[Brule]

I'm worried for many of the Australian users of E90 that have n54s.

I have had 335i for 2 years or so and find it most important to check your engine via logging.

If you have JB4 or Cobb running anything over stock maps you should check how the engine is running via logging.

Variants such as fuel ambient temps, modifications and tune determine how your engine runs and you can get all the data via logging.

Most tuners ask for logging to be done in 3rd gear from 3k rpm to 6-6.5k wide open throttle. This enables the tuner to see how your engine is performing with mods, fuel, ambient temps, load etc.

If you don't know anything about logging just do a bit of research or just put your logs out there on e90 or other forums and ask.


Happy logging

[JB4-335]

I'm a logging nut!!
I've accumulated well over 600 logs over the last 4 years.

Can't get enough data

[ATTN]

Excellent thread.

Due to bad weather of late here in Sydney haven't had the chance to do any recent logs.

With my last log my timing on Cly#1 is good, Avg Ign is low and boost is mixed out about 17.5psi on map 5 and Afr on both is pretty well synced

Need to do another log though to check my other Cly timing values, as I didn't set my JB4 correctly to show the rest.

[Asps91]

im going to do a log and throw it up once i work out how to use the cobb accessport lol

[LotusBMW]

Originally Posted by Brule

I'm worried for many of the Australian users of E90 that have n54s.

I have had 335i for 2 years or so and find it most important to check your engine via logging.

If you have JB4 or Cobb running anything over stock maps you should check how the engine is running via logging.

Variants such as fuel ambient temps, modifications and tune determine how your engine runs and you can get all the data via logging.

Most tuners ask for logging to be done in 3rd gear from 3k rpm to 6-6.5k wide open throttle. This enables the tuner to see how your engine is performing with mods, fuel, ambient temps, load etc.

If you don't know anything about logging just do a bit of research or just put your logs out there on e90 or other forums and ask.


Happy logging

So let's say you're running a JB4 on map 5, DPs and DCIS. You do some logging. You figure out what it means, and then? Change maps? Disable JB4? Get a back end flash?

Doesn't the JB4 and factory computer make allowances or adjustments in timing and boost, for fuel quality, intake temps etc etc.

Perhaps you could explain what issues you seem to think exist and what solutions are available. Maybe an example or 2? No point in information unless you can do something with it.

[JB4-335]

Originally Posted by LotusBMW

So let's say you're running a JB4 on map 5, DPs and DCIS. You do some logging. You figure out what it means, and then? Change maps? Disable JB4? Get a back end flash?

Doesn't the JB4 and factory computer make allowances or adjustments in timing and boost, for fuel quality, intake temps etc etc.

Perhaps you could explain what issues you seem to think exist and what solutions are available. Maybe an example or 2? No point in information unless you can do something with it.

A lot of the time people think the car feels and goes well but once you log it's not the case and the car is actually unhappy with the current setting. The main things to look for in a log are:

* Making sure AFR are within a safe range (anywhere between 11.5-12.6 depending on setup/fuel)

* Timing doesn't take any dips over 3 degrees above 4000rpm.

* Fuel pressure is holding the correct psi (both LPFP & HPFP)

* Boost is on target and not overboosting or underboosting.

* Fuel Trims are all in check and the car isn't maxed out on fuel.

* Making sure there's no major Throttle Closures. Small TC's are common and nothing to worry about.

These are only some of the things to keep an eye on. There will be many variables in a log depending on car to car so don't expect your logs to look just like the other person's.

[LotusBMW]

So, across all those variable if 1 or some are not right, what next in my scenario with JB4 etc?

[Scotty89]

Well the idea is if you're over boosting or underboosting it indicates a mechanical leak or restriction, so you investigate your waste gate or vacuum lines, pipe connections etc.

If your fuel pressures are low, your either trying to run too much fuel flow (E85 mix is too high), so either less e85 or otherwise upgrade fuel pump.

If you're getting timing drops, it is usually the system detecting knock and cutting timing to prevent it - so get higher octane fuel, or lower the intake temperatures.

I got some logs and posted them on n54tech (as the JB4 has a lot of help there) and Russell from Burger Motorsport posted back within the day, suggested some changes - I logged again and reposted and it's now a cleaner log than it was previously. My car's not perfect, but it is slightly better than it was.

[ATTN]

Originally Posted by LotusBMW

So, across all those variable if 1 or some are not right, what next in my scenario with JB4 etc?

One would assume, to take it to someone to address and fix. Ideally you'd want your car to run safely and happy or else there could be catostrophic damage.

At least you've narrowed down to whatever it is that isn't right, so that would be a good starting point to address.

[Asps91]

In laymans terms what do us cobb owners select to log?

[Brule]

When you have cobb connected you can choose from a big list or parameters to log

This is what I log normally

I always read logs on datazap. sign up its free quick and easy to read


Time (sec)
Accel Ped. Pos. (%)
Actual Load (load)
Boost (PSI)
Boost Mean Abs (PSI)
Boost Setpoint Factor (Factor)
Charge Air Temp (° F)
Cyl1 Timing Cor (°)
Cyl2 Timing Cor (°)
Cyl3 Timing Cor (°)
Cyl4 Timing Cor (°)
Cyl5 Timing Cor (°)
Cyl6 Timing Cor (°)
Lambda (Bank1) (AFR)
Load Requested (load)
MAF Req. (WGDC) (g/s)
RPM (RPM) Req.
Boost Abs. (PSI)
Timing Cyl. 1 (°)
WGDC Bank 1 (%)
WGDC Base Value (%)

[Brule]

Originally Posted by LotusBMW

So let's say you're running a JB4 on map 5, DPs and DCIS. You do some logging. You figure out what it means, and then? Change maps? Disable JB4? Get a back end flash?

Doesn't the JB4 and factory computer make allowances or adjustments in timing and boost, for fuel quality, intake temps etc etc.

Perhaps you could explain what issues you seem to think exist and what solutions are available. Maybe an example or 2? No point in information unless you can do something with it.

Map 5 is auto tuning to a certain point. I have not had jb4 for a year but when I had it on map 5 the lowest boost would be around 15psi and timing around 5-7 degrees and on bp ultimate my car kept getting timing corrections and very high IAT's over a single 3rd gear run. In this case you need could either find a higher octane fuel or run a lower map such as 2 or 1.

If you have not got e85 or race fuel you can get a back end flash which will help slightly.

Example of this was I could not run map 2 FBO with jb4 only on pump fuel but i could run "flash only" boost which is around 15psi with higher low end torque with the back pump flash. flash only is when you set menu 4 - 2 and it ignores your map choice and run the flash only.

[LotusBMW]

Thanks. Sounds to me like I'll just run map 5, the supporting mods and 98 Ron fuel which you should be running as a minimum anyhow. It's probably safe enough in my application and it's certainly fast enough already.

Unless I want to fiddle and analyse for the fun of it, which of course is why we like modding our cars.

[7smurfs]

Good advice.

1. Make sure you are running the latest firmware - otherwise update it!

2. Log x3 WOT 3rd gear runs when engine is warmed up ofc.

3. Post it to n54tech to review

4. Adjust your values according to the n54tech guys

5. Relog / repost / rinse & repeat until satisfied

[Mayuri Krab]

Originally Posted by 7smurfs

Good advice.
2. Log x3 WOT 3rd gear runs when engine is warmed up ofc.

Problem for me is there isn't a safe stretch of road near my area to do a WOT 3rd gear pull, let along 3 pulls, seeing how you will be hitting ~160km/h or so near redline in 3rd gear.

During the day, there's always moderate traffic or hidden speed cameras, during the night visability is too bad (I live in a 'pesudo rural' suburb so the major highways have no lights) and hence dangerous for full on 3rd gear pulls.

[BMJ]

have not logged yet, but since switching to the +IC drive map my car has never felt better. TBH i took the COBB off and was about to switch to JB4 as I was just not happy with the COBB OTS maps. I could feel timing issues and i had strange gear changes. all on the sport map.

after running S1 Drive +IC map and doing a few solid pulls the car was smooth as silk just like stock but with way more. so I have left it on drive and have never changed.

[Brule]

Lotusbmw

I previously stated that map 5 may be too aggressive for bp ultimate in above post.

[LotusBMW]

So, it sounds like in your opinion the whole JB4 / Cobb plug and play thing isn't as advisable as most are being lead to believe. One way or the other they need to be professionally tuned. Either using logs over the net or on a Dyno. The latter I'm guessing you don't recommend as all the IP is in the US. Is that the gist of what you're saying?

[Brule]

Plug n play is good. I used jb4 an logged alot. I found that even though jb4 map5 is an auto tuning map. It was too aggressive for my fbo setup in 30 degree heat. I wanted other users to realise the only way to know if your car is running well is to log
The runs. Each Tim the weather changes or the fuel from the servo changes it affects how your car is running especially if it is an aggressive tune.

[Socket]

I'm running map 5 with nil mods and BP ultimate
Boost sits around 12-14 with the occasional spike at 17
Car seems to be running ok
Not able to log cause I gotta get a USB cable and a laptop
Should I switch down to map 2 with my current set up or is map 5 only a problem when FBO?

[CashedUpBogan]

For those of you who don't have a laptop, install the JB4 app and purchase a USB OTG cable to connect to your phone. You can log via this method and read the logs on your desktop.