All COBB Tuning AccessPORT for 135i Discussion Here

[b1aze]

Is it me or is your individual timing corrections high in almost all of your cylinders?

[AZ_1Zeries]

My timing corrects in all cylinders sat at 0 during the entire WOT pull. Cycl 2 went ~(-3) for a short blip after I let off throttle.

[Ænema]

Originally Posted by AZ_1Zeries

My timing corrects in all cylinders sat at 0 during the entire WOT pull. Cycl 2 went ~(-3) for a short blip after I let off throttle.

Yeah man, that log looks good. REALLY good

[Derek8819]

Is Cobbs site down for you guys? I cannot get into the Maps page or to the BMW support page to download the APManager?

[Adam135]

Originally Posted by Derek8819

Is Cobbs site down for you guys? I cannot get into the Maps page or to the BMW support page to download the APManager?

Nope. Works for me.

[Derek8819]

Thanks, had to try another computer, must not like my desktop for some reason.

[b1aze]

So I can't figure out what monitoring parameter is the current manifold pressure, like to measure vacuum. MAP reads in the 300s but I'm guessing that's a mV reading and not a direct pressure measurement without a gain/offset of the sensor.

Halp?

[AZ_1Zeries]

What would cause Charge Air Temp to climb excessively under WOT? I just had my car dyno'd at a shop and also had them do a log on my AP. Charge Temp rose to 170F and I had corrections in all Cylinders. Will post a graph shortly

[AZ_1Zeries]

[AZ_1Zeries]

Here's the dyno printout

[b1aze]

Originally Posted by AZ_1Zeries

What would cause Charge Air Temp to climb excessively under WOT? I just had my car dyno'd at a shop and also had them do a log on my AP. Charge Temp rose to 170F and I had corrections in all Cylinders. Will post a graph shortly

Just the fact that you aren't getting actual airflow over the whole car will cause serious IAT climbs. Even putting a fan over the IC won't really replicate the cooling airflow of a car from a 30-100mph pull.

[Suds]

I have to agree, this is one of the main differences between dynos is the air flow.
Usually the first dyno curves you see at the speed shop show torque vs. mph, before they convert to rpm on the curve. I guarantee the air flow from the fans do not simulate the air into the front of the car for a 4th gear pull which will exceed 140 mph.

[AZ_1Zeries]

Thanks and that makes sense since the Charge Temp did not rise like that when I logged on a few highway pulls. Just surprised that it climbed so much? Can anyone who's done a dyno on an E30 tune confirm their IAT went up a similar amount?

So do you guys think my timing corrections were due to the higher IAT? Would increasing my E85 ratio alleviate that issue?

[Suds]

Originally Posted by AZ_1Zeries

Thanks and that makes sense since the Charge Temp did not rise like that when I logged on a few highway pulls. Just surprised that it climbed so much? Can anyone who's done a dyno on an E30 tune confirm their IAT went up a similar amount?

So do you guys think my timing corrections were due to the higher IAT? Would increasing my E85 ratio alleviate that issue?

Damn, that's like voodoo sht, if your IAT's were over 20 degrees over ambient you need an FMIC and the dyno pull is suspect to overheating the inlet air temp.
So was that a stock inner cooler in your pulls or just poor airflow.

[1911A145]

Originally Posted by AZ_1Zeries

Thanks and that makes sense since the Charge Temp did not rise like that when I logged on a few highway pulls. Just surprised that it climbed so much? Can anyone who's done a dyno on an E30 tune confirm their IAT went up a similar amount?

So do you guys think my timing corrections were due to the higher IAT? Would increasing my E85 ratio alleviate that issue?

Simply put, there isnt enough air flowing to simulate real world conditions. It's normal to see IAT's rise like that in a dyno shop. Maybe next time try adding some iced water in a spray bottle and right before a run spray down the intercooler and make sure the shop uses a fan on the intercooler and over the engine with the hood open to combat some of those affects. You should see a pretty big difference.

[AZ_1Zeries]

I have a helix fmic installed. On the street pulls I've logged post E30 my temp would only climb 10F or so. But I don't think I pulled as hard. This chart was for a 4th gear pull all the way to 132mph. I do suspect the airflow was inadequate but, I'm going to do a few more highway pulls/logs to confirm my charge temps are stable. The car is running ACN91oct instead of the recommended 93oct.. Sadly, I don't have access to 93oct. Think I'm going to increase E85 to 35-40% to clean up the timing for the next dyno.

[b1aze]

If you aren't getting timing pull on the street with the current fuel mix you have, don't mess with it. Most good tuners will be able to account for the increases IATs on the dyno and it will be accounted for.

It may have "pulled harder" because you aren't actually moving a 3300lb car on the dyno. Again, the dyno plot shouldn't be used as an end-all deciding factor to add E or change timing corrections because its not real world.

[AZ_1Zeries]

Yep, I would only be increasing E85 specifically for the dyno as I said to alleviate the timing corrections prolly caused by the excessive IAT inherent with dyno runs. I have no intention to change my Mix ratio for street/track use if my Charge temp remains stable real world.

[syenisch]

I am experiencing a stutter/hesitation at higher RPMs at WOT on all maps but the stock-like map. What parameters should I be monitoring to try to diagnose the problem?

[euro2fast4u]

I am amazed at how easy tuning on these engines are, its almost fail proof great numbers btw !!

[135Pats]

Originally Posted by syenisch

I am experiencing a stutter/hesitation at higher RPMs at WOT on all maps but the stock-like map. What parameters should I be monitoring to try to diagnose the problem?

The same parameters you always want to be looking over in a datalog, timing, AFRs, timing corrections, WGDC, fuel trims, boost req vs actual boost, boost taper as you approach redline. That'll cover the basics and should point you in the direction of whatever problems you may be having.

Originally Posted by euro2fast4u

I am amazed at how easy tuning on these engines are, its almost fail proof great numbers btw !!

Yup, the N54 takes to power modding about as well as anything on the market right now. As long as you don't spin the guts out of the turbos at high revs and have the proper supporting mods, it can deliver 380+ whp reliably for years. It's a bit of a primadonna engine in terms of peripheral problems, but the block is pretty bulletproof. Don't see many of these things coming apart, and when it does happen it's either a 1 in 1 million type thing, or the motor was being pushed extremely hard.

[euro2fast4u]

Yea, I meant tuning was. The amount of data you are given is astonishing. but its the way all these newer engines are being run. Being able to see how much knock you are getting on a certain cylinder is amazing. Im still tuning with my ear lol i would love to get my hands one of these for a weekend