Mike Kojima posted on January 01, 2009 02:50
As an interesting note, at the Edmonds.com 370Z introduction event we noticed that the rear differentials of the display cars were fitted with AN fittings and braided steel lines leading to an electrical pump feeding a ducted under-car cooler. We know that differential overheating was a problem with the 350Z under racing conditions and some of the track demo press cars were fitted with diff coolers for this reason. It looks like the 370Z also has these issues as well. The issue with differential heat will not affect street driven cars, only car being used under racing condition for long periods of time, longer than the typical 20-30 minute track day sessions.
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| This pre-production test 370z had an oil cooler for the differential, perhaps as a precaution against journalistic abuse at track press events. |
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| An electric pump circulates the oil from the diff to an under car heat exchanger. |
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| A big bar and plate heat exchanger lives within this ducted housing, This helps keep the diff oil cool. The 370z probably has low airflow around the diff due to its superior aerodynamics and doesn’t cool the diff well. The 350Z has this same condition. |
The 370Z’s R200 differential is plenty strong; however, the cars improved underbody aerodynamics preclude good air circulation around the differential. Z’s used in endurance racing or equipped with aftermarket clutch type differentials should probably install a diff cooler and a finned high capacity oil sump like the one made by Greddy or the Euro differential cover sold by Nissan Motorsports..
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| For causal track use with the stock VLSD, Nissan Motorsports sells this Euro spec diff cover for the R200 differential. It has a larger oil capacity and cooling fins. Greddy also makes a similar product with even more oil capacity. This bigger unit will probably work better with an aftermarket clutch type limited slip which creates more heat. |