1Z/AHU - mild performance, MAF or no MAF?

Hi,

My 78 Bus has a 1997 Passat 1Z. I'm running the DLC1019 nozzles and stock turbo and a custom Malone tune.

I don't plan on any big power upgrades because 1. It's a bus and 2. The transaxle was very spendy and I don't want to break it.

I'm planning on asking Malone about making some revisions in the tune and am pondering whether to go MAF-less at the same time. My reason would be just to simplify the intake.

I read some older threads on the ALH where someone said you'd have more smoke or a less responsive setup without a MAF.

What are the upsides/downsides to a MAF-less setup on the 1Z/AHU?

Thanks much!
Mark

If you already have a MAF intake, there's no smart justification to remove it unless your engine is tuned to an extreme state that saturates the sensor. It's not like the older hot-wire MAFs are unreliable compared to the newer hot-film sensors - quite the contrary. What do you mean, precisely, by "simplify the intake"? As it is, it is not very unwieldly at all; the Passat intake doesn't have the plastic hose with the reduction of cross-section that the ALHs do and you can basically put the MAF sensor close to the snorkle of the compressor inlet and if you must, a cone air filter if space and routing is a problem.

If you're going to do any revisions in your vehicle not for a large power increase per se but for less smoke, better response and driveability, an upgraded turbo is the most sensible way to go. 1Z's always smoke more than an ALH of the same power output. If you're getting a revised tune anyway, it would be a perfect time to go with a VNT. A GTC1549VZ supports 170 HP, spools incredibly quickly and are very cheap from eBay across the pond. Your SoCal neighbour john.jackson9213 in the San Diego area has a 1Z Passat with this turbo. Different car, I know, but maybe you can arrange to meet for a ride.

Edit: Took a read of your build thread. If even more low-end grunt is desirable so that 4th gear is more usable, look into a GTD1449VZ, PN 04L 253 010H or GTD1446VZ 04L 253 014C. Incidentally, the latter is used in the 150 HP TDI in the newest T6 Multivan. 1300-1500 RPM will be useful then.

Thanks, TDIMeister!

I'm not looking to change turbos right now, also don't want to boost power significantly as the trans may not take it. I will keep your notes for when the old turbo is worn.

My thinking with MAF-less was just to remove one more piece from the system that eventually needs replacing, also free up a few inches more space so maybe I can simplify the air filter setup.

Thanks,
Mark

I run, and most of my customers choose to remove the MAF. Malone Tuning does a great job with this sort of software.

My Ranger - ALH | 1749VB | Race520 | Malone Stage 4 doesn't smoke at all with regular driving and will only smoke when the accelerator is >80% and I am giving it the beans. Even then it's only a wisp of smoke - not even close to "rolling coal". My experience with responsiveness is that I can't tell the difference between MAF and MAFless. I do enjoy the fact I have the Ford airbox and no wires running to it - very clean install.

Thanks, David!

Why force tune one way, when you can have both. Just have your tuner make it both ways in tune. Simple to tune both open loop and closed loop running maps. Plug in map sensor for closed loop best fuel economy, and unplug it for open loop when racing.
Best of both worlds. Been doing this way for past 15 years ;-))