Oil recomendations for race car 4agze

[beeker]

For those that know their stuff only please, whats the recommend rating and also type (mineral, semi, or full sync).

I change it 2x a year or after a major events, and the engine is std except for a 12 psi pully. In good condition, and doesn't blow smoke at all.

Some have said a 20/60, some 5/40, some say dont do fully sync ??

thx in advance.

[IH8TEC]

oil has been a mystery to me as i'm trying to decide myself on what to run, i finally decided on the castrol race 10W60 until i walked into repco and saw the price

still undecided so will be watching what others recommend, i used to run penzoil 20W50

[matt dunn]

I run Protec, or the old GTX2, in the black bottle,

mainly because mt turbo guy say's that synthetic is no good for turbo's,
But on a supercharged engine you'd have more options.

Matt

[beeker]

I run Protec, or the old GTX2, in the black bottle,

mainly because mt turbo guy say's that synthetic is no good for turbo's,
But on a supercharged engine you'd have more options.

Matt

So in terms of ratings 5/40 v's 10/60, what are your thoughts ?

[loose_unit]

Penrite HPR15 15W/60 would be my choice. Was running HPR30 in the starlet which is 20W/60 and mineral. Took loads of abuse and was still running mint at 240,000km.

[Burning Angel]

you should read this

http://supramania.com/aehaas/ (originaly posted by cat007)

its kinda hard to get your head round but once you understand it oil selection becomes easier.

the idea is to generate 10psi of oil pressure per 1000rpm when up to temp.

this gives enough pressure to support hydrodynamic bearings and gives flow to aid in cooling.

ideally you want to run a full synthetic with a low first number ie 5w or 10w
and the second number depends on the particular engine, which can only really be found by experimentation

so good oils are

castrol edge 5w30 0w40 and 10w60(which is pretty much a racing only oil)

pennzoil 5w40

shell helix 5w40

mobil 1 5w50(good for older/loose tolerance engines)

[matt dunn]

So in terms of ratings 5/40 v's 10/60, what are your thoughts ?

Welll in my experience, I used to run GTX Protec
which was 15w-40,
and the oil light flicked on and off at idle, (25psi sw)

If you bought the same stuff in bulk, 205L drum,
it came as 10w-30, and the oil light was always on solid at idle,
and would flicker on the track at the hairpin etc,

so IMO, the higher the numbers the better.

Now it is called
CASTROL GTX MODERN ENGINE
and is 15w-40, and dont know what it is like in bulk.

[IH8TEC]

i have magnatec in my engine atm, 10w40, i get a solid 30psi on idle, and about 80psi max tit, but i agree with matt, the higher the number i found better for oil pressures.

[Burning Angel]

So in terms of ratings 5/40 v's 10/60, what are your thoughts ?

Welll in my experience, I used to run GTX Protec
which was 15w-40,
and the oil light flicked on and off at idle, (25psi sw)

If you bought the same stuff in bulk, 205L drum,
it came as 10w-30, and the oil light was always on solid at idle,
and would flicker on the track at the hairpin etc,

so IMO, the higher the numbers the better.

Now it is called
CASTROL GTX MODERN ENGINE
and is 15w-40, and dont know what it is like in bulk.

in the case of your engine you did need a thicker oil, which you found out by experience.
but not all engines will run the same pressure and therefore need different oil.

pressure is not made by the oil pump, its made by restriction to flow (ie. bearing clearances etc) and how thick the oil is when HOT.

80 psi at full revs sounds about right, but you wouldn't want to go to a thicker oil as that would sacrifice flow, on the other hand if you were only getting 60psi at max revs it would suggest the oil is too thin for your application and you should go to a thicker one (ie. 10w30 to a 10w40)

so what im getting at is that the ideal oil for an engine can only really be found by experimentation. but an educated guess would suggest around a Xw40 oil.

[Bazda]

I used to run a pennzoil GT race 25/50, this was ok but nothing great.

I then changed to Motul GT300V I think it was, full synthetic, 20/50, was great, but only problem was it got very hot very fast. Still provided good lubrication even over 120deg C .

I thne changed to a kendall GT1 semi synthetic 20/50, this seems to be very good. and idle i'm around 30-35psi and full revs 70psi.
On the race track its always 60-75psi no matter what corner.
Temps seem to be good on this oil as well.
But trying to buy it in NZ... fail. You will have to buy it out of america .

I'll prob keep with this stuff and buy it from america.

I heard the valvoline race stuff is pretty good as well.

[tsoob]

I was running mobil 1 fully synthetic but i $&#$% my turbo now running penzoil mineral 20/50 on steve murch's recomendation for my setup.

[Allister S]

So just from experience I've only ever run Mobil 1 15W50 - never anything else.

Over 15 years and 80,000kms on this and engine certainly looks like new inside. No oil cooler fitted, std AE92 AFM engine except 12psi pulley. Car used in Rallys, sprints and on track and road.

Warm 30psi idle, 70-80psi full revs. I won't change now just because I've had 0 problems.

[IH8TEC]

i dont see why a fully synthetic oil will stuff turbo's. maybe is just me,

[matt dunn]

I was running mobil 1 fully synthetic but i $&#$% my turbo now running penzoil mineral 20/50 on steve murch's recomendation for my setup.

Did he recommend to say away from fully synthetic, or just say not to use that?

i dont see why a fully synthetic oil will stuff turbo's. maybe is just me,

It is because oil is used for cooling the turbo, and fully synthetic oils dont absorb heat well, and so dont take heta out of the shaft.

makes them give better oil pressure as the oil stay's cooler and so thicker,
so good for NA, but no so good for Turbo's.

But everyone will always have different idea's on different oils anyway.