Ka24de Load Scale Calculation

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apex128
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Ka24de Load Scale Calculation

Post by apex128 »

Hey guys,

I am tuning my ka-t on nistune and have been having trouble finding which boost levels reach which load indexes. This makes it hard for me to know when to start pulling timing / adding fuel. I'm trying to do 3/4 of a degree for each psi, but I have no way of knowing which maf reading corresponds to what psi. I read about finding the 0psi index, then multiplying it in order to find the index for one bar, but idk how to find my 0psi index, and I don't see how to find the 8psi index either.
Any help would be greatly appreciated.

Thanks.
apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

Bump. Need help here guys.
adamky
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Re: Ka24de Load Scale Calculation

Post by adamky »

Do you have a boost controller of some sort? I've always had trouble figuring out that whole " x degree of retard per psi" because like you said, your load scales will be so different on different injectors, MAFs, etc., so how would you correlate that info? I just know from years and years of being on these forums what it takes to make a conservative timing map to start with.

Are you running the Feature Pack on your ECU? The Feature Pack now uses an additional fueling/timing/scaling parameter called the Total Injection Multiplier and it's a bit trickier to get the hang of adjusting this.

If you can post up your tune along with a log, I'd be happy to look it over.
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apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

I have an isis mbc, but I can't get it to do anything really. I'm just going to stick with 8 psi for now. I don't believe I am running the feature pack either.

Here is a link to the map: https://drive.google.com/open?id=0B4E7n ... zk2UnplWVU

I will upload my log later today. It contains a second gear pull up to 5500rpm.

Thanks for helping out!
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BigLoukaT
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Re: Ka24de Load Scale Calculation

Post by BigLoukaT »

Not a lot of experience tuning maf setups, but how I slowed my engine down and focused on certain loads/engine speeds is by left foot brake boosting. Easy to hold steady speed and high load for a enough seconds to find yourself in the log and note the tp load at that point. For a maf setup, I would concentrate on finding 0 psi at 3000, 4000 and 4500 and 5000 as your starting point. Reduce all timing to the right of 0psi load by 10 degrees or so, and do a pull or more brake boosting to see where 8 psi lands you. Be careful to make sure you're not hitting higher than 8 psi though.
1990 S13
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MS DIYPNP
npx from 240sxforums wrote:i figure from my very limited knowledge about the 240 and under the hood about cars in general i would follow the sr20det trend.
apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

I'll try the brake boosting thing when I get the chance. Here is my log: https://drive.google.com/open?id=0B4E7n ... GViR1kzamM
adamky
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Re: Ka24de Load Scale Calculation

Post by adamky »

Okay, sorry it took so long...
I looked at the tune and log. For starters, during WOT, you are hitting load values that are off the map, and this makes doing any further tuning impossible. I would say that your timing map probably wouldn't be completely off IF you could fix this issue. For now though, your timing is low because you are maxing out your load values way too early. Ideally, you want to use all of the resolution you can, meaning that even under high boost, your max load never goes above the max TP/load in your map. In your case, that's 144. But if you look in your log, @ 04:47.8 you hit a max of 167 TP (MSB). If you're only running 8 psi, that's quite a ways off.

So, first things first, let's fix that. I'm not really familiar with the S14 ECUs and their different tables. However, I do know that in order to fix the issue with your load going off of the map, you need to lower your K-value (KCONST TP Multiplier). I'd try to lower it by ~25% to start. I believe that you also need to increase your "Injection Adjust" table to get idle AFRs back in check.

Questions:
1. What are your plans for the car? How much boost do you plan to run?
2. I notice the latency is set at 720ms. Do you know if that is correct for those injectors?
3. Also, why are you not logging AFR in Nistune?
4. I don't see any info on your current setup. So, give some details on everything.
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apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

1. I am planning for this to be a street car, with possible occasional track use. I want to run 8psi for now, and then once everything seems reliable enough, I will shoot for more boost.
2. I left the latency stock. I read that I should use k const for cruise afr, and make small adjustments to latency for the idle afr. The idle and cruise afrs seem ok, so I just left it. How do I know what to set the injection multiplier for my new injectors?
3. Not logging afr in nistune due to not having the wideband wired up to an analog adapter. I have an aem uego, so I am pretty sure I can get it to work with just an analog connector.
4. My setup is a stock s14 ka, automatic OBD II ecu, deatschwerks 370cc injectors, deatschwerks dw200 fuel pump, z32 maf, newly rebuilt isr rs3871 turbo, isr intercooler, no bov, isr bottom mount turbo manifold.

I am a little confused as to how the k const can effect load scales. I thought the k const was just a total multiplier for the injection. Is this wrong?
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Re: Ka24de Load Scale Calculation

Post by adamky »

I just went through this on my car. I upgraded to the Feature Pack and couldn't use any of my old tunes. I had to start with a stock, "feature pack" base tune. The Total Injection Multiplier was a new concept to me at this point. During some emails with Matt, he explained how adjusting my K-value would shift how far you go across your map.

I can't find the email right now, but here's his reply on the Nistune forums: http://forum.nistune.com/viewtopic.php? ... 56&p=24977
Basically, you adjust K to adjust how far across the map it takes you, and the Total Injection Multiplier is what you use to get cruise AFRs back in check.

Like I said, I am not familiar with the S14 maps but it looks like "Injection Adjust" does the same thing as the Total Injection Multiplier does on the S13 FP tunes. But I could be completely wrong about that part. The description of the functions sounded similar, so I made a guess.

And yes, you are correct that latency is the thing that affects idle the most. I'm just not sure what latency should be for SR injectors and that's the type of thing you would want to know for a starting reference point. It makes sense that it might be the same as KA, but I would double check. My Nismo 740cc injectors required higher latency than stockers.
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adamky
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Re: Ka24de Load Scale Calculation

Post by adamky »

Found his email reply. Keep in mind this is all referring to my S13 ECU with the Feature Pack, so the table names aren't exactly the same as yours will be.
Adjust your strategy here…



1. Take base tune and adjust factory MAF and injectors to what you have

2. Warm up vehicle and hold light cruise (whilst driving, someone else to make adjustments) until fuel trim is close to 0%, and AFRs should be 14.7:1 with such trims

3. To make adjustment to trims with factory maps in cruise, adjust TIM

4. Next boost the vehicle and monitor highest TP index reading (eg 150). Look at max scale of fuel/timing TP which is 104 for S13 KA24DE

5. If the TP goes too high then lower K constant (TP multiplier) or too low then increase K constant until you get full use of the map

6. For example if it reads TP index = 150 / 104 = then K constant needs 44% increase

7. Once you adjust K this will affect fueling, so lower TIM by similar amount to get mixtures back to 0% trim (14.7:1 AFR)

8. After this then adjust latency and TP min for idle improvement




When adjusting timing, using a dyno look for no increase in power and then you know you have reached the threshold where next you will hit knock. Listening for knock only is not the ideal way to tune, but better than not listening!
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adamky
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Re: Ka24de Load Scale Calculation

Post by adamky »

I'll upload my current tune and a fairly recent log tomorrow and post it here, along with some screenshots. You can see how I have my load scales setup and I can explain which column correlates with how much vacuum or boost.

In the meantime, here's an example of that last part that 8-bit posted a long time ago: viewtopic.php?p=459706#p459706

Here's another post of his where be clarified how he sets up his load scaling: viewtopic.php?p=320186#p320186
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modulation
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Re: Ka24de Load Scale Calculation

Post by modulation »

" and have been having trouble finding which boost levels reach which load indexes"

I wrote some simple computer programs that help group boost and load together.
Then another one that lets me change my load scale numbers, and see where boost would then go.
It has really helped because I can clearly define different load scale numbers for different boost levels. Have low boost in certain column, mid in others, and high all on their own. Then I can adjust timing for each level. I've used these when I've changed turbos and had to increase my max load index, as well as when I just upgraded to larger injectors/maf.

If you want to send me a csv I can see how hard it would be to adapt my programs for other file formats besides nistune.

Edit: saw your log posted above, I guess I forgot not everyone logs boost or has a way to.

This shows boost level and the load index it fell under.
Screen Shot 2017-03-12 at 8.05.44 PM.png
Top array is user defined, and represents load index scale.
Other numbers show what boost levels would fall under what index. I change the top array around until I get as close to as different columns for boost levels as I can.
Screen Shot 2017-03-12 at 8.05.59 PM.png
apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

I tried lowering my k const by 25%, but it caused the car to run lean. Setting the latency to 580 (the correct value for sr injectors) made it even leaner. The car stalled out and died. Why would the k const work fine for cruise and idle, but be too high for boost? If I set my k const for cruise and idle, it is around 450, which I think is way too high. Having such a high k const causes the load scalers to be way too high as well (167 max load for only 8 psi on a .64ar turbo). Why is it doing this? How do I get the k const to be consistent with cruise and boost? I do not have the feature pack.
apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

Bump. I really want to learn this.
apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

_______________bump
adamky
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Re: Ka24de Load Scale Calculation

Post by adamky »

Post this on the Nistune forums. If you don't get a reply in a few days, e-mail Matt at: info@nistune.com. Matt is a super nice and helpful guy and usually responds within a day or two to forum posts and e-mails.
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apex128
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Re: Ka24de Load Scale Calculation

Post by apex128 »

Thanks man I'll try it out.
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