Thread: 300Tdi boost pressure - how much is enough?

I reckon it can't go above 30, cos that's the limit of the gauge I bought

work it hard enough and it'll peg it and you'll sit there thinking... how badly did I just bend the bowden tube?

which you'll work out when it doesnt return to 0 but if you havent changed and rewheeled the turbo you'll start to struggle at around 22 you'll fight it to 25 but unless you have an EGT fitted calibrated and running pre turbo dont.

I tapped 2 holes into the manifold, one of them comes prefitted with a blanking bolt the other is just a boss point for a drilling for a shield thats not fitted.

Originally Posted by Blknight.aus

work it hard enough and it'll peg it and you'll sit there thinking... how badly did I just bend the bowden tube?

which you'll work out when it doesnt return to 0 but if you havent changed and rewheeled the turbo you'll start to struggle at around 22 you'll fight it to 25 but unless you have an EGT fitted calibrated and running pre turbo dont.

No, the turbo is stock. In the car's current state of tune it would be lucky to bend a blade of grass, which is why I have embarked on the process of doing the timing belt, and head gasket to bring it up to scratch so I can then try and tune it properly. Hence the boost gauge. The budget doesn't currently run to a turbo upgrade.
My EGT is pre turbo, but I have no idea how someone working in his carport would calibrate it.

Originally Posted by Blknight.aus

I tapped 2 holes into the manifold, one of them comes prefitted with a blanking bolt the other is just a boss point for a drilling for a shield thats not fitted.

OK, so one for the waste gate and on for the gauge I guess. Why not a T?

what gate now?.. something that opens that wastes my preciously generated heat and gas flow? not having that,

the official story is....

at the time I was doing the work someone needed a demo hand on drilling and tapping a BPST thread and I just happened to have an aluminium thing that was convenient so having one tapped and leaving the normal threaded plug for later made no differenceto me so a learning opportunity was not wasted.

the real story is...

Id run out of T pieces on the day I did mine

Originally Posted by Blknight.aus

what gate now?.. something that opens that wastes my preciously generated heat and gas flow? not having that,

the official story is....

at the time I was doing the work someone needed a demo hand on drilling and tapping a BPST thread and I just happened to have an aluminium thing that was convenient so having one tapped and leaving the normal threaded plug for later made no differenceto me so a learning opportunity was not wasted.

the real story is...

Id run out of T pieces on the day I did mine

Originally Posted by johntins

Where are you taking the feed from? I was thinking of drilling and tapping the bolt ( plug ) at the back of the manifold. Is that what you will do?

I removed the bung at the rear of the manifold and used an appropriate reducing bush and elbow to take the feed for my boost gauge.

Aaron

Originally Posted by johntins

My EGT is pre turbo, but I have no idea how someone working in his carport would calibrate it.

If your EGT gauge starts from 0 C you can do some basic checks with an ice bath and boiling water. [If the scale starts at, say 200 C, bad luck.]

Take the probe out, wipe it clean and stick it into an ice/water slush and stir for about a minute. Gauge should read very close to 0 C.

Next put it into vigorously boiling pure (demin?) water - should read very close to 100 C unless you are at a a very high altitude (difficult in Oz). (Note, it must be actively boiling the whole time. A kettle you bought out from the kitchen could well have fallen below 95 C by the time you get to the garage).

If these checks are OK there's a good chance it will be working adequately at higher temps too. A better check would be by using a known metal melting point. I believe pure aluminium melts at 651 C. That would be a good check if you had the wherewithal to perform the check.

PS: The boiling water check is good to check your coolant gauge occasionally too.

My boost gauge is plumbed into the Bung on the back of manifold and has a t piece for waste gate and boost gauge I'm in the process of plumbing coolant gauge and pyro