experimental cold air

[cannondale27]

Interesting...but I am missing something...sensors are sensing either the air or pressure in the chamber is changing..and if there is more it will try and richen it up..if the ECU can't find combination it has been told to look for I assume it will just guess..

Is it a speed density from idle to full speed?

Whare can I read more about that system?

It's speed density from idle to full. MAP sensor is a baro sensor so altitude and current Baro do change mapping. If a Turbo were added and more pressure were sensed it would add more fuel to a point but NA there is never any more pressure than atmospheric pressure so no adjustments are made no matter how much flow is increased even with porting which is reason you need a tune at a point.

 

[Mtnviper]

Yes, if the air temp drops the ECU will automatically add fuel to correct for the cooler/denser air. Most code written for ECU's will be good down to -40F, so it has the ability to change fueling at various stages down to that. If the temp drops below -40F (burr) the fuel control will essentially be maxed out at -40F.

Yes it uses speed density from idle to full speed. When the ECU goes in to closed loop and uses the O2 sensor for fueling corrections, it is only making small corrections/changes to the base calibration. The O2 sensor typically does not permanently change the base calibrations programmed within the ECU, it only adjusts them "on the fly". Once the key is turned off the ECU reverts back to the base calibration.
With a narrow band O2 sensor found on the Viper and most cars/trucks, the O2 sensor is used to try and fine tune the air/fuel ratio to 14.7 to 1 primarily for emissions purposes.

Narrow band O2 sensors are not used during wide open throttle, because at WOT you want a richer fuel mixture then 14.7 to 1 for max power and to prevent lean mixture (burnt pistons) engine damage.

There is a pretty good article which covers speed density here http://www.ecmtuning.com/wiki/sd101

Bill

 

[ishpeming fan]

I already done airbox mod. Today I added a cold air intake from the front of the sled going to the frogskin of the bottom of the air box mod.
I hope this will help
View attachment 122673
View attachment 122674

that looks awsome,but wouldnt normal snowdust from trail riding with a group cause to much snow ingestion and cause premature wear to the motor?

 

[ZR7000]

I already done airbox mod. Today I added a cold air intake from the front of the sled going to the frogskin of the bottom of the air box mod.
I hope this will help
View attachment 122673
View attachment 122674

How did this end up working out? Do you have additional pics of the routing to the airbox? Nice set up.

 

[Alsim]

How did this end up working out? Do you have additional pics of the routing to the airbox? Nice set up.

Sorry ZR7000. I don't have any picture cause I sold my Viper. I did the Stringray airbox mod and just reroute the air flow near the lower opening at the bottom with a piece of pipe for more cold air.

 

[gpxsrx]

I did the same lowers air temps significantly.

 

[ZR7000]

View attachment 151307 I did the same lowers air temps significantly.

How much reduction were you seeing?