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For you guys and gals who don't know, I have a highly modified 146 ti facelift on a w plate. it has turbo conversion high lift cams, custom re-map etc etc.
I also have another 146 ti on an x plate that i bought a couple of months ago. bit of a runabout messabout car as my other one is seriously lacking in reliability due to being highly modified. it's blown head gaskets, had a cracked head, melted con rods etc etc.
My new one I added a nitrous oxide EFi kit to it. single fogger in front of the airflow meter. armed via a switch and kicks in via a full throttle microswitch. put it on for a cheap way to seriously increase power as it seems as flat as a witches *** compared to my other one. currently on the 50bhp jet although i doubt it's getting an extra 50bhp as it seems to me like it runs lean when the nitrous is engaged.
What i want to know is- 1 are the standard injectors capable of supplying enough fuel to generate an extra 50bhp when the gas is on. 2 am i going to blow the head gasket, put a rod through the block, make the crankshaft run a bearing or otherwise cause a catastrophic engine meltdown by using the gas. car has 62,000 miles on clock and full alfa service history, also just had full cambelt and balance belt kit, variator, oil and filter change using selinia 20k 10w-60 racing oil, air filter and iridium plugs. anyone have any expirience of nitrous and the later plastic top twinspark motor?????
 
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surely u need an extra fuel injector that operates at the same time as the nitrous one? how are the std injectors going to know they need to pump loads more fuel in?
 

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the reason you put the fogger in front of the airflow meter is so that it monitors the extra air being fed into your intake stream and the ecu adjusts the fuelling accordingly. yeah hot wire type airflow meter- the voltage required to keep the hot wire at a constant tempreture is directly proportional to the volume of air that passes over it.
commonly known as a dry type nitrous kit. the wet kit is the one your thinking of where fuel/nitrous mix is fed in post airflow meter in proportional amounts.
 

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Personally I wouldnt know the answer about the injectors but I have nos on the 75. You 50bhp kit might be giving you 30bhp If you lucky. On that basis when you modify the engine with ported heads exhaust and air filter you can achieve 20-25bhp gain and the ecu and injectors cope fine so I would suggest that it wouldnt be a problem at all. Its when you go bigger I.e I have a 200bhp wet kit and it only gives me 155bhp at the fly. But i run it through the ecu so that the mapping switches when the button is pressed. Get it on a set of rollers and do a run to check the co2 mixture to ensure that the car is still running a good mixture other wise it will eventually melt something, But as I said with a simple 50bhp kit I would suspect that there would be very little to worry about.
 

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the reason you put the fogger in front of the airflow meter is so that it monitors the extra air being fed into your intake stream and the ecu adjusts the fuelling accordingly. yeah hot wire type airflow meter- the voltage required to keep the hot wire at a constant tempreture is directly proportional to the volume of air that passes over it.
commonly known as a dry type nitrous kit. the wet kit is the one your thinking of where fuel/nitrous mix is fed in post airflow meter in proportional amounts.
Remember that the Air flow meter assumes a normal atmosphere mixture of gasses - you are enriching that mixture with more oxygen (in the N2O)

One other thing a N2O jet does is cool the air dramatically - expanding from the compressed cylinder. It could influence the reading if the too cold air blow too directly on the sensor.

A last question rather than comment is - can the standard injectors keep up with the extra fuel it needs to supply?

Good luck
 

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Best have the NOS injector after the MAF if you ask me - and a 5th fuel injector next to it too. I know it complicates things a bit but its what I'll be doing eventually. Supercharger is not worth the money next to a NOS install that comes in at under a grand.
 
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