Nissan 370Z Forum - View Single Post

ChipsWithDips · 04-21-2012, 06:10 PM

Just wondering if anyone has measured the inner diameter on the main length of the tubing used for their intakes. I'm mainly interested in the numbers for Stillen Gen III or AEM intake, but if you want to post diameters for others feel free.

Since the airflow measured by a MAF is dependent on the diameter of the tubing it sits in, this means that if you change the diameter of the tubing, it will throw off your tuning and likely run extra lean. There seem to be three approaches to dealing with the issue:
1. Keep the tubing a smaller diameter along the majority of the length(seems to be stillen approach, is it exactly same diameter as stock MAF tube along the whole length? I know there is a short flare right where the filter goes, I'm not concerned with that)
2. Go to a larger tubing, but choke down diameter right at the point where the MAF sensor goes in (Injen for example)
3. Use a black box to modify MAF signal to correct for different flow reading (AEM ETI intake)

I'm assuming that AEM took advantage of this signal modifier to allow for larger piping diamter, just wondering how it compares to other intakes on the market. I may try to get a custom intake built, similar to AEM, but using uprev tune instead of a black box to compensate for altered flow signal.

04-21-2012, 06:10 PM	#1 (permalink)
ChipsWithDips Enthusiast Member Join Date: Mar 2011 Location: Austin, TX Posts: 279 Drives: '11 Gunmetal 370Z MT Rep Power: 14	Question for aftermarket intake owners Just wondering if anyone has measured the inner diameter on the main length of the tubing used for their intakes. I'm mainly interested in the numbers for Stillen Gen III or AEM intake, but if you want to post diameters for others feel free. Since the airflow measured by a MAF is dependent on the diameter of the tubing it sits in, this means that if you change the diameter of the tubing, it will throw off your tuning and likely run extra lean. There seem to be three approaches to dealing with the issue: 1. Keep the tubing a smaller diameter along the majority of the length(seems to be stillen approach, is it exactly same diameter as stock MAF tube along the whole length? I know there is a short flare right where the filter goes, I'm not concerned with that) 2. Go to a larger tubing, but choke down diameter right at the point where the MAF sensor goes in (Injen for example) 3. Use a black box to modify MAF signal to correct for different flow reading (AEM ETI intake) I'm assuming that AEM took advantage of this signal modifier to allow for larger piping diamter, just wondering how it compares to other intakes on the market. I may try to get a custom intake built, similar to AEM, but using uprev tune instead of a black box to compensate for altered flow signal.