Thread: T-off to Wastegate broken on a Tdi, what Damage can be Done?

anywhere on the manifold is fine.

the stock turbo is optimised for about 14-16 psi,
It will reasonably perform out to the 21/22 mark
It will hit its limits at 26/27

very very vaguely....

compare it to engine output VS fuel consumption under load

Peak torque where the engine is most fuel effieciant is say 1900 rpm
Peak power where you are delivering more power in exchange for more fuel is at 3200 rpm
if you want to burn exponentially more fuel you can run the engine to the limiter and hit 4000 rpm.

THe limitign factor I've found for the stock tdi turbo is the exhaust and inlet with turbine slip happening first and then compressor stall.

fitting a 3 inch exhaust and permanently operation of the wastegate will prevent turbine slip but will drive you into the realm of compressor stalling.

Originally Posted by Blknight.aus

Worry more about your EGT than the boost

Ok, so what is a 'safe' range for EGT? Mine has the gauge but I've never really known what upper limit I should be looking out for.

Also, I am going to be doing the timing belt soon. I thought I'd upgrade the intercooler while I had it apart. Any recommendations for a good I/C? D1 with air and a LR gearbox cooler fitted.

Originally Posted by johntins

Ok, so what is a 'safe' range for EGT? Mine has the gauge but I've never really known what upper limit I should be looking out for.

I've been told a MAX of 720 degrees Pre Turbo is all u should go to & I would have thought that u wouldn't want to stay up at the Temp for too long either..... Temp Post Turbo I would assume a MAX of around 650 or so, but others on here would know better than what I would....

Had a bit of spare time after work, so took the chance and pulled the inlet air hose off to give me access - Job done in 10mins or so and it's back to normal......

Originally Posted by johntins

Ok, so what is a 'safe' range for EGT? Mine has the gauge but I've never really known what upper limit I should be looking out for.

Also, I am going to be doing the timing belt soon. I thought I'd upgrade the intercooler while I had it apart. Any recommendations for a good I/C? D1 with air and a LR gearbox cooler fitted.

http://www.aulro.com/afvb/1521229-post17.html

saves me a lot of retyping.

Theres lots out there, your budget and quality preference will drive what you get.

its planned job have a chat with roverlord first to see what hes got then MR automotive.

Next do a general search on here and then ask for people opinion on what you find from here.

I walked a different line for intercooling.

Originally Posted by Blknight.aus

I walked a different line for intercooling.

What, something like this? Intercooler information - Build your own - Laminova

Thanks for the link to your other post on EGT's. I'll go out and stick my head under the bonnet to see if my gauge is pre or post, but I've never seen it above high 4's, so I guess that's ok.

no, my charge air cooling works along the lines of.

coolant cooled turbo charger
coolant - charge air intercooler
stock air to air intercooler up the front.

The biggest hold up for me for maintaining full noise is heat. I can ramp maximum power for maybe 30 seconds before the cooling system temp starts to come up, as that happens the cooling on the turbo and the first cooler become less effective so the IAT at the manifold comes up and I start loosing charge density. less air density means I need more fuel to make the same power (overfuelling a diesel raises EGT and engine temps in its own rights) with the hotter air inside combustion chamber at the start point the EGT's go up. higher EGT's add more heat load. More heat load overwhelms the cooling system once the cooling system is overwhelmed the temperature start to rise...

The only solution is to back off slowly let the cooling system get itself back under control and wind up again.

whats this mean in the real world?

I can do 120 KPH under almost all conditions with no limitations ( I generally dont because that puts my fuel consumption at V8 figures)
I can overtake at up to 150 kph BUT.. I can only do that for 30 seconds or so before the engine temp has gone from normal to the bottom end of "dangerously hot"
I then have to do <~100 for about 5 minutes before the cooling system gets back down to normal before I can wind back up to 120.

Alternatively. I can drive to the limit of the cooling system and keep the temperature on the upper limit of normal and "begining to get hot" and modulate the power application to keep it there. The problem with that IS... I have no headroom on the cooling system, if I try to push it it begins to cook up immediately. (I also dont generalydrive like this because that puts my fuel consumption at toyota levels.)

AND...

I also cant just back off completely immediately. IF I drop the RPM's much below 1700 there isnt enough coolant flow to get the heat out of the block, head and turbo so the coolant temperature spikes upwards which, if Im already sitting on the bottom of "dangerously hot", is bad. Higher coolant temps=higher cooling system pressure which at the very least means coolant venting out of the expansion tank cap.

Ah, the Territory!!