VNT disappointing

[optimax90]

Recently fitted a vnt to my disco td5 manual. Have silicon hoses, boost box alive maf, alive intercooler, alive map, foam air filter and modified air box, egr removed , centre muffler replaced
Doesnt go any better with vnt as it did with standard turbo, blows more black smoke and has less power on take off. Initially after i fitted the vnt i had white smoke very bad, put it down to oil in the intercooler etc. this cleared itself, now scratching my head why no better performance.
Any ideas??

[Tombie]

Who supplied the VNT?

Was the Alive Map written pre-VNT?

How did you plumb the hose that actuates the VNT? to where?

[Tombie]

Have you stuck a boost gauge on the engine? What boost are you getting?

[optimax90]

Yes the map was pre vnt. Went well. Ive got the vacuum hose on the wastegate actuator as it was, how should it be? BAS supplied the unit. Is the reading from nanocom for turbo pressure ok.

[Tombie]

Don't attach to modulator - goes direct to nipple on pipe leading to intercooler.

Then just bend old hose back onto modulator to seal it up. (Leave plugged in)

[optimax90]

Thanks , i will try that i will also get a reading off nanocom.

[twr7cx]

Thanks , i will try that i will also get a reading off nanocom.

What reading will you get off Nanocom? The Nanocom cannot give you your boost pressure any more as the turbo boost box is tricking the signal. You will need a proper mechanical boost gauge now.

[twr7cx]

Yes the map was pre vnt. Went well. Ive got the vacuum hose on the wastegate actuator as it was, how should it be? BAS supplied the unit. Is the reading from nanocom for turbo pressure ok.

This is likely to be your issue. The electronic modulator should not be used. The VNT wastegate will sort itself out. By pass the modulator and directly connect the vacum line to the VNT.

[justinc]

Yes, you MUST remove the Wastegate controller/ hoses and attach directly from pressure side to the Nozzle actuator.
This is most likely NOT a problem with the VNT or mapping.

JC

[optimax90]

Swaped actuator hose to metal pipe before intercooler, seems a bit better, still sluggish and black smoke down low. Highest reading from nanocom .97 turbo pressure ?

[justinc]

Swaped actuator hose to metal pipe before intercooler, seems a bit better, still sluggish and black smoke down low. Highest reading from nanocom .97 turbo pressure ?

Nanocom will not read correctly if boost box connected.

JC

[twr7cx]

Swaped actuator hose to metal pipe before intercooler, seems a bit better, still sluggish and black smoke down low. Highest reading from nanocom .97 turbo pressure ?

As I said in post #7, the Nanocom is useless for reading the boost pressure level if you have a turbo boost box fitted as the whole function of the turbo boost box is to alter the boost pressure signal to the ECU, therefore the Nancom will read the altered signal, not a true signal.

[djam1]

I have just done the same conversion and have had a different result to you

Before I put the VNT on I ran the car with the standard turbo no boost box and the Nanocom showed 1.3 Bar Max
I put the Boost box on and it went to a max of .9 bar with the standard turbo

I then put the VNT on and it will run up to about .97 bar on the Nanocom this is simply to give a hint of what it is possibly boosting to

I too have an Alive map from Gary Wood I had him tweak the map for the VNT and the results are startling.

No smoke either white or black worth noting
Does it create a lot more power? probably not, but it does make the torque available across a broader span of the rev range making the car much more driveable.
Pete told me that it wasn't necessarily the higher boost that made the difference but the volume of air

Pretty well everything the car is required to do it will do with a simple light touch of the throttle

[justfishing]

Hello,
I had the same when i fitted my VNT. black smoke and went a little better but not what i expected.......UNTIL i got a MAP from TD5 Inside.. FOR the VNT and away she went...... Had a LOT of trouble with the Boost box it never worked, supplied by your vendor that's why I made my own.
You really need a MAP file for the VNT to get the best. Now I am getting about 15 psi plus at or below 2000 rpm. To see how mine is going I have a boost gauge to keep a check on the boost. You will not get the pressure or performance if not enough fuel is going in to the engine. Also after fitting the VNT it amplified that fact my MAF was not the best. A new MAF cured the lag and black smoke, you could try unplugging to see how it goes.
Ian

[Aaron40]

And.... how did the changes go? Are you getting a better result now Optimax90?

[Benny_IIA]

Hello,
I had the same when i fitted my VNT. black smoke and went a little better but not what i expected.......UNTIL i got a MAP from TD5 Inside.. FOR the VNT and away she went...... Had a LOT of trouble with the Boost box it never worked, supplied by your vendor that's why I made my own.
You really need a MAP file for the VNT to get the best. Now I am getting about 15 psi plus at or below 2000 rpm. To see how mine is going I have a boost gauge to keep a check on the boost. You will not get the pressure or performance if not enough fuel is going in to the engine. Also after fitting the VNT it amplified that fact my MAF was not the best. A new MAF cured the lag and black smoke, you could try unplugging to see how it goes.
Ian

X2 chat to jose from td5 inside he will sort you out...

Your map will need some adjustment to run 100% with the boost box and vnt fitted..

Which turbo did you get ?