[thisisluka]

Hey y'all - in the process of building my 135i club sport / track tool project, I've known about, and run into just about all of the fun temperature management games that need to be played with these things when pushed hard on track.

I want to dive in beyond the basics for track use, and focus more towards advanced, or uncommon methods and optimizations for heat management. First post might be a bit of a long one, but wanted to kinda get out all the ideas & info I had.

I've had some theories and questions I really couldn't find too many answers to, and I wanted to ponder to the guys that are really pushing their n54's hard on track before testing and doing a few myself, and hopefully start a thread to keep all the info and data in one place, to help others in the future trying to tackle the same.

The car is currently being used for HPDE + time trials in SCCA Max 1 group in my local Chicago chapter, with the goal to eventually run as many time attack events I can afford, and be competitive running in SCCA nationals / Gridlife / Global Time Attack / NASA next season. It's not a dedicated track car, but the philosophy is to be able to drive to and from events no matter how far away (with a spare set of wheels / tires if its a true hike) and still be able to enjoy it on the weekend on backroads or take the girlfriend for an ice cream. I know this has its own compromises, but I'm willing to make them.

In the process of making a full build thread, but cooling wise, my setup consists of CSF Racing Rad w/ distilled water & 2 bottles of water wetter, MHD Track Coolant targets & "Max Cool" when on track, Trackspec e92 M3 Center Hood Louvre, VRSF 1k Race 7.5" HD IC, 185º Oil Cooler Tstat, Dual 25 Row Oil Coolers w/ custom 10AN lines/fittings with shrouding and my fender well guards cut with mesh to allow ample airflow & protect from rocks. Also running Rotella 5w-40 if that makes a difference to anyone.

Now, getting into it:

For starters heat wrapping and insulation: gold foil or heat wrap around the downpipes / inlets / outlets / coolant lines (mainly stuff around the hot side of the motor near or around turbos). Has anyone seen any worthwhile effect in this ballpark? Area gets warm to say the least, and I can only imagine, especially with how hot the stock twins get, that some sort of insulation could contribute towards a respectable delta.

Secondly, has anyone seen any temp benefit of relocating the coolant reservoir? I know this is a double edged sword, since most that do are running hot side inlets, which means the potential for hotter pre-turbo IAT's if not heat shielded or ducted properly. However, the idea of moving that big plastic bottle of coolant as far away from the turbos sounds like a good idea.

E85 usage: Of the 4 events that I've competed in this year with the car, I've been on stockers w/ 93 pump gas running the OTS MHD v10 Stg2+, and have generally been ok avoiding limp mode, in addition to running the heat on max to take off some temp from the heater core after a few hot laps. Didn't have the time to shake down the car on any e85 maps between the other stuff it needed before each race or track day, but have heard from a few friends that this also assisted in mitigating temps for them on different platforms.

Lastly, upgraded turbos: In a perfect world, would love to run a log twin scroll manifold and a spicy single turbo knowing that doing so would help temps while being able to run a hearty amount of power, but realistically going to be looking towards running hybrids or larger upgraded twins to keep cost & complexity down, and spool time / responsiveness up. I've seen a thread or two with success of an Australian 335i endurance race car running upgraded RB's, but no idea what sort of power they're pushing due to classing and what I can only imagine would be endurance reliability / longevity. Ideally, I'd like to be in the ballpark of 500-550whp/wtq on an e85 map, give or take 50whp for temp / reliability sake with an optional on the fly kill tune for when on a hot lap or two when the competition ramps up.

Thanks for bearing with my short bible on n54 shenanigans, eager to hear what any of you think or have to offer!