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Title: MED9.1 HPFP KLLFPRSG Post by: Dave9n3 on April 04, 2020, 08:19:25 AM Hello,
Time has come to bump rail pressure up to meet the extra fuel demands. I've changed all the rail pressure related tables to allow for a higher rail pressure, last one I am unsure of is KLLFPRSG. From the FR (Kennlinie Liefergrad HDP Gradientenbegrenzung prsoll) it looks to be some sort of factor or coefficient of the HPFP versus rail pressure. What is the value in the table for/relating to? The stock values I have are at 1D92C4 in 1K0907115J - do these below values look correct? 5 = 0.269864 6 = 0.299876 7 = 0.329827 8 = 0.359839 9 = 0.389790 11 = 0.449753 Since I am lifting the rail pressure to 13Mpa I presume this table should be adjusted, both the axis and the table? If so have people just used these existing values to calculate the new ones for the higher pressure? like so? 5 = 0.269864 6 = 0.299876 7 = 0.329827 8 = 0.359839 9 = 0.389790 10 = 0.41979 11 = 0.449753 12 = 0.479704 13 = 0.509704 If someone could chime in to give their view that would be great, I presumed the changes should be fairly linear as pressure rises, so just used the same increments to effectively 'extend' the table to find out the values for higher pressures. I was going to change the final axis value to 13Mpa and then use the calculated value in the table, thinking that the computer would interpolate between the 9Mpa and 13Mpa. I may well be way off so hopefully someone can correct me if i'm being an idiot. Title: Re: MED9.1 HPFP KLLFPRSG Post by: jacktfsi on April 06, 2020, 02:39:18 PM Hi,
Sounds like your on the right track, best thing to do is change maps 1 by 1 so you can see what does and doesn't effect fuel pressure. You'll then see what needs changing and what doesn't, log and see if fuel pressure increases. cheers. Title: Re: MED9.1 HPFP KLLFPRSG Post by: Dave9n3 on April 06, 2020, 02:45:47 PM Hi, Sounds like your on the right track, best thing to do is change maps 1 by 1 so you can see what does and doesn't effect fuel pressure. You'll then see what needs changing and what doesn't, log and see if fuel pressure increases. cheers. Cheers for the response! I've actually been looking into it further right now. The FR description of KLLFPRSG is something like 'Characteristic curve delivery degree HDP gradient limitation prsoll' I'm presuming the map is essentially just like the characteristic curve of the pump. Since its a fixed displacement pump I think my method of extrapolating values, to find new ones for higher pressures may be correct. Unfortunately there isnt actually a function description for HDRPSOL in the FR - it states Bosch were awaiting the info from VAG. I then looked at MED17 FR knowing it may be similar and found the same. function description for the HDRPSOL section. Anyway I believe I've changed enough maps for the rail pressure to be increased but i just like to know what i'm changing and why. Have you ever changed this table and or have you fitted larger HPFP internals? I currently have stock HPFP internals. Title: Re: MED9.1 HPFP KLLFPRSG Post by: jacktfsi on April 06, 2020, 03:44:22 PM Cheers for the response! I've actually been looking into it further right now. The FR description of KLLFPRSG is something like 'Characteristic curve delivery degree HDP gradient limitation prsoll' I'm presuming the map is essentially just like the characteristic curve of the pump. Since its a fixed displacement pump I think my method of extrapolating values, to find new ones for higher pressures may be correct. . Unfortunately there isnt actually a function description for HDRPSOL in the FR - it states Bosch were awaiting the info from VAG. I then looked at MED17 FR knowing it may be similar and found the same. function description for the HDRPSOL section. Anyway I believe I've changed enough maps for the rail pressure to be increased but i just like to know what i'm changing and why. Have you ever changed this table and or have you fitted larger HPFP internals? I currently have stock HPFP internals. From what I’ve read of the FR that seems correct, I’ve seen some tunes with just the rail pressure axis increased with stock values but I believe the way you’ve done it is correct... Regarding the fuel pump, I’m currently in the process of doing this for the first time With an auto tech HPFP, I’ve got the formula worked out for the VHDP along with the 2 other maps that need editing - if you need any help with these let me know and I’ll post what I know of the process and the equation to work out the VHDP. Coronavirus is putting a hold On most things were I am at the moment too so I’m just reading and making map-packs to fill my time! |