[bcoffin23]

I recently picked up a 2015 228i m-sport (blue brakes, dual radiators, slick top, ZF8). Took it to the track once already and it did great. I'm not an expert driver by any means but have ~50 track days under my belt.

Anyone in here consistently taking their N20/N26 to the track (20+ times/year)?

I'm interested in what common issues arise and any premptive fixes to put in place, specifically around keeping the engine healthy and running full sessions (20-25min).

[ScottSmith]

I track mine quite a bit, but there are a lot of differences between my setup and yours, centering around the fact that I have an E46 chassis.

I didn't have temperature issues until I got a new hood with smaller louvers. If you're willing to cut holes and vent the area behind the radiator it may help keep temps under control.

I upgraded from the stock intercooler to the smallest G-Plus radiator which helped intake temperatures some (though the truth is I didn't need it). It also evened out the temperatures due to the higher mass. This is useful since I have to dyno quite a bit to ensure I'm legal for my race class (NASA ST4).

I have an S55 oil thermostat and an external oil cooler, though I don't believe it is necessary. A friend with an E46 B46 used the stock cooler successfully for more-than-stock power levels in racing conditions, and the coolers on the B46 and N20/N26 are nearly the same weight. I plan on going back to the stock oil/water heat exchanger.

The biggest thing that I've done is run an accusump. That was easy to plumb in using the S55 oil thermostat housing; it'll be a bit harder with the stock heat exchanger. The current plan is to weld an AN-8 bung onto the oil filter housing where the N55 oil pressure sensor goes. I'll also drill out the passageway so hopefully it supports enough flow. The oil pressure data on this motor is quite scary and there are multiple reports of blown motors, so I guess I'd worry about this, esp as your performance picks up and if you run Hoosiers or some other sticky DOT.

Also I run 100 octane exclusively. With gas prices what they are in California, and the fact that most pumps today can't charge more than $9.99, it's almost a bargain compared to the 91 we normally get in California for $6+. Since mine isn't a street car I don't have to worry about flushing the tank when I get to the track or anything like that.

Every now and then I take a peek at the timing chain guide, but I don't expect it to be an issue for me since I don't have auto stop/start and I'm not driving it all the time. Also the accusump helps prelube the motor before I start it, which perhaps helps set the tensioner.

In general I'm running less power than a stock tune (approx 210rwhp) though I am running more torque (300 ft lbs). You'll probably get more heat issues if you run more power, though the torque means I am pushing the motor some.

I did blow up one engine at the track, but I've chalked it up to either very high intake air temps on the dyno, or excessive leakdown (the motor was a bad rebuild I did) leading to oil in the cylinder and thus excessive knock. #4 piston blew to smithereens, took out part of the oil pump on the way out and poked a hole in the plastic oil pan, causing a half-spin at 100mph. I now use the Uro aluminum oil pan. I tried adding baffling which didn't help; perhaps Navardi's solution works better than the one I cobbled together. FWIW the main and rod bearings looked fantastic on that motor, so I'm feeling comfortable with the accusump.

[bcoffin23]

Originally Posted by ScottSmith

I track mine quite a bit, but there are a lot of differences between my setup and yours, centering around the fact that I have an E46 chassis.

I didn't have temperature issues until I got a new hood with smaller louvers. If you're willing to cut holes and vent the area behind the radiator it may help keep temps under control.

I upgraded from the stock intercooler to the smallest G-Plus radiator which helped intake temperatures some (though the truth is I didn't need it). It also evened out the temperatures due to the higher mass. This is useful since I have to dyno quite a bit to ensure I'm legal for my race class (NASA ST4).

I have an S55 oil thermostat and an external oil cooler, though I don't believe it is necessary. A friend with an E46 B46 used the stock cooler successfully for more-than-stock power levels in racing conditions, and the coolers on the B46 and N20/N26 are nearly the same weight. I plan on going back to the stock oil/water heat exchanger.

The biggest thing that I've done is run an accusump. That was easy to plumb in using the S55 oil thermostat housing; it'll be a bit harder with the stock heat exchanger. The current plan is to weld an AN-8 bung onto the oil filter housing where the N55 oil pressure sensor goes. I'll also drill out the passageway so hopefully it supports enough flow. The oil pressure data on this motor is quite scary and there are multiple reports of blown motors, so I guess I'd worry about this, esp as your performance picks up and if you run Hoosiers or some other sticky DOT.

Also I run 100 octane exclusively. With gas prices what they are in California, and the fact that most pumps today can't charge more than $9.99, it's almost a bargain compared to the 91 we normally get in California for $6+. Since mine isn't a street car I don't have to worry about flushing the tank when I get to the track or anything like that.

Every now and then I take a peek at the timing chain guide, but I don't expect it to be an issue for me since I don't have auto stop/start and I'm not driving it all the time. Also the accusump helps prelube the motor before I start it, which perhaps helps set the tensioner.

In general I'm running less power than a stock tune (approx 210rwhp) though I am running more torque (300 ft lbs). You'll probably get more heat issues if you run more power, though the torque means I am pushing the motor some.

I did blow up one engine at the track, but I've chalked it up to either very high intake air temps on the dyno, or excessive leakdown (the motor was a bad rebuild I did) leading to oil in the cylinder and thus excessive knock. #4 piston blew to smithereens, took out part of the oil pump on the way out and poked a hole in the plastic oil pan, causing a half-spin at 100mph. I now use the Uro aluminum oil pan. I tried adding baffling which didn't help; perhaps Navardi's solution works better than the one I cobbled together. FWIW the main and rod bearings looked fantastic on that motor, so I'm feeling comfortable with the accusump.

Thanks so much for all the detailed information! Really interesting about the n20 in your e46 chassis. Is that a "common" swap?

Good to hear that generally heat doesn't seem to be a major issue at stock power.

Your comment about the oil pressure issue is definitely my biggest worry. I'm still with stock suspension and just running a 200tw tire with some EBC yellow pads and Motul brake fluid.

I'd like to move to a coilover setup, camber plates, 255 square setup with stickier rubber but am really worried about oiling.

Sounds to me that it would be wise for me to straighten out oiling prior to any modes that would impact lateral Gs.