Originally Posted by
CristianTabush
Oil and piston tuning I find very useful in several different circumstances. They are far more important outdoors than indoors though.
1.Bumpy tracks: More pack helps out on tracks that are bumpy. It prevents the car from bottoming out over bumps and chassis slapping. This is much more important in mod than in stock.
Not normally one to post in here, but I read your top comment with interest, as I actually feel the opposite. On very bumpy tracks, I tend to reduce the pack as much as possible, as otherwise the car will 'skip' over the surface. This is especially the case, IMO, in mod, where your tending to hit the bumps harder. Thats why I tend to use 4hole pistons on my 411, but with a heavier oil.. this works in combination to reduce the pack (and hence make the high speed damping softer), whilst maintaining the body control (low speed damping). This is different to rebound mind, which is what tends to be set to help the tyres to stay in countact, again, IMO.
2.Hot weather: For every 15 or so degrees of temperature, I tend to go up about 50cst. Here in Texas, we'll be racing in the winter in 40-50 degree weather and in the Summer we get to run in 100+ temps. That means that when it's cold I am at 300-350 and when it's hot I run around 450-500. If I don't compensate for the heat, the car has no damping.
Do agree with this, and same also goes for diff oils too... all the oils we use are susceptable to heat, and thin out at higher temps.
3.High bite: While I have limited experience with the T4 on high bite, I have always run heavier oil in higher grip conditions. Typically more so in the front. Going to heavier oil in the front will mellow out the reaction time of the car and this makes it easier to drive.
Totally agree that a heavier oil helps to mellow the car, as it numbs the response time. Soft springs and heavy oil seems to work well on high grip, to help avoid traction roll, and make an easier to drive car.
4.Pack can help in mid-to high speed transitions. Like chicanes.
Don't really agree with this, as I feel that it's more related to rebound setting, rather than the pack. Higher rebound will help to push the piston back down, and hence help to keep the tyres in contact with the ground.
Overall though, I do these days prefer a 4hole piston over a 3hole, certainly outdoors. My target there is to have a shock setup that is supple over the bumps, but still with a decent level of roll control... which comes down to tweaking the shocks to alter the high and low speed damping.
Regards
Ed