Mapping question.

Discussions concerning the M7790 cpu

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robertsr20
 

Posts: 21
Joined: Tue Oct 06, 2009 10:01 am
Location: Guanajuato México.

Mapping question.

Post by robertsr20 »

Hi everybody have one question, today start to tune my new proyect.
Is a B13 SR20DE+T CR 9:5 to 1, T28 turbo, 444cc S15 Injectors, Z32 maf and walbro fuel pump.
my question is why have these jumps in the tp scales? is normal?
Image

Jump 74 to 84 and tp 88 to 96 at 4000 rpms.

Thanks.
TM_S13
 

Posts: 246
Joined: Mon Dec 29, 2008 11:29 pm

Re: Mapping question.

Post by TM_S13 »

I'd say that's mainly because the scale ain't 100% adjusted...
to confirm that you can try and "hunt" the TP values on the *.csv file, in excell, and adjust the TP load scale and re-read the log with those changes....

it happen because TP load values when rising are raising for example, in the case you mentioned, 74 -> 84 and 88->96, because TP load is something like 75 then jumps all the way through to 86~87, and it goes from 87~89 jumping to 94~95.

hence why in the map table the trail goes like that.

I might be mistaken so anyone please fell free to correct me
robertsr20
 

Posts: 21
Joined: Tue Oct 06, 2009 10:01 am
Location: Guanajuato México.

Re: Mapping question.

Post by robertsr20 »

Hi TM_S13,

I'll try these today thank you.
PL
 

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Joined: Fri Feb 03, 2006 3:29 pm
Location: Adelaide, South Oz
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Re: Mapping question.

Post by PL »

You can adjust the load scales to whatever you want. When going DE to DE+T you'll probably need to change them quite a bit. A linear scale is always a good starting point.

These days I've been adjusting load scales to give better resolution in the high load area. So the curve is steeper in the first half "vacuum area" and then flatter in the "on boost" area. This gives me better resolution for different boost levels, so I can adjust timing values more accurately for different boost levels.

Timing for a boosted 9.5:1 engine will be critical unless you're running an ethanol blend fuel.

PL
steve_s13
 

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Re: Mapping question.

Post by steve_s13 »

on DE + T i find Im doing the exact same thing Pete... You really need to adjust the scales to fine tune, Ive even been adjusting the RPM scale also
PL
 

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Joined: Fri Feb 03, 2006 3:29 pm
Location: Adelaide, South Oz
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Re: Mapping question.

Post by PL »

Yeah, DE+T engines seem to be soooo critical with IGN timing. A bit too much and they'll knock like crazy, a bit too little and the power just dies.

PL
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