[Sail Boat]

Here's a controversial thread!

Question: Why did you add/want to add power to your car?

Between the ages of 20-22, I spent tons of money making my Subaru Legacy GT faster, because more horsepowers was more better. Downpipe, catback, intercooler, COBB Accessport, custom AP tune, blah blah blah... eventually I made 300 whp. It was fast. I was happy.

Then it would break, all the time. CEL this, limp mode that. I was sad.

I found myself asking... Does all this time and money really justify buying the cheaper Legacy GT? Once I meet my power level goal, is the rest of the car up to the task? Why do I even want to go fast in a straight line? Why didn't I just save up and buy an STI?

Back to my question, which I've edited:

How do you feel about adding power to your car? Are you worried about pushing the N55 and 6MT/8HP past their reliability thresholds? Do you think it would have made more sense to use those tuning dollars to buy an M2 or used M3/M4? Undoubtedly, these M cars have all the supporting upgrades, from cooling to drivetrain... not to mention they can be had with a warranty. Personally, I think the M235i has almost too much power for its supporting systems. Other than straight line speed, are we gaining anything else by potentially sacrificing longevity? And let's be honest... even with the best reasonable tunes and upgrades our cars just aren't straight line fast. (Not talking about big turbos and whatnot)

When I did HPDE last summer, my M235i got very hot. As such, I plan on adding a larger radiator, larger oil cooler, and a larger transmission oil heat exchanger. I can't image how my car would struggle if it had to manage another 50 hp/tq without an upgraded cooling system... obvious reliability concerns aside.

[Maynard]

To fill the giant empty hole where my love for humanity used to be?

[nikman011]

Because I look good naked

[CP911]

Originally Posted by Sail Boat

When I did HPDE last summer, my M235i got very hot. As such, I plan on adding a larger radiator, larger oil cooler, and a larger transmission oil heat exchanger. I can't image how my car would struggle if it had to manage another 50 hp/tq without an upgraded cooling system... obvious reliability concerns aside.

Since you already admitted you should've gotten the STI in your previous situation, wouldn't it make sense to spare yourself all the $ and effort in this case as well by simply trading in the m235i for a m240i? B58 engine solves all the heat issues you are about to address!

[XutvJet]

When you say "very hot", what exactly does that mean? The US-spec M235/M240 come with numerous cooling systems and heat exchangers to keep oil and coolant temps at bay. Do oil temps and coolant temps run relatively high (i.e., 240-250 degrees) during hard and even normal driving? Sure, but it's designed to do that. This isn't the N54 or a Nissan Z where those type of temps result in limp modes.

The biggest issue I see is heat soak of the intercooler and the OEM spec oil. That's easily addressed with a slightly larger IC and running a robust oil redesigned for high temps/hard driving. Better pads and brake fluids aren't a bad idea either.

If you're looking for a full on track car, this isn't the right car. In you want something to occasionally use for the track fun, it's fine.

[Dylan86]

More power = more fun

For me, track use with the m235 with about 360-380whp is perfect, which is why I tuned it to make the desired power level. The car ban be pushed, hard, reliably, imo, without issues. You'd be best to add an intercooler and meth if you want to really push hard and long, it'll keep temps in check.

Ran the car hard for 6x20min sessions, twice last year, and it never showed signs of heat soak, but I have a large aftermarket IC + Meth, cooling the intake temps.

[wjones14]

Originally Posted by Sail Boat

When I did HPDE last summer, my M235i got very hot. As such, I plan on adding a larger radiator, larger oil cooler, and a larger transmission oil heat exchanger. I can't image how my car would struggle if it had to manage another 50 hp/tq without an upgraded cooling system... obvious reliability concerns aside.

How do you know it got hot? Was it hot enough to trip a warning light?

If you're using custom gauges or something, was it the coolant, oil, or transmission that overheated? Or all three?

I've taken mine to 3 track days and no signs of anything overheating.

[XutvJet]

I've owned my M235 6MT (moonroof delete) for two years now. I haven't added any power mods yet. I wanted to fully understand and get used to the dynamics and power of the car and let the motor fully break in. Right now, what I want most is a the M Performance LSD.

My lightweight M235 should easily do low 13s 108-110mph in the 1/4 mile on street tires. There are some occasions where a little extra power would be nice, but overall, this is a pretty quick and fast car, even by today's standards.

What I like about the stock power is it's general tractability and usability on the street. I feel like I can use most of the power on the street without getting in way over my head and that's what makes the car fun. Sure, you can buy a new V8 Camaro or Mustang and easily outrun these cars, but you can't effectively use all that power on the street.

As I've grown older, I've learned that it's far more fun to drive a slow car fast and such cars are far more fun on the street which is where I spend 99% of my time. I used to be obsessed with power and how fast the other guy is. Those days are LONG gone. I don't give a crap about how fast the other guy is or that I could buy a faster car for less money. I'm not interested. I'm more interested in driving fun, improving dynamics, improving sound, and improving looks.

If i want as substantially faster car then I'll buy one. There's just WAY too much compromise when you try to add 20%+ more power to a car. Been there, done that.

Power wise, I feel like all my car needs is maybe 30-50whp/wtq to be just right and that power needs to be delivered in a similar OEM fashion. I was interested in the Dinan Stage II piggyback since it seems to add the most linear power, but now the flash tuning is taking off and I'll likely go that route once I decide it's a reliable option. I really hope Cobb jumps on board as I really like the Accessport on my prior 2012 WRX hatchback. I've also played around with the idea of buying the Dinantronics Sport Tuner and running it in the 2psi gain setting and adding a high quality catted downpipe.

[XutvJet]

Originally Posted by wjones14

How do you know it got hot? Was it hot enough to trip a warning light?

If you're using custom gauges or something, was it the coolant, oil, or transmission that overheated? Or all three?

I've taken mine to 3 track days and no signs of anything overheating.

Agreed. I monitor boost, IAT, coolant, and oil temps via my Torque App. When driving the B roads really hard, the oil and coolant temps hold steady in the 240-250 degree range. I've never experienced any limp mode or warning lights.

[BEM-S4]

Originally Posted by XutvJet

Agreed. I monitor boost, IAT, coolant, and oil temps via my Torque App. When driving the B roads really hard, the oil and coolant temps hold steady in the 240-250 degree range. I've never experienced any limp mode or warning lights.

Me neither. I've recently upgraded to an Active Autowerke intercooler as well just as a "better safe than sorry" move but no problems whatsoever here.

[Sail Boat]

Originally Posted by XutvJet

When you say "very hot", what exactly does that mean? The US-spec M235/M240 come with numerous cooling systems and heat exchangers to keep oil and coolant temps at bay. Do oil temps and coolant temps run relatively high (i.e., 240-250 degrees) during hard and even normal driving? Sure, but it's designed to do that. This isn't the N54 or a Nissan Z where those type of temps result in limp modes.

The biggest issue I see is heat soak of the intercooler and the OEM spec oil. That's easily addressed with a slightly larger IC and running a robust oil redesigned for high temps/hard driving. Better pads and brake fluids aren't a bad idea either.

If you're looking for a full on track car, this isn't the right car. In you want something to occasionally use for the track fun, it's fine.

Transmission oil temperatures (8HP) in particular. I hit limp mode at Summit Point, I suspect this is transmission related. Temperatures hit 280 consistently. Also not referring to temperatures when driving on the road, just the track... I hope our cars aren't overheating with street use!

I agree with you. Was the M235i designed to run hot? No doubt. Was it designed to run dozens of laps in the summertime? Definitely not. Will installing upgraded heat exchangers help resolve this issue and protect the engine/transmission? Very likely. BTW, have you seen the size of the transmission heat exchanger? It's tiny!

I disagree with you. The M235i is the best weekend track car I've ever owned. Maybe when I can afford a GT3 I'll revisit that claim!

[XutvJet]

Originally Posted by Sail Boat

Transmission oil temperatures (8HP) in particular. I hit limp mode at Summit Point, I suspect this is transmission related. Temperatures hit 280 consistently.

Should have bought the 6MT Same general box as the 1M, M2/3/4. Different clutch though.

[Sail Boat]

Originally Posted by CP911

Since you already admitted you should've gotten the STI in your previous situation, wouldn't it make sense to spare yourself all the $ and effort in this case as well by simply trading in the m235i for a m240i? B58 engine solves all the heat issues you are about to address!

Interesting! By chance do you know what cooling was upgraded or is it just the superior design of the B58?

[Sail Boat]

Originally Posted by XutvJet

Should have bought the 6MT Same general box as the 1M, M2/3/4. Different clutch though.

haha seriously... I've raved about the 8HP but the MT seems more tolerant to track use.

[XutvJet]

Originally Posted by Sail Boat

Interesting! By chance do you know what cooling was upgraded or is it just the superior design of the B58?

Heat management during track usage in the M240 waits to be seen as hardly anyone is racing these cars yet. The B58 has a superior intercooler design which does a better job maintaining consistent and cooler intake temps, but it runs a closed deck block which could impact it's ability to regulate heat under hard use. With that said, the M3/M4 run closed deck blocks and don't seem to have much issue dealing with heat so if BMW employed a similar design, the M240 would likely be fine. Like others noted, a slightly larger aftermarket IC goes a long way on the M235 and regulating intake temps.

As for the 8AT, the M240 runs the same 8AT and cooling setup so it likely would experience the same issue, perhaps worse since it's putting a bit more power down (+20whp/30wtq).

[Rayscott]

I own a 228ix. I would like a little more power so I may get Dinan 1 tune down the road. There are lots of reasons people want to boost their power. Tracking, more mojo on the street, bragging rights etc. I'm an old muscle car guy (66 GTO) and more power and noise got more girls. LOL.

[B58togo]

Originally Posted by Sail Boat

Here's a controversial thread!

Question: Why did you add/want to add power to your car?

Between the ages of 20-22, I spent tons of money making my Subaru Legacy GT faster, because more horsepowers was more better. Downpipe, catback, intercooler, COBB Accessport, custom AP tune, blah blah blah... eventually I made 300 whp. It was fast. I was happy.

Then it would break, all the time. CEL this, limp mode that. I was sad.

I found myself asking... Does all this time and money really justify buying the cheaper Legacy GT? Once I meet my power level goal, is the rest of the car up to the task? Why do I even want to go fast in a straight line? Why didn't I just save up and buy an STI?

Back to my question.

What's the point in adding power to our cars? How can we justify pushing the N55 and 6MT/8HP past their reliability thresholds? Wouldn't it have made sense to use those tuning dollars to buy an M2 or used M3/M4? Undoubtedly, these M cars have all the supporting upgrades, from cooling to drivetrain... not to mention they can be had with a warranty. Personally, I think the M235i has almost too much power for its supporting systems. I really don't see what there is to be gained by adding more power other than straight line speed, and let's be honest... even with the best reasonable tunes and upgrades our cars just aren't straight line fast.

When I did HPDE last summer, my M235i got very hot. As such, I plan on adding a larger radiator, larger oil cooler, and a larger transmission oil heat exchanger. I can't image how my car would struggle if it had to manage another 50 hp/tq without an upgraded cooling system... obvious reliability concerns aside.

So I’m a little confused how you can say your 300whp Legacy was “fast”, but a ~370 whp JB4 M240i isn’t “fast”.

[Sail Boat]

Originally Posted by B58togo

So I’m a little confused how you can say your 300whp Legacy was “fast”, but a ~370 whp JB4 M240i isn’t “fast”.

Don't be confused. "Fast" is relative and purely subjective.

[xantdieselx]

Originally Posted by Sail Boat

Transmission oil temperatures (8HP) in particular. I hit limp mode at Summit Point, I suspect this is transmission related. Temperatures hit 280 consistently. Also not referring to temperatures when driving on the road, just the track... I hope our cars aren't overheating with street use!

I agree with you. Was the M235i designed to run hot? No doubt. Was it designed to run dozens of laps in the summertime? Definitely not. Will installing upgraded heat exchangers help resolve this issue and protect the engine/transmission? Very likely. BTW, have you seen the size of the transmission heat exchanger? It's tiny!

I disagree with you. The M235i is the best weekend track car I've ever owned. Maybe when I can afford a GT3 I'll revisit that claim!

Interesting. I was at BMW PDC running the M235i all day at temps well into the 80's with the a/c on and not one overheating issue (unless of course you count the brakes which is another discussion entirely) It's actually what sold me on the M235i.

[M235SDCA]

Originally Posted by Sail Boat

Here's a controversial thread!

Question: Why did you add/want to add power to your car?

Between the ages of 20-22, I spent tons of money making my Subaru Legacy GT faster, because more horsepowers was more better. Downpipe, catback, intercooler, COBB Accessport, custom AP tune, blah blah blah... eventually I made 300 whp. It was fast. I was happy.

Then it would break, all the time. CEL this, limp mode that. I was sad.

I found myself asking... Does all this time and money really justify buying the cheaper Legacy GT? Once I meet my power level goal, is the rest of the car up to the task? Why do I even want to go fast in a straight line? Why didn't I just save up and buy an STI?

Back to my question, which I've edited:

How do you feel about adding power to your car? Are you worried about pushing the N55 and 6MT/8HP past their reliability thresholds? Do you think it would have made more sense to use those tuning dollars to buy an M2 or used M3/M4? Undoubtedly, these M cars have all the supporting upgrades, from cooling to drivetrain... not to mention they can be had with a warranty. Personally, I think the M235i has almost too much power for its supporting systems. Other than straight line speed, are we gaining anything else by potentially sacrificing longevity? And let's be honest... even with the best reasonable tunes and upgrades our cars just aren't straight line fast. (Not talking about big turbos and whatnot)

When I did HPDE last summer, my M235i got very hot. As such, I plan on adding a larger radiator, larger oil cooler, and a larger transmission oil heat exchanger. I can't image how my car would struggle if it had to manage another 50 hp/tq without an upgraded cooling system... obvious reliability concerns aside.

These are certainly good questions and yes personally I did have these concerns, but there are a lot of people on these forums that push these cars way harder than I am. Certainly there are additional risks and chances of more maintenance headaches, but it seemed like from everything I have read that the N55/8AT is a pretty durable platform and tuner friendly. It doesn't take too much in the way of mods to really wake the car up.

Also I don't really drive the car hard all that often - most of the time it is just to work and back. But having the little bit of extra power / torque makes it a LOT more fun when I do.

[Anthony235]

I've been modding cars for 20+ years and have learned lots of lessons. Many of the same lessons as you probably. My car is FBO+tune and I have not had any issues. I've tracked my m235i a few times. No heating issues, etc. But I don't track during summer months. Only Fall/Spring. Too hot for me and the car here in SoCal to track during the summer. That's something I decided on early in my track day "career".

I've ran a larger oil cooler and radiator in previous cars. I highly recommend not doing it unless you're absolutely sure it's required. How are you determining your m235i is getting too hot?

[B58togo]

Originally Posted by Sail Boat

Don't be confused. "Fast" is relative and purely subjective.

Except that when you’re objectively comparing two vehicles, you’re removing the subjectivity and adding context. Sorry, but you can’t say a 300 whp, 3500 lb car is fast and then a few sentences later, say a similar weight car with substantially more power and a superior transmission (ZF8) is not fast. There are tune-only M240i X-Drives running upper 11’s. There are tune only RWD M240i’s running low 12’s.