i use penrite syn5 5w-60.
i had it at wakefield and after 4 laps 125 was not uncommon.
i have since fitted a 25row cooler in the r/h brake duct{have to redo plumbing-relocate bov,s} and soon another in the other one.
crusing it sits dead on 85. on the old pac it gets up to 110. it takes about 5mins to come back down, at speed
.
i should also note that some oil thermostates dont really work.
this is for the remote oil filter/thermostate blocks ive used.
i had a m..........cone...s one and i had to remake the valve so it actually put more than 50% thru the cooler once warm.
the washer that was suplied as the valve with a 3mm clerance arond it was replaced with a modified 1" welsh plug that seals properly and shuts of the bypass once warm. it works like a charm now. but i wanted a neater one that i didnt have to use sandwich blocks for guages etc.
so a hks type r one was used.
the hks one needs to be modifeid as well, to achieve more than 50% bypass. its a bit more complicated but, all you need to do is remove the thermostat {27mm bolt thing}and shim up the valve about 9mm or so!!!
and trim the spring the same. it took a couple of goes to get the right balance of warm up time vs cooler flow. but this spec works really well.
from my brief time in the decina spas v8 supercar development series pits.
i noticed on the live datalog screen the water temp sat at 85ish and oil sat at 85ish as well. i asked one of the mechanics and he said for every 5 degrees above 85 they lost 10hp.
now i know why they use such big coolers. and the gibson gtr had two 25 row coolers in the brake ducts all cowled in properly.
i know im craping on abit but im determined to get my gtr oil temp as stable as the water. :lol: