help diagnose my track limp mode issues

[berns]

Hi guys -- been in N54 world for many years, first with my E90 and now with my E82 track car.
The new 135i has been great, dead reliable and SUPER fast on track. I've been plagued with some heat issues, as you'd expect with two tiny turbos and hot SoCal track days. I've addressed quite a few of the normal problems with upgrades.

Log here: https://datazap.me/u/berno/motiv-2-107-ambient-willow-springs?log=1&data=3-6-14-15-21-23

Cooling -
CSF Radiator with factory diluted coolant / distilled water / water wetter
VRSF 7.5" Race FMIC
Custom twin Setrab 19-row oil coolers running in series, no thermostat, -10AN lines

Motor -
Simple full bolt-on stock turbo car with VRSF silicone stock location inlets, etc... N20 map sensor, upgraded NGK's, Stage 2 LPFP, the usual

Oil temps were a problem, going up in excess of 280* and I believe causing boost and power to cut, so I built my oil cooler kit and temps have improved dramatically. Even in yesterdays 107* heat, oil temps never went above 260*. Car could definitely use some improved ducting and probably hood ventilation, but I'm just not sure what's causing the issue at this point or if I've gone beyond a certain temperature threshold.

Unfortunately, my log times out on track, it seems, so I don't believe there's data of when this event happens, but basically, I'm full throttle, everything's fine, then I'll shift and almost experience a huge shift bog that just doesn't recover, then randomly at throttle, boost will come back on and it'll be gone by the next gear. At this point, clearly, my lap is finished, I'll do a cooldown and pit in.

Fortunately, for Time Attack events like yesterdays Round 2 with GTA at Big Willow, I only need one perfect lap. That turned out to be what I worked with and still came away with 1st place in Street RWD and fastest in Street class yesterday.

Any ideas what's going on? Would love to get to the bottom of this so I can go out and at least do 3-5 hot laps in heat. Meth is banned from most racing series, so that's not an option.

Thanks for the help and feel free to ask me any questions. Here's an old video from Big Willow, my first time there, so my line is shit. No video from yesterday, too hot to deal with cameras.

 

[berns]

Don't forget calculated exhaust temp / cat protection. That cap needs to be raised for track work.

Never heard of this -- is it in the flash or does it have to be coded?

 

[rac]

Never heard of this -- is it in the flash or does it have to be coded?

Flash. Fuel -> EGT NOx SET POINT (CAT Protection Mode)

DME estimates EGT, go above limit and limp or power reduction results. cant remember which but I remember having that problem early on when I started tracking. easy one to resolve by raising that limit. Not saying that is your problem - just remember it for future use if necessary.

For the record I am confident there are many power reducing avenues the dme has available to it that we do not know about, and that it gives you some leeway on frequency of events it dislikes. Not such a big deal for road pulls and straight line motorsport but can be a real nuisance on a circuit.

 

[berns]

Just wanted to update the thread here. @rac thanks for that tip. Next time I'm down at EAS I'll see if we can go in and code that CAT protection mode out.

Since starting this thread, I've finally replaced my blown LPFP sensor and am now getting real readings instead of a flatline. Yay.
I also smoke tested the system and found 2 pretty significant boost leaks in the intercooler piping connections. I also switched back to the MHD OTS Stage 2 91oct tune and hit two track days. One at Laguna Seca during nice 80-85* days, where I was able to run lap after lap for 15-20 minutes straight with no limp mode issues.

The other day was at Buttonwillow on a boiling hot 105* day. Again, I ran into some kind of rolling limp mode out of nowhere after about 2 laps in the heat. This has to be temperature related, either based of ambient, IAT, or some other kind of temperature based failsafe. Oil and water temps were perfectly fine, oil never exceeded 255* and coolant never exceeded 220*. IAT's on the other hand were definitely above 140 at points. Unfortunately my on-track logging is really difficult with the current setup, I need a smaller android device that is easy to mount sturdy, with a cable that won't come out. WHY IS THERE NO MHD BLUETOOTH YET?! I miss having JB4 just so I could log with my iPhone in my pocket while racing.

Following a tough day at the track, I was on my way back to LA from Buttonwillow, just cruising, and I got a CEL followed by zero boost and a slew of codes:
2ABC - Boost-pressure sensor, electric
3100 - Boost-pressure control, deactivation

I cleared while driving, no luck. Got home, let the car sit till the next day, bam, codes gone, back to boost as usual. So strange.

Meanwhile, I took some logs tonight just to make sure all is well. To me, this looks perfect, but what this isn't my forte. Pic of the car and a video from my recent trip to Laguna Seca too.

-Alex

https://datazap.me/u/berno/mhd-s2-ots?log=1&data=2-3-4-5-6-7-8-9-10-20-31

 

[rac]

I'll see if we can go in and code that CAT protection mode out

No coding required, just max out the temp in tuner pro. May already be done in the latest mhd flashes.

I miss having JB4 just so I could log with my iPhone in my pocket while racing.

Yeah but do you miss all the extra limps!? I never had any consistency on track with the JB4. Good enough for road use tho.

Conservative flash is definitely the way to go for reliability on track.

 

[frontside0815]

Log Looks 100% better than all of the other logs before.
I think my opinion to drive a MHD OTS Map was right.

I think 2ABC was the code i got when i shot my N20 sensor.. Maybe have a look at the Connection there. Maybe try changing it out, but i am really not sure!

My opinion is that this is for sure not a CEL because of temp´s! IAT doesnt do a checklight (at least not if its above 200 Fahrenheit or something and the rest is all fine). Maybe your sensor has Problems when the engine bay is that hot, dont know.. Worth a try i would suggest.

 

[berns]

No coding required, just max out the temp in tuner pro. May already be done in the latest mhd flashes.

Yeah but do you miss all the extra limps!? I never had any consistency on track with the JB4. Good enough for road use tho.

Conservative flash is definitely the way to go for reliability on track.

My E90 was pretty inconsistent but I didn't take the time to develop it nearly as much for track duty. Anyway, I went with Flash-only this time for a reason. Just wish there was more being done in the usability area. I am thinking of how I can make my air intake more efficient in receiving actual cold air. The stock airbox was probably best, but with my oil cooler the way it is, I can't fit the stock snorkel anyway.

Log Looks 100% better than all of the other logs before.
I think my opinion to drive a MHD OTS Map was right.

I think 2ABC was the code i got when i shot my N20 sensor.. Maybe have a look at the Connection there. Maybe try changing it out, but i am really not sure!

My opinion is that this is for sure not a CEL because of temp´s! IAT doesnt do a checklight (at least not if its above 200 Fahrenheit or something and the rest is all fine). Maybe your sensor has Problems when the engine bay is that hot, dont know.. Worth a try i would suggest.

I'll take a look at the wiring for the N20 sensor. It's just the sensor and the BMS harness. I have never gotten a temperature related CEL on track, it's always been 30FF. I believe this was related to my boost leaks in the intercooler piping, AND I think it was probably triggered because my old tune was requesting 18psi and only making 13-14. Now with no boost leaks and on MHD OTS Stage 2, boost is perfectly aligned with target, so I'm hoping no more 30FF codes.

 

[frontside0815]

Hey Berns,

too funny, but yesterday i had another track day with my E82...
We had 95* and i experienced exactly the same you did: While my Water and Oil temps were quite "ok" after 1 lap wit Full throttle the car didn´t acclerated anymore... It just drove like 30HP and sometimes when you continuied to give it full throttle it would gain boost around 5.000RPM.

On my last stint i had the tablet connected, unfortunately i have exactly the same Problem you have: No Mount for the big tablet, so the tablet lost Connection after a few rounds... I have to check the logs it made (Auto logging on) but i think there are no real things to see.

Car drove perfectly fine after cooling down and drives fine at the Moment...