Thread: 300Tdi boost pins and rings

In a 110. I put a boost pin in after I fitted a VNT, rather than adjust the pump. Smoking was an issue (taking off and hard acceleration) so I increased pre-load on the pin by adjusting the star wheel, and also adjusted the top nut to give it more time in the low fuel position. It helped somewhat.

I fitted a timing ring (boost ring) a couple of weeks ago and fitted it with the recommended number of washers to start with. I didn't notice any improvement to acceleration at all, but I think there is less smoke at full throttle.

At freeway speeds I use an overdrive, so keep revs to around 2,000rpm @ 100kph, so I may notice better dynamic advance response if I stayed in 5th and got the revs to 2,500. There's no issue accelerating to 120kph for overtaking in sixth, but that was the case before the ring as well. I fitted the ring the same time I replaced a leaking exhaust manifold gasket, so the lower noise might be giving me a perception of less power, thus cancelling out the perceived improvement.

I'm undecided about the efficacy of the ring, but if it reduces smoke it's worth it. I noticed that it's a popular mod with big diesels in the USA using the Bosch pump, so figure it's been tested beyond the Land Rover community.

I'll drive it awhile and talk to more people before adjusting the ring for a bit more timing pin travel.

The ac compressor will swing out of the way without degassing it.