Are you able to get the turbo chatter from a tdi if i was to fit Allards Phase 4 VT2 turbo kit?

Many thanks

Are you able to get the turbo chatter from a tdi if i was to fit Allards Phase 4 VT2 turbo kit?

Many thanks

No. You can get BOVs for tdi's but you need a labomtomy to justify having one.

Here is a post I wrote on the Saab Forum when ask about fitting it to a 1.9 CDTI

"In your petrol engine your turbo is spinning at say 100k revs.... suddenly your throttle closes, and turbo is still spinning due to inertia... consequently the air has nowhere to go because the thottle plate is shut... so the dump valve opens and allows this air to escape to the atmosphere(or back into the air box if a recirc is fitted)... this has the benfit of allowing the turbo to keep spinning in a partial vacuum for a longer period of time, and therefore takes less time to get back up to speed after you reapply the throttle..

On a diesel engine it isn't required because there is no throttle body (Not like you get in a petrol), so the air doesn't get trapped like it does on a petrol engine.... in fact the excess air actually reduces the emmissions output from the engine and also has a mild intercooling effect on the combustion chambers

You can get electronically actuated valves for the cdti but TBH the only thing you will get out of it is a Noise and it might actually adversly effect the performance. A DV cannot increase performance. There is nothing for it to do other than go PSCHTTTTTTTT and unless it's perfectly actuated and it gets it spot on it will loose you boost pressure.

The boost pressure is generally highest on a diesel when the accelerator is on the floor and the engine is as max power, just before a gear change. If a dump valve is set to relieve the pressure just below max boost, it will sound similar to that on a petrol engine, but it will be dumping air while the engine is on power, not when the accelerator has just been released. All it can do is make the turbo less efficient. The wastegate tries to control the boost pressure and that will just increase the exhaust back pressure if the pressure is being dumped by a dump valve.

Now also figure in the fact the fact the cdti turbo is a VNT and this works works by adjusting the gas throat section at the inlet of the turbine wheel in order to optimize turbine power with the required flow velocity. At low engine speed and small gas flow, the turbocharger reduces the throat section, increasing turbine power and boost pressure. At full engine speed and high gas flow, the VNT increases the throat section, avoiding turbocharger overspeed and maintaining the booster pressure required by the engine. How do you think sticking a remote control hole (Which is what the valve is really) in the system will effect this? It will defeat the object totally and all it will do is work against it.

I would really like to see a dyno run of a standard car and the one fitted with a DV back to back. I think the run with the valve would show early boost loss and spikes where the VNT is struggling to compensate. The only way it could be perceived to increase performance is if you mapped around it which is pointless because you might as well have just mapped a standard engine"

Edited 6 August, 201015 yr by Decron

I get chatter out my standard turbo. It's noticeable due to me having a bmc cda and de cat straight through exhaust. But it's not when the engines on max power but when it's at low revs just as the turbo spools and u dip the clutch.

A diesel with a dump valve is pointless and as said above will loose you boost

Can I point out that a Waste gate and a Dump Valve are two separate things.

A Dump valve is on the Inlet side of the turbo and a Wastegate is normally on the Exhaust side (turbos without VNT)

"A wastegate is a valve that diverts exhaust gases away from the turbine wheel in a turbocharged engine system. Diversion of exhaust gases regulates the turbine speed, which in turn regulates the rotating speed of the compressor. The primary function of the wastegate is to regulate the maximum boost pressure in turbocharger systems, to protect the engine and the turbocharger." (Quote from Wikipedia) It can be built in to the turbo or mounted externally.

The Dump or Blow-Off valve has been explained above.

However, I have a feeling this "Phase 4 VT2 turbo kit" will have variable inlet Guide Vanes to control the boost and not the old-style exhaust waste-Gate.

Edited 6 August, 201015 yr by Jim H

Yeh I knew they were different but the op asked if he could get chatter from it. Chatter is normally more from a wastegate than a dump valve as was said above a dump valve makes the same ptschhhh noise where as a wastegate makes more of a whoosh noise or chatter as other people call iti

tbh id feel a right d!ckhead if i had dump valve on a diesel, folkes are bound to laugh surely? but each to there own

Any diesel dump valve I've ever heard hasn't been loud and it certainly doesn't sound like a petrol one.

But I do like the chatter I get off of mine. Most folk don't believe it's a diesel cos it's not everyday they hear a diesel doing it

Any diesel dump valve I've ever heard hasn't been loud and it certainly doesn't sound like a petrol one.

But I do like the chatter I get off of mine. Most folk don't believe it's a diesel cos it's not everyday they hear a diesel doing it

You fitted a DV to your fabia vrs?

whats the point? :S

I don't have a dump valve on it! I've got a bmc cda and a de cat exhaust so I get chatter off it when I change gear at low revs just before boost fully kicks in

I don't have a dump valve on it! I've got a bmc cda and a de cat exhaust so I get chatter off it when I change gear at low revs just before boost fully kicks in

ah ok Do you find that the DMC cda works better then the standard airbox and replacement panel filter? I always hear things about those induction kits not being quiet so effective - letting in hot air etc.

Run a proper cold air feed and get the proper kit as it's made from carbon fibre, and you're sorted. Mines is a proper bmc cda and it's never hot to the touch. I've got a cold air feed behind the headlight as I don't want it restricting air flow and it's fine. Never noticed much difference with anything bar noise, it's made the engine a tad bit louder as I'm always asked if I have an air filter on it.

If anything it's possibly sharpened up the throttle. Needs cleaned but being a metal mesh kit they work better when dirty than clean due to the dirt helping filtration. But don't quote me on that as I'm not entirely sure if that's true or not lol

Try before you buy:

*ding* Can you let me off at the next stop please, driver?!

:rofl:

i had a DV fitted to my ford mondeo 1.8TD R reg i did some slight engine tuneing on it and had a ST24 body kit and exhausts ect fitted to it yes i know i was young but you live and learn. The DV was fitted by Derv Doctor now to be fair that did sound very similar to a petrol DV dont know how they did it but it was better than i expected and i never had any engine problems after haveing it fitted.

It certanly got alot of positive comments from people who would come up and ask what engine it was even though it said TD on the wing supose its everyone to there own. I personal dont like to be a sheep so i try to do things a little different put my own touch on my cars with out makeing it look like its just crashed into the Ripspeed section at halfords.