Cobalt SS S/C Tuning Issues

[SJSchafer]

Here is the config file. It is the one that you posted for me to use 7 or 8 posts back. I got setup with it, and just added the aem wideband o2 option as an EIO input.

Anybody else have any ideas?

Thanks.

Try this:

[SJSchafer]

If you are tuning, I would recommend going with a safe conservative 11.4 accross the board. Then once you are all tuned in you can up it to 11.8. Any higher than 11.8 is getting risky. To get to 11.4, you take 14.7/11.4= 1.289. Enter 1.289 under all the fields of your PE table. You can scale it later if you want, once your VE and stuff are tuned. If you would like a good step by step on VE and MAF tuning, there are some on the site. You just have to look for them. If you want I can give you the link to a great how to on another site. Just send me a PM.

[neo01]

Here is the config...

[neo01]

Hey Guys. I seem to have gotten a tune put together that seems to work properly. The only issue seems to be the timing. It runs perfect afr at idle (something I haven't seen since she was stock) but when turning it over at startup, there is a delay before it fires up. I am not too sure where to look to fix this, and I don't want to screw around with my timing too much. Can anyone give me some ideas?

Thanks.

[Fire]

you are getting misfire at high rpm, im guessing at 5500 -6000 and higher?
i agree your PE table is fubaR. rich as hell. i made an excel cheatsheet that gives you a visual that shows commanded afr in a decimal number for you to input. aim for an 11.2 afr. to start. any leaner than 11.8, and your risking your engine.
anomalous, check the sheet

[Julex]

Saying leaner then 11.8 is risking your engine is false. First off some ss/sc's run 13 from the get go, I run 12.1 with a ton of power. Really you should start with 11.8 and work your way up to 12.1 or maybe a tad higher.

Also if you hover over the enrich table in the editor OR go to help it will explain it.

Also you only need to change Injector flow rate if your running up to 42lbers, but with 60lbers you can do a few things, 1 is adjust MAF table accordingly, or adjust Flow rate modifier Vs volts.

Bill has a great and accurate injector conversion table in the first sticky I believe.

For now get all your normal driving tuned, after that THEN tune PE, becuase if you adjust PE now and change the MAF table or injector table you will throw the pe calculations out. Remember even though you have it so the equation equals 11.8 afr that's relying on your car being close to stoich, obviously the MAF table will be the best way to get it there. Good luck

[SJSchafer]

Saying leaner then 11.8 is risking your engine is false. First off some ss/sc's run 13 from the get go, I run 12.1 with a ton of power. Really you should start with 11.8 and work your way up to 12.1 or maybe a tad higher.

Incorrect. If a stock ss/sc is running 13 AFR at WOT, there is a problem. The factory tune commands 10.8.

Also you only need to change Injector flow rate if your running up to 42lbers, but with 60lbers you can do a few things, 1 is adjust MAF table accordingly, or adjust Flow rate modifier Vs volts.

Wrong on "1". Never make up for fueling errors by increasing air.

For now get all your normal driving tuned, after that THEN tune PE, becuase if you adjust PE now and change the MAF table or injector table you will throw the pe calculations out. Remember even though you have it so the equation equals 11.8 afr that's relying on your car being close to stoich, obviously the MAF table will be the best way to get it there. Good luck.

I agree with tuning MAF, then PE. I would take it a step further and say:

1 - Fueling tables
2 - MAF normal driving
3 - VE normal driving
4 - VE PE
5 - now that your transitions are smoothed, tune MAF PE

[Julex]

First off, look through the forum, I've been here for a while, and unlike your 07 the 05 and 06 some commanded 13 afr. WHICH is still "ok", STOCK.


I don't think you understand the MAF table, Yes it increases air, but it also DECREASES air. For a LONG while untill a few months ago, the MAF table was the ONLY way known to make 60lbs work in the cobalt.

And my basic statement should be taken in basic terms, tune MAF table as it is the final way to fine tune fueling, then the car should be close to commanded. Then set PE afr, and if not correct one or 2 things, adjust the PE afr more to get it to read the AFR you have chosen, OR adjust the MAF table.

VE table I'm pretty sure is not used when the car is still reading the MAF sensor, but if the MAF sensor fails it falls into reading the VE table, so really it's your choice when to do them in order. I personally did it first since I run MAFless (Speed Density.)

Also there is not much reason to adjust the VE for PE.. as again the VE is basically a "just incase" table. (because I am in SD I adjust the PE AFR table to adjust PE fueling, it was faster and more direct.

[SJSchafer]

First off, look through the forum, I've been here for a while, and unlike your 07 the 05 and 06 some commanded 13 afr. WHICH is still "ok", STOCK.


I don't think you understand the MAF table, Yes it increases air, but it also DECREASES air. For a LONG while untill a few months ago, the MAF table was the ONLY way known to make 60lbs work in the cobalt.

And my basic statement should be taken in basic terms, tune MAF table as it is the final way to fine tune fueling, then the car should be close to commanded. Then set PE afr, and if not correct one or 2 things, adjust the PE afr more to get it to read the AFR you have chosen, OR adjust the MAF table.

VE table I'm pretty sure is not used when the car is still reading the MAF sensor, but if the MAF sensor fails it falls into reading the VE table, so really it's your choice when to do them in order. I personally did it first since I run MAFless (Speed Density.)

Also there is not much reason to adjust the VE for PE.. as again the VE is basically a "just incase" table. (because I am in SD I adjust the PE AFR table to adjust PE fueling, it was faster and more direct.

I understand the MAF table very well, thank you. The MAF sensor uses a filiment that is cooled by air flowing past it. It uses the frequency in hz to tell how many gal/sec of air is entering the intake. It is a 3rd order polynomial which means it should always be smooth and follow a defined curve.

That said, if you run a good MAF table with 42s and you have to adjust it for 60s, you are trying to make up for fueling miscalculations. Air does not increase or decrease by adding different injectors. Fuel does, so:

IFR table
Offset table
Min PW
Short PW adder table.

Chances are with a stock tune, the MAF was incorrect to begin with. Same with VE, so you will want to tune them.

The VE is used in MAF for several things. The one that impacts normal drivability is transitions. Also, the ECM is constantly comapiring the MAF to VE to test for inconsistancies. Having them too out of wack can cause limp mode.

As far as a stock ss/sc commanding a 13 AFR at WOT, I'll have to take your word for it. I have seen stock tune files for 05s and 06s and they all START around 13 or so but grade to 10.8 @ rl. Maybe you are thinking of ss/na?

You are correct that VE will not have much to do with running PE, except when entering PE. You know that little burst knock that people get when hitting the throttle hard? With proper Fueling and VE tables it almost completely disappears. So where tuning VE for PE doesn't have a large effect, I believe it has enough of one to still warrant doing it. Besides, I like my tables to be nice and smooth.

[Julex]

I understand how to adjust for 60's but before anyone understood to change the Volts multiplier table you adjusted the MAF table which is not a wrong way to do it, since the only TRUE way to adjust the MAF table would be a benchflow test since we don't have anymeans of controlling variables, such as adjusting by wideband, which assumes fueling is 100% correct, etc.

I believe it's up to the user to choose which way they want to adjust, obviously volts offset would be easier and simpler, but you still have to adjust the MAF table.


Yes they do constantly compare MAF against the VE table, but it won't go into limp mode if they are to far apart, it will go into SD though, as it "assumes" the VE tables are correct, since the MAF sensor could malfunction. Obviously you will have to adjust VE tables at somepoint in the tuning process, I recommend doing them first if your running SD, or before PE, if your running with the MAF sensor.

[SJSchafer]

I understand how to adjust for 60's but before anyone understood to change the Volts multiplier table you adjusted the MAF table which is not a wrong way to do it, since the only TRUE way to adjust the MAF table would be a benchflow test since we don't have anymeans of controlling variables, such as adjusting by wideband, which assumes fueling is 100% correct, etc.

I believe it's up to the user to choose which way they want to adjust, obviously volts offset would be easier and simpler, but you still have to adjust the MAF table.


Yes they do constantly compare MAF against the VE table, but it won't go into limp mode if they are to far apart, it will go into SD though, as it "assumes" the VE tables are correct, since the MAF sensor could malfunction. Obviously you will have to adjust VE tables at somepoint in the tuning process, I recommend doing them first if your running SD, or before PE, if your running with the MAF sensor.

I agree with you on the order, hence the above post:

"1 - Fueling tables
2 - MAF normal driving
3 - VE normal driving
4 - VE PE
5 - now that your transitions are smoothed, tune MAF PE"

So we really don't disagree much at all, do we? Well, except for the limp mode part, but even there I will concede the possibility that if you find yourself in SD and your VE is screwed, you will go into limp.

Honestly, I have only been tuning for a couple of months, but I have learned a lot the hard way. Some stuff I've figured out from bits of info here and there, but I have been slapped upside the dome by some really smart people too. Just trying to get good info out there. I believe that the more people search for the correct numbers wherever possible, rather than just looking for a result, no matter the means, the more exceptional tuners we will have out there and the more Siemens and other manufacturers will realise that not giving someone enough info to properly dial in their stuff is not acceptable. Just so you know where I'm coming from. I've seen you around and know you know your stuff.

BTW, have you actually seen an offset tabke that would be close to correct? I used my own methods to calculate mine, but I know they are at least a touch off in a couple of areas. Nobody else seems to be doing any better with it than I am. Redhardsupra has calculations ready to go for the full table, but not enough known true info...

[ssnipes]

first off it is good to go leaner in lower RPM and then as the RPMS build you go richer. allows for good power down low and as the pressures and heat build in the higher RPMS your rich enough to with preventing knock. thats my threory any way that I have learned from others.

[SJSchafer]

first off it is good to go leaner in lower RPM and then as the RPMS build you go richer. allows for good power down low and as the pressures and heat build in the higher RPMS your rich enough to with preventing knock. thats my threory any way that I have learned from others.

Agree. I assume that when people are saying PE commanded AFR, they mean at rl.