[allthatisntnow]

Ive noticed that towards the end of a 20 minute session, trans temps are reaching around 102C (215f) in ambient 14C (57f). Good news is, they seem to stabilise at this level and don't exceed water temps at any point. However on some faster straights where 120+mph are achieved the car seems to hit a wall in higher gears and won't rev past 5k. I know this may not necessarily be transmission related (as those temps don't seem too bad for track work) but given engine oil temps stabilise at 112-114C even running 400hp, I've got a feeling it may be a step back for transmission preservation. No error codes are thrown and the car doesn't enter limp mode. Dynamic traction is on (another possible culprit) shifting with paddles. Anyone encountered anything similar and/or had any luck installing an auxiliary trans oil cooler? (i know its supposed to have one from factory, but it must be the size of a walnut).

I have done a search but couldn't find anything on this issue.

Thanks.

[Anthony235]

Did your car come with all season tires? If so, car might be limited to 130mph.

[zipphreak]

My 235xi came with A/S and was limited to 130mph.. although i haven't hit a track in the Northeast that i have been able to get up to 130 haha.

The straights at Loudon and Palmer are short.. The new Club Motorsports in Tamsworth looks very promising, 2.5 miles of pure bliss.

[bryan_G01]

My oil hangs at 244f all day, even on track.

i ran dinan stage 3 at NJMP thunder in 95f degree temps, no issues. Bounced of the limiter at 130 on straight.

shortly after ripped and tossed dinan tune out, went flash, now i can hit 140 on same straight.

Only issue i have ever have is getting limp mode when i have less that 1/4 tank of gas while tracking. Just keep the tank filled before sessions and im good. This also seemed to only happen after i installed the fuel-it lpfp.

I had the oem charge pipe explode on me while on track at LRP, i swapped it for the ER when i got home.

I hit 136mph on the limerock straight almost every lap. You can see the car hit limp mode on lap 16 (fastest lap) from gas levels. I was dropping time like crazy at that point, probably could have ran a 1:01.9

[allthatisntnow]

Thanks for the replies guys. My car came with MPSS so as far as I'm aware the limiter should have been set to 155mph. Im thinking it may be a heat soak issue. Although AITs usually don't usually climb above 30C during a session, they may have done so on that day as ambient temps were higher. First time I've encountered any issue if it was the case though. Putting on a bigger intercooler to see if it totally remedies the situation. I try to keep fuel well above 1/4 (although its surprising how thirsty these things get - well into single figure mpg drains the tank quick!) and i have experienced a limp mode event when near the 1/4 tank mark but can't say for sure that was the trigger.

[bryan_G01]

get rid of those mpss if your going to be on track.

[zipphreak]

My car is a 2015 m235xi 8 speed auto, 45k miles on the ODO.

No issues at the track yesterday or today.. Temps were around 83f yesterday, and 77f today ambient. Flogged the m235xi pretty hard around Palmer motorsports park. Absolutely no sign of limp mode, even with the JB4 on map 2 I have a Wagner Evo 2 perf IC and ER Chargepipe that are working out very well. But even previously without them I never hit limp mode, ambients are pretty low compared to other parts of the country.

I did my fastest lap with the 2, at 1:59 on this track. I'm running all stock suspension, except i have GCv2 camber plates and Dinan Springs/bumpstops.

[allthatisntnow]

Originally Posted by bryan_f22

get rid of those mpss if your going to be on track.

Absolutely, i use NS-2Rs as wets and Cup 2s in the dry. Never even bothered trying the PSS on a track day as everyone seems to be unanimous in the opinion that they're a bit $h!t on track.

[bryan_G01]

Cups are expensive, try the re71r's as you can drive on them on the street without too much noise.

Nitto 01s are a solid choice too but loud as f*ck.

[zipphreak]

Hankook RS4's are not bad as well

[Anthony235]

Originally Posted by zipphreak

Hankook RS4's are not bad as well

Tire rack has a review up on them now. Seems like a great all around tire for the street/track.

[BirdsEye]

I've noticed the same issue as the OP, was on track the other day (Mallory Park) and there are 2 straights were I was hitting 110/115 easily, but once up to that speed the car feels like it's lost 100bhp. I turned off JB4 (map 0) and it seemed to be fine then so I put it down to jb4 pushing the car harder than it liked. I'd imagine an intercooler would fix, as I was checking coolant and oil temps and they seemed perfectly ok, so I can only assume it was IATs climbing.

Surprised to hear MPSS is poor on track? Is it specific to this car as the info I've read is that its the best tyre for daily performance and a few trackdays...unless you guys mean you need something more serious than mpss.

[Anthony235]

Originally Posted by BirdsEye

Surprised to hear MPSS is poor on track? Is it specific to this car as the info I've read is that its the best tyre for daily performance and a few trackdays...unless you guys mean you need something more serious than mpss.

It's all relative. MPSS is a good street tire, but there are tons of better tires suited for track work.