Alpha-N and closed-loop

CivicVTi · Post by **CivicVTi** » Tue Feb 06, 2007 5:06 am

I have a question about max closed loop threshold when using Alpha-N. Say I set it at 70KPa, does the ECU disable closed loop when the calculated TPS exceeds the corresponding MAP value?

Post by **Hondata** » Tue Feb 06, 2007 10:01 am

When using TPS based lookup the closed loop threshold is the calulated MAP from TPS, not the actual MAP.

CivicVTi · Post by **CivicVTi** » Tue Feb 06, 2007 3:47 pm

Yes, this is what I was talking about. Thanks Hondata.

So, considering the large airflow for relatively low throttle openings when using ITBs, I guess a good value for max closed loop threshold is around 20% throttle. What do you suggest?

Post by **Hondata** » Tue Feb 06, 2007 6:22 pm

Probably between 10 % and 20%. It will increase with rpm. Datalog and check TPS at cruise rpm and throttle. Make sure you tune the fuel tables to a reasonable AF ratio so that if it does switch into open loop you're not going to get a drastic change in AF ratio.

CivicVTi · Post by **CivicVTi** » Wed Feb 07, 2007 5:01 pm

OK, thanks once again.

EGHATCH · Post by **EGHATCH** » Sat Feb 24, 2007 8:49 pm

Hi,

what ITBs are you using? i'm having a hard time tuning itbs. whenever i set MAP to alpha-n, the columns (TPS %) shows -9, -8, -7, up to 0%, when i believe it should be 0% to 100%.

CivicVTi · Post by **CivicVTi** » Sun Feb 25, 2007 4:58 am

Right click on the load values and edit them. You can use whatever values you want. From my experience you need high resolution for low throttle openings (0%, 2%, 5%, 8%, 10%) and low resolution for high throttle openings (50%, 70%, 100%).

TUning ITBs is a little tricky. I suggest a dynapack and careful tuning. Be careful not to overadvance the timing as the timing map has a completely different pattern than the MAP based one. Keep in mind that especially at low revs, you have almost full power with throttle as low as 10% and so you need to decrease timing a lot, almost to the full load value.

It tool me 3 hours to tune a Toda ITBs equipped K20a2. The outcome is very good and driveability is almost like stock.

EGHATCH · Post by **EGHATCH** » Sun Feb 25, 2007 7:56 am

i see what you mean. i have to manually edit all the column values? it will take me forever. lol

CivicVTi · Post by **CivicVTi** » Sun Feb 25, 2007 3:00 pm

Sorry, I meant load indeces. For example, right click on '-9%' and change the value to whatever you like (say 1%).

EGHATCH · Post by **EGHATCH** » Tue Feb 27, 2007 1:45 am

yeah i got what you mean,
but you can't edit the column value higher than the next column, you get an error message that says you cant go above the value of the next column. :(

it's weird, because some base programs, whenever i enable alpha n, the column values look fine, say, 5% - 105%

but most of the basemaps, when enabling alpha n, you get weird column values, like -9%, -9% to 5%. whats up with that

CivicVTi · Post by **CivicVTi** » Tue Feb 27, 2007 9:25 am

So start with the high load columns and edit them to an even higher value so you can go back to the low load ones and use the values you want.

hyro · Post by **hyro** » Wed Feb 28, 2007 3:08 pm

i already discovered this! awesome !!

i run with itbs, and mapping with map pressure was very hard.

hyro · Post by **hyro** » Wed Feb 28, 2007 3:34 pm

Hondata wrote:When using TPS based lookup the closed loop threshold is the calulated MAP from TPS, not the actual MAP.

so, the value you have to put in is tps % ?

hyro · Post by **hyro** » Wed Feb 28, 2007 3:46 pm

can i use the boost tables to have more resolution?

CivicVTi · Post by **CivicVTi** » Thu Mar 01, 2007 5:01 am

I think you can. Haven't tried that though. But I think the extra resolution will just increase tuning hassle and time.