www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You

Order your TDIClub merchandise and help support TDIClub


Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI Conversions

TDI Conversions Discussions on converting non TDIs into TDIS. More general items can be answered better in other sections. This is ideal for issues that don't have an overlap and are very special to swaping engines.

Reply
 
Thread Tools
Old April 28th, 2019, 17:12   #16
[486]
Veteran Member
 
Join Date: Mar 2014
Location: St.Paul, MN
TDI(s): 02 golf ALH
Fuel Economy: 42 stock, 47-49 now
Default

Quote:
Originally Posted by CasaEd View Post
Until you sort out the control mechanism for that vnt turbo you're never going to get a decent level of power, all you are achieving is to move the power to a different part of the rev range, if you close the vanes too much the boost will be too high and if you open them too much you will have low boost.
ehhh
near full open, turbine efficiency does go down a little, but anything less will be just the same as any fixed geometry turbine housing, just that you can adjust what the effective volute size is

you are limited in the fuel you can put to it though as it is a little baby thing, but by no means is it improper to use a VNT in a fixed position

I would certainly scab on a wastegate however, even if you've gotta put it on the little EGR port.
[486] is offline   Reply With Quote
Old April 29th, 2019, 13:19   #17
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

Near full open turbo efficiency drops more than just a little bit, think about how the ECU on a Tdi controls the boost pressure and at low rpm's with vanes near full open the power would be very low. A fixed geometry turbo works by bypassing the exhaust turbine so is not like a VNT in a fixed postion. How are you going to control the boost if you throw a lot of fuel in it with bigger nozzles and the turbo spools up to an over-boost situation ? If you were to route the egr port to by-pass the turbo you're back to square one, low boost, So as previously stated, control the vanes either mechanically, with vacuum or pressure can.
CasaEd is offline   Reply With Quote
Old April 29th, 2019, 18:12   #18
[486]
Veteran Member
 
Join Date: Mar 2014
Location: St.Paul, MN
TDI(s): 02 golf ALH
Fuel Economy: 42 stock, 47-49 now
Default

Quote:
Originally Posted by CasaEd View Post
A fixed geometry turbo works by bypassing the exhaust turbine so is not like a VNT in a fixed postion. How are you going to control the boost if you throw a lot of fuel in it with bigger nozzles and the turbo spools up to an over-boost situation ? If you were to route the egr port to by-pass the turbo you're back to square one, low boost, So as previously stated, control the vanes either mechanically, with vacuum or pressure can.
turbos without wastegates have been a very popular option in the MDT/HDT/tractor/stationary world for a VERY long time

diesels are neat in that you can choose a turbo that'll move enough air for the power you want, then it'll self-regulate without any sort of control at all
add more load/fuel, EGTs go up, it makes more boost and levels off the EGT rise (within reason)

the thing is that the gt1749V on an ALH is sized for like 60hp when treated like that
it gets by with the 90hp rating by kneecapping the turbine efficiency with over-opened vanes

ETA: and I was saying to add an external wastegate on the EGR port, not just an open pipe or whatever you seem to think that I was suggesting
[486] is offline   Reply With Quote
Old May 1st, 2019, 12:02   #19
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

I knew what you meant by waste gating the EGR pipe, I've had my say on the subject, if the OP wants to struggle trying to make a good set up that's up to him. MDT/HDT Tractors and stationary engines are another subject.
CasaEd is offline   Reply With Quote
Old May 3rd, 2019, 16:11   #20
jackfolstam
Veteran Member
 
jackfolstam's Avatar
 
Join Date: Oct 2016
Location: CA
Fuel Economy: 42mpg
Default

What I'm trying to do is restore the 14psi I was previously seeing. I set the rod back to where it was at that time (start moving at 3-5inhg) and I'm still getting 9psi.

The goal of originally moving the rod was to try and get a little more performance out of it. I have looked at some of Libby's posts but with so many pictures down its not possible to copy his design. I do see posts about an Arduino but haven't looked enough to see if there is adequate info for me to tackle that project. Then I have an AHU harness and ALH harness and I think actually all of the electronics required (however from the junkyard). Actually I need a mk4 80 pin ecu.

Sent from my SM-G900V using Tapatalk
jackfolstam is offline   Reply With Quote
Old May 4th, 2019, 10:19   #21
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

Forget the 80 pin ECU, go for the 121 pin ECU so you can Flash Over OBD, A bit more work but worth the effort
CasaEd is offline   Reply With Quote
Old May 6th, 2019, 21:17   #22
jackfolstam
Veteran Member
 
jackfolstam's Avatar
 
Join Date: Oct 2016
Location: CA
Fuel Economy: 42mpg
Default

I opened the LDA today to take a look, hadn't opened one before but I expected the boost pin to have a different taper around the circumference when this one appears to be symmetric:


I'm not sure what the star wheel does? It doesn't appear to be connected to anything but a metal tab that it ratchets on, on the left.

There's also a little hole in the aluminum LDA housing, below the diaphragm, that leads to the outside. The hole is in the middle of a fitting that's screwed into the side of the housing, not sure what's inside the fitting.

I did screw down the adjuster on the top outside of the lid, looks like it pushes the diaphragm down and adjusts where it the boost pin starts before pressure is applied by boost but it drives no different.
jackfolstam is offline   Reply With Quote
Old May 7th, 2019, 13:20   #23
CasaEd
Member
 
Join Date: Mar 2017
Location: Portugal
Default

The star wheel can be moved up and down, up increases the pressure on the spring and down decreases it. If you're looking for more fuel then you need to refit the pin with the steepest slope facing towards the front of the pump. The hole you describe is just a vent . When you adjust the top screw it pushes the pin further in wich increases fuel too, also if you remove the plastic shim under diaphram that also allows the pin to go down further. Be warned though, too much fuel will push the EGT's up.
CasaEd is offline   Reply With Quote
Old May 10th, 2019, 13:53   #24
jackfolstam
Veteran Member
 
jackfolstam's Avatar
 
Join Date: Oct 2016
Location: CA
Fuel Economy: 42mpg
Default

Quote:
Originally Posted by CasaEd View Post
The star wheel can be moved up and down, up increases the pressure on the spring and down decreases it. If you're looking for more fuel then you need to refit the pin with the steepest slope facing towards the front of the pump. The hole you describe is just a vent . When you adjust the top screw it pushes the pin further in wich increases fuel too, also if you remove the plastic shim under diaphram that also allows the pin to go down further. Be warned though, too much fuel will push the EGT's up.
Thanks for the advice. Regarding EGT, I had a probe on my 1.5L idi, with just the load screwed turned in all of the way which was an additional 1/2 turn from factory, I could make a James Bond smokescreen in a split second, and get EGTs to 1300F in just a few seconds. Now with an ALH and light mods (OMI, 2.5" exhaust, FMIC, slightly advanced timing, IQ=2.0) in a <2000lb car, I have to floor it for about 15 or 20 seconds up a steep grade to get to 1300F. I feel like that temperature is conservative though after reading about how high some people here push it.

Right now the mtdi does not smoke at all, so I'm being pretty brave without an EGT gauge, and I just won't push it too hard up the steep hills here.

Also, I figured out the boost; I finally got the bright idea to hook up a vacuum hand pump to the turbo and pull vacuum while driving. The rod was adjusted so long that it was beyond my comfort zone to shorten it. It took 10inHg to get it to 15psi while floored, and now have adjusted the rod to be there all of the time. Now I have a much less concerning problem; the intercooler pipes are blowing off.
jackfolstam is offline   Reply With Quote
Old May 11th, 2019, 17:52   #25
oil_me
Veteran Member
 
oil_me's Avatar
 
Join Date: Oct 2004
Location: Woodstock, NY
Fuel Economy: 51,38,43
Default

Here's a good resource for adjusting/tuning our pumps.
https://www.landroverweb.com/Pdf-fil...ines_Rev_2.pdf
__________________
'91 GlacierBlue Audi 80Q M-TDI 51.8 mpg http://www.motorgeek.com/viewtopic.php?f=6&t=45645 http://forums.tdiclub.com/showthread.php?t=344436
'99.5 Black Jetta TDI, 200k, '02 ALH, 11mm IP, RC3+,Titan/nozzles PDliftpump, Racepipe, OMI, 2.5 SS exh., lower IC , Shine, Panzerplate,52/47
oil_me is offline   Reply With Quote
Old May 12th, 2019, 06:32   #26
Exenos
Veteran Member
 
Join Date: Apr 2014
Location: Ontario
TDI(s): 02 Golf
Default

Combine that pdf with this link http://dodgeram.org/tech/dsl/more_power/Power_ve.htm and you can get a pretty good idea of tuning a ve pump
Exenos is offline   Reply With Quote
Old May 16th, 2019, 13:40   #27
jackfolstam
Veteran Member
 
jackfolstam's Avatar
 
Join Date: Oct 2016
Location: CA
Fuel Economy: 42mpg
Default

So I was wrong. When I hot pipe the truck it boosts to whatever I set the control rod to. A quarter turn either way gives a massive change in pressure and in what RPM range.

When the intercooler is in the loop the gauge reads 9psi max regardless of rod position. I took the intercooler out, capped it, pumped it up to 25 psi and submerged it in water to find no leaks.

The gauge is reading at the intake manifold. Maybe it's just pressure drop? But this setup was working before. I might put a nipple in the hot side piping with the IC installled to measure the pressure drop. But it also feels slower with the IC installed. And i can hear the turbo spool much clearer.
Maybe there's a leak in the hoses that connect to the intercooler? I included those in the IC pressure test. And I replaced them with brand new as well.
Maybe the intake manifold is bad? I took it off of my E-ALH swap so it is known good, with a new gasket.
A new thought: maybe while WOT, the engine is rotating enough due to torque, that it is yanking some of the hoses apart at the connections and causing a leak? When it is hot piped the hoses are all floating around in the engine bay and not mounted to anything, so they wouldn't be pulled on by the motor. I put all new engine mounts on while filling all of the gaps with window weld. The same setup holds on my eALH swap.
What is it about installing this IC that is causing the problem?
jackfolstam is offline   Reply With Quote
Old May 17th, 2019, 12:23   #28
glenn1179
Veteran Member
 
Join Date: Oct 2005
Location: wausau, wi
TDI(s): na
Default

Make a coupler to put on the turbo inlet so the entire intake system can be tested while it is installed? I made my own adapter with a rubber coupler, pvc end cap, and a tire air valve. This covers the general process https://turboboostleaktesters.com/ho...ost-leak-test/
glenn1179 is offline   Reply With Quote
Old May 21st, 2019, 09:53   #29
jackfolstam
Veteran Member
 
jackfolstam's Avatar
 
Join Date: Oct 2016
Location: CA
Fuel Economy: 42mpg
Default

Quote:
Originally Posted by glenn1179 View Post
Make a coupler to put on the turbo inlet so the entire intake system can be tested while it is installed? I made my own adapter with a rubber coupler, pvc end cap, and a tire air valve. This covers the general process https://turboboostleaktesters.com/ho...ost-leak-test/
I did the same from the turbo outlet hose to the intake manifold inlet hose, had minor leaks but tightening the clamps solved that, but adding the intake is an idea I hadn't though about.

But, I did put in another nipple right after the turbo and ran two gauges, to see if it's just pressure drop. Turns out the cheap gauge is failing and reading low, sometimes zero. The VDO gauge I just got reads the same on either side of the intercooler. So I started at 9psi and tweaked the rod to get 14psi, yay! But then it went down again? Adjusted the rod, it's back, next run, gone, was the vacuum actuator getting hot and changing position or something? No, the lock nut was coming loose because I was hand tightening it and I guess the engine vibes and the spring pressure of the vacuum can were making the rod shorter as it drove. I think. That was last night, so tonight we will see if it's still sitting pretty at 14psi (after tightening the lock nut).
jackfolstam is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
very low boost. Pressure deviation low. specific N75 question im confused johnsongti VW MKIV-A4 TDIs (VE and PD) 14 May 25th, 2018 01:25
🔴► Mk5 Jetta Tdi seem low on power, No CEL, I think low boost problem.. supak111 TDI 101 7 March 17th, 2015 19:22
BRM bobbles in low load low boost fueling conditions... ScratchRob13 VW MKV-A5 Golf/Jettas 3 September 15th, 2010 05:59
low boost, low mpg, low power koabi VW MKIII-A3/B4 TDIs 19 November 23rd, 2007 14:45
HELP! 03 Jetta with Low Boost code and low power 4vdubs TDI 101 1 October 18th, 2005 11:55


All times are GMT -7. The time now is 15:43.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.18304 seconds with 13 queries
[Output: 125.83 Kb. compressed to 106.49 Kb. by saving 19.34 Kb. (15.37%)]