Bobby Singh's Audi A4 3.0 TDI Project car

[Bobby singh]

December 2015 - Bosch CP3

Christmas break fun..

Next task was to source a fuel pump that would be able to supply enough fuel without causing rail pressure drop.
After considering different Bosch pumps - I went with Bosch CP3. The pump is fitted to some early V6 models.
I managed to get all the required parts from a car that was being broken. Pump, gear, bracket, belt etc



Got M12 adapters for the fuel lines:




With some luck the bracket mounted nicely, but I had a issue with finding a gear that would keep the belt tight





All mounted up but the M12 90deg was a little tall



Ended up purchasing OEM feed and return



Finally got the CP3 working after some more tweaking in the tune.
Now I can inject close to 100mg in the mid range without rail pressure drop
The first generation of V6 that used the CP3 pump only had 0.5 bar feed pressure so with 4bar feed pressure we have a excellent start.

Big Turbo

Well I knew it would be only a matter of time before I fitted a bigger turbo.
So it all came together in the Christmas / new year break.
To be honest I had the turbo before I had even purchased the car. It was a nice unit and when it came up for sale I just had to have it.

The turbo itself started is a borg warner John Deere s200v. As stock the turbine is really healthy as 56mm ex but only 44.5mm ind compressor wheel. Lucky for me the unit came modified with a 70/51mm CW. The compressor housing also came with anti surge modification already done.

Turbo pictures







Parts collection - Oil return, feed, compressor housing outlet, flange, V bands etc





The green cable is the turbo speed sensor

S200 Vs 2260 compressor housing



Fitting

Turbo unit removed



Custom oil return



Custom oil feed



Modified 3" downpipe



Modified the Y collector and welded the S200 flange directly to it.
Y collector also housed the EGT probe (cut the boss from a broken 2260) and emp adaptor.

The actuator set up was a very fiddle job - getting the angle and throw correct in relation to the turbo lever took a lot of hours.

But finally a VCDS output test could be done with no errors

Ignore the TIP it was something just to get the car running.



After deleting the EGR cooler water pump, temp sensor and rad outlet sensor I noticed the lambda sensor wasn't behaving itself.
Turns out the rad outlet sensor is used some how to make the lambda sensor to function.

That meant I had to plumb the sensor back in.



Heat protection



Bi Turbo MAF

As the stock MAF sensor was maxed out at 900kg/h the options were map based smoke limiter (time consuming to get right) or bigger MAF.
For a cleaner tune decided to go with the A6 Bi turbo MAF rated upto 1400kg/h so nice improvement over stock.

The housing is bigger over stock so custom 90mm TIP was needed, but on a plus note the MAF fitted the stock air filter perfectly.



Looks pretty good



Dyno result



420hp / 830nm
As you can see the power is still going up at 4k but egt was already 900deg so kept it safe.
Maybe more rail pressure next.


Smoke video

https://youtu.be/PhtA79cmHrY

February 2016 - Turbo Speed sensor

As the s200 has a default speed sensor it would be crazy not to make use of it.
According to BW they say no more than 152k rpm.
Looking on the turbo shaft there is a flat area which would mean 1 pulse per turn - confirmed by using a scope.

I decided to use the EGR input as in VCDS there is a raw voltage display. After some testing on the egr i found the ground, 12v and the input.
Using a input signal from my phone @ 2.5khz i calibrated the voltage shown in vcds to 4.5v which is approx 150k rpm.

Here are some pictures of the home made pulse to voltage convertor

Melted the OEM EGR plug to expose the pins:










End result shows the turbo has rpm of approx 145k so still some more scope left

I've also calibrated the voltage so the coil light flashes when we get overspin - I've been trying to get the car to limp with a certain voltage/shaft speed is seen, but this is more difficult that expected.