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      06-14-2011, 10:17 PM   #417
Orb
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Quote:
Originally Posted by Turkeybaster115 View Post
+1 I wrote and posted pics on this thread of a Friend's E90 M3 which I rode in at the track. It was 86 muggy degrees, and his IND oil temp gauge read 290-300F, while the OEM guage read 270F. The temp probes are obviously in two different locations.



+1. I'm the only one, it seems, who used 30/70+water wetter.



This is where I disagree with you. If by manual mode you mean using the paddle shifters, then you are wrong. Using the paddle shifters, causes coolant temps to spike rapidly!! Your typically in the 2-3-4 upshift/downshift, and the clutch packs will get very hot when you do this. This heat is transfered to the trans fluid, and then to the coolant. I leave the tranny in DS mode, and the computer doesn't allow radical downshifts/upshifts, while staying fairly aggressive, and keeps coolant temps low. I don't know how much heat traction control is adding, but remember, we have an open differential. Traction control is the only thing stopping one wheel from spinning faster than the other. Turn off, at your own risk! The car's handling is pretty on point, but TC off in the hands of a novice is dangerous.
Hum, I am not sure you understand this but it is simple. First, manual mode has less slip than DS mode as the mechtronics are programmed with greater amount of locking but it is at the cost of smoothness. You are making assumption to some end? There is in BMW document on this site that I posted a few years ago about this transmission.

I think you misunderstood what I wrote. It is only during a traction control event (when the brakes are applied) that a parasitic load is created. If the transmission did not slip (clutch for manuals) then we have a failure or stall the engine.

Although this topic is interesting there are limited options in the end and those should be the focus point. It is well documented that the water jacket between cylinders 5 and 6 have localized boiling problem under high loads. A high performance radiator may not correct this problem. This best approach is using a better heat transfer medium (pure water) and water wetter. A wetting agent is the best possible solution in this case and pure water enhances heat transfer a great deal but at the cost of lowering the boiling point. There some give and take in the fluid properties when you using certain mixture so some experimentation may produce results one may not expect. The next thing is adding a high performance radiator which can improve overall heat reject up to 30% being the same design (size and fitment) just by having a good slat and fin design. Having an auto means your overall heat load is higher which is equal to 2% of the engine load at the crank higher when compared to manual transmission…this is an issue.

Last edited by Orb; 06-14-2011 at 10:37 PM.