STi Power gains...
#1
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.
This was done to a STi 7 Wagon. Semms the oil really lets the cams do what they were designed for...make more power.
#4
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).
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).
Trending Topics
#8
Scooby Regular
Join Date: Sep 1999
Location: £1.785m reasons not to be here :)
Posts: 6,095
Likes: 0
Received 0 Likes
on
0 Posts
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]
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]
#10
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.
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.
#15
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.
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.