Total timing and scan tools

[Force Fed Mopar]

What's normal to see on a scan-tool at around 15-16 psi at WOT? I'm seeing 14 on a Snap-On scanner. Shows 12 at idle and 33ish cruising at 45 in 5th. Do you add the initial timing to this number? I have my initial set to 12, if you add it that makes 24 degrees total timing at idle and 26 at 15psi@WOT, and 45ish while cruising.

[ShelGame]

The 12 degrees 'base timing' is not really timing added to the total. It's just a reference point - you can't time an angine at 0 deg advance, for example. It won't run. So, when you pull the CTS, the computer sets the timing to 12 deg and you adjust the distributor until the 12 deg mark lines up. This is how the computer knows the HEP is lined up with the engine crank angle.

Now, if you set base timing at 14 deg as opposed to 12, then you will need to add 2 to whatever the scantool shows as the computer will not be able to detect that change.

[turbovanman²]

The 12 degrees 'base timing' is not really timing added to the total. It's just a reference point - you can't time an angine at 0 deg advance, for example. It won't run. So, when you pull the CTS, the computer sets the timing to 12 deg and you adjust the distributor until the 12 deg mark lines up. This is how the computer knows the HEP is lined up with the engine crank angle.

Now, if you set base timing at 14 deg as opposed to 12, then you will need to add 2 to whatever the scantool shows as the computer will not be able to detect that change.

Ahhhhhhhh, I didn't know that, thanks. I always thought it was added.

[Force Fed Mopar]

The 12 degrees 'base timing' is not really timing added to the total. It's just a reference point - you can't time an angine at 0 deg advance, for example. It won't run. So, when you pull the CTS, the computer sets the timing to 12 deg and you adjust the distributor until the 12 deg mark lines up. This is how the computer knows the HEP is lined up with the engine crank angle.

Now, if you set base timing at 14 deg as opposed to 12, then you will need to add 2 to whatever the scantool shows as the computer will not be able to detect that change.

Gotcha, that's sorta what I was thinking. Me and Kevin were arguing about it the other day while discussing my cal

So do the numbers I posted look right, or a little high or low?

[turbovanman²]

They look right but each combo is different, so if your not pinging, then add more,

[ShelGame]

14 sounds about right. It really depends on the cal...

[Force Fed Mopar]

They look right but each combo is different, so if your not pinging, then add more,

Well it's pulling harder at part-throttle than at WOT, I was thinking I needed more timing at WOT but when I compare the tables in MP Tuner the part-throttle table actually has less timing. So, we are thinking that maybe it's too much timing and the knock sensor is picking up knock and pulling timing. I think I'm gonna match the WOT table to the part-throttle table and see what it does.

14 sounds about right. It really depends on the cal...

It's a modded T-nator v10 cal I believe, set for 40's and a 3-bar map on a stock-headed 2.2 T2 pushing 20psi. Kevin has done all the work on it so far.

[DodgeZ]

Well it's pulling harder at part-throttle than at WOT, I was thinking I needed more timing at WOT but when I compare the tables in MP Tuner the part-throttle table actually has less timing. So, we are thinking that maybe it's too much timing and the knock sensor is picking up knock and pulling timing. I think I'm gonna match the WOT table to the part-throttle table and see what it does.

I'd guess you are just leaner at part throttle. Of course that was before you added 5psi more boost. Get a wideband on it. I moved the timing around a little and it didn't help. Of course the tuning was when your turbo was dieing and you had boost leaks. The timing should be close to the CSX Stage 2 which is close to your setup. You need to figure out what makes your power loss light come and go also.

It's a modded T-nator v10 cal I believe, set for 40's and a 3-bar map on a stock-headed 2.2 T2 pushing 20psi. Kevin has done all the work on it so far.

Shelgame, after a rescale it seems that I have take a bunch of fuel out of the PE table. Makes me wonder if I am doing something wrong or if there is a problem script. Can you take a look at the cal?

[turbovanman²]

Well it's pulling harder at part-throttle than at WOT, I was thinking I needed more timing at WOT but when I compare the tables in MP Tuner the part-throttle table actually has less timing. So, we are thinking that maybe it's too much timing and the knock sensor is picking up knock and pulling timing. I think I'm gonna match the WOT table to the part-throttle table and see what it does.

As Kevin suggested, its probably leaner at P/T, this is also typical of stock cals, its richer on top so it doesn't pull as hard as the leaner P/T.

[Force Fed Mopar]

I'd guess you are just leaner at part throttle. Of course that was before you added 5psi more boost. Get a wideband on it. I moved the timing around a little and it didn't help. Of course the tuning was when your turbo was dieing and you had boost leaks. The timing should be close to the CSX Stage 2 which is close to your setup. You need to figure out what makes your power loss light come and go also.

You were looking at the gauge Maybe it's just never knocked? lol but, does anyone know how to test a knock sensor? Is there a knock gauge that works on our sensors?

As Kevin suggested, its probably leaner at P/T, this is also typical of stock cals, its richer on top so it doesn't pull as hard as the leaner P/T.

Well what good is that

[ShelGame]

Shelgame, after a rescale it seems that I have take a bunch of fuel out of the PE table. Makes me wonder if I am doing something wrong or if there is a problem script. Can you take a look at the cal?

Everything looks like it's scaled correctly to me. How old are the +40's? Some of the newer ones seem to flow quite a bit more than the original +40's. I sometimes scale for 58pph injectors. I suspect that they are actually 550cc/min injectors, but rated at 43psi. Which would make them flow about 58pph at our 55psi base fuel pressure.

[Force Fed Mopar]

I bought them used a while ago, maybe 5-6 years ago?

[ShelGame]

The only way to know for sure is to get them flowed.

[DodgeZ]

Everything looks like it's scaled correctly to me. How old are the +40's? Some of the newer ones seem to flow quite a bit more than the original +40's. I sometimes scale for 58pph injectors. I suspect that they are actually 550cc/min injectors, but rated at 43psi. Which would make them flow about 58pph at our 55psi base fuel pressure.

I recall talking about that before and forgot. I'll build another cal scaling to 58 and using the AFR tool.

thanks

[Force Fed Mopar]

I think some of my issue is that the car doesn't ever warm up w/ a 180 t-stat.

[DodgeZ]

I think some of my issue is that the car doesn't ever warm up w/ a 180 t-stat.

I thought you said it read more then 180 on the scan tool?

[Force Fed Mopar]

Did I? lol I can't remember. I changed the t-stat to a 192 unit and it seemed to help, I got it to spin a little in 2nd last night at WOT. Could just be the conditions though (cooler weather, night, going uphill).

[MopàrBCN]

SOrry for hijacking this: but to come back on the base timing:

To my understanding - and correct me if I am wrong:

That 12º in the cal I understand to be an offset in the cal and has to match with whatever the engine is set to be the base timing physically.
Would this mismatch, then whatever advance the smec commands would mismatch accordingly, correct?

[Force Fed Mopar]

SOrry for hijacking this: but to come back on the base timing:

To my understanding - and correct me if I am wrong:

That 12º in the cal I understand to be an offset in the cal and has to match with whatever the engine is set to be the base timing physically.
Would this mismatch, then whatever advance the smec commands would mismatch accordingly, correct?

If I understand you right, then yes, it will mismatch by however much the base timing is off. Like, if you set the base timing at 14* and the cal is set for 12* base, then the advance the computer gives out will be 2* more than what it thinks it is. I think it basically moves the whole timing curve up or down.

[MopàrBCN]

Ok, that is my interpretation!