[A13EX F Cooper S]

I've read somewhere that the injectors for the mini are different to normal ones as the jet is split into 2 and also angled.
is this true?

the reason I ask is I am considering a larger throttle body but dont want to max out the standard injectors and make th engine run lean would fitting a large throttle body mak it run lean?

I currently have the following fitted:

15% puley
intercooler
full exhaust
decat
manifold
iridium plugs
air filter
remap

finding second had jcw ones 380cc is like finding a needle in a haystack with no needle in it so are there any other injectors from any other car that will fit as i'll do a bit of scrap yard hunting if they are.

oh and one more question can i just plug them in or do i need to remap the car again?

[Penguinracer]

I'm open to being corrected if I'm wrong but my understanding is that the MCS has sufficient duty cycle in it's standard ECU/Injector combo to safely fuel the engine's needs until it's producing up to about 250 bhp.

Sure the injectors will be working hard - but they'll be okay until the MCS is reaching the outer limits of what is a practical road tune.

Didn't Roland dyno his car at 270 bhp with standard injectors & at 273 bhp with bigger ones - I hope this gives some perspective.

[A13EX F Cooper S]

thats what i thought 240+ needs bigger injectors,
my problem is i think i'm close to that figure and the throttle body might tip me over.

also a throttle body means more air ... more air needs more fuel ... more fuel needs bigger injectors.

I dont want to risk blowing up a second engine lol

[St00ge]

I doubt a throttle body will give you much more power....New injectors can be a good idea, even with the mods you have. Remember, JCW fit their injectors to a car that runs 207 bhp, so, can't be a bad idea.

[Penguinracer]

We must remember that because the JCW was offered with a full factory warranty it was tuned to run a similar air/fuel ratio to the standard MCS in the interests of cylinder head temperatures & valve seat lubrication.

I'd be inclined to think that the JCW uses larger injectors to run a little rich just to be on the safe side.

My car is at the point where it's not far away from needing injectors - I'm guessing it's getting on for 240 bhp using the following:

(1) Hartge Conversion (210 bhp);
(2) 8mm HT leads;
(3) Iridium Plugs;
(4) 40kV coil;
(5) GTT 63mm throttle body;
(6) GTT timing sprocket;
(7) Schrick cam;
(8) GTT Induction kit;
(9) GTT Intercooler;
(10) GTT catchcan & vent;
(11)GTT tension pulley;
(12) GTT tension stop;
(13) GTT Twin bearing idler pulley;
(14) GTT modified by-pass valve;
(15) Scorpion Exhaust manifold & metal sports cat (same as Prodrive Scooby cat);
(16) Scorpion exhaust system all the way back.

At the track it's doing about 10 -13 mpg, so I can't really imagine it needing much more fuel.
It may be a borderline case - I'm open to suggestions.

[St00ge]

Well as was mentioned, the stock injectors have handled roland's 270bhp car, so obviously enough fuel can be injected. The problem is the duty cycle. I think the injectors shouldn't be stressed to more than an 80% duty cycle, or so i've been told. Which would mean no more than 270cc/min on stock injectors. It might be able to cope, but not for long....

[Penguinracer]

A fair point - it pays to have a bit of headroom - the last thing you want is the engine running too lean when under stress.

Roland posted an interesting thread to the effect that the Mini's ECU is surprisingly capable & can monitor the fuel flow irrespective of the injector size.

Essentially it will seek to flow the required fuel whether that means working a smaller injector harder or running a larger injector well within it's rating.

It would be helpful if one of the tuners could give a definitive answer as to when an increase in injector size becomes necessary to maintain healthy safety margins.

Only the GTT 250 & 260 kits include larger injectors if that means anything.