I currenty have the greddy SMIC. It was tuned on the dyno nice and good.
Now I'm installing a Greddy FMIC. Do I need to re-tune the car? Are the air-fuel ratios going to change now that the car will have cooler intake temps?

 

Probably just need a little tweaking, not a full re-tune. You'll likely be looking at cooler intake air temps. You could probably just road tune it, BTW.

Dale

 

Lets say I cant tune it for a little while..could I run a risk of blowing the motor?

 

Logic would suggest that as long as you keep the boost the same you should be ok. But I think it's wrong.

Logic also suggests that the FMIC is much more efficent than a SMIC. Thus you will have more air even at the same boost level. Much colder air = more air particles given the same boost level.

Just don't WOT till you get it tuned and you will be fine. Or if you can't keep the lead foot at bay don't install the FMIC till you can get it tuned.

Wanna sell your SMIC?

 

Sorry man I already sold it for a good price! I wouldnt do it man they get heat soaked so quick and on hot days it sucks.

 

no prob

 

The ECU can adjust for cooler intake temps, since it has a sensor for the air temp, but realistically no one really gets their cars custom tuned for a wide variety of temps. So even though the ECU could account for this change, it is probably a good idea to re-tune.

Changing the IC also changes the flow characteristics, which is something the ECU can't adjust for, even if you had a perfect tune before. This is another good reason to get a re-tune.

However, it is likely that your current map is close enough to what you need that you won't blow up the car on the first drive. If you want to be extra safe, you could add a little fuel across the board until you can get the car re-tuned.

You could also get a wideband and tune / verify your tune rather than having it retuned on the dyno.

-Max