Darren

Shhhhh stop telling people how to go faster!

911racer

Great article. I would love to spend a weenend wth the author tuning my car. I think that would get me 2 seconds easily.

I would also like to have a real suspension expert spend two days with me too just tuning the car and teaching me what to do in different situations. Antother 2 seconds.

mark kibort

now, its 4 seconds for aero plus tuning with a pro. How about another 2 seconds for the pro driving, thats 6 seconds! I ran a stock car in WCGT, with NO aero, and was only 6 seconds off the leader. So, you tell me that with aero, proper set up, (which all of the top cars had) and a pro driver, that my car would be just as fast? Hmmm, do you think the extra 200hp that the leaders had, made any difference? Oh yeah, thats 2 more seconds, SO, with all the things that are worth 2 seconds, my car could have won speedGT and beat the field by 2 seconds if it only had the power everyone else had. thats funny.

Look, I was trying to make a point that I didnt think the time was there for 2 seconds on most tracks. even with Bobs response, his time at the track included set up and instruction. I dont know the track, Thunderbolt, but I imagine if he saw real gains in lap time, i bet there were a few 80-100mph turns where grip was important, and could be helped by some nice aero mods.

Im a big fan of aero and have done a lot of testing with most all the standard mods. (ie, splitter, hood vents, fender vents, wings, but not underbody trays or diffusers yet)

I have a replica of my race car ready to go, but missing all the aero. Im going to make a point to get out to a faster track, and bolt on stuff to see the difference, on the same day. Ive always wanted to do that.

mk

mark kibort

Like I said, Chris is credible with this kind of advice, It is just a little knee jerk reaction from me, because I get so sick and tired hearing of everyone's 2 second a lap gains from rubbing magic powder into the paint.
Like I said, it really depends on the track. I dont think you can give the 2 second qualifyier at tracks that might not benefit from aero near as much.

Thats a great point you bring up last as well. for a time trial, maybe, for a race, the difference might be less. Track layout is a huge factor. You speak of back to back laps with and without a wing, and all I can say is that if you are tuned for a wing and you just rip it off, then, what you have done is more than just remove a wing, you have changed the aero balance of the car, unless you removed the splitter too. also, spring and shocks might need to be altered to really quantify the difference. Do you know the difference in speeds of a track like Road Atlanta vs tracks like Sears and Laguna. put it this way, I just saw a video of a guy in the rain at RA, that goes faster than we do on our tracks in the dry. . Point is, looking at RA, sure, all those very high speed sweepers, S's, and carocels? (even Limerock, albeit short, has a long straight and some fast turns) Absolutely, I can believe some big time to be gained there. Laguna, Sears, even Thunderhill, not so much.

How much slower were you going down the main straight, and how fast? a huge factor of drag due to downforce is speed. Again, generally, the drag loss might be 5hp at 100mph for most wings we see at the track, however, it might feel like 3x that at 150mph.

Darren

My cat's breath smells like cat food.

cgomez

Obviously we setup the car optimally (at least to my liking; shocks, etc) setup the car for each condition, including lowering the front end a bit to balance the aero effect of the front splitter with the bigger wing.
Speed loss was around 3-4mph at 140mph aprox (accelerating out of slow corner were the aero doesnt help). On a straight (like before T1 at Daytona) after a fast section the speed loss is minimal because there's compensation due to the fact you exit faster the fast corner thanks to the Wing.

I don't know why the big fuzz around this fact of science. Aero downforce has one of the largest effects on performance after tires. Its public knowledge (wikipedia stuff). That's why all rulebooks (but NASA GTS classes) put a restriction on the size of Aero aids you can use.

NASA GTS "free aero" rules are a joke. This would be the future GTS cars if they only regulate power and weight:

mark kibort

I hear you and you were on a track that was pretty fast. We, unfortunately, dont have tracks out west that pay that type of dividend here. I can remember putting my new wing on and playing with 2 degree increments, and running around the Sears Point carrocel expecting the car to be firmily planted in the rear. It helped, but it wasnt breath taking, I could still get it to step out on the exit, although much more controlable. (probalby 65mph sweeping turn, Ill have to check the guys I was running nose to tail with to see their telemetry output) didnt help times much, but it sure was a little safer on the edge.

I agree, that GTS will eventually go that way, heck, after all, Redline Time trial cars are loolking a lot like that picture you posted of the euro racers. forget about regulating only power and weight, what about absolute weight? probably more of a factor. what would you rather run, 3000lbs with 8:1 HP/weight or 2000lbs, 8:1 HP/weight? I think that they have a great thing going and Hope to do a few races this seasons with the NASA GTS group.

bobt993

Hey Gomez, DTM would certainly be interesting, but I think the tube frame moves them up one class..............

Who said anything about 6 secs a lap? I was figuring a second per corner so on a 12 turn track that would add up to more like 12 seconds if my math is correct. ................ As far as race craft, I think a very wide wing say 10 feet may make it impossible for the car behind you to pass without contact, but if your 12 seconds a lap faster, it won't matter anyways...............................

gums

I saw that article and thought that parts of it were pretty interesting, but it was largely sophomoric. Further, it misses a few points, like the Pikes Peak car that is shown with enormous wings; the real reason being because it goes into very thin air.

mark kibort

Hey, I love the discussion, but through this media, this discussion gets to be more of a bash fest for anyone taking apart, or questioning, the "numbers".
In the end, you can see my point, if you have any experience doing this stuff.

6 seconds a lap you say? How about 14.2 seconds a lap? This can be "proved" you go by everyones tried and proven ways of going faster, all of which have been argued to death here. I was just thinking about those discussions and here are where all that time comes from, including the 2 seconds for aero and 2 seconds for set up talked about here.

aero - 2 seconds
instruction- 2 seconds
pro set up - 2 seconds
hoosiers vs toyos - 2 seconds
PFCs vs Pagid -.8 second
motons - 2 seconds
stoptech - .2 seconds
smaller/lighter wheels - 1 second
pro driver, driving - 2 seconds.
More torque, same HP - 1 second

There, do all of the above, and you can take your 2:32 Road America, or 1:37 Road Atlanta racer and run 2:17 /1:22 respectively and now nearly win your class in GT2 PCA. (or 1:40 to 1:25 at Laguna Seca and beat the ALMS GT2 top pros! )

Thats where I was going with my comments. Its great to add the areo and it certainly helps, but to what extent, it really depends on so many factors.

Gary R.

You forgot this...

Bryan Watts

Thin air is not really the reason for the huge wings (thin air IS the reason for the turbo motors)...maximizing low/medium speed grip for acceleration on a slippery dirt surface, often at large yaw angles, is the reason for the very large wings on a Pikes Peak car.

mark kibort

agreed you would want more low speed grip on a slippery surfaces like dirt, etc, but keep in mind, at pikes peak, you do have 20-30% less air to push through, and if you want the same grip as you had at sea level, you need roughly the same increase in wing size. Turbos surely help fight the lack of air, by craming more air to help make up the difference, especially absolute boost designs.

cgomez

More ideas for NASA GTS:

Geo

I can't remember.... Were those a spec wing?

I read an article in Race Car Engineering a few years back about a BTCC team that didn't expect a small wing to do much. They put on a small element from a F3 car and were amazed at the improved performance. Wish I could remember the issue that was in.

Also, a few years back Race Car Engineering had a nice primer on aero, including explaining exactly how and why splitters work and had CFD data/images to illustrate. A must read IMHO.