Not trying to be clever,I have nothing to prove to anyone.Just trying to help someone with a problem.Rustyskull asked a question - What is considered overboost and is that what his truck is suffering from.He stated that the only change to his Disco is the turbo,its still running a stock ecu tune. I answered that question for him,stating that he needs to see what the ecu can see to ascertain what is causing his juddering/power loss under full throttle/load conditions.As James Martin stated this is classic TD5 overboost symptoms.This is very easy to prove via live data from the ecu,and is how I and all of the 60 odd garages I work with would prove the issue.No extra padding or complications need to be discussed or argued over at this stage.Further on when ecu boost values can be seen and recorded it will be the time to suggest other tests or addtions to the car.Diagnostics need a clear and orderly approach,one step at a time.
Luckily Rustyskull has a Nanocom on the way and seems happy with the way forward.Your childlike rantings offer no extra help to him.
firstly asking or naming a member for help like james martin this is a weakness as your forgetting the type of issue the OP has has in the first place
it certainly not a ****ing contest either . i would just like to know how a boost gauge wont work in fault finding ?
i never said an electronic reading isn't the way to go either and yes a nonocom is a useful tool to have... and the OP will be to discover other issues and run other tests along the way forward
but i still ask why wouldn't a boost gauge see a boost spike or over boost or boost creep? hopefully james martin backs you up on this . ........ and like i said my boost gauge works well touch wood ... i have used my boost gauge also to diagnose over boost as well as loosing boost scenarios and some small boost spikes ...also its a nice feature to have you can become custom how the engine responds and drives while comparing boost levels in each gear with rpm/ road speed as well as towing specially at higher speeds when the boost gauge works more than the tacho does ie engine load
like i said your diagnostic skill lack. and when they do you cry out and named members ... yes one step at a time i agree but many people miss a few steps and jump to far ahead start the end and finish at the beginning
you need to start with the basics first along with the information provided
the over boost has cured while the larger turbo was fitted .... as there was no mention about over boost with the stock turbo... and he isn't over boosting either while driving through other gears with the larger turbo .....but only noticed this in 5th gear while slowly climbing up to 70 MPH like i said you boost gauge can move more than the RPM reading
i can concur and relate with this issue even with the stock turbo set up ..... as our freeways /motorways are 100 kph now slowly accelerate due a speed limit change or over take to 110 kph zone .... i would over boost on the stock turbo as i had boost creep due to waste gate issues .... and this was with out an electronic reading ps do the math an work out KPH to MPH
now that he has changed the A/R ratio to a larger turbo his issues has appeared...now that the inducer an exducer of a turbo impellor play a big roll in how that turbo spools up to make power as well as when the turbo makes power under load ie more heat . for kentic energy means efficiency .... now if the waste gate isnt set correctly or to small for the job he will notice boost spike and or boost creep .... a simple boost gauge reading will detect this as long as the boost gauge reads the correct area like the manifold
RuskySkull has a fair idea what needs to be done as he was asking about a map earlier ... whether it was to tone it down or waken it up in curtain areas... this depends but this depends on his set up and information provided also
a simple bleed off may work.... but who knows because a simple boost reading is just to hard
i have a few turbos laying around in my work shop from 16.1 litre engines.good to go as well as a few VGT turbos from smaller engines .. you do get the newbies who mentions why not install this on your 4wd it would be a beast .... . hence i dont want to wait 3 weeks before it kicks in and when it does its to late