1.6TD Wastegate setting?

[reiney]

Hi all,

Any suggestions on optimal setting for the wastgate adjustment screw on the 1.6TD motors? The stock setting ran about 9 psi max and the low-rpm response was very good. I cranked it in some and get about 15 psi max now but response time is noticibly slower. My 5-speed trans. broke and I just finished installing the aricooled (DK) 4-speed so the geraing is a little taller and the van is even more slug-like off the line now. Can I just crank the wastegate adjustment in all the way? Will this give me "always-on" boost?

Thanks much!

[?Waldo?]

Yes, you can. It will give you fuel controlled boost. More pedal = more boost. Are you intercooled? EGT gauge installed? Which turbo?

Andrew

[reiney]

Hi Andrew,

Yes; intercooled & EGT. Not quite sure which turbo but looks like stock. Came from Germany via "Quality" German Auto in So. Cal. and I think was originally in a Vanagon/T3? K14?

Reiney

[?Waldo?]

Yup, that should be a k14. That's how I'd run it, with the wastegate fully closed. With decent fueling it will likely max out at around 18-20 psi.

Andrew

[reiney]

Is 18-20 psi a "safe" level for this motor? I'm trying to get ready for a couple of road trips and don't really want to do a head gasket job at this point in time. I guess the variable geometry turbos are the cat's meow or maybe an outboard boost controller? Would be nice to have a "city/highway" switch ...

Thanks again,

Reiney

[?Waldo?]

The wastegate setting really shouldn't have any affect on how quickly it spools. It just controls the max psi. I have quite a few miles on various 1.6TD engines running 20 or more psi without issue. Then again, your mileage may vary. Any un-beaded boost hoses will pop off.

Andrew

[danfromsyr]

isn't more 'air' & less fuel run cooler or is there a crossing point where it gets hot again?
I was wanting to bump mine from the stock 9psi to ~12psi.. maybe 15.. but 18-20 seems high... I've been holding back for the install on my intercooler.. (Saab Turbo for the DS tailight)

I was under the understanding that soot "unburned fuel' made the exhaust run hotter?

also I want to add a EGT to mine using a slick digital display machinery temp pyro disply.. where do you have your EGT probe?
Preturbo? Post turbo?
and what numbers should I be on look out for in either of these locations?

Dan
_________________

[?Waldo?]

More air OR less fuel lowers EGTs. Without an intercooler, above 15spi or so the heat from compressing the air overcomes the benefit of the added air in the combustion chamber. With an intercooler, increased boost lowers EGTs progressively.

I would strongly recommend mounting the EGT probe pre-turbine. If it is mounted post turbine the numbers are variably inaccurate due to the varied amount of heat that is turned into useful work by the turbocharger. There isn't really any way to get a meaningful reading post turbine. I have heard 1500° as the max "safe" operating temp, above which engine internals start to melt. I personally wouldn't ever want to see temps that high. I like a good safety cushion and so don't like to see above 1250-1300 sustained pre-turbine. I would also strongly recommend the 1/8" westach EGT thermocouple from Aircraft spruce. If you ever compare the response to that of a standard VDO, Autometer, etc. thermocouple you will thoroughly understand. The extra thermal mass of the larger probes cause very slow reaction times. The gauge will often still be climbing after you've crested a hill which makes me wonder if the reading from those probes is ever even useful.

[reiney]

Hi Dan,

I've got an Autometer Sport Comp Digital gauge with the probe pre-turbo as Andrew suggested. I also have a Saab intercooler in the DS tail-light but I need to cut out some metal on the bottom of the pillar to improve air flow. I have a small fan on it now but will be installing a larger one when I get the pillar cut since mine is partially blocked by my intake snorkel arrangement.

Andrew,

I've been methodically going through all the fuel system & pump diagnostics to make sure everything is OK before I start pump tuning. Checked timing, max no-load rpm, and accelerator cable stop so far this week. I've adjusted the max fuel screw a few times trying to get it so that I just see an occasional puff. Up next is checking the internal pump pressure as soon as I can locate a "banjo extender" or get up to Tencent's and use his lathe.

I was wondering if you did the "governor mod" to your pump as I think this may be the at the heart of my performance issues. I can't seem to get past aprox. 3800 rpm in any gear and performance below 2000 rpm (where there is virtually no boost) is not great. Once I get the revs up, acceleration seems good and I'm relatively happy with how it runs on the highway.

I've been re-reading the gov. mod threads and I'm unsure as to whether it is best to remove the intermediate spring or just shim it. Any thoughts?


Thanks!

Reiney

[reiney]

Paging Dr. Libby ...

[?Waldo?]

I cut a hole through the firewall and ran my air cleaner above the transmission. With the intake on the same side as the intercooler, you will be reducing the airflow through the intercooler fairly significantly.

The performance issues you describe are the precise reasons I will be fitting a mechanically controlled VNT to my 1.6TD vanagon. Aside from that as far as fast spooling, the k14's pretty much as good as it gets on the 1.6TD. You can always dump more fuel to spool it up, but adjust the aneroid to clear the smoke when boost comes up.

I haven't really done enough experimentation with the governor mod to give what I would consider worthwhile feedback. My understanding is that the intermediate spring causes a gradual decline in fueling until it is compressed then the main governor spring cuts the fuel fairly abruptly. Let me know what the results of any of your experimentation are. Max no-load rpm will be directly linked to when the governor cuts out the fuel. You might adjust that higher and just use good judgment on when to shift.

Andrew

[reiney]

Hey,

Thanks for the reply; much appreciated.

I had to get my intake up away from the ground. I clogged my filter in about 3 weeks once we moved to the new place at the end of the 2 mile dusty road.

Performance was great with the 3H 5-speed. Topped out at 55 on the highway but very zippy around town. Don't have the cash for a rebuild right now but I'm hoping to put it back in someday.

Wondering whether or not the step up in piping size to intercooler and back is having a significant impact; the runs are pretty short but I could probably cut the volume in half again with a smaller unit. Had a crazy idea about being able to mechanically bypass the intercooler from the driver's seat. Some sort of linkage/valve nightmare I guess

I don't seem to have any way to tweak the boost enrichment. My pump has the odd lay-down-canister setup. Clears the deck lid just fine but is apparantly not adjustable.

Were those your Mercedes pics w/ the custom actuator for the VNT? Very nice work!

[?Waldo?]

You can adjust the aneroid some on the JX pump, but not as much as on the Golf/Jetta style. The decklid interference is pretty minor and easy to remedy with the jetta pump and so it is my preference especially considering the necessity for uber-rare injection lines with the JX pump. But, it's what you've got, so moving on.

Here's an interesting read:

http://vwdiesel.net/phpBB/viewtopic.php?t=5843&postdays=0&postorder=asc&start=0

This is my VNT Mercedes build:

http://vwdiesel.net/phpBB/viewtopic.php?t=10365

Andrew