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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: lbreton on December 24, 2007, 09:42:54 pm
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Guys,
What do you think of this product? The rep says it may add an RPM input to the control scenario. Your max boost could then be set a bit lower in the lower RPM ranges. It was designed for waste gate control...but perhaps it can be used on VNT. I do not have personal experiance with VNT's, so I do not know. I understand that they are controlled by vacuum, not pressure. Is it an on off scanario..or is it more of a proportional control?
http://www.exileturbo.com/products/item_details.asp?idProduct=4
There is a manual that can be downloaded for reviewing the hook-ups and schematics.
LAB
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I don't think it would be ideal for a VNT as you really should have a throttle position sensor as well.
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I don't think it would be ideal for a VNT as you really should have a throttle position sensor as well.
You are listing a GT1749V (VNT 15?) on a m-TDI in your signature. How are you controlling it?
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Mechanically off of the throttle via some springs, with an actuator to control total boost.
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Mechanically off of the throttle via some springs, with an actuator to control total boost.
8)
Let me see if I understand this. You have a standard boost pressure actuator on the turbo. You also have a cable running from the actuator to the throttle cable..connected by a spring. When in low throtle postion, the spring is assisting the actuator..or holding it back? Do you have pics on here somewhere?
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1 spring to hold the vanes normally open, 1 spring connected to a throttle cable which pulls to close the vanes, a stronger spring than the other one. A VNT(vacuum) actuator which was cut apart and converted to work by boost which also opens the vanes. There are I think 4 of us with slightly different designs of the same concept. http://www.66rover.com/rover%20rebuild/index.html under 051907 I have pics of how it operates. The cable operated cam was off a Subaru carb I had sitting around. I later added a tab on the bottom part of it so that instead of just counteracting the spring(which hooks to the cable) it forces the shaft up, opening the vanes. http://vwdiesel.net/phpBB/viewtopic.php?t=1306&postdays=0&postorder=asc&highlight=fspgtd+vnt+actuator&start=15
is the thread telling you how to modify the actuator. Libbybapa used small screws to hold it together. I found that a 2 1/2" header flange was a perfect fit and used that. http://www.youtube.com/watch?v=XIKVn16Sh5k is Tintin's solution to the vanes. There was another recent post with someone elses design as well.
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It's expensive, but It's a good alternative, it should be know how the controller will behave with a VNT turbo.
For sure, that take TPS and MAP sensor, I think MK4 TDI N75, RPM is useless, but if you have a big VNT, it will be useful to limit the boost at low RPM.
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1 spring to hold the vanes normally open, 1 spring connected to a throttle cable which pulls to close the vanes, a stronger spring than the other one. A VNT(vacuum) actuator which was cut apart and converted to work by boost which also opens the vanes. There are I think 4 of us with slightly different designs of the same concept. http://www.66rover.com/rover%20rebuild/index.html under 051907 I have pics of how it operates. The cable operated cam was off a Subaru carb I had sitting around. I later added a tab on the bottom part of it so that instead of just counteracting the spring(which hooks to the cable) it forces the shaft up, opening the vanes. http://vwdiesel.net/phpBB/viewtopic.php?t=1306&postdays=0&postorder=asc&highlight=fspgtd+vnt+actuator&start=15
is the thread telling you how to modify the actuator. Libbybapa used small screws to hold it together. I found that a 2 1/2" header flange was a perfect fit and used that. http://www.youtube.com/watch?v=XIKVn16Sh5k is Tintin's solution to the vanes. There was another recent post with someone elses design as well.
thats s lot of info :shock: thank you. I think I need to read through it a couple more times. It looks like both yours and TinTin's allow for different vane positions, relative to your throttle position, not just open or closed. Very inventive. I read in the one link that the N75 is a modulating valve. A true modulating valve would operate like that as well, so I would assume the output from the ECU to this valve must be 0-12V to accomplish this. I am not sure if the solenoids in the Exile controllers are modulating or not.
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It's expensive, but It's a good alternative, it should be know how the controller will behave with a VNT turbo.
For sure, that take TPS and MAP sensor, I think MK4 TDI N75, RPM is useless, but if you have a big VNT, it will be useful to limit the boost at low RPM.
yes expensive. When you add up the parts, probably makes sense..microprocessor -250.00, pressure transducer - 200.00, solenoids, and misc...It makes a guy just look back at the OEM ECU. What would really be nice is just a stripped down code and harness for the OEM ECU's. Inputs - MAP, TPS (calibrated to a cheaper option from a domestic?), Injector Pump Feed, Air temp, N75 ouput. Just delete all the other inputs/ouputs and operation modes from the code. Anything else you think would be important? This route would cost about the same, very easy to install, good for bench testing, and do more. Then add a custom software to plug your laptop in and tweak numbers..sota like megasquirt.
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Hi.
Look at this - this is home made VNT turbo controller (vacum controlled) stored in my m-TDI Golf MKII. It works well, it's easy to do and not expensive.
http://www.forum.vwgolf.pl/viewtopic.php?t=147110
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Hi.
Look at this - this is home made VNT turbo controller (vacum controlled) stored in my m-TDI Golf MKII. It works well, it's easy to do and not expensive.
http://www.forum.vwgolf.pl/viewtopic.php?t=147110
Hi Ventil,
Thanks for the submission. That is a nice simple set-up you have there. I can not read much but the schematic makes mostly sense to me. I see you have two voltage regulators (7805 - 5v and a 7512 - 12v) supplying power to K8004 (DC to PWM) and the MAP sensor mpx4250. So you have adjusted a ref voltage so that the PWM duty cycle varies with the output voltage from the MAP (0-5V?). The variable duty cycle is controlling the factory N75 (0V = 0%, 5V = 100%?). The large resiters are voltage dividers to modify the ouput voltage to the N75. I am also thinking you might be able to modify the signal by creating a voltage divider in the MAP feed using a TPS and another voltage divider. If you could explain a bit more or correct any of misinterpretations, that would be great.
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Hi.
Look at this - this is home made VNT turbo controller (vacum controlled) stored in my m-TDI Golf MKII. It works well, it's easy to do and not expensive.
http://www.forum.vwgolf.pl/viewtopic.php?t=147110
Hi Ventil,
Thanks for the submission. That is a nice simple set-up you have there. I can not read much but the schematic makes mostly sense to me. I see you have two voltage regulators (7805 - 5v and a 7512 - 12v) supplying power to K8004 (DC to PWM) and the MAP sensor mpx4250. So you have adjusted a ref voltage so that the PWM duty cycle varies with the output voltage from the MAP (0-5V?). The variable duty cycle is controlling the factory N75 (0V = 0%, 5V = 100%?). The large resiters are voltage dividers to modify the ouput voltage to the N75. I am also thinking you might be able to modify the signal by creating a voltage divider in the MAP feed using a TPS and another voltage divider. If you could explain a bit more or correct any of misinterpretations, that would be great.
Hi! My english isn't good but i think, You understand me.
K8004 is the kit (DC to PWM) from Velleman company. Here you can download K8004 datasheet in english (PDF format) http://www.sklep.avt.com.pl/go/_info/?id=42796
MAP sensor is a INTEGRATED PRESSURE SENSOR 20 to 250 kPa (2.9 to 36.3 psi) 0.2 to 4.9 V OUTPUT - here You can download datasheet in english (PDF format)
http://www.datasheetcatalog.com/datasheets_pdf/M/P/X/4/MPX4250AP.shtml
First voltage regulator (12V, 6A) is for K8004, second (5V, 1A) is for MAP sensor. The variable duty cycle is controlling the factory N75 but i add this large resistors to reverse output voltage. Those resistors are connected to output K8004 (load +, load -) but N75 is connected - one lead to drain of T2 MOSFET and one to source of T2 MOSFET. This way when input is 0V - output is MAX (about 12V) and when input is 5V - output is MIN (about 0V).
When output is max the N75 connect full vacum to turbo - variable vane are closed makes turbo to full pressure. When turbo pressure going up the output voltage going down connect free air to actuator - in this moment variable vane are opened and turbo reduce pressure. N75 needs 50Hz voltage so You need to connect condenser 100nF (0,1uF) parallel to C3 on K8004 plate. Points A and B on my illustration You can connect together or add diode (diodes in rows) to make open variable vane later.
Additionally You can build simple Frequency to DC converter and make limit the boost at low rpm - on low rpm converter gives 5V on K8004 input and when rpms going up the voltage on F to DC converter output going down.
I think now I explain better.
Nice work...
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seems too complicated. i like the mechanical linkage better :wink:
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And how you set the desired boost? example: 18PSI... you have a boost spike?
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And how you set the desired boost? example: 18PSI... you have a boost spike?
I read through the links he enclosed. The output from the MAP is .2V to 4.9V for 2.9 to 36.3psi. For 18psi, the output would be about 2.25V. It looks like trim pot RV2 on the K8004 can be used to adjust the duty cycle relative to your input voltage, so if you set it so duty cycle is 100% at 2.25 volts, that will give you a 18psi max. The sensor has a resolution of 20mV/KPA, and a 1.5% temperature deviation.
I think this circuit could be taken further by splicing a pot (TPS) into the feed to the dcin to modifiy the boost level relative to the throttle position.
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And how you set the desired boost? example: 18PSI... you have a boost spike?
You can set the boost with RV2 trim. If You don't need full boost on low rpm You can set initial low output voltage with RV1 trim. If You want to opposite, You can set RV1 to minimum and connect diode (diodes in rows) between A abd B points on K8004. Boost spike is about 0,5 sec - when I have adjusted 1,3 bar boost - for 0,5 sec I have 1,5. I think is not to much but of course You can to reduce this witch RV1 trim.
I think this circuit could be taken further by splicing a pot (TPS) into the feed to the dcin to modifiy the boost level relative to the throttle position.
Yes, of course, You are right.
bar(http://www.pro-auto.com.pl/pub/EVC/wire_eng.jpg)
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You can set the boost with RV2 trim. If You don't need full boost on low rpm You can set initial low output voltage with RV1 trim. If You want to opposite, You can set RV1 to minimum and connect diode (diodes in rows) between A abd B points on K8004. Boost spike is about 0,5 sec - when I have adjusted 1,3 bar boost - for 0,5 sec I have 1,5. I think is not to much but of course You can to reduce this witch RV1 trim.
Thanks Ventil, your control system is a gem.
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I made it for my m-TDI with VNT GT2052 - but everyone, who wants VNT turbo can do this - it's really simple and works well.
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Can i use TPS insdead of mpx4250?
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And how is the Cruise mode solution?
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Can i use TPS insdead of mpx4250?
:?:
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Anyone who knows much about electronics, how much would it cost to make Ventil's system above?
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ca 20$ for k8004, 8$ for big resistors an 'd condensers, 35 $ for used N75 valve, 2$ for scrapyard N75 connector wire.
im planing to use TPS insdead of pressure sensor
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I want to built a Vnt controller too. Is this the complete List?:
Voltage Regulator 7805 5V 1A
Voltage Regulator 7512 12V 6A <- I cant find
K8004
4 Resistors 10 Ohm 15 - 25 W <- I can choose between 11 W and 25 W.
MPX4250 <- I find only MPX 4250DP i think there i no difference
diodes 1N4148
condensors:
1µF 10V <-
0.01 µF <-which voltage
470pF <-is it realypico Farrad which voltage
4x 0.1 µF <-which voltage
sorry. perhaps these questions seem stupid to many people but im more the mechanic than the electrician!
Are there any new ideas? Easier ways?
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Thought I'd post in here, and pimp the controller I'm building over in the IDI section. If you're not familiar with it, worth a read as it will be FULLY featured, and hoping for a price of around 120-150GBP. The schematics (all be it the early design) are over there to :) Source code is still in production, so as of yet, nothings available.
To help out T3-mtdi,
the voltage reg @ 6A is a) hard to get and b) expensive. From a quick look, you should be able to get by with a 5 amp version (which at 12V is a fair bit of juice....) to get all the parts, just search through digikeys website. The 5A 12V reg from Nat Semi will do the job, I think part number LM2588S-12-ND, but I haven't looked to far into the schematics to be 100% sure on current draw, if you can't get that, could always run 2 in parallel, then you'd have 10A capability :)
As for the resistors, go for 25w, as means they can handle more power. Just means they are generally bigger and more expensive.
The MPX4250-DP is a DIFFERENTIAL pressure sensor, not an ABSOLUTE pressure device. Google the difference :)
Yes, the value really can mean pico farad :) And the voltage has to be over the maximum it will normally see. For most stuff, it is 16V rated, but not sure on his flyback design (if any) from the N75, which can see high voltage spikes.
Hope this is of some help.
-Gavin
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TPS?
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wow, that jeep is bad ass, one of the best things ive ever seen on here, thats a real inspiration
just one question, is that pop off dump valve thing realy needed?
my VNT control is nearly the same as that but mine dont work very well, urs looks a bit more sturdy, think im gona copy you
hydm