Overheating on track only

[Mike R]

I would add that to achieve the perfect water temps, I ALWAYS remove the front number plate on my cars when on track, as it disrupts the air flow to the cooling systems (something which most people seem to overlook ).

[Mark CSL]

Just a thought but how accurate do you think the gauge is ?
Has any one tested it ?

[Mike R]

Originally Posted by Mark CSL

Just a thought but how accurate do you think the gauge is ?
Has any one tested it ?

Setra has (we had a conversation at the 'ring) - he said that the OEM oil temp gauge does over-read by some 15-20° - however, I'm not sure if that is °C or °F

[alexk]

Originally Posted by Mark CSL

Just a thought but how accurate do you think the gauge is ?
Has any one tested it ?

Yes I have been testing it the last 2 months or so.

The temperature gauge for temperatures between 84 and 94 C shows bang on the middle (this is the buffering function of BMW's gauges).
95 C and then it goes to 3/4
83 C and you are 3mm below middle.

At the same time, the car's manual shows normal water temperature is between 1/4 and 3/4.

So I am starting to wonder whether the issues most of us see on the track (cars with an issue excluded) is down to the:
1. Operation of the gauge
2. Behavior of the engine under different loads.

[alexk]

Originally Posted by shimmy

If you come off the throttle within 1-2 corners the water temps drop quickly.

So shimmy why the water temp in the gauge drops so quickly is because it's just 1C difference between 3/4 and 1/2 (from 95C to drop to 94C).

[Graham]

I've just come back from the Ring at DN10 track day, worst I've ever seen for my car on temps, was 28 degrees though. I was having to let off down the straight and then it was more or less ok for a lap. If I did the full straight I was getting between the dot and the red mark by halfway round the lap and had to let off when the temp quickly dropped back down. I know it's an extreme circumstance given the abuse is higher than normal and the temps, but I think I need to give my 9 year old cooling system a refresh now.

[rstoughy]

I suffered this again over the 2 days at the ring this week.
Every time however it was caused by catching slower cars and the refusal of them to move over to allow me to pass. When collecting the dirty hot air from them I observed a rapid rise in the water temp up into the red.
Backing off and pulling out of the disrupted air flow and it would return to normal within a minute or so.

A couple of pals were running their M3's with the electric fan mod and commented that they never had a problem.

Wed was 24 deg c and Thurs 28 deg c so fairly warm.

[Graham]

Originally Posted by rstoughy

I suffered this again over the 2 days at the ring this week.
Every time however it was caused by catching slower cars and the refusal of them to move over to allow me to pass. When collecting the dirty hot air from them I observed a rapid rise in the water temp up into the red.
Backing off and pulling out of the disrupted air flow and it would return to normal within a minute or so.

A couple of pals were running their M3's with the electric fan mod and commented that they never had a problem.

Wed was 24 deg c and Thurs 28 deg c so fairly warm.

My mate was in my car and said the same thing when I was behind a car about the hot air when I mentioned my temps had suddenly risen, the thought didn't occur to me!

[shane@mbtech]

I've never noticed high temps.

Mostly out in front though, maybe that's why

[shane@mbtech]

Originally Posted by alexk

So shimmy why the water temp in the gauge drops so quickly is because it's just 1C difference between 3/4 and 1/2 (from 95C to drop to 94C).

Doubt that very much Alex.