hey guys i hope i dont get flamed for this but i have been researching aux injection. there is heaps of info on here and i know everyone has diff ideas, i just want to clarify where the air intake temp sensor needs to be placed? most of the ones i have seen the air temp sensor is before the aux injectors but when i told me tuner thats where i would be placing them he said no he wanted them after the aux injectors. does it make any difference before or after? or is it just personal preference?

and also the placement of the injectors... i see howard colemans injectors are in the silicone coupler just before the throttle body elbow, and i think his air temp sensor is before that just after the intercooler. if the injectors are place there is that classed as pre turbo injection or do ther need to be placed before the cold side of the turbo even before it goes through the intercooler?

and does it make any difference if i do a straight water or a 50/50 mix?

Thanks Mark

 

right alot more reading later and i have sorted out the injector placement of pre turbo! but i would still like to know the best placement for the ait sensor?

 

I prefer after the aux injection nozzles. This allows any changes in air temp due to the injection to be tuned for. If you're using the stock IAT sensor then it's best to get it out of the UIM as it heat soaks. If you're using a Fast reacting IAT then the stock location is best.

 

cool thanks, so a fast acting ait sensor is an aftermarket sensor that fits in the factory spot right? am looking at going pre turbo straight water with a boost based system like yours! a bit more research to come yet, thanks

 

Yeah wannaspeed.com has the fast reacting iat sensors

 

cool thanks i will have a look at there site! I read your whole thread on building your wi system, i must say its an awesome idea! apart from putting in a low level switch that trips a led, is there anyway you can do a fail safe for blocked nozzles? only thing i could think of is a flow switch.. it would always be on when not boosting or squirting water, but if it stayed on under boost it wood mean blocked nozzle of stuck sonenoid... any thoughts? thanks heaps

 

what about the cooling of the sensor by water. is this an accurate representation of the actual temperature of the Air??

 

I never notice much cooling by water injection. In my experience it keeps the temps from getting out of hand even at very high boost levels, but doesn't really lower them. In any case the water will not give any false temp readings. The sensor doesn't care if it's air or water it will read correctly either way.

 

A little late to the thread, but I'm intentionally placing the injector AFTER the IAT. I will NOT be tuning for AI, just adding it to reduce knock values for safety. My thinking is that if the system fails for any reason, placing injection after the IAT has no negative consequences.