DA / Ignorance Rant

[Logan1234]

I'll start by saying that I'm pretty patient with kids who are learning about cars but magazine racers who know everything and/or aren't willing to listen/learn can be pretty annoying.

My car (2012 SS M6) is stock with 600 miles and I ran several 13.7's @ 106 (2.1 60') tonight. There were two teenage guys (separate conversations) that came over to talk about my car.

The first kid tells me I should be running a 13.1 because that's what they run in Motor Trend. I told him I completely agree but with poor traction, high temperature (83 degrees), humidity (22%), and track altitude (1470') the DA is probably over 3000' (actual was over 3600') which is like being down 30-40 horsepower and causes slower times. His reply was "yeah, but you should be running like 13.1's".

Same kid later told a high boost SRT-4 that his dad's Hemi Ram would blow the Neon away.

The second kid comes up and says 13.7 is pretty good for a V-6 so I tell him no, it's a V-8. I tell him the same thing I told the first kid and he pauses, tries to process what I've told him, then replies, "so it's not a V-6"?

Side note: My wife's 2011 5.0 Mustang M6 (3.73's, K&N Air Filter, & Flowmasters) ran 13.3's most of the night; she would slowly catch up and creep by in her 3rd & 4th gears while I was winding out 3rd gear.

[The_Blur]

Not everyone is going to understand the math and science of racing. Personally, I'm terrible at estimating track times based on dynos, weight, and conditions. I recognize the influence of conditions because at some point it was explained to me that humidity and other factors can really influence how fast a quarter mile is.

A lot of kids get into cars because they want something cool to drive and it's a nice way of escaping what they have to do daily. Depending on the age of the kid, we could be talking about getting away from school, and a car hobby would involve less thinking than doing their homework—a kind of break from their assignments. What's ironic is that cars require advanced engineering, and a lot of kids grow up loving certain cars without realizing how the topics they study by requirement could someday place them in a wind tunnel with the next hot item on 4 wheels doing calculations to see how it will perform.

[SGOS252382]

I run 12.1 and some kid in a stock VW GTI thought he could beat me.
Its frustrating, but I've learned to just ignore them. They have to learn everything the hard way.

[Pro Stock John]

I don't typically humor folks who don't really know what a given car can/can't run.

my car ran 4 mph slower the last time I was out, that was a bummer. My cars have always slowed really bad right after it rains...

[SGOS252382]

Originally Posted by Pro Stock John

I don't typically humor folks who don't really know what a given car can/can't run.

my car ran 4 mph slower the last time I was out, that was a bummer. My cars have always slowed really bad right after it rains...

Yeah, a combination of warm and humid air will really slow you down. I used to go to our local 1/8 mile every Friday night. Frequently in the summer, we would get an evening thunderstorm. I'd wait and run my car once the track dried. My car would always run a tenth or two slower after the T storm. My engine didn't like all that added moisture in the air.

[Pro Stock John]

In the past, I hardly had a car a month before I started making changes. I'm at 5 weeks and I'm already dying to change stuff because I can't imaging running mid 13's all summer.

Another pet peeve for me is the "whydontcha" crowd.

"Why dontcha add a blower you'll go low 12's..." Ughh.

[blackflag]

13.7s sound right for that DA. Also less power = slightly slower 60' time.

[Cuda7050]

Originally Posted by Logan1234

I'll start by saying that I'm pretty patient with kids who are learning about cars but magazine racers who know everything and/or aren't willing to listen/learn can be pretty annoying.

My car (2012 SS M6) is stock with 600 miles and I ran several 13.7's @ 106 (2.1 60') tonight. There were two teenage guys (separate conversations) that came over to talk about my car.

The first kid tells me I should be running a 13.1 because that's what they run in Motor Trend. I told him I completely agree but with poor traction, high temperature (83 degrees), humidity (22%), and track altitude (1470') the DA is probably over 3000' (actual was over 3600') which is like being down 30-40 horsepower and causes slower times. His reply was "yeah, but you should be running like 13.1's".

Same kid later told a high boost SRT-4 that his dad's Hemi Ram would blow the Neon away.

The second kid comes up and says 13.7 is pretty good for a V-6 so I tell him no, it's a V-8. I tell him the same thing I told the first kid and he pauses, tries to process what I've told him, then replies, "so it's not a V-6"?

Side note: My wife's 2011 5.0 Mustang M6 (3.73's, K&N Air Filter, & Flowmasters) ran 13.3's most of the night; she would slowly catch up and creep by in her 3rd & 4th gears while I was winding out 3rd gear.

I also find it very annoying to see magazines run a car on some dusty, dirty abandoned air strip and then post the recorded time as some official 1/4 mile time. It may not hurt a low hp car much, butit kills high horsepower cars with relatively small tires. You can't quantify the benefits of a well prepared track on cars like the Camaro LS3.

[6point2]

Went to a track last weekend and the DA was over 7600. It gets frustrating looking at the times on here as people with a CIA and Exhaust have better times than my Supercharged LS3 :( Then we have the same people who walk up and say things like "that should be in the high 10's with your mods.... nope, not here.... lucky to break into the 11's.

[Cuda7050]

Originally Posted by 6point2

Went to a track last weekend and the DA was over 7600. It gets frustrating looking at the times on here as people with a CIA and Exhaust have better times than my Supercharged LS3 :( Then we have the same people who walk up and say things like "that should be in the high 10's with your mods.... nope, not here.... lucky to break into the 11's.

Yep, had a car that ran 10.40s at sea level then 11.70 in Denver if memory serves me correct. I find it even more fustrating when you get that rare day with -350' DA and all you do is blow the tires away.

[FNBADAZ06]

If you want to read up on Density Altitude and it's affect on your car's power output, check out my thread on CorvetteForum that discuss' this in detail

The more you know about the workings of your car and the impact local weather conditions have on your performance envelope the happier you'll be.

http://forums.corvetteforum.com/c6-z...-about-da.html

[Pro Stock John]

My old rule of thumb was that I would run a tenth slower for every 700 increase in DA.

I remember once years ago running 11.7@113 locally and then running Bristol the next weekend, in the heat and high DA I cranked of a 12.4@108.

[Cuda7050]

Originally Posted by Pro Stock John

My old rule of thumb was that I would run a tenth slower for every 700 increase in DA.

I remember once years ago running 11.7@113 locally and then running Bristol the next weekend, in the heat and high DA I cranked of a 12.4@108.

Nice! My rule of thumb used to be .08 for every 1000ft DA change. But its diferent for diferent cars. I used to win allot of races because of my extensive records on how my car was affected by DA, wind, traction and time of day nuances at individual tracks. But since computerized ET predictors became the norm most of those knowledge based advantages are available to even the newest drivers.