Hi all, Just thought you would like to know a little something I witnessed last week. At a workshop that changed the factory oil out of a STi 7 for a oil designed for use with hydralic cams and the power gain on the dyno was over 10kw @wheels.
This was done to a STi 7 Wagon. Semms the oil really lets the cams do what they were designed for...make more power.

 

and wear out the engine 10 times faster.

 

I doubt that the oil is of a low quality....just designed for this type of engine, whereas the factory oil is not designed to optimise hydralic cams.

 

I'm not meaning that.
What happens is that these oils and more in general oils for racing are less thick to reduce frictions and therefore increse Output power. This is often associated with very low levels of the fluid for the same reason above. The price you have to pay is a much shorter life of the engine ( that in motor racing is relatively superficial).

 

this was an off the shelf Castrol product so I'd question whether it would affect engine life at all...

 

STi 7 Wagon ?

 

Yep, STi is still available in the wagon in most markets i think?

 

Bruiser, Take it you are referring to hydraulic lifters/tappets, ie the bit that maintains valve clearance?

Common problems I'm aware of with oil that is not optimised is that there is not enough hydraulic pressure with lighter oils giving increased clearance and a loss in lift or the exact opposite, where the lifters either jack up or lock due to too much pressure caused by higher viscosity oils.

IIRC most problems due to oils being too low a viscosity giving rise to the lifters sinking at higher revs, with loss of power.

Caronte - race engines use solid lifters - not hydraulic.

My guess is that the optimised oil will be higher viscosity.

Bruiser - Can you confirm for us?

D

[Edited by Diablo - 6/26/2002 9:28:46 AM]

 

10kw from an oil change - now thats a new one on me!

I DONT think so.. - but if you feel the difference than thats good for you...

 

Diablo- I will confirm all the details for on Tuesday as I am back at the workshop.
But as for the power increase...witnessed it on a dyno, and they have done it too more than one car.
I'll get details about the brand, grade of oil etc....
I don't know the in's and outs of the new engine design so Im a little vague on explanation, but will try to get as much as possible for you.

 

STi 7 wagon is only produced to JDM spec, so u can't get one officially from dealers in most export areas, apart from a few markets.

 

New Zealand must be considered important enough I suppose...
We get all the good stuff.....

 

Its not fair................

 

Bruiser
It's not a case of inportance but practicality......how many sheep can you get in the boot of a saloon (sedan)?

 

steve,

what is being described is totally possible.

the clearance between the valve and the cam is maintained by the hydralic lifter. if the oil is not viscous enough, pressure is relatively lower, and so the valve spring of squeezing the oil out of its gallery. This means that the valve when on lobe is effectively shorter, meaning less lift.

less lift = less air

less air = less power.

So it isnt a nieve case of oil = less friction = 10kw more at the wheels = bollocks.

there is more to it.

 

Adam...is that not basically what I said

D

 

DAVE T-S- Its awkward to get the buggers in, but it saves time getting to the stockyards...

 

Diablo, that is exactly what you said, but I had to put it in idiot language so that steve could understand

Only joshing with ya steve!

 

Adam

Very funny - you read too many manuals - you do have a day job??

 

Adam can you send me a reading list please so I can be as jocular as you

 

Doesn't an STI 7 have solid, bucket/shim type followers, like all STI variants before it??