flow needed for optimum performance? If you don't do any other mods what gain would bigger injectors give you?

If you do not mod the engine at all or re-map it there is no need to change the injectors :D

If you try and extract more power from the engine with mods and mapping you need more air / fuel in the cylinders and for this you might need to change the injectors and fuel pump to ensure enough fuel enters the cylinders :D

Shaun

I drove one with 740's in my car as I had to do a 200mile drive before I had a chance to have the car mapped. I spent the whole time watching the boost gauge and never took the car over 0.5 bar which was a real pain when I came to a really really steep hill. Personally I wouldn't take the chance if you don't have to. On a plus point I got cracking mileage on my drive :)

newage are very good at adapting in closed loop etc..

as OP is talking classic size injectors I presume it is a classic which won't cope very well.

Simon

yes its a classic,iv got my car booked in garage for the parallel fuel rail setup to be fitted aswell as injectors and exhaust headers,garage is about 2miles from me and once i get it home im not touching it lol,not until remap anyway :D
simon:the apexi fc didnt turn up so i will be arranging geting simtek with u :thumb:

no problem.. drop me a pm or email when ready etc

Thanks
Simon

iv done this, but iv got an adjustable FPR, so il regulate pressure down to just over 2bar to check everything its tickety boo then have the car transported to mapping and whack it back up to 3

i have a adjustable fpr to but i dont want to be messing around with it...i think im going to get it back home on my recovery truck than risk anything going wrong lol

i also thought about this and decided against as i didn't want any problems
if it was just injectors and u had apexi fc then u could of adjusted the ratios on the hand controller to suit , but u have had a few things u say so i wouldnt risk it

Get in touch with a local recovery service and trailer it bk home safer imo

edit - just noticed u got a recovery truck so i wouldn't even think about driving it

defo goin to take it there and back on my recovery truck now lol,getting remap not long after its done as it would be a better excuse to do so :norty:

That's what happened to my car ... previous owner carried out major mods incl 740 injectors, ran it lightly prior to getting a map, it went pop when he gunned it in a moment of madness. When engine was stripped down it had suffered from bore wash.

TX.

now im 100% bringing it back home on my truck lol
cnt be bothered with another rebuild so on may 19th when car has these fitted im bookings remap same day :D

If you were only going from 380's to 440's the classic ECU can handle that fine and compensate, possibly even 550's although it would start to run a tad rough with 550's, however such a big jump to 740's is quite substantial and i wouldn't advise anyone to run their car even 1 inch like that. Injectors are always the last thing you change just prior to remap.

Those of you with tow trucks or trailers....lucky sods!! :D