blow-off w/MAF

I have a Ysi (driver mount) a mondo blow-off valve and a pro-m 117mm meter. What happens if I vent to atmosphere instead of routing back to intake pipe?

It will cause a rich condition. The MAF is reading the air that is going into your engine. If you release the air that the MAF has already seen to the atmosephere the ECM has noway of compensating for it. So the injectors will be spraying fuel for the amount of air the MAF has read, causing the rich condition. This is the easyist way to explain it I think.

One way around it would be to use a blow through MAF and put the Blow off valve infront of the mass air, or before it can read the air.

I hope this helps.

Thanks for the reply chuck its appreciated. If your letting off the gas at the end of a run or after a burnout and the blowoff vents, the a/f goes rich for an instant, what exactly will this affect? This a track only car, dont want the extra plumbing if its not needed.

It will probably throw the CEL and die with a big injector but it's worth a try if you thing it's worth it.

Thanks for the info guys.