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jwasbury jwasbury is offline
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Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,307
Reviving an old thread here...

I was searching the forums for "CHT" references and found this discussion interesting, so wanted to add some data.

Since my rebuild (back on the road this past April), I've added a CHT sensor and have been monitoring it in realtime (also have datalogging capability). My experience has been that the CHT, like oil temp, is very much influenced by ambient air temps. 150C (300F) seems to be normal in cooler temps (50-70F). When it gets hot (like this past weekend in the Northeast, nearly 100F), I am seeing 170-180C (350-360F).

No matter the ambient temps, I will normally see the CHT rise fairly quickly by 10-15C with hard acceleration on boost, or during a long uphill pull. Going back downhill, or with the throttle closed the CHT drops quickly. During the intense heat yesterday, I briefly maxed at 190C (375F) during a longish uphill pull at a constant 75mph speed in top gear (probably 2800rpm).

I also notice that dropping a gearand increasing the rpms will typically reduce the CHT by 5-10C due to the increased airflow.

A photo of my digital dashboard...this is a windows XP touch screen UMPC running innovate logworks. This shot taken on the way home from Hershey, I-78 eastbound cruising (and just shy of 400 miles on the rebuilt engine):
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Jacob
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930
Old 07-06-2010, 10:57 AM
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