i am interested in what the numbers actually mean on atf oil data sheets and what differences if any a higher or lower figure actually mean in a real world racing situation (i have listed the specs for comparable valvoline fuchs and castrol products for discussion below)
i am sure the topic of specification comparison is of interest to a lot of people out there who like myself simply dont know what the numbers mean or which ones are important and end up just using atf brand XX (or other fluids) that racer jo uses in his setup because thats what seems to work ok and hasnt had a problem... yet
however with all of the technical information and data sheets etc that is available nowadays i really want to be able to make these choices on an informed basis using actual numbers and specs rather than just going with whats worked kind of ok for racer jo in the past...
applying this directly to my setup... i have a 700hp drag car running a built powerglide with transbrake and manual valvebody the atf im currently running is valvoline dex3 which gets changed at 50 runs or so and comes out nice and clear red, no unusual smells etc.
my trans builder said to use a dex 3 atf from a recognized brand, and not to put synthetic atf in there as it is too slippery and causes problems with band and clutch packs etc
here are three similar dexron 3 products from valvoline castrol and fuchs. the only reason ive picked these three is that i have the information handy and they seem to provide the figures for the same attributes to make an easy comparison...
i realize a lot of people are using full synthetic atf,type 5, tractor oil and other varieties of oil in their transmissions and the type of oil is covered in other threads... so im not asking what i should use instead of dex3...
my questions are :
1* what do the numbers mean or more correctly which are the important ones to consider for a drag car
2* does a slight change in say the kinematic viscosity or the viscosity index as per the figures below mean that one fluid is 'better' than another (ie noticeably or are the three so close it doesnt matter?
3* which of the numbers mean that the atf will perform (noticeably) differently on the drag track either through the day or over time as the atf has done more runs?? (ie as it warms will the car get differing times etc) and how much different (eg the 100c kinematic viscosities are pretty close how much higher or lower would make a noticible difference in the atf performance? is 0.1 a big deal or does it need to be say 1.0 higher to matter etc...
thanks in advance for any education people can offer me
VALVOLINE DEX3
Viscosity @ 100°C, mm2/s, ASTM D445 7.1
Viscosity @ 40°C, mm2/s, ASTM D445 34.7
Viscosity Index, ASTM D2270 175
Density @ 15°C, kg/L, ASTM D4052 0.857
Pour Point, °C, ASTM D5950 -42
Flash Point (COC), °C, ASTM D92 216
CASTROL ATF DEX III
KV @ 100 0C (cSt) 7.2
KV @ 40 0C 36
cP @ -40 0C 17,600
viscosity index 186
pour point deg c 42.5
FUCHS TITAN ATF 4000
density 15deg c 0.862 g/ml
flash point din iso 190 deg c
pour point din iso -50 deg c
foaming tendency seq ii astm 30/0 ml
kinematic viscosity 40 deg c 37.8 mm2/s
kinematic viscosity 100 deg c 7.6 mm2/s
viscosity index din iso 174
i am sure the topic of specification comparison is of interest to a lot of people out there who like myself simply dont know what the numbers mean or which ones are important and end up just using atf brand XX (or other fluids) that racer jo uses in his setup because thats what seems to work ok and hasnt had a problem... yet
however with all of the technical information and data sheets etc that is available nowadays i really want to be able to make these choices on an informed basis using actual numbers and specs rather than just going with whats worked kind of ok for racer jo in the past...
applying this directly to my setup... i have a 700hp drag car running a built powerglide with transbrake and manual valvebody the atf im currently running is valvoline dex3 which gets changed at 50 runs or so and comes out nice and clear red, no unusual smells etc.
my trans builder said to use a dex 3 atf from a recognized brand, and not to put synthetic atf in there as it is too slippery and causes problems with band and clutch packs etc
here are three similar dexron 3 products from valvoline castrol and fuchs. the only reason ive picked these three is that i have the information handy and they seem to provide the figures for the same attributes to make an easy comparison...
i realize a lot of people are using full synthetic atf,type 5, tractor oil and other varieties of oil in their transmissions and the type of oil is covered in other threads... so im not asking what i should use instead of dex3...
my questions are :
1* what do the numbers mean or more correctly which are the important ones to consider for a drag car
2* does a slight change in say the kinematic viscosity or the viscosity index as per the figures below mean that one fluid is 'better' than another (ie noticeably or are the three so close it doesnt matter?
3* which of the numbers mean that the atf will perform (noticeably) differently on the drag track either through the day or over time as the atf has done more runs?? (ie as it warms will the car get differing times etc) and how much different (eg the 100c kinematic viscosities are pretty close how much higher or lower would make a noticible difference in the atf performance? is 0.1 a big deal or does it need to be say 1.0 higher to matter etc...
thanks in advance for any education people can offer me
VALVOLINE DEX3
Viscosity @ 100°C, mm2/s, ASTM D445 7.1
Viscosity @ 40°C, mm2/s, ASTM D445 34.7
Viscosity Index, ASTM D2270 175
Density @ 15°C, kg/L, ASTM D4052 0.857
Pour Point, °C, ASTM D5950 -42
Flash Point (COC), °C, ASTM D92 216
CASTROL ATF DEX III
KV @ 100 0C (cSt) 7.2
KV @ 40 0C 36
cP @ -40 0C 17,600
viscosity index 186
pour point deg c 42.5
FUCHS TITAN ATF 4000
density 15deg c 0.862 g/ml
flash point din iso 190 deg c
pour point din iso -50 deg c
foaming tendency seq ii astm 30/0 ml
kinematic viscosity 40 deg c 37.8 mm2/s
kinematic viscosity 100 deg c 7.6 mm2/s
viscosity index din iso 174