Cobb AP Tune: questions and discussion on timing/iat/afr and other things....

[HaveBlue83]

Right now there isn't a lot of info out on the FiST and the COBB tune other than "oh wow the car is now really fast!", etc etc etc.

I have a good amount of tuning know-how, as do others. Some may be totally new to this. Given the fact that we all now have a device inside the car that can display a hundred different values in groups of 6 in real time, Questions will arise. Here I will post mine, and other may have theirs to add to this. maybe (IF WE CAN) post up logs and whatnot.


My main questions/comments:

-is timing a set number at a set RPM, or is it commanded via other parameters?

-under 2500rpm the car definitely sees great and noticeable gains. above that tho, it feels stock. Right now I am not really seeing much of a reason to use anything but the OEM tune. when I tuned the FoST with an SCT OTS tune from Unleashed I noticed a felt difference everywhere in the powerband, and it was awesome. I loaded the tune and let it be for over a year. on this car I feel like post 2500rpm there was no retuning at all. sad face. is this a "the fmic is holding it back", or something else to understand why the dyno sheets show small gains after the initial hit? I saw iat's go from 87deg to 101 on a pull.

-the interface is leaps and bounds above the SCT platform. thank you for that. the hardware & software work awesome and flashing is fast!


-i'm looking at a log via excel showing all the data. looks like (stock tune Stage 0) shows:

Stock A/F R:
14.0 @ 1800
13's up to 2500
high 12's from 2500-4300
12.5 from 4500-5200
low 12's from 5200-5800
High to mid 11's from 5800-6200 (I lifted after that)

Stock timing was:
10deg lowering down to 1 from 1800-2500
1-15deg slowly increasing to redline from 2500 on up.

 

[Kip2MyLou]

I currently have stage 1 v1.02 and I love it. I feel like I don't need to shift down when passing somebody on the highway now. The whole car just feels more responsive on the throttle than stock. Now with the last map, v1.01 I felt the car lacked something; it wasn't as nice as the v1.00 tune. But the tune I'm running, v1.02, is a great balance of them both and I'm really liking it.

And I'm about to install a high flow filter, maybe an intake later and FMIC.

And with saying all that I haven't installed v1.03 yet, which is the newest tune. But I hear it's the same as v1.02, just with FFS and launch control, if I'm not mistaken. There's no performance changes. Somebody correct me if I'm wrong on that, so I can go hurry up and install it. Ha.

 

[iso100]

-is timing a set number at a set RPM, or is it commanded via other parameters?

It definitely uses more than just RPM and I'm willing to bet the number of variables it monitors is in the double digits. Off the top of my head I'm sure it watches IAT, MAP, RPM, Load %, Boost Actual, etc.

-under 2500rpm the car definitely sees great and noticeable gains. above that tho, it feels stock. Right now I am not really seeing much of a reason to use anything but the OEM tune.

On my otherwise stock car it's a big difference. There's the big lump of additional torque down low as you mention but it doesn't disappear at 2500. Reference this graph:
https://static.cobbtuning.com/dyno/...010&rgb1=000000255&runid2=5011&rgb2=204000000

In terms of torque gains there's still 7ft/lb gain over stock at 4400.

This one shows a gain of 10ft/lb at 4800:
https://static.cobbtuning.com/dyno/...953&rgb1=000000255&runid2=4961&rgb2=204000000

The smoking tire Fiesta does show how gains are gone after 4k:
https://static.cobbtuning.com/dyno/...969&rgb1=000000255&runid2=4970&rgb2=204000000

I'm guessing it's largely due to the fact that boost pressures aren't raised beyond stock levels with the current tunes. There are some small gains way up at 5900 as well.

 

[iso100]

Oh and this Stage 3 graph sure tells a totally different tale. You can still see the telltale tiny turbo HP curve (flat) but there's tons more area under both curves. We're talking a 26hp/25tq increase at 5600.

https://static.cobbtuning.com/dyno/...010&rgb1=000000255&runid2=5040&rgb2=204000000

 

[HaveBlue83]

thanks for the input iso100. I like your info.

I DO see the IAT's rocket up during a single pull, so OBV a garrett core FMIC would help immensely and I'm sure then the tune could be opened up a bit after you give it better, cooler air to use. I'm guessing that's the bottleneck, and STG2 is a FMIC and Intake so it must be. yeah baby turbo's are flatter so it will taper off. thanks again for that.


EDIT: that online database is cool!

 

[iso100]

You're welcome. I don't think the IATs are that bad but with Cobb doing FMIC at Stage 2 it must have room for improvement.

 

[Cts5555]

Have - please stop trying to compare the Bosch MED17.2 ecu to ANY aftermarket Ecu you may have had limited knowledge of previously, they cannot be compared.

As for your comments regarding 'Melting stuff' at 12.5:1, the stock car runs leaner than this, and even with some back to back dyno testing, exhaust temps stay below 900*c on a stock vehicle. During initial design and prototyping of the ecoboost engines, EGTs of over. 1100*c were noted and posed some problems for the material development stages.

And please stop quoting ethanol and referring to AFRp scale, use Lambda and you won't look silly

IATs, below 45*c is considered acceptable, under 40*c preferable as an upper limit, although some poorly designed setups have been seen to run over 90*c with relevant tuning - needless to say intercooler improvements on these vehicles net good gains. 10*c change in true IAT roughly (very roughly) equated to a 3%- 3.5% change in air density at sea level.