Boosted timing tables for 2/3bar OS

[Texas_WS6]

Someone might have requested this already, but I am going to request it again. Can you make a new timing table for boosted timing like you did for boosted PE? If while using the 2/3 bar SD OS, the high octane timing table is not used due to the removal of the MAF sensor, can we replace that unused table for this? You could do like the boosted PE does with having programmable parameters that if met, the boosted timing table would be used. Then one could build a timing map for both boosted and none boosted. I would like this because I could run aggressive timing while no boost is present and conservative timing when it is. It would take out the chance of having too much timing as it goes under boost. This should help make the vehicle more responsive.

[Texas_WS6]

Does any one else have an opinion on this? Am I missing a sympler way to do this?

[ns158sl]

Yes that would be extremely helpful if it were available. If you do a few searches on it, I think someone said that there isn't enough room on most PCMs. I do think there was one PCM it might fit on but i can't remember now. Frost and a few others have figured out ways around this by using different tables, but you'll have to search for it.

Eric

[WS6FirebirdTA00]

The high octane table is active in the 1/2/3 bar OS. That is one of the benefits is that you can use high and low octane, IIRC.

[Bill@HPTuners]

Sorry we just don't have the resources to change the LS1 custom os's any further.

[Texas_WS6]

The high octane table is active in the 1/2/3 bar OS. That is one of the benefits is that you can use high and low octane, IIRC.

Oh I thought because the MAF was removed it reverted to the Low Octane Table. I am glad to learn the High octane table is usefull.

So what is the best method to go about getting the most out of the tune before the boost comes on? Right now I am just guessing the point at which boost comes into play. I am just cutting timing above 60 g/cyl and right before my stall converter speed. Is there a better way to do this?

[Frost]

There are other ways to get what you want... here's a hint; AFR Spark Correction Base

[LosLS2]

There are other ways to get what you want... here's a hint; AFR Spark Correction Base

Thanks. I never noticed that.

[Texas_WS6]

There are other ways to get what you want... here's a hint; AFR Spark Correction Base

Thanks, I will try and use this, but I bet you will get a PM from me with questions.

[DRTWRK]

There are other ways to get what you want... here's a hint; AFR Spark Correction Base

Are you talking about having some adjustability between the Main Spark Advance timing tables limit in g/cyl and whatever g/cyl the engine produces?
If so, would the Spark Correction ADD be applicable with a turbo where boost is not related to RPM? Or where at any given RPM there won't be a specific AFR requirement?

[Frost]

Are you talking about having some adjustability between the Main Spark Advance timing tables limit in g/cyl and whatever g/cyl the engine produces?
If so, would the Spark Correction ADD be applicable with a turbo where boost is not related to RPM? Or where at any given RPM there won't be a specific AFR requirement?

I'm not really following you... but I can show what I am talking about.

My example pertains to GenIII firstly. Here is a screen shot of a recent 2bar centri-charged car. In this example, in PE (no boost) commanded AFR is about 12.8 and 6.5deg are added back to the "spark soup" which cumulatively makes up total timing whenever commanded fueling = 1.15 EQ. When in boost up to 110kPa we are commanding 1.20 EQ (about 12.2 AFR) and getting 5 deg of spark added back in. Commanding 1.25 adds 3 deg. If you look at the last transitional cell in the BE table you see 1.273 EQ. Looking at the AFR adder, it falls between a column with a value and a column with 0. In this case, it will use interpolation and the proper middle (well, interpolated) spark value will still be added.

A very important side note; for several reasons, whenever using the 2/3 bar OS's, you MUST tune the TPS/PE table to get make sure that the car ALWAYS enters PE just before boost. In applications such as turbos that can make light boost at light throttle in higher gears, if you get boost BEFORE PE values are satisfied, though you may command a richer value in BE, the STFTs will remain active and fight the AFR back to stoich. You also want to get this done to be able to use the lighter fueling and more spark at the appropriate times leading into boost to keep things nice and crisp. Using TPS alone for PE triggering will put you in PE in places that you don't need it such as 20% throttle at 1400 RPMs. Pulling off in first or second can use that much throttle but not need PE, though in the higher gears 20% at 1400 may make 1-2 psi. The best bet is to make your TPS enable for PE happen early and low, like around 20% in the problem spots and set the MAP enable up to about 85 kPa. This way, you get PE when you need it according to MAP and stay in closed loop otherwise. It will get PE in before BE as well, so trimming will stop.

[Texas_WS6]

Now this is good info. I can see how this works and how it will help. Thanks Frost!

We might want to make this a sticky.

[Bugermass]

So are the High/Low octane tables used in SD or not? If they are, is the g/cyl calced somehow from the VE table?

[4.8t]

wow, i learned something today. so i can increase my high load no boost pe area timming without worrying about running to much timing for the boost area's. you know i have a "kick" area when coming slow out of boost while going up hill (turbo loaded) that this may fix. thanks frost!

[WS6FirebirdTA00]

So are the High/Low octane tables used in SD or not? If they are, is the g/cyl calced somehow from the VE table?

Yes they are used and yes that is how it is calculated. If you have a custom x bar OS then the hi and low work as intended. If not, then it reverts to the low octane.

[LSxpwrdZ]

I use the AFR Spark Advance Table to actually pull timing as the fuel mixture gets richer. I don't have my laptop in front of me at the moment to show screne shots but basically the more boost you run the slightly richer you want the fuel mixture so I set my Main Spark tables up normally and as the car reaches boost it will command richer fuel mixtures that will also look up on this AFR Spark Advance Table to pull timing the richer the fuel mixture goes or the more boost the car see's. If that makes any sense to you all.

Like stated earlier the car must be in PE for all this to work so I set the TPS engagement really low and then set the MAP engagement to around 75-80kpa that way partial throttle even above the enable TPS will still be stoich but as soon as it starts seeing 75-80kpa or more it will enter PE!

[Nitroused383]

Subscribed Good info here

[carlrx7]

very impressive

[Monty]

So you can actually use this AFR Spark Advance Correction -Add to remove timing ?