[ac328]

isn't the additional oil cooler suppose to prevent the overheating?

[Ramos]

Not while doing hot laps on track on a warm day no it doesn't
though it should like you imply

[ac328]

Limp mode is inevitable?

[Bubbles]

Originally Posted by ac328

Limp mode is inevitable?

Not always, but expect timing to get pulled. My issue is high air intake temps.

[bayerischeperformance]

if you are having issues with high oil temps we are currently experimenting with the 535i oil cooler.

It mounts up right with the radiator and has a very large surface area

[Blue335i]

if you are having issues with high oil temps we are currently experimenting with the 535i oil cooler.

It mounts up right with the radiator and has a very large surface area

Now you tell me. Just put in a VKwerks OC.

And yes, limp mode, if you run hard and it is above 70 (and Automnatic) it will get too hot.
No runs on my VKwerks yet, report later.

[bayerischeperformance]

Originally Posted by Blue335i

Now you tell me. Just put in a VKwerks OC.

And yes, limp mode, if you run hard and it is above 70 (and Automnatic) it will get too hot.
No runs on my VKwerks yet, report later.

Ya. We didn't go with an aftermarket setup to keep costs down along with the issue of grand am penalizing us or having to much ducting to keep airflow to the oil cooler optimal. The surface area on the 535 oil cooler is very large needing less ducting and making it more efficient

[leftcoastman]

Originally Posted by bayerischeperformance

Ya. We didn't go with an aftermarket setup to keep costs down along with the issue of grand am penalizing us or having to much ducting to keep airflow to the oil cooler optimal. The surface area on the 535 oil cooler is very large needing less ducting and making it more efficient

Two things to mention:

1) I've seen a stock 535i limp on track due to oil temps.

2) You are now feeding hot air to the radiator. In my data logging, the oil temps (even with stock cooler) were sub 300 degrees, which doesn't trigger limp. My coolant temp, however, sometimes got above 240degrees, which gets close to limp.

That said, if it's a full blown race car without AC and running 80-90% distilled water, it may not be a problem.

[Blue335i]

So, are you saying, increase the water % vs antifreeze will run the car cooler? Is 80-90% optimal?

[leftcoastman]

Originally Posted by Blue335i

So, are you saying, increase the water % vs antifreeze will run the car cooler? Is 80-90% optimal?

Yes, coolant is a poor conductor of heat.

80-90% is chosen because you still have some coolant in there, to lubricate and prevent rust. That's what I plan to run this year.

The coolant and water wetter may react and form nasty looking brown globules, but it isn't really harmful, imo.

[nicknaz]

I ran 100% distilled water and water wetter in my bike during the summer and switched to coolant + distilled water for winter storage/riding. it's bad juju to stuff your bike AND leave coolant all over the track to mess up the day for everyone else.

not sure how 'modern' car engines react to not having any coolant though

[bayerischeperformance]

Originally Posted by leftcoastman

Two things to mention:

1) I've seen a stock 535i limp on track due to oil temps.

2) You are now feeding hot air to the radiator. In my data logging, the oil temps (even with stock cooler) were sub 300 degrees, which doesn't trigger limp. My coolant temp, however, sometimes got above 240degrees, which gets close to limp.

That said, if it's a full blown race car without AC and running 80-90% distilled water, it may not be a problem.

i'm not saying it would prevent a car from going into limp mode. There are two different routes you can go as far as oil coolers. You could get a very dense(thick) but smaller surface area cooler or not as dense with a very large surface area.

We chose the OEM one due to restrictions on the amount of ducting allowed. With a smaller surface area to get the full efficiency of the oil cooler you need to direct the air towards the surface. We've seen grand am penalize people for having to much ducting for cooling purposes

[GB///M]

Originally Posted by Blue335i

Now you tell me. Just put in a VKwerks OC.

And yes, limp mode, if you run hard and it is above 70 (and Automnatic) it will get too hot.
No runs on my VKwerks yet, report later.

I have to disagree with that because i have an auto 335i and was on my way to six flags last summer when it was like 85 degrees. I was literally driving like 100 mph the whole way, but i was really beating it with 5 people in the car. I was putting it to the floor a lot especially when cutting through the traffic and my oil temp never went past halfway and still to this day has never gone past halfway

[leftcoastman]

Originally Posted by Donnie-Bay

I have to disagree with that because i have an auto 335i and was on my way to six flags last summer when it was like 85 degrees. I was literally driving like 100 mph the whole way, but i was really beating it with 5 people in the car. I was putting it to the floor a lot especially when cutting through the traffic and my oil temp never went past halfway and still to this day has never gone past halfway

The street and the track are not even comparable.

Unless you were braking down to 30mph and accelerating to 150mph repeatedly for at least 20 minutes, you were not subjecting it to anything near track use. I don't break 240 on the street but used to get 295+ on track.

[The HACK]

Originally Posted by Donnie-Bay

I have to disagree with that because i have an auto 335i and was on my way to six flags last summer when it was like 85 degrees. I was literally driving like 100 mph the whole way, but i was really beating it with 5 people in the car. I was putting it to the floor a lot especially when cutting through the traffic and my oil temp never went past halfway and still to this day has never gone past halfway

Driving on the street != driving on the track. The reason why "limp mode" is triggered is due to heat not being evacuated fast enough with a lot of WOT 2nd gear pulls all the way to redline where speed of moving air isn't sufficient to provide cooling. Cruising at 100mph with foot buried to the floor isn't the same thing, the amount of load on the engine isn't the same as 2nd gear and 45-60mph repeatedly.

This is a post I made on another forum:

http://forums.bimmerforums.com/forum...7&postcount=26

As you can see from the chart posted, limp mode starts at 302 degrees Fahrenheit oil temperature but 242 degrees Fahrenheit coolant temp. From some of the data I've seen, coolant is just as likely the culprit for limp mode as it is oil. Even with a factory oil cooler installed it is still likely to trigger limp mode since the factory oil cooler is installed in a poor location. The amount of airflow forced through the cooler is not as efficient as say, were the cooler be installed in front of the lower air-dam. But judging from the data available to me, I'd have to say BMW knew that the radiator is already taxed heavily to cool a very hot running engine and putting an aux. oil cooler in front of the radiator would actually be detrimental to stave off limp mode.

There are a couple of solutions that I've heard of that does a pretty good job. Running a 90/10 water to coolant plus water wetter (only reason I recommend adding a touch of coolant, is that you may want some coolant in the system IF you should blow a hose, since you can't smell steam, but you CAN smell coolant) seems to pretty effectively drop the coolant temperature by anywhere between 10-15 degrees consistently. Or, adding a larger aftermarket oil cooler in the factory mount location seems to help, since there's a heat exchanger between oil and coolant a lower running oil temp may help coolant temp.

I'm actually looking for someone in the So. Cal area to test this out:

http://www.bmracing.com/PRODUCTS/Hi-...7-diameter-fan

It's a fin-and-plate cooler with a fan that kicks in at 175 degrees Fahrenheit. The fan should force some additional ambient air through the cooler to drop the oil temp to a more reasonable temperature. PM me if you're in the So. Cal area and would like to test this and see if it works BETTER than the OEM solution.

[GB///M]

Originally Posted by leftcoastman

The street and the track are not even comparable.

Unless you were braking down to 30mph and accelerating to 150mph repeatedly for at least 20 minutes, you were not subjecting it to anything near track use. I don't break 240 on the street but used to get 295+ on track.

Your right dude i never really thought if it that way. I wanna take it on a track soo bad but im scared the car will let me down...

[GB///M]

Originally Posted by The HACK

Driving on the street != driving on the track. The reason why "limp mode" is triggered is due to heat not being evacuated fast enough with a lot of WOT 2nd gear pulls all the way to redline where speed of moving air isn't sufficient to provide cooling. Cruising at 100mph with foot buried to the floor isn't the same thing, the amount of load on the engine isn't the same as 2nd gear and 45-60mph repeatedly.

This is a post I made on another forum:

http://forums.bimmerforums.com/forum...7&postcount=26

As you can see from the chart posted, limp mode starts at 302 degrees Fahrenheit oil temperature but 242 degrees Fahrenheit coolant temp. From some of the data I've seen, coolant is just as likely the culprit for limp mode as it is oil. Even with a factory oil cooler installed it is still likely to trigger limp mode since the factory oil cooler is installed in a poor location. The amount of airflow forced through the cooler is not as efficient as say, were the cooler be installed in front of the lower air-dam. But judging from the data available to me, I'd have to say BMW knew that the radiator is already taxed heavily to cool a very hot running engine and putting an aux. oil cooler in front of the radiator would actually be detrimental to stave off limp mode.

There are a couple of solutions that I've heard of that does a pretty good job. Running a 90/10 water to coolant plus water wetter (only reason I recommend adding a touch of coolant, is that you may want some coolant in the system IF you should blow a hose, since you can't smell steam, but you CAN smell coolant) seems to pretty effectively drop the coolant temperature by anywhere between 10-15 degrees consistently. Or, adding a larger aftermarket oil cooler in the factory mount location seems to help, since there's a heat exchanger between oil and coolant a lower running oil temp may help coolant temp.

I'm actually looking for someone in the So. Cal area to test this out:

http://www.bmracing.com/PRODUCTS/Hi-...7-diameter-fan

It's a fin-and-plate cooler with a fan that kicks in at 175 degrees Fahrenheit. The fan should force some additional ambient air through the cooler to drop the oil temp to a more reasonable temperature. PM me if you're in the So. Cal area and would like to test this and see if it works BETTER than the OEM solution.

That sounds great i wish i was in the so. cal area so i could test it out. Also that 90/10 water to coolant solution sounds interesting i think im going to try that when i actually take it to the track next month. Ill def let you know if i ever come out west by so. cal. Thanks for the information though i have a much clearer understandin on this now.

[leftcoastman]

The Hack -

I disagree with some of the things you state on the other forum. I believe the Dinan just runs the pump at 100% earlier. It does NOT run it at 120%, for example.

When I'm tracking the car, I am certain the pump is already running 100%.

For everything else you said, I agree. I have found that an upgraded oil cooler and running 90/10 water/coolant with a bottle of wetter works pretty well. I also have some upgraded front brakes + fluid + race pads. Seems to stave off limpishness pretty well.

BMW designed the car for the masses - which generally do not track the car. Keep in mind the E46 M3 used to have serious problems on track also, usually with brakes.