COBB AP/ATR Beta Fuel Scaling

[silvapain]

Originally Posted by phate Look at the correlation between boost (vacuum) and the STFT's. You have very high STFT's as vacuum increases. That looks like a very small vacuum leak, to me. This is obvious, but: To check, just flash back to your other map and see if it does the same thing. If STFT's go crazy, it's a vac leak. If all is peachy, then it's the scalar.

I'm getting a steady 21 inHg vacuum at idle and my idle trims are stable, so I don't think it's a leak. I can do a vacuum and boost test anyways to verify.

I'll flash back to my MAF-scaled E85 tune tonight and see.

[Enki]

Originally Posted by phate Look at the correlation between boost (vacuum) and the STFT's. You have very high STFT's as vacuum increases. That looks like a very small vacuum leak, to me. This is obvious, but: To check, just flash back to your other map and see if it does the same thing. If STFT's go crazy, it's a vac leak. If all is peachy, then it's the scalar.

This is the exact same thing I was seeing. I pulled my inlet, patched any rough/scraped/scratched areas with RTV, lubed up the connections to ensure a positive fit, then retightened the easily accessible bolts on my intake mani and so far that seems to have fixed my high vacuum trim climb.

[Dano]

I have nothing to contribute at this time except a round of

at a boys! great work from all.

[Enki]

To clarify my above statement:
My trims would only climb ABOVE 12 inches of vacuum. Idle and WOT was pretty much dead on.

[dougefresh_]

So if you're boost based, what is the difference between using these scalars I haven't seen (on Cobb's site somewhere?) for E85, and just re-calibrating your maf? I run a D010 w/m w/ 50/50 and just calibrating the maf for it.

Sorry for the noob q, I just came across this stuff tonight, and learning the E85 ropes for the big switch (well, small switch... 2 gals).

[Enki]

Uh, changing one cell vs 100?

[dougefresh_]

Originally Posted by Enki Uh, changing one cell vs 100?

If that's all it does, I can see it being very useful if you want to try multiple mixtures of E85 if there are set scalars for different % mixtures. I thought there was more to it than that, but it's late and I'm tired.

I saw a few people mention FTs... so these scalars just for your fuel trims and not wot afrs? I'm still playing w/ my meth, and boost, and will likely run a couple gallons of E85 in the near future to gain some timing. I don't mind recaling my maf twice, lol. I still think I'm missing something here :/

[rfinkle2]

Originally Posted by dougefresh_ If that's all it does, I can see it being very useful if you want to try multiple mixtures of E85 if there are set scalars for different % mixtures. I thought there was more to it than that, but it's late and I'm tired. I saw a few people mention FTs... so these scalars just for your fuel trims and not wot afrs? I'm still playing w/ my meth, and boost, and will likely run a couple gallons of E85 in the near future to gain some timing. I don't mind recaling my maf twice, lol. I still think I'm missing something here :/

I think the goal of the project is to enable people with a decent 93 octane maf cal to easily convert a map to a particular e85 mixture through the scaling done "back office".

I think David may have mentioned (in one of the threads) that if necessary, tweaks can still be made to your maf cal, but the idea is to get you pretty close to running the afr's you were on pump both open and closed loop.

Good to see you around Douge.

[atvfreek]

Originally Posted by dougefresh_ If that's all it does, I can see it being very useful if you want to try multiple mixtures of E85 if there are set scalars for different % mixtures. I thought there was more to it than that, but it's late and I'm tired. I saw a few people mention FTs... so these scalars just for your fuel trims and not wot afrs? I'm still playing w/ my meth, and boost, and will likely run a couple gallons of E85 in the near future to gain some timing. I don't mind recaling my maf twice, lol. I still think I'm missing something here :/

Right now to run 3+ gallons of e85 we have to scale the the shit out of the maf sensor, which causes an overly inflated maf reading. Doing this causes all of the load tables to also read very high, and you literally have to adjust a shit load of tables to keep things happy. They are trying to get it so we can basically change one fuel table and be pretty much ready to go. To get an idea 4gallons of e needs about 10% more fuel.

From what I've played with though is 2 gallons needs very little adjustment, so if that's all you want to run. Toss it in at your next fill up and start playing. Lol.

Tappin

[Dano]

roger that...if your petrol maf cal is good there is no need to change it with 2-2.5 gallons of E. There should be no AF shift with that little concentration. I had to hit 4 gallons before I saw any shift and I went from 2.5 to 4 so somewhere in between there is when the shift occurred.

also between the two I had to add a shit ton of timing to make up for the slower burn

[superskaterxes]

i had to adjust my trims after my first 2 gallons. MS6 tank is bigger too.

[rfinkle2]

My wot afr's were good through 3 gallons, but @ 3 gallons, my trims were pretty bad.

Can't explain it, but it happened.

[rfinkle2]

Ahhh shit. I may have made a table change and resaved the map without the "keep non-table data" option checked. Can anyone confirm this error would effectively take the e85 tweaks out the guys are working on for us?

[Cobb Tuning]

Originally Posted by rfinkle2 Ahhh shit. I may have made a table change and resaved the map without the "keep non-table data" option checked. Can anyone confirm this error would effectively take the e85 tweaks out the guys are working on for us?

Making ANY changes in ATR to that map is pretty risky, as you would need to have that box checked or it wipes my change to your maps out.

-David@COBB

[rfinkle2]

Originally Posted by David@COBB Making ANY changes in ATR to that map is pretty risky, as you would need to have that box checked or it wipes my change to your maps out. -David@COBB

Understood. (one of the reasons I wanted to be sure before flashing)

I tried to e-mail you yesterday so I could run the map, but you must be swamped with work.

Changes made remain in the map per our e-mail.

[dougefresh_]

Thanks fellas, that helps a lot. I didn't realize that after a certain %a big change can occur. I only ran 2 gals of E85 once (to rule out false kr... it wasn't false, lol), and it didn't affect my trims much, maybe 4-5%. I'm leaning towards 3 gallons now, so it sounds like this will def be helpful.

[GLORIFIEDBOZO]

whoa, how did I miss this thread. will have to catch up tonight

[Todd98SE]

I just went from 2 gallons to 3ish gallons per tank and my trims skyrocketed to anywhere between +4 to+9. I was slightly worried but everyone's comments seem to confirm the same thing.

Did I mention how much I love E85, it makes Cali 91 octane cars actually fun to drive without constantly worrying about BAT's and KR all day.

[Dano]

that does seem to be the tipping point for LTFT to shift but OL can go higher before AF shift is seen. @cld12pk2go first ran into this back in the spring with ramping up his E85 concentration. He saw LTFT shift way before he saw AF shift at WOT. I too experienced the same an in fact I am not scaled yet on E35. IIRC, my LTFT is +10ish but I am not too worried about CL trims ATM. My WOT AF is about .1 leaner so I have seen no reason to rescale my entire map for that. I am glad cobb is on this scalar before I make my jump to 5050 so I won't need to scale all my load related tables in the spring when I make the switch.



Perhaps @David@COBB would care to speculate on the lack of AF shift at WOT?

[silvapain]

On my third day using my original MAF-scaled E85 tune and no DTCs.

I did notice the same +25 STFTs at extremely low throttle though. Perhaps it was always that way; never really payed close attention to STFTs before.

I'll go back to the COBB beta scaled map, do a MAF cal, and see of that helps.

EDIT: I think instead I'll take my E85 adjusted MAF scale, reduce all values by 40%, and then put it into my COBB beta map. My trims should theoretically be identical to what they are now.

Tapadatass

[Enki]

Don't forget the checkbox, Silva.

[silvapain]

Originally Posted by Enki Don't forget the checkbox, Silva.

LOL. Thanks.


Tapadatass

[rfinkle2]

Originally Posted by Enki Don't forget the checkbox, Silva.

I felt like a , although it wasn't the first time, and definitely won't be the last.

I felt almost as silly as when cld12pk2go caught a decimalization error when I posted one of my comp tables.

[silvapain]

Took my E85-adjusted MAF scale and divided it by 1.40 (%40) and put it into my COBB beta map. flashed my car with the beta map, and took it to Best Buy in town for an errand. DTC 2096 popped up shortly before I got back home; so it took just two key cycles and ~30 miles to get the DTC.

I'm going to go through my beta map thoroughly to make sure I didn't miss anything.

[rfinkle2]

I was able to put about 50-60 miles on a test map Cobb provided, as well as get some good logs for David.

I just e-mailed him everything 10 minutes ago.

[Cobb Tuning]

For those of you I have made maps for, please Email me back your notes/observations/logs.

Thanks,

-David@COBB

[djuosnteisn]

I'm on the 2nd of 5 scaled maps. I'll be flashing the 3rd at lunch, and should have the last 2 done tomorrow. Then i'll compile all the results.

So far, your scaling percentages are looking great David.

[silvapain]

An interesting thing I've noticed:

My current MAF-scaled E85 tune has all LTFTs either at 0 or slightly negative (~ -2% to -4%). When I took that MAF scale and divided by 1.4 and placed it into the COBB beta map, all my LTFTs were positive (~ +5% to +12%). My LTFT breakpoints have been setup to be equivalent (i.e. I multiplied my pump gas breakpoints by 1.4 to get my E85 breakpoints).

I've been working a shit-ton this week and haven't been able to play more with the tunes; I'll try tonight.


Tapadatass

[rfinkle2]

Originally Posted by David@COBB For those of you I have made maps for, please Email me back your notes/observations/logs. Thanks, -David@COBB

Do you need me to re-send my logs David?

[Enki]

Originally Posted by David@COBB For those of you I have made maps for, please Email me back your notes/observations/logs. Thanks, -David@COBB

Due to weather, I have not been able to install my brakes for testing, and haven't bothered to flash the map (as I've not driven the car in more than two weeks). Hopefully I'll be able to provide some relevant data in the next couple of days.

[Cobb Tuning]

Originally Posted by rfinkle2 Do you need me to re-send my logs David?

Nope. Your logs looked fine.

One of my calibrators would like if you could go back to full 93 octane and dial in the MAF again - and then we'll re-run the test with another patched map. It's hard to make good graphs/plots without a good base(93) to compare to.

-David@COBB

[rfinkle2]

Originally Posted by David@COBB Nope. Your logs looked fine. One of my calibrators would like if you could go back to full 93 octane and dial in the MAF again - and then we'll re-run the test with another patched map. It's hard to make good graphs/plots without a good base(93) to compare to. -David@COBB

Ohhh. I hope I followed the directions correctly.

I would be happy to do that if that is what is asked.

It will likely take me about a week to burn through this tank of e85 mix, but will get on this right away.

[superskaterxes]

david,

i havent done any testing for you guys but certainly would like to. im about a 30% blend and my tank is almost empty.

right now my curve is pretty dead on but i can go back to 93 since im empty and double check and then u can send me a rev. let me know.

[Enki]

Brakes getting done tomorrow morning, will have relevant data the next afternoon (at the latest).

[Dano]

Originally Posted by rfinkle2 Ohhh. I hope I followed the directions correctly. I would be happy to do that if that is what is asked. It will likely take me about a week to burn through this tank of e85 mix, but will get on this right away.

a week or 10 WOT runs...lol

[cld12pk2go]

Originally Posted by Enki Since the MAF is no longer scaled, his calculated load values should be much more reasonable than they ever were when the map was manually adjusted for the fuel. Logs? I don't think we have any injector adjustment stuff in these maps. Correct me if I'm wrong, but I'm pretty sure we are just talking about scaling fuel requirements via scalar instead of MAF (for use eth guys). Anyone?

Originally Posted by silvapain Correct. This beta map from COBB let's those of use running Ethanol blends make one scalar value change and not have to use the MAF scale to 'trick' the ECU into running the correct amount of fuel to hit our AFR targets. This won't gain use any more injector headroom.

Originally Posted by phate Whatever it is, as long as it works and we don't have crazy load values anymore, I'm down

Originally Posted by silvapain A very basic primer on how the ECU determines injector pulse width: 1. The ECU gets a voltage signal from the MAF, and using the MAF scale, turns that into mass airflow (g/s) 2. The ECU determines RPM and calculates load 3. Based on RPM and load, the ECU determines spark advance, VVT, and AFR target 4. Using mass airflow and AFR target, the ECU calculates fuel requirement in mass rate (g/s, lb/hr, whatever) 5. Using a scalar that represents injector size (lb/hr; on DI this would also incorporate fuel rail pressure), the ECU determines required injector pulse width (in milliseconds) It's the scalar in item 5 that COBB is adjusting I believe. It's a static percentage.

Originally Posted by Lex 3. People hitting load caps because of MAF scaling have this issue resolved. **Here's something interesting ** Just like you can scale up for E85 you can also scale DOWN. If we have an unkown load cap/table at say ... 2.0 load - scaled your MAF DOWN so that you are at stockish loads and use this multiplier to get the correct AFR. This is called tricking the trick And it's a hack in the opposite direction to deal with an uncovered table or cap.

I guess I am late to the show here, but this scaler is going to be pure WIN!

I am really curious if it will push up the power level that we hit Load Cap V2™, as the calculated load will be dropping by a large percentage if we don't have to fudge the MAF curves.

How do I get in on the Beta SW?

Hell yeah.

[rfinkle2]

@cld12pk2go, PM David and Evan.

David is a bit more active on msf.

[Dano]

I wonder if this new scalar is the same or similar to what the scoobies have to set their injector size in CC? Cobb is just telling the ECU we have smaller injectors than OE so IPW is increased to meet the fueling demand.

[silvapain]

Originally Posted by Dano I wonder if this new scalar is the same or similar to what the scoobies have to set their injector size in CC? Cobb is just telling the ECU we have smaller injectors than OE so IPW is increased to meet the fueling demand.

That's exactly what this does in effect. I don't know I the number specifically represents the injector size, or if it's just a percentage adjustment though.

Too bad it just doesn't work on my car. On the COBB beta map my car hunts around for idle upon pressing the clutch, the AFRs are all over the map, I get a P2096 DTC, and the car feels slow as crap.


Tapadatass

[Dano]

roger that...what it is "called" is up to cobb...lol in Romraider its called injector size or something like that...not sure if that's the only scalar they use but I did see it.

sorry to hear the cobb scalar isn't working on your car....are you sure you aren't running boost_creep's ECU? lol