Boost pressure at manifold - where do I connect my gauge?

[Troll Hunter]

As in the title. I've got a 300 Tdi Def and I want to measure the pressure at the manifold, so where do I connect? The options seem to be to drill the outlet pipe of the intercooler, or to drill somewhere on the manifold itself. I'm sure that this has already been done, so all experience, advice and suggestions will be gratefully received.

Many thanks in advance.

Mike

[Nigelw]

On the back of the manifold(the end closest the firewall) there is a bolt, it may be possible to replace this if there is space enough with a small barb fitting to connect up to?

I did similar on my 200Tdi but that bolt is in the center of the manifold facing the head, it was a couple of unions to reduce it to fit the barbed fitting, perhaps you could use a 90° bend on there to get ease of access? I don't run a full time boost gauge so removed and put bolt back in once I'd finished playing.

HTH.

[Troll Hunter]

Brilliant, Nigelw, thank you very much. I've never noticed that plug, and there's plenty of room between the manifold and the firewall to fit reducers. One puzzle, though,the LR Parts Manual calls this a drain plug! What situation could require a drain plug in the inlet manifold of a diesel engine?

Mike

[qwakers]

Some one having a 'incident' whilst wading perhaps?

[ejparrott]

My boost gauges are T'd into the line from waste gate to FIP, most of the kits I've looked at have specified this.

[CwazyWabbit]

I used the same place as Nigel, you can fit a banjo bolt.

Pretty certain I used one of these but check the thread first http://www.ebay.co.uk/itm/12MM-BANJO-FOR-6MM-HOSE-M12x1-5-BOLT-FUEL-OIL-/391305501556

[Diesel_90]

I have removed the manifold, drilled and tapped a 1/8bsp thread I to the inlet manifold on my 300tdi. I have also removed the bolt in the back of the inlet manifold, drilled and tapped to take a boost gauge for other people. Not such a permanent modification, replace the bolt and it's back to standard

[GW8IZR]

I drilled and tapped the side of the manifold for mine, 300tdi on a 4 cyl LT77 meant not much room at back of manifold.

[Boydie]

There is a kit available and it is on a thread here somewhere, it consists of a banjo fitting that screws into the tapping once the rear bolt is removed, the hose then runs to your gauge - east to fit and there is even less room on my Disco than on your Defender so you won't have any trouble fitting it. I used the banjo bolt and fitting off a Defender rear axle at the local wreckers, The threads were wrong so I had to tap the hole out and use a helicoil so if you can obtain a proper kit, do so.

[Santanaman]

I ended up drilling a hole in the pipe going from my intercooler into my manifold......in part because I attempted a hole/helicoil in the actual manifold and cracked it (the manifold)....which apparently engines don't like! Tried both methods on my friends 200tdi and got the exact same psi measurements in both. I don't think either or is better for measuring, but it sure is a lot cheaper to replace the pipe from the cooler to the manifold than the manifold itself.

[Boydie]

If the manifold is aluminum its easy enough to get any crack welded up

[Troll Hunter]

Thanks for the advice and experiences. I've now got a banjo fitting with a 4mm bayonet fitting to replace the existing plug at the rear of the manifold, so tomorrow I should connect the boost gauge, the wastegate and the FIP to this new location. This should counteract some of the pressure loss through my horribly deformed turbo discharge pipe. If I find the boost is above 16psig at the manifold then I'll go back to the original offtake at the turbo outlet.

Mike