JFettig
New member
- Joined
- Dec 28, 2011
- Messages
- 282
I've been running compounds on my Passat TDI for the past few months, spending a ton of time tuning and most everything is worked out but the one thing that I'm baffled on is drive pressure in lower gears. In 5th gear drive pressure is roughly 1:1, 4th gear its roughly 1.1:1 until higher RPM and 3rd gear its 1.5+:1, 2nd gear is at least that or probably more. I'm running 60psi Autometer gauges and the drive pressure gets pegged approximately 70psi(straight down) in 3rd gear or below.
Fuel mapping is the same 3rd through 5th, timing, duration,etc. 2nd an 1st its reduced. I have a feeling people will say too much duration, not enough timing - maybe so, I have to start bumping timing up now that I have the other issues fixed but timing map was created based on engine sound as well as AFR. I run 18-19AFR at WOT, 45-50psi depending on tune. 20psi at atmospheric turbo(need to drop this a bit). I am running a 38mm wastegate to bypass the VGT, 18psi spring and pressure is modified by the vacuum signal to the turbo(ask for more boost, wastegate gets fed vacuum). At WOT and 50psi and 20psi at the inlet the vanes are 100% open, at 45psi and 15psi at the inlet vanes are about 80% open.
Any input/experience would be appreciated! I know it doesn't quite translate to trucks, maybe what I'm experiencing is common?
Fuel mapping is the same 3rd through 5th, timing, duration,etc. 2nd an 1st its reduced. I have a feeling people will say too much duration, not enough timing - maybe so, I have to start bumping timing up now that I have the other issues fixed but timing map was created based on engine sound as well as AFR. I run 18-19AFR at WOT, 45-50psi depending on tune. 20psi at atmospheric turbo(need to drop this a bit). I am running a 38mm wastegate to bypass the VGT, 18psi spring and pressure is modified by the vacuum signal to the turbo(ask for more boost, wastegate gets fed vacuum). At WOT and 50psi and 20psi at the inlet the vanes are 100% open, at 45psi and 15psi at the inlet vanes are about 80% open.
Any input/experience would be appreciated! I know it doesn't quite translate to trucks, maybe what I'm experiencing is common?