Setting up TDI torsion value for best FE

Vekke

Veteran Member
Joined
Jun 8, 2009
Location
Finland
TDI
Audi A8 with 1.2 TDI VW Lupo 3L --> 2L (retired)
I have done vast research over 1000 km just test driving and setups on tdi timing or torsion value as it is said on vag tdi. I made a custom program that injects same amount of fuel 16mg/stroke all the time for full rev range on a 1.4TDI which is 3 cylinder diesel engine. So its not exactly same amount of fuel if rpm rise there is more fuel injected per hour, but still its constant amount per stroke. If you would have level road for testing you would get even better results, but you have to use what you have.


https://youtu.be/sJeLCH_rc5Y

Test road was 6,3 km long full of uphills and downhills and I doubled that for fine tuning. Just by changing the timing, meaning adjustable cam you are able to get 5-10% improvements on a diesel engine at least. Problems arise when you change your drivebelt it often does not go exactly same place.

I moved adjustment from -2,2 torsio to 2,2 which was best setup for this car and the time went from 267 seconds to 243 seconds and to back direction from 278s to 253s. I started the test from 70 km/h speed and put the pedal to the floor. This way car would accerelerate and the small differences in start speed would not have so big impact to end result.
-2,2 =12600m/267s+278s=12600m/545s=23,1 m/s--> 83,1 km/h avg speed car needs about 8,5 hp for this avg speed
2,2=12600m/243s+253s=12600m/496s=25,4m/s-->91,4 km/h avg speed car needs about 10,5 hp
During the testing top speed got 10 km/h higher from 105->115 km/h and car was able to keep much higher speeds at uphills and steady sections as well.

https://ecomodder.com/forum/showthre...ToStep=40-65-1

As you can see there is big differences out there you just need to dig them out in testing.

All those values were inside VW tolerance +-3,0 degrees for diesel engines!!! It is well known fact that some diesel get much better fuel consumption than others, and I believe this is the main reason for those differences.

1.4TDI Audi A2 can now drive on 6th gear from 75 km/h and before any ecu modifications limit was aroung 90-95 km/h speed range. 100km/h is about 1750rpm. Now I am able to go 80 pretty easily if there is no big uphills.

I did same testing also on 1.9tdi and results were pretty much the same, there drive speeds got higher so avg speed wise it was not so big high speed difference but energy consumption was higher at higher speeds... On the Audi A4 best value is not inside the +-3,0 tolerance, but car still works really well.

Best torsion values were not same for different cars so you need to find out which is best setup for your car. Cheap and easy method would be to make a stopper under gas pedal or hand throttle to have always same throttle position on diesel car. But for this stopper method you really need flat road as pedal request changes based on rpm and many other factors...

How to find the best values tips from TDIclub:
------------
I found this kind of instructions: Quote:
Originally Posted by MPG MASTERS 1 View Post
Since I am apparently out of range of the cam sensor because I get 0.0 TV on block 4, my question are:
1. Does the TV number send that number to the ECU to tell it when to fire the injector or is that number only given for the mechanic to see where the cam is in relation to the crank?
The cam position sensor works in tandem with the crank position sensor. Cam sensor tells the next cylinder to fire. Crank sensor tells what timing.

2. Is it the crank sensor telling the ECU when to fire the injectors?
Yes and no. It must have the cam sensor feed or it's a 50/50 chance the crank sensor will get it wrong.

3. Since I am out of range and the TV is zero 0.0 and the engine runs fine, I wonder what or where the injector id getting its firing signal.
If you have a failed crank sensor, the engine will not run. If you have a failed cam sensor, the default is 0.0. The engine will default from the crank sensor and try option #1, then option #2. The choice being which piston is on the firing stroke.

4. (More Scary) Will the slot range on the pulley keep you from moving so far as to damage the engine by hitting a valve with the piston?
If you have the cam sprocket bolts centered in the adjustment with the crank lock and cam lock installed, you can move the adjustment all the way from stop to stop and not cause an interference hit.

Block 15 at -1.4 was .401/h, at +1.5 it was .601/h at unknown - value it showed .201/h, then I moved cam Clockwise a fair amount to try to get back in range and the TV still showed 0.0 and the Block 15 also still showed .201/h.
All Block readings were at idle.
We use the VCDS block 15 liter per hour block to get the engine to get some windage of the range of fuel usage. The lowest read will still be a range of about 1 degree. Once we find the range, we use block 13 for the lowest variance between injectors. We also will run block 15 at 2000rpm, looking for the lowest fuel usage. Usually around 2.4l/hr is relatively normal.
---------
That is how you can find lowest idle fuel consumption but it is not the best for drive speeds rpm. You can try to find it by revving it standstill at 2000rpm but on road you have boost and its not constant so driving tests are required.

My lowest idle fuel consumption was at +6,6 torsio 0.3 l/h and best drive consumption was at +2,2 where idle was about 0,35-0,4 l/h. From start it was at -2,2 and idle fuel consumption was 0,6 l/h. To get more data on idle fuel consumption you can put fan at full and long ligths on to get two figures to compare.

So if your TDI is not getting the same fuel consumption figures on road as your friends at same speeds its fault could be badly timed torsion value. Your idle fuel consumption tells already something
On working TDI values should be
1.2TDI 0,3 l/h
1.4TDI 0,3-0,4l/h
1.9TDI 0,4-0,6 l/h

If you have installed some huge wheels etc that rise the fuel consumption it will be higher. If torsion value and the idle fuel consumption is within spec you need to search the fault from dragging brakes etc.
 

losmi88

New member
Joined
Sep 20, 2012
Location
Belgrade
TDI
Seat Leon TS
I'm interested in your opinion, my car is a golf 5 2.0 tdi bmm when I put the torsion value 0 idle consumption is 0.8-0.9, what can be the problem?
 

Steve Langley 85

New member
Joined
Sep 16, 2021
Location
Uk
TDI
2.0
I'm interested in your opinion, my car is a golf 5 2.0 tdi bmm when I put the torsion value 0 idle consumption is 0.8-0.9, what can be the problem?
Exhaust cam is responsible for fuel consumption. Mine is slightly advanced to reduce valve overlap and turbo lag, my fuel consumption sits at 0.7. Before I advanced it it sat at 0.6. Torsion value only relates to the intake cam and 0 is good, but slightly negative (advanced) is better for low down power and torque.
 

Flup

New member
Joined
Sep 11, 2021
Location
01420
TDI
2006 Volkswagen Jetta 1.9L Automatic 6 Speed
I have done vast research over 1000 km just test driving and setups on tdi timing or torsion value as it is said on vag tdi. I made a custom program that injects same amount of fuel 16mg/stroke all the time for full rev range on a 1.4TDI which is 3 cylinder diesel engine. So its not exactly same amount of fuel if rpm rise there is more fuel injected per hour, but still its constant amount per stroke. If you would have level road for testing you would get even better results, but you have to use what you have.



Test road was 6,3 km long full of uphills and downhills and I doubled that for fine tuning. Just by changing the timing, meaning adjustable cam you are able to get 5-10% improvements on a diesel engine at least. Problems arise when you change your drivebelt it often does not go exactly same place.

I moved adjustment from -2,2 torsio to 2,2 which was best setup for this car and the time went from 267 seconds to 243 seconds and to back direction from 278s to 253s. I started the test from 70 km/h speed and put the pedal to the floor. This way car would accerelerate and the small differences in start speed would not have so big impact to end result.
-2,2 =12600m/267s+278s=12600m/545s=23,1 m/s--> 83,1 km/h avg speed car needs about 8,5 hp for this avg speed
2,2=12600m/243s+253s=12600m/496s=25,4m/s-->91,4 km/h avg speed car needs about 10,5 hp
During the testing top speed got 10 km/h higher from 105->115 km/h and car was able to keep much higher speeds at uphills and steady sections as well.

https://ecomodder.com/forum/showthre...ToStep=40-65-1

As you can see there is big differences out there you just need to dig them out in testing.

All those values were inside VW tolerance +-3,0 degrees for diesel engines!!! It is well known fact that some diesel get much better fuel consumption than others, and I believe this is the main reason for those differences.

1.4TDI Audi A2 can now drive on 6th gear from 75 km/h and before any ecu modifications limit was aroung 90-95 km/h speed range. 100km/h is about 1750rpm. Now I am able to go 80 pretty easily if there is no big uphills.

I did same testing also on 1.9tdi and results were pretty much the same, there drive speeds got higher so avg speed wise it was not so big high speed difference but energy consumption was higher at higher speeds... On the Audi A4 best value is not inside the +-3,0 tolerance, but car still works really well.

Best torsion values were not same for different cars so you need to find out which is best setup for your car. Cheap and easy method would be to make a stopper under gas pedal or hand throttle to have always same throttle position on diesel car. But for this stopper method you really need flat road as pedal request changes based on rpm and many other factors...

How to find the best values tips from TDIclub:
------------
I found this kind of instructions: Quote:
Originally Posted by MPG MASTERS 1 View Post
Since I am apparently out of range of the cam sensor because I get 0.0 TV on block 4, my question are:
1. Does the TV number send that number to the ECU to tell it when to fire the injector or is that number only given for the mechanic to see where the cam is in relation to the crank?
The cam position sensor works in tandem with the crank position sensor. Cam sensor tells the next cylinder to fire. Crank sensor tells what timing.

2. Is it the crank sensor telling the ECU when to fire the injectors?
Yes and no. It must have the cam sensor feed or it's a 50/50 chance the crank sensor will get it wrong.

3. Since I am out of range and the TV is zero 0.0 and the engine runs fine, I wonder what or where the injector id getting its firing signal.
If you have a failed crank sensor, the engine will not run. If you have a failed cam sensor, the default is 0.0. The engine will default from the crank sensor and try option #1, then option #2. The choice being which piston is on the firing stroke.

4. (More Scary) Will the slot range on the pulley keep you from moving so far as to damage the engine by hitting a valve with the piston?
If you have the cam sprocket bolts centered in the adjustment with the crank lock and cam lock installed, you can move the adjustment all the way from stop to stop and not cause an interference hit.

Block 15 at -1.4 was .401/h, at +1.5 it was .601/h at unknown - value it showed .201/h, then I moved cam Clockwise a fair amount to try to get back in range and the TV still showed 0.0 and the Block 15 also still showed .201/h.
All Block readings were at idle.
We use the VCDS block 15 liter per hour block to get the engine to get some windage of the range of fuel usage. The lowest read will still be a range of about 1 degree. Once we find the range, we use block 13 for the lowest variance between injectors. We also will run block 15 at 2000rpm, looking for the lowest fuel usage. Usually around 2.4l/hr is relatively normal.
---------
That is how you can find lowest idle fuel consumption but it is not the best for drive speeds rpm. You can try to find it by revving it standstill at 2000rpm but on road you have boost and its not constant so driving tests are required.

My lowest idle fuel consumption was at +6,6 torsio 0.3 l/h and best drive consumption was at +2,2 where idle was about 0,35-0,4 l/h. From start it was at -2,2 and idle fuel consumption was 0,6 l/h. To get more data on idle fuel consumption you can put fan at full and long ligths on to get two figures to compare.

So if your TDI is not getting the same fuel consumption figures on road as your friends at same speeds its fault could be badly timed torsion value. Your idle fuel consumption tells already something
On working TDI values should be
1.2TDI 0,3 l/h
1.4TDI 0,3-0,4l/h
1.9TDI 0,4-0,6 l/h

If you have installed some huge wheels etc that rise the fuel consumption it will be higher. If torsion value and the idle fuel consumption is within spec you need to search the fault from dragging brakes etc.

New to the Site, My Vehicle 2006 Jetta 1.9L TDI BRM New Head, Timing Ect gets 30 MPG set the Torsion value to +1 as VW manual said but after reading your post Its seems i should be getting better, my uncle has the same year he gets 48-52 mpg. I'm a little confused by the values here What Block values these are take from VCDS Block Group 004, 013 and 015 ?, ?-0,? l/h are these values taken if i can get clarification would be greatly appreciative?.

Chart
1.2TDI 0,3 l/h
1.4TDI 0,3-0,4l/h
1.9TDI 0,4-0,6 l/h
 

PakProtector

Veteran Member
Joined
Jan 5, 2014
Location
AnnArbor, MI
TDI
Mk.4's and the Cummins
My '04 BEW got set to zero at its last TB, and it turns me 45 mpg...so I do believe I will be shooting for that value when I do the belt in near future.

Douglas
 

Driver01

New member
Joined
Aug 16, 2022
Location
Latvija
TDI
1.9 tdi ATD PD
Very interesting. I have a 1.9tdi PD ATD audi a3 2003 . It have a 0.6 torsion value, but consumption was about 12 litres on 100km its a lot. So i adjust to -1,7 . Will see whats happenin now .
Maybe someone have a 1.9 pd atd ?
What torsion value u have?
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Driver01, The injectors are suspect. The injectors can be relatively close to each other, but there is no method, as in the VE pumps Injection Quantity adjustment to increase or reduce fueling. It is 'supposed' to be optimized by the programming. I think it is most optimized by having the correct injector nozzle.

Flup, A small point, you move the cam sprocket with a spanner. I adjust the CAM BOLT in relation to the SPROCKET. It ends up doing the same thing, but moving the cam bolt is more precise method, in my opinion.

I expect you have read the compendium blog, "The Question about Torsion Value", which I started, but had valuable information added by several parties. Generally, the lower the torsion value to create the closest balance with the injectors is as good as it gets. Setting maps for fuel and boost requires tuning skills. I would wish the program weren't so 'automatic', as that leaves personal preferences out of the equation.
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
2004 VW Touareg V10 TDI, 2012 Audi Q7 V6 TDI, 1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
I've done some similar adjustment on my PD cars, its for sure made a big difference. My one car I found that -3.4 was optimum, still working on figuring out on my other ones.
 
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