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Posts posted by Puffwagon
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Here is the example;
The only difference in the tune from these log pics is me smoothing out the boost curve via the wgdc table and a small sd table change to fix the lean spot just after 161 seconds.
The timing maps are unchanged between the logs, in the first pic the line is still 19 degrees and the dip is 14 degrees.
I didn't rev it out as much after I fixed it but you can see that the timing hadn't dropped off while at WOT. I lined up the blue line for reference.
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I have my vehicle running the custom os, extended tables, 4 bar boost sensor etc.
My timing tables axis max load is 2.6 whereas I will hit 6.0 load in the log. This works fine for the most part however I've noticed that if my boost control isn't spot on it will go into other load ranges, 5.7 etc etc.
This is all very normal except I've noticed that my timing will have a dip or vary if I don't have a near perfect boost curve.
There must be some sort of extrapolation going on, the only other thing I can see causing the variation/dip in timing is the wg pressure trending downward.
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If you're worries about poor fuel quality here's some info;
An engine can still knock with very low timing, running 91 will give you an idea of how much timing it will take, maybe 4 degrees or so at stock boost levels, then you need a safety after that. To be 100% safe you would let it remove enough timing to get it down to 0 degrees or slightly less, ie -2 degrees.
You really need some kind of warning system that something is going wrong, wideband at a minimum, preferably boost as well, have the knock sensors working, iat table at stock settings and have boost safeties in place. Providing you stay away from the ragged edge you will have some more leeway there before things go wrong.
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You can change the amount of knock it can take out, have a look through the various knock parameters and compare a turbo file to get an idea of what's in there.
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The track at Mallala has e80, might be a bit of a hike for you tho Roland.
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The quotes are to help with the stoich change. Either change the stoich value or change the slopes to run E85.
A built motor will want about 18 degrees total timing but a stock motor isn't as strong. Considering you can run 13 degrees of timing at 13psi on 98 with a stock engine, you can decide how much timing is safe for your engine.
On 4/15/2022 at 12:45 PM, Roland@pcmtec said:Yes it's definitely possible to do with the custom os.
On big boost cars is common to do this. Eg if you are running 18psi on 98 and 35psi on e85 you would normally have to fudge the slopes or speed density due a combination of a variety of effects. No more than a few % though
Completely agree. End of the day if the car operates in the range of conditions your require it to with acceptable timing, afr and safety limits then it doesn't really matter how you achieve it. The short cuts are often much simpler and more reliable than doing it "properly". It's also a hell of alot faster.
Which calibrations do you find stoich doesn't work in? It should be used in all.
On 4/15/2022 at 3:20 PM, Puffwagon said:It didn't do anything in my territory, HACH4A6/PCMA5A6. We spoke about it recently on the forum and you said you might consider removing it from the software cos it doesn't do anything anyway.
On 4/15/2022 at 4:36 PM, Roland@pcmtec said:- 1
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That clip is cut too short to see much but glad you got it sorted.
Haha I was getting worried that my own dual 525's were going to run out 🤣
I've been looking for another gauge to add, I've got the advanced ethanol gauge but need one like the other one you've got there. Will be adding that in future to track oil and fuel pressure in the log.
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So it's working now?
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Have you run it up again?
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Let us know how you get on, I've been thinking about dropping my base pressure to offset the injector pressure at high boost levels but haven't tried to yet.
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I have used the Ryco filters but I swapped to a washable stainless filter from Goleby's.
When the pump is running out but the injectors have room, you can add fuel to the speed density table. If it starts going lean at 5000rpm, get in there and drop the cells it runs through at WOT by 500 to 1000 numbers from 5000rpm and up and it'll richen up.
I haven't tried dropping the base pressure but it should be as simple as changing the slopes and breakpoint to suit.
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17 minutes ago, Roland@pcmtec said:
This is not how you should tune spark tables
Let's take it one step further and say you shouldn't even touch an ignition map, unless you either have the experience to know what it needs or are using knock detection equipment.
Now where's a big stick and a dead horse?
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Haha yep the list is never ending!
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Info from the Walbro site says a 525 is good for 100gph/378Lph at 78psi, the Raceworks calculator says the engine needs 359Lph for 700hp.
While myself and others have made over 500rwkw with this pump, undoubtedly with falling pressure and near zero return flow, I think we're seeing some data show us that the pump is only stable to around 450rwkw.
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A 460 and a 525 can also suck the pot dry pretty quickly if the fuel level is low. Fill the tank to the brim and see if it helps.
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48 minutes ago, JMSMotorsport said:
Yep just seems odd. I just had pump apart again and fiddled around with socks and put it back in and it’s actually worse that’s what’s leading me that way.
Is there a split in the fuel line between the pump and the top of the pot?
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Yeah they usually have a plastic skeleton in them to hold their shape but I think it's only the expensive Holley socks that are the bees knees. I suppose it is possible that it's not able to draw enough fuel at wot.
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There isn't a split in the reg reference line? A single 525 with a relay feed should be fine at that power and boost level.
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Yeah getting it go go low enough is the issue you face with return restrictions.
If it will pull down to 3.5 bar with the vac line connected you're fine.
You can test the return limit now if you want by seeing how low it can go. Just bridge the fuel pump relay to keep the pump running with the engine off and turn the reg down until the gauge stops going down.
Low pressure at high load and WOT indicates a fuel supply issue, usually it's a blocked fuel filter or insufficient pump capacity.
Fwiw I've run several hundred kw more on a stock feed line.
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I don't know about the sniper bucket, I've only used the stock unit.
For the stock unit, the return system in the pot is one return restriction and another restriction is at the quick connect on the return line. If you look at the hole in the return connector, it is tiny.
I don't think a single 525 will warrant opening up the return line connector, but the only way to make sure is to at least have a gauge in the fuel reg and see what it does at idle.
I quickly went from 1x 460 to 1x 525 to 2x 525 with a fpr800 and I had already modded the pot from the outset. I only started further return mods and bigger reg when I fitted 2x pumps.
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1 hour ago, JMSMotorsport said:
What’s the consensus is that big enough lines? To make 450rwkw on E85
Stock feed line is fine.
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To explain the log, the first part is me setting up the equations for the fuel temp and ethanol percentage. Then the weird up and down bit is what the car has started doing the past couple of days as it warms up. I probably changed something but I'll check another day. After that you'll see the cam timing doing stuff, every time you see the wideband reset is obviously when I reflash it. The last two wot spikes in the log are everything back to normal, the previous spikes are with the cam offset changed.
Anyhow it's past beer o clock so yerp 🍻
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My car was idling at -30 overlap.
auF12259 made no change.
I changed auF11468 from -70 to -60 and the overlap changed from -30 to -20. I then changed it to -45 and the overlap was around 0 give or take.
It now idles very lumpy and also changed the idle trims in neutral from 1 to 0.87 and the drive idle trims are 0.98 with a medium choppy idle.
I had it going to -20 cam angle at wot before and now it goes to +15.
Interestingly enough the overlap has changed back to -30 at idle after about 300 seconds but still had the adjusted overlap at wot. Both wot tests were done in the driveway on the brake. It has leaned out quite a bit at wot.
I then put it back to stock, the idle stayed at -30, smooth idle, wot went to -20 and fuel returned.
I'll upload a log for shits and giggles.
I haven't tried the other parameters.
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I'll try logging those tables later and see if it shifts the offset
chasing odd trims
in Diagnostics
Posted
Could be a subtle variation in fuel pressure?