My humble request of tuning experts
#33
Something else I blogged but didn't flag... during my "Boost Limit" testing, I ran into an interested phenomenon. Keep in mind that my BDEL table is maxed and i use a #58 Pill to control...
my WGDC from 2k to 3.5k has been 80 percent...always...never changed it after I found this was the general area I wanted to boost...BUT...I had my "Boost Limit" table erroneously set to 250 load across the board. When the load crossed 250 at 3.5k, its as if all other table were forgotten. It would continue boosting PAST 270 (close to 280) whereupon it would suddenly plummet to 210, then rise back to around 220, tapering normally. When I removed the BL table, my boost calmed down. my spike is consistantly 260, where I want it. There is no post-peak canyon, it just holds nicely til it tapers at about 6k.
What does this mean? It may sound counter-intuitive, but I would raise your boost limit table past your desired boost...not maxed out, but like 10-15 steps above it. this seemed to do the trick of eliminating BOTH overboost spike and cut for me.
my WGDC from 2k to 3.5k has been 80 percent...always...never changed it after I found this was the general area I wanted to boost...BUT...I had my "Boost Limit" table erroneously set to 250 load across the board. When the load crossed 250 at 3.5k, its as if all other table were forgotten. It would continue boosting PAST 270 (close to 280) whereupon it would suddenly plummet to 210, then rise back to around 220, tapering normally. When I removed the BL table, my boost calmed down. my spike is consistantly 260, where I want it. There is no post-peak canyon, it just holds nicely til it tapers at about 6k.
What does this mean? It may sound counter-intuitive, but I would raise your boost limit table past your desired boost...not maxed out, but like 10-15 steps above it. this seemed to do the trick of eliminating BOTH overboost spike and cut for me.
#34
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Well that's an interesting theory on boost limit, but not the one I'm familiar with.
I thought the boost limit table (in combination with the boost limit timer) were the safety feature which brought the scary fuel cut.
For instance, mine is at 265 tapering to 245 at redline. So if my load were to stay over 265 for over a second (my boost limit delay), fuel cut would be reached.
It sounds like codgi and Titanium are implying that this is not the case or perhaps not the only purpose of these tables. Any other thoughts?
I thought the boost limit table (in combination with the boost limit timer) were the safety feature which brought the scary fuel cut.
For instance, mine is at 265 tapering to 245 at redline. So if my load were to stay over 265 for over a second (my boost limit delay), fuel cut would be reached.
It sounds like codgi and Titanium are implying that this is not the case or perhaps not the only purpose of these tables. Any other thoughts?
#35
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^^ I wasn't implying that at all
. I was just curious to see what you had your boost limit set to.
Why I suggested lowering the WGDC table a cell above where the spike occurs is because from what I have read here, adjusting it at the rpm where the spike occurs might already be too late to prevent it from spiking.
I am meddling with my boost limit table right now. I have it set to 300 across the board with boost cut timer set to 1000ms.
![Smilie](https://www.evolutionm.net/forums/images/smilies/smile.gif)
Why I suggested lowering the WGDC table a cell above where the spike occurs is because from what I have read here, adjusting it at the rpm where the spike occurs might already be too late to prevent it from spiking.
I am meddling with my boost limit table right now. I have it set to 300 across the board with boost cut timer set to 1000ms.
#36
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^^ I wasn't implying that at all
. I was just curious to see what you had your boost limit set to.
Why I suggested lowering the WGDC table a cell above where the spike occurs is because from what I have read here, adjusting it at the rpm where the spike occurs might already be too late to prevent it from spiking.
I am meddling with my boost limit table right now. I have it set to 300 across the board with boost cut timer set to 1000ms.
![Smilie](https://www.evolutionm.net/forums/images/smilies/smile.gif)
Why I suggested lowering the WGDC table a cell above where the spike occurs is because from what I have read here, adjusting it at the rpm where the spike occurs might already be too late to prevent it from spiking.
I am meddling with my boost limit table right now. I have it set to 300 across the board with boost cut timer set to 1000ms.
I am going to look at changing the WGDC...I'll report here when I find out if it works.
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