Turbo upgrade for TDI?

[gregozedobe]

All good mate. Although i can hear what i am pretty sure is the waste gate fluttering at full boost on a cold day/night in 2nd and 3rd gears at around the peak torque rpms. Also if i bring it to full boost and lift off at about 2000rpm can hear (what i am assuming is) the wastegate dump.

Off to the workshop to put it on the hoist and prove one of us wrong.

Because diesels run effectively wide open throttle all the time (power output is controlled by fuel injection and boost), they have no need to relieve excess intake pressure when you lift off. In fact when you lift off there is a reduction in boost as the exhaust wheel of the turbine will be driven less hard (as there will be less exhaust gases being produced and your EGT will drop immediately as well). Some misguided individuals fit BOVs to their diesels, but if they function at all they typically reduce or limit VNT performance.

Remember the VNTs (that I've seen) have an actuator that looks like a wastegate actuator, but it is connected to the variable vanes.

How old is your TDI ?

I'm happy to go with empirical evidence to prove who is right , and even more important is to have correct information.

[bluey]

Garrett catalog has really interesting sections on turbo design and how to choose a diesel turbo based on engineering thinking complete with maths for the brave.

This thread (in Spanish - use Google to translate) has some interesting pics of a Polo Cup race car upgrade with Seat FMIC and GT1749VB turbo.

[GoLfMan]

This thread (in Spanish - use Google to translate) has some interesting pics of a Polo Cup race car upgrade with Seat FMIC and GT1749VB turbo.

thanks for the link bluey! did you read some of the comments he was making, with those upgrades 230hp and 500+nm of torque is possible


a FMIC that big thats OEM!!! Group buy for the TDI polo fellas?
now thats what im talking about

[bluey]

thanks for the link bluey! did you read some of the comments he was making, with those upgrades 230hp and 500+nm of torque is possible

Bear in mind he is talking racing car performance with racing car reliability!

Then you would be looking to upgrade clutch, gearbox and brakes as well as suspect engine components. FWIW, a salesperson at the local VW parts place said they could order any global VW part - just need a part no. Not sure how much they will ask for shipping....

[Transporter]

Anybody interested in increasing horsepower in his Golf or Polo should download and read carefully the VW self studies programms 316 2.0L 103kW TDI Engine and 368 2.0L 125kW TDI Engine from erwin website to see that there are some important internal changes made to 103kW to get just these extra 22kW from BRM, BMN engines (125kW) and still enjoy the car for many years to come. Such internal changes are much more expensive than any power upgrades offered by "performance" companies.
Without these internal changes your car will be less reliable (engine will not last for very long) - should you use the increased performance regularly.

[bluey]

Golf 2.0L yes, but Polos have 1.9L engine. I understand the 1.9 is a more reliable engine historically, particularly because the 2.0 block is a rebored 1.9 and subsequently has narrower walls between cylinders and is therefore a bit prone to head gasket failure, esp when uprated.

I thought the parts list link (earlier) gave a reasonable idea of all the uprated parts in the higher output 1.9 TDIs.

No doubt there is a similar self-study program on the 1.9TDI, but erwin is too expensive for non-professional mechanics to maintain an annual subscription. I am saving up all my queries for a forthcoming "erwin day" when I can subscribe and download everything I want and print it all out.

[Preen59]

Because diesels run effectively wide open throttle all the time (power output is controlled by fuel injection and boost), they have no need to relieve excess intake pressure when you lift off. In fact when you lift off there is a reduction in boost as the exhaust wheel of the turbine will be driven less hard (as there will be less exhaust gases being produced and your EGT will drop immediately as well). Some misguided individuals fit BOVs to their diesels, but if they function at all they typically reduce or limit VNT performance.

Remember the VNTs (that I've seen) have an actuator that looks like a wastegate actuator, but it is connected to the variable vanes.

How old is your TDI ?

I'm happy to go with empirical evidence to prove who is right , and even more important is to have correct information.

Yes you are correct there in saying all that. However, the wastegate bypasses exhaust gas through a passage next to the exhaust impeller to slow the turbo and cut the boost (on internal wastegated turbochargers, that is). Pretty much all turbo diesels have a waste gate, and that is how they control the peak boost.

Clearly the new variable vane turbochargers are a completely different kettle of fish. I'm not quite sure how they control boost. I was assuming that they had a wastegate and the variable vanes were used only for allowing the turbine to spool up faster at a much lower RPM.

I have noticed from looking at the top of the turbocharger (it's a high mount on the Caddy) the actuator that controls the variable vanes. I unfortunately was unable to get the van up on the hoist yesterday to take a look, as there is currently a 325i minus a waterpump on there.

I spoke to a reliable VW mechanic yesterday about this and he said that he doesn't think the VNT turbos have a wastegate, so it looks like you may be right.

My caddy is an '07 model.

a FMIC that big thats OEM!!! Group buy for the TDI polo fellas?
now thats what im talking about

Mate, the Caddy has a MASSIVE FMIC on it, it's actually a bit bigger than the radiator. You don't need to go sourcing parts from outside Australia.. You should see what is available locally first.

[bluey]

This motorsport company has pics of their FMIC kit for Polo 96kW TDI. There's other stuff too worth having a look... (not thinking of sourcing but just for ideas).

That's interesting the Caddy has a FMIC. I just thought it had the same 1.9 as the Polo but its 77 (vs 74) kW and 250 (vs 240) NM. I presume its a BLS engine also found in Golf and Audi A3 - power/torque curves. So VW figures for a teeny bit more power/torque, they need a FMIC. Caddys/Golfs also come with 6-speed DSG. Does the Golf have FMIC too???

[Transporter]

You're bouth right.
Some VNT turbocharges don't have wastegate and some do have.

[GoLfMan]

Mate, the Caddy has a MASSIVE FMIC on it, it's actually a bit bigger than the radiator. You don't need to go sourcing parts from outside Australia.. You should see what is available locally first.

yeh i know, ive already got a galant VR4 IC for my thing, the Seat FMIC looks to be a nice OEM fit with the outlets in the correct position which would really make the pipework easy
im notsure that the caddy FMIC would fit???

[GoLfMan]

Bear in mind he is talking racing car performance with racing car reliability!

Then you would be looking to upgrade clutch, gearbox and brakes as well as suspect engine components. FWIW, a salesperson at the local VW parts place said they could order any global VW part - just need a part no. Not sure how much they will ask for shipping....

yeh thats true

however, Tim from Dub Addiction already imports parts from Seat in Europe, ill put it to him to order in those Seat sport FMIC's for the TDI boys and see how we go!

[bluey]

This thread at TDIclub talks about lots of different Polo mods apart from nozzle upgrades - inc turbos; hybrid turbos; SMIC vent; FMIC (inc potential problems fitting). ..plus link to photos of Cupra FMIC install in Polo (German) including complete OEM parts list!

[GoLfMan]

This thread at TDIclub talks about lots of different Polo mods apart from nozzle upgrades - inc turbos; hybrid turbos; SMIC vent; FMIC (inc potential problems fitting). ..plus link to photos of Cupra FMIC install in Polo (German) including complete OEM parts list!

im really liking the idea of the Seat FMIC, its a nice and easy OEM fit

[bluey]

im really liking the idea of the Seat FMIC, its a nice and easy OEM fit

Main downer being the price @ 883 euros (as listed).

[GoLfMan]

Main downer being the price @ 883 euros (as listed).

yeh ouch, thats a blow to the hip pocket, that South African kit is only $700 and it comes with everything!