Shift points for TDI

[powerlifter405]

Originally Posted by ecomodded

With my ko3 turbo when at 1000 rpm and i give it half throttle my boost goes from 0 to 20lbs for a spike then settles at 15 lbs until i release the gas pedal.
At 1900rpm my car is making full torque, I need about 1/4 of the torque to accelerate, attempting to use the whole torque is non sensible unless you are in a race or are trying to tow a house.

Anybody with a boost gauge and vnt turbo should be aware of boost levels.

~ A health monitor for the turbo ~

A boost gauge may be the best thing you could do for your turbo, You can see over boosts and no boost problems and anything in between.

I'm new to the eco thing but gauges are smart for any turbo'd vehicle.
I'm always eyeing mine, trying to keep EGT's as low as possible in the highest gear. At a bare minimum a boost and egt. One thing some turbo guys forget is EBP. The more EBP you have 1) You stress components more 2) That is increased rotational resistance. The factory 6.4 Twin turbo is 1:1 WOT and is about 10-20% higher at cruise. W/ a non-VNT/VGT/VVT (brand dependant) a waste gate and proper A/R housing is important as well but often over looked by rookies, sometimes resulting in an over-sped/blown up turbo.


Theres a fella on PSN who's building a mazda diesel and IIRC he's set up to have about 15lbs boost max and the rest is waste gated and hes getting 32-35 in his mini 4x4 at the moment. Someone else has a 500-600 dyno hp 5.9 in a 1/2 ton dodge w/ the 6spd who, @ 55 on flat ground has acheived 50mpg. He's supposedly had difficulty repeating it but claims high 30's/low 40's when driven properly. He matched components carefully and runs 308 gears and the 6spd trans and the whole thing is lowered. Rant, my bad but point is he trys to drive just above idle 12-1300.

[Varn]

I got to try a TDI.

Originally Posted by ecomodded

With my ko3 turbo when at 1000 rpm and i give it half throttle my boost goes from 0 to 20lbs for a spike then settles at 15 lbs until i release the gas pedal.
At 1900rpm my car is making full torque, I need about 1/4 of the torque to accelerate, attempting to use the whole torque is non sensible unless you are in a race or are trying to tow a house.

Anybody with a boost gauge and vnt turbo should be aware of boost levels.

~ A health monitor for the turbo ~

A boost gauge may be the best thing you could do for your turbo, You can see over boosts and no boost problems and anything in between.

[AndyBees]

As I stated previously, my 2000 Jetta with the ALH TDI engine has given me just under 51 mpg overall average since I have owned it (March 2002). It now has almost 308k miles on it. The vast majority of my driving has been the norm............doing nothing special to attain the results.

As I think I also stated, I'm in the process of installing an '02 ALH TDI engine in an '84 VW Vanagon. I'm trying to finish the project in time to head north to Alaska.... August 6th being the date of my window closing. I plan to maintain records on the performance as well as a Thread on the trip.

It will be interesting to "learn" the best shift points for the TDI/Vanagon set-up. I did rebuild the transmission, including the installation of taller 3rd and 4th gears. On paper, at 65 mph with 205/75/14 tires, the .77 ratio 4th gear and the 4.57 R&P, the RPMs should be about 2850. That is about 700 RPMs lower than the stock gearing but, about 550 RPMs higher at that same speed in the Jetta! So, I'm hoping that 30 to 32 MPG will be attainable!

The project is in the TDIclub.com, TDI Conversions.

[ecomodded]

Varn the tdi's are nice to drive, i can literally barely feel my jet ski behind when towing,including accelerating from a stop. My previous vehicle a 3L v6 Ford Ranger Struggled towing the same set up, Nutz.
Too bad they don't make a pick-up.
Powerlifter, Good points you made.
Wow, twin Turbo's on the F350, That is pretty damn sweet.
I dream of adding a second k03 to my beetle..
I notice people throwing big turbo's on their cars without much concern for spool up times,seems like most are interested in max hp gain.
Andy i bet if you shifted at 1500rpm you would see even a higher mpg. Just shift quicker, I rarely skip gears, if on a decline i will.

[amdown]

Originally Posted by ecomodded

With my ko3 turbo when at 1000 rpm and i give it half throttle my boost goes from 0 to 20lbs for a spike then settles at 15 lbs until i release the gas pedal.
At 1900rpm my car is making full torque, I need about 1/4 of the torque to accelerate, attempting to use the whole torque is non sensible unless you are in a race or are trying to tow a house.

Anybody with a boost gauge and vnt turbo should be aware of boost levels.

~ A health monitor for the turbo ~

A boost gauge may be the best thing you could do for your turbo, You can see over boosts and no boost problems and anything in between.

K03 is a wastgate turbo and it makes a boost spike, with VNT this spike is much lover, because actuator can regulate boost much more precisely.

[ecomodded]

My boost spike is 20-22 lbs it last for 1-1.5 seconds,
and only when i punch the gas.
What is the boost spike on the vnt turbo?
I personally am happy i have the waste gated turbo on my car, it spools up instantly can be be adjusted via different waste gates and has none of the issues associated with the VNT turbos.
The Audi TT uses a waste gated ko4 turbo.
I am curious if the VNT turbo has a boost spike as well.
I seem to remember reading that it does spike.. but its not my turbo so i never really looked that hard into it.

[AndyBees]

Based on a ScanGauge, my VNT15 (no mods), will max out at Manifold Absolute Pressure (MAP) slightly above 32 psi. Generally, at idle, the MAP is about 14.2 psi in my neck of the woods (about 1000 foot elevation). Doing the math, that would be 17.8 psi maximum boost.

I see that boost response while taking the RPMs up steadily but agressively in 1st and 2nd gears........ it's not exactly instant and begins to drop back well below the MAP of 32 psi at about 3200 RPM, give or take, depending on the terrian.

Yes, below 2100 RPM, there is a definite lag in boost. But, the "advice" is to never do a WOT below 2100 RPM. In fact, I've never done a "sudden" WOT with my car since I've owned it. When I do WOT, it's always on a gradual basis being a little more aggressive toward the end.

[ecomodded]

Must be the fins slowly opening up to catch exhaust that takes the time for boost to build on the VNT.
With mine the waste gate opens up and it gets full flow.
I rarely give my car full boost mostly on steep hills on fast roads, then the car is using full torque and boost.

[ecomodded]

And wow the VNT15 has a fairly high boost spike. That should keep things moving freely you would think.
I wonder if its the EGR that's leaking oil and crude to the turbo that is causing the sticking vanes/ mechanism.

[AndyBees]

When I learn how to post pics, I'll stick some up of several VNTs that I have worked on.

Typically, the problem is not with the VANES (actually, I've never seen a problem with the Vanes). Directional Vanes, since they change the angle of exhaust gas hitting the Turbine blades of the Turbo. The issue is that exhaust gasses pass around the 9 levers and get inside the rotating ring that operates the Vanes........ you will see this in the pics. The crud builds up and eventually causes it to become "sticky."

You can go to TDIclub.com and search my Albums for the VNT 15 photos. I think this link will get you to the VNT 15 photo album.... TDI VNT 15 - TDIClub Gallery