Megasquirt Advice and discussion.

***TitaniumTT*** · 12-10-2009, 09:08 AM

It should be noted that 15psi is not 15psi in all cases. Which is the main reason a MAP based system much more sensitive to changes in airflow. Taking two extremes, the stock HT-12s vs a GT45R. @ 15psi of MAP, a GT45 will flow much more air than the HT12's. So, by bolting on a GT45 you need to re-tune a MAP based system due to the drastic change in VE. When you start to mod a stock MAP based system and you increase the effiecency of the turbo's, you change the output of the compressors slightly. 15psi may still be 15psi, but the actual flow is changing and the Lambda's are now incorrect. A MAF based system is still subject to changes in VE but much less so tan a MAP based because it is measuring the airflow through the sensor, not just how much pressure is in the manifold

12-10-2009, 09:08 AM	#25
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son Posts: 4,581 Rep Power: 10	It should be noted that 15psi is not 15psi in all cases. Which is the main reason a MAP based system much more sensitive to changes in airflow. Taking two extremes, the stock HT-12s vs a GT45R. @ 15psi of MAP, a GT45 will flow much more air than the HT12's. So, by bolting on a GT45 you need to re-tune a MAP based system due to the drastic change in VE. When you start to mod a stock MAP based system and you increase the effiecency of the turbo's, you change the output of the compressors slightly. 15psi may still be 15psi, but the actual flow is changing and the Lambda's are now incorrect. A MAF based system is still subject to changes in VE but much less so tan a MAP based because it is measuring the airflow through the sensor, not just how much pressure is in the manifold __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

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