i suspect that while i don't understand the difference in these examples between downforce not being the opposite of reduced lift. i DO get they they are NOT directionally proportional! i'm not seeing that any of you guys understand what i'm unclear about either.

i was never attempting to quantify one ( downforce ) against or VS "reduced" lift. it was a purely semantical question, and the answer ultimately doesn't matter as i was NOT ( again ) attempting to quantify one over the other. but thanks for trying to enlighten me.

 

i take it to mean that you are thinking that the downforce and the reduced lift occur at the same place. but this wouldn't always be true.

 

yes, and no. my confusion stemmed from the fact i couldn't figure out how ( other than semantically! ) there could be any "difference" btw "downforce" and "reduced lift", but i now see they are not interchangeable as either terms,.. OR phenomena, and that they are NOT one and the same.

i think.. whew!

 

https://www.6speedonline.com/forums/...g-harness.html

 

Ya. It has to be. I designed the Aero for my vette and it makes 1600# at 150mph. At 75, I can barely tell it's there unless I'm in a huge sweeper. If it's under a few hundred pounds, it's not worth much. Probably better for mpg over grip.

 

Very different. Lift is due to poor aerodynamics and packed air. Lift creates drag and bad grip. You can improve that and get zero downforce but improved performance. Down force creates extra weight over sections of the car but can also make or increase drag. It takes a massive amount of R&D to make a big downforce car that creates no little drag. Diffusers is usually the biggest help there. Flat bottom cars is the ticket there.

 

I'm beginning to understand the difference! thx for taking the time.

 

The gt2/3 front bumper is a good example. The vent on top pulls from the bottom, reducing lift under the front of the car.

 

that i understand ( whew ). so this, in conjunction with the downforce created by the gt2? ( or even moreso using the gt3 blade + increased height relative to the lower gt2 rear wing ) work in concert with one another?? to keep the front "lift" reduced ( front splitter/lip? ), while doing much the same thing for the rear of the car..e.g. "downforce".

so that's all they are designed to do..yes? keep the car as low to the ground as is possible overcoming the laws of physics that want it to "fly"? sort of??

is that all there is, besides the physics of one over the other e.g.; front to rear proportionality?

if so, then i'm catching on ( however slowly ). everyone else has known all this already, no doubt.

 

Just think of a car as a teeter toter. (Sp?) If you push the back down, the front comes up, vise versa. I had to add a 4" splitter to balance my 70" wing with a 12" cord(width). My wing is designed to create 1200# at 170 mph. The force exerted doesn't necessarily mean 50/50. Like 500# in back, and 500# in front. It's tuning just like a ecu. Trial and error. My wing makes way more than my splitter, but its balanced.
I took an instructor out once because I was losing grip on a dog leg that was about 140mph. Full throttle corner. I thought I was off line or doing something wrong. We discussed it and added just 1° to my wing and it then stuck like glue. It's awesome to see that stuff really work. If you look at the bottom of a 458 Ferrari, it's all flat with a diffuser and blades to accelerate the air off the back. That car makes 800# of downforce with just that, so its zero drag. Back when racing was racing, the old f1 cars and prototypes aimed their exhaust gasses over the diffuser and wings to add downforce. I think the new 918 uses that technology for high speed downforce. Fluid dynamics was always my favorite subject in school.

 

appreciate the info. i'm trying to understand the vast difference btw front aero splitters and wings of various sizes on the rear and without having wind tunnel results ( which i wouldn't understand anyway ) this is the next best way. thx for explaining it.

 

I'll never forget the account I read by a driver who had just switched to Porsche and was having issues with a turn losing grip. His crew chief told him - go faster! He finally did and the car stuck like glue. Neat stuff!

 

thats it! stick it like glue.. we don't need no stinkin downforce ha!

 

Driving with downforce is scary at first. The invisible hand pushing you down.

 

or like the earlier 911 variants, never lift the throttle in a turn... Certain rules eh?

djcooper@rennkit.com