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My second T4, operation de-chav

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  • Had a re-shuffle in the garage

    two hours moving stuff around and I now have some space to work in and all my projects in one spot. I count at least four fairly substantial projects in this shot



    That's not counting the tiger cub hidden under the dust sheet.

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    • Originally posted by Activ8 View Post
      My VCDS states mg/s where as yours displays mg/R? The 850 displayed is the result of making airmass mapping changes and not something I have written. BUT it's just a display and may be limited it could be worth locating the switch/factor used. 850 is the original figure and maximum axis number. There's nothing in the maps or switches that actually changes but something records the change.
      Any idea why the value is 850, surely it should be circa 500 as 2.5litre / 5 cylinders = 500? (assuming atmos pressure = 1)

      Aren't most of the calcs made by this figure - what do you use when you calculate fuelling maps?

      If I go for bigger injectors, should the SOI become later as the duration will be less?


      actually..... thinking about this...... if the pumphead has not changed then the duration should not change. Any idea what the limit would be on stanadyne nozzles?
      Last edited by regcheeseman; 1 October 2018, 01:26 PM.

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      • 850 is the maximum specified in the X axis for the airmass tables for the AJT. Range 0-850. The ECU uses kg/Hour to calculate airmass the 850mg/s is the OEM max display value for the 70mm MAF.

        I use actual airmass for the AFR and smoke maps.

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        • For larger injectors shorten the duration in the lower rev and fuel regions and increase them in the upper.

          Never gone beyond 60mg with Stanadynes with no issues but not tested beyond. Really need time pre-writing the maps then running them on a rolling road to see the real changes.

          Comment


          • Originally posted by Activ8 View Post
            For larger injectors shorten the duration in the lower rev and fuel regions and increase them in the upper.

            Never gone beyond 60mg with Stanadynes with no issues but not tested beyond. Really need time pre-writing the maps then running them on a rolling road to see the real changes.
            Cannot solely concentrate on the theory unfortunately, consideration must be given to the mechanical gubbins...

            The flow rate is governed by the pump piston - the injector may or may not accommodate this flow rate, though I'd assume that the injector rate far exceeds the piston rate.

            Ultimately the duration of the delivery is also controlled by the pump piston, no matter how much larger the injectors, the pump can only deliver at a set rate. However the pump may stop delivering before the injector has had enough time to deliver the requested amount - which is why I ask about the stanas mechanical limit, sure you can keep pushing them but the extra diesel will not get injected.

            Why increase the duration at high revs and reduce at low revs - what's the thinking there? ...... ooooh hang on......brain fart

            The pump piston only delivers over approx 36 degrees of crank rotation max, so at WOT, trying to deliver

            at 4000 rpm that give 66.6 rps or 0.015 secs per rev - which means a 0.0015 second window to deliver fuel
            at 1000 rpm that gives 16.6 rps or 0.06 secs per rev - which means a 0.006 second window to deliver fuel

            was it 51mg being delivered at max? how do injector sizes relate to flow rate - how long does a .206 need to flow 51mg?

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            • If your timing is bang on there's only a 20° electrical window to inject the fuel - recall my mentioning putting a hybrid 2.4 pump on so you could expand the fueling window dramatically.

              It was 51mg in v2. Colin ran 60mg in v3 for 3 months. You loose an injection hole moving to Bosch 0.206's.

              Have you had or worked on a VP44?

              Last edited by Activ8; 2 October 2018, 12:18 PM.

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              • Originally posted by Activ8 View Post
                If your timing is bang on there's only a 20° electrical window to inject the fuel - recall my mentioning putting a hybrid 2.4 pump on so you could expand the fueling window dramatically.

                It was 51mg in v2. Colin ran 60mg in v3 for 3 months. You loose an injection hole moving to Bosch 0.206's.

                Have you had or worked on a VP44?
                where do you get 20 degrees from???? Cant see what you mean by electrical window? There's no electrical control?

                Not seen a VP44 - looks like standard CAV architecture that's been around about as long as I have

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                • Find the pump map! Then xref to the 12 SOI maps.

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                  • Ran some AJT mapping experiments during the week and now convinced you can definately run 70mg/stroke through the Stanadynes. [emoji6] Using the same map data in the AXG software you can go even further but unsure why at mo.

                    Comment


                    • Originally posted by Activ8 View Post
                      Ran some AJT mapping experiments during the week and now convinced you can definately run 70mg/stroke through the Stanadynes. [emoji6] Using the same map data in the AXG software you can go even further but unsure why at mo.
                      How do you know they were flowing that though? or even if the pump can deliver that? - I don't doubt that either can manage those figure just curious to know how you physically validate your figures.


                      Going back to an earlier post regarding air mass - with 1 BAR of boost i.e MAP showing 2000 (i.e atmospheric pressure plus 1 bar boost), should my measured air mass = 1000 as 2.5litres divided by 5 cylinders x 2 bar = 1000

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                      • Originally posted by regcheeseman View Post
                        How do you know they were flowing that though? or even if the pump can deliver that? - I don't doubt that either can manage those figure just curious to know how you physically validate your figures.
                        I dont know the specific flow compared to the mapping data I suppose you could set something up. I drafted 4 increasing IQ maps and tested the BHP / Torque figures. All were confirmed with £160 worth of rolling road and some labour trading / exchange with a contact!

                        Originally posted by regcheeseman View Post
                        Going back to an earlier post regarding air mass - with 1 BAR of boost i.e MAP showing 2000 (i.e atmospheric pressure plus 1 bar boost), should my measured air mass = 1000 as 2.5litres divided by 5 cylinders x 2 bar = 1000
                        Which post? If ATM, both inlet & boosted air temps are identical then yes. What's on your mind?



                        Comment


                        • Originally posted by Activ8 View Post
                          Ran some AJT mapping experiments during the week and now convinced you can definately run 70mg/stroke through the Stanadynes. [emoji6] Using the same map data in the AXG software you can go even further but unsure why at mo.
                          How do you know they were flowing that though? or even if the pump can deliver that? - I don't doubt that either can manage those figure just curious to know how you physically validate your figures.


                          Going back to an earlier post regarding air mass - with 1 BAR of boost i.e MAP showing 2000 (i.e atmospheric pressure plus 1 bar boost), should my measured air mass = 1000 as 2.5litres divided by 5 cylinders x 2 bar = 1000

                          Comment


                          • Saw you in braunton earlier from a distance Reg. Pulling out from braunton garage, van looks really smart

                            Comment


                            • Originally posted by UncleTravellingMatt View Post
                              Saw you in braunton earlier from a distance Reg. Pulling out from braunton garage, van looks really smart
                              Cheers bud - weekly run to Squires for chips.

                              Had some fun a bit later on when a boy racer in a 1 series BMW was going a bit quick on a roundabout so I tucked in behind and then pushed him along, he tried to shake off the van and failed, after a bit he had to pull over and let me by

                              He tried to pass it off as a left turn into a housing estate, then pulled out again a few cars later.

                              Comment


                              • Really??? Based on that last logrun you posted you didn't even make 1 bar of boost not even at 4k.... must be running flat as a witches tit?

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