BV43 installed! AFN Passat - actuator adjustment required?

Hi all,

Finally installed a BV43 turbo on my Passat TDI 110bhp.
Deleted the EGR, fitted a front mount intercooler, put a professionally ported head on too.

Here is the boost log with the new turbo:




It feels a tiny bit laggy low down, but pulls just as well as before at the top end.
Which is reflected in the charts really.

Duty cycle only hits 55% and actual boost lags requested throughout. Before, I had 77% duty cycle at 4000rpm and actual boost followed requested well (OEM map)

So should i shorten the vacuum actuator on the turbo to make it more responsive? There are no boost spikes at the moment.

Its a warm day here, so outside pressure is 867mbar and 22Celcius.

Otherwise, can a boost leak give the same signs?

Thanks

Yep shorten it 1/2 a turn go test and come back.

Johan adjusted the stopscrew on mine...
so the base spool is a bit better...

JW

Thanks guys,

So just to make sure i have this clear in my head:

Looking at this photo:



I can either adjust the stop screw (the thread shown just behind the rod) or I can adjust the rod length itself, or both.

- The spring return on the actuator (working against the vacuum) is failsafe and puts the blades in the minimum position when in the position shown above (so you can't overboost if there is a lack of vacuum (pipe come off, etc), which is good)
- The stop screw affects low end boost. As the rod moves all the way to the stop at low revs (and so blades go straight round to max angle position) to pull in as much air as possible.
- The rod affects the entire range and 'sensitivity' of the turbo response.
- A low duty cycle means the ECU is requesting more boost. So I'm at 55% duty cycle which makes sense as the ECU is not seeing the boost its requesting so keeps trying. (it should be at 75-80%)

Is that correct?

In which case do I need to wind out the stop screw thread a bit (shown above) so the blades reach an even higher angle to pull more air in at low revs?
Or does the rod need shortening to remove the lag and make the actuator more sensitive (so less vacuum is required for a given vane position, so the solenoid keeps up more easily)?

And is this all adjustable with the turbo on the car? Looks like a tight squeeze to adjust? I guess i remove the two bolts holding the actuator in position and then swing it back to reveal the stop screw and rod length adjustment nuts?

We had similar problems with AFN and BV43 last week. With the rod 1-2 turns shorter the thing started to react as it should. I think you should first shorten the rod and if thats not enough then adjust the stop.

Bigger nozzles...
Is it really only 867mbar? How high are you?

35 meters above sea level so barametric pressure is normally about 950-1100 mb so his readings are a little low.

With the standard turbo and MAP sensor the other day i had 999mbar at 8 Celcius.

I've now swapped the pipe from intercooler to the PD130 item (return to the inlet manifold), so am using a different 2.5 bar MAP sensor (off the PD130 engine) which has a different sealing diameter inside - i couldn't use the original.

So do you think this new MAP sensor is reading incorrectly?

Yep...

PD130 has 3bar MAP.
That is why your actual boost reads so low. Turbo is ok, don't touch it .

The PD130 Passat has a 2.5bar sensor as far as i'm aware? If I fitted a 3 bar sensor i'd have much higher boost, as for the same voltage it'd give 20% more absolute boost, which is a lot (currently i have 1 bar/14psi of boost with the standard ecu map, which is 28psi absolute, so the 3 bar sensor would up it to almost 34psi absolute, so 20psi boost.

A lot more! This is not what i'm seeing. max boost is correct still with this swapped sensor from the PD130

It has 3 bar map The diagnostics are only calibrated to 2500mbar but the sensor is 3000mbar.

Hi Hatemi,

I think you're right. (!)

I thought it was 038906051B when i bought it, but it has the C on the end.......like on the PD150 Golf ARL

So why isn't it responding differently with a 3 bar and targetting 20psi boost and not 13-14psi? Or is it, and I can't read it?

Do you read it from a boost gauge or VCDS only?

Hello Ben,
The change from a 2.5 bar sensor to a 3 bar sensor will really confuse the ECU.
A 2.5 bar sensor output calibrated to read 0.3v at 0 bar and 4.8v at 2.5 bar. The 3 bar sensor is calibrated to output 0.3v at 0 bar and 4.8v at 3 bar. The relationship is linear so if you know the output voltage of the sensor you can work out the pressure.
Your 3 bar sensor is measuring the pressure correctly and outputting a voltage but that voltage is lower for any given pressure as the 2.5 bar sensor output is 0.556 bar/volt and the 3 bar sensor is 0.667bar/volt.
So the 2.5 bar sensor will output 3.9v at 2 bar pressure. The 3 bar sensor will output only 3.3v for the same pressure. Thus the ECU will think the pressure is only 1.67 bar.
To correct from a 2.5 bar sensor to 3 bar you need to multiply any pressure readings by 1.2. Replotting your diagram you get

So the turbo is overboosting the demand by some way but it's not being damaged as it's only peaking at 2.3 bar. I am fairly sure the sensor can be corrected for in the remap. You would then need to check this. It seems that there is a longer travel on the stroke of the actuator on the BV43 compared to the VNT17 or VNT15 as the ECU has the benefit of the actuator position on the original application so to get the expected and actual to follow it requires some shortening of the rod.
Again I am sure somebody who knows what they are doing could sort this better when the car is remapped.
Karl

038906051D is the 2.5bar MAP that goes in a 12mm hole.

thanks for all the info guys!
that all make sense.
and thats why its showing only 867mbar, as its 1.2x out.
So pressure on that hot day was 1040mbar which makes much more sense.
I was going to buy a 3 bar MAP sensor when i run it on the dyno, so i'm glad i now have one!
Was silly of me to have fitted the 3 bar sensor by accident. Not sensible. I honestly thought it was the 2.5 bar version.
As JFettig says my AFN 2.5 bar doesn't fit the hole of the PD130 intercooler pipe, so sounds like i need the 'D' version. Thanks for the info.

I currently have a tunit chip installed which is backed off from th 'max fuel' setting as it was previously smoking. I could turn it up now, but i don't think i will - just want a proper remap now with the R520 Bosio injectors I have Turbo-Johan is hopefully doing this in August - just need to uprate the clutch first

Thanks again guys.

bhodgkiss said:

Turbo-Johan is hopefully doing this in August - just need to uprate the clutch first

Thanks again guys.

Click to expand...

give me a heads up on that date in August...
I'll make sure I'll also be at Johan's shop

JW

Post some pictures of this setup - pd130 intercooler pipe and all.

JFettig said:

Post some pictures of this setup - pd130 intercooler pipe and all.

Click to expand...

I agree

Since it looks like you have vagcom, please do a butt dyno run:

http://www.ross-tech.net/vag-com/examples/dynoplot6.xls

Hi all,

Yes i have Vag Com (VCDS)

I'm now away from my car for two weeks but will get some pics and info as soon as i'm back.

But it should be fine to leave as it is? EGT's should be lower (running leaner), there is now no smoke at all due to more air, and the turbo is happy with the boost. any reason why i shouldn't leave it as is?

Struikie - yes i'll certainly let you know about August! Still need an AWX PD130 dual mass flywheel and Sachs uprated friction disc and pressure plate if you know anyone who can source them at a good price? Or Southbend, of course

What ever happened to the pictures?

I do have some pics somewhere, will try and post at some point. Its all remapped since the posts above.

Hello guys!

Sorry to wake up an old thread, i have got an AVF quattro audi!
With bv43 from 2.0pdtdi 170!
I have got some wierd issues,maybe some1 can help me or something!
My setup 1.9pdtdi avf quattro 6 speed manual
egr off,decat,fmic,kevlar clutch and BV43
My probelm is with this setup, turbo build boost very very slowly,like 2000rpm 0,8 0,9 bar maybe!But after 2200rpm i got like 1,7bar
Doesnt matter if you adjust n75 maps and give fuel at low rpm,just smokes but the spool is the same!
My theory is that the stop screw maybe off i mean what happens when the vanes close too much?
So when i got WOT at low rpm ecu goes to 19.9% vanes but i cant build up decent boost!
I tried even with fixx vacuum at the actuator the results was even worse!
Car feels slow,and sluggish
I measured the vacuum at the tandem i got stabile -1bar,then i measured vac at the turbo at idle stabile -0,7bar
Any1 has got some logs or something about this bv43 would be nice!
And what do you guys thing of this stop screw thing? how can i check that?
In vcds when i go to basic settings rpm goes 1400 and boost oscillate like 90mbar

You can make the actuator arm a turn or two shorter but i suspect your n75 map is not really up to scratch. The bv43 from the pd170 is quite slow to make boost under 2000rpm's anyway so i suggest you look on ebay for a used bv43a turbo from the CR170 bhp models and have the cartridge swapped into the pd housings. The CR version has a lighter Billet alloy compressor wheel and 2 extra blades compared to the PD compressor wheel. I had a AWX audi a4 with a pd170 turbocharger and it worked really good with the right map ! However the CR turbo spooled a good 200rpm's lower than the pd turbo.
I would also check all the solenoid are not leaking vacuum, that would explain your vacuum drop from tandem pump to the n75. Try and simplify vacuum layout and see if the check valve is flowing in one direction only ! You don't need anti shudder valve, EGR valve so you could remove them from the system !

Also check your tandem pump, The vacuum outlet. If you have The original LUK pump, The outlet might move and leak vacuum. A good option would be a Bosch one crom euro4 8V engines like bpw, bxe, bke, bkc, bmm.


I tuned a car with same configuration and the spool is quite good, like 1.4bar at 2100. I think I already told you that in ecuconnections. It pulls nice and feels powerful.

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Hello guys!
Thank you for you answears!
Okay about tandem pump it was replaced witch an original bosch one because of vaccum pipe leaking,like 1 year ago.
I measured the vacuum at the tandem i got stabile -1bar at he n75 i got stabile 0,7bar
I have turbned,shortened the actuator arm,but nothing happened,turbned out half the stop screw again nothing,turned in stop screw nothing changes...
The actuator arm touches the stop screw with 0,6bar vacuum.
I made a few logs with these settings :
https://kepkuldes.com/image/HsaA00
https://kepkuldes.com/image/HsaQsB
Only very little changes below 2000rpm...
This could be a software issue?

Have you checked there are no boost leaks?

Log also Channel 10 to see how is maf VS boost. If maf is greater than 474*boost than the air enters the turbo but is leaked somewhere between turbo and inlet manifold.
Seeing your n75 duty cycle at 4000rpm being less than 70 means that is too easy to keep boost in limits.

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Okay its a great idea i will check for boost leaks i have got fmic,will check as soon as possible!
If iam not mistaken my car dont use maf readings its uses map its switched with the software
About th 70% percentage maybe i have to adjust rod lenght?whats the ideal value at 4000rpm?

Thank you guys!!