Over the years, its become very apparent that the evo’s suffer from a drop in oil pressure around right handed turns. With race tires (and even these new 200 treadwear “street” tires) pushing well over 1.2 lateral G’s even without much aero, this problem can become a major problem.
Some simple things we’ve done to help band aide this problem include:
Overfill- Make sure you have oil a little over the full mark.
Type of Oil- We’ve tried a few different brands of oil along with a few different weights of oil. The best results seem to come of the Amsoil Dominator 10-30.
Kiggly HLA- From their website:
-Actively Regulates Lash Adjuster Supply Pressure to a Constant 15psi
-Reduces Oil Flow Into the Head, Keeps More Oil in the Pan
-Air Bleed at the Highest Point Helps Oil Quality and Aeration to Lash Adjusters
The above seem to help just a little, but not enough. We were still seeing big drops in pressure around nearly every right hander. Here is a few screenshots from our TraqMate:
Gingerman Raceway:
Blackhawk Farms Raceway:
So our next attempt is an Accusump system. Its a pretty basic system consisting of a pressurized canister that will pressurize the motor’s oil system when the oil pump is starved from oil.
More info here: http://www.accusump.com/accusump_tech.html#whatis
Update- 9-2-2015.
Just completed Road America this last weekend and so far the basic accusump system seemed to have helped, but not cure the issue. There is a few upgrades we can do to help increase the efficiency of this system, so we will continue to advance this setup and post more later.
Graph of the oil pressure at RA-
You can see the pressure start to drop to its lowest pressure going around the carousel. I wish I could find my logs I did years ago when I was at RA. They used to be into the 20psi range. pretty scary stuff.
I want to add the electronic valve and pressure switch on the accusump so it doesn’t open until it sees less than 55psi. This is another $300 upgrade bringing this total system to $600ish. But if it works like it all should, its worth it.
More to come.
