Factors that will affect your 1/4 mile time: Newbie's must read!!!

[Doppler Bob]

Ok everyone. Just as some background about myself, I'm a 23 year old who had the fortunate luck of growing up with a father who owned a very successful drag strip for 22 years (New York International Raceway Park in Leicester, NY near Rochester). Over the years I've gained insane insight into the world of drag racing, some of which most average or inexperienced racers would never know or even consider to be a factor in your times. Here's some, and please do add if I missed anything.
1. WIND
Most racetracks have an American Flag a flyin'. My father had one right next to the starting line. It wasn't happenstance... he put it there so that racers could look to see the wind direction and roughly how fast it was moving. A headwind slows down cars up to two to three tenths (thats like a 15.0 vs. a 15.3) Crosswinds (perpendicular to the car) can also slow you down, and a tail wind can help you gain speed and lower ET. Remember this and take note when you run!

2. Heat/Humidity
I have a degree in meteorology and in a bunch of physics classes I really got to figure out how heat and humidity affect motor performance. Heat is the number one power reducer, which is why we are always trying to eliminate it (TBS, COLD air intake, interCOOLERS). A hot day will slow the car down, its just how it works. Consequently, too cold will also have adverse effects.

ALSO, and even some advanced racers may not know, but tracks have an ideal temperature as well. Traction compound turns to sludge when its too hot, especially when the sun is overhead. Most of the fastest runs occur after 3pm or so, or even near dusk, when the track isn't sucking in all the light from the sun. Ideal track temp is about 68 degrees or so, which means early or late season for most. Now this effect with street tires is far less that those with 500hp, and slicks, obviously.

Humidity, you simply want less. The more humid it is, the less oxygen there is, the lesser the "quality" air going into your car.

3. WEIGHT
I've seen people take out spares/seats etc. Maybe even go on a diet? LOL. What about gas? I see so many people show up to the track with a FULL tank of gas. FYI, a gallon of gas weighs 6.18lbs. Our fuel capacity is 13 gallons. You do the math... but I don't like an extra 60 lbs in my car if I don't need it. Figure out the mileage to the track and then leave home with the bare minimum for your truly ideal times.

4. I think that if you post on here, especially for newer or more inexperienced people... you should list all applicable mods, the RPM you launch at, and whether you power shifted or granny shifted. Some people don't know how or aren't willing to power shift and that is pretty much the difference between the 15.2 guys and the 14.9's stock.

5. Altitude
Some tracks will be able to tell you, or you can find an experienced racer in the pits with the handheld computers that give you the altimeter. This also effects engine performance based on air density most of the time. Higher pressure will usually give you a better running car. Consequently, high pressure usually means sunny days too!

6. For our cars (Si's etc.), unless you are putting down insane horsepower, there is NO NEED to roll through the water. I go right around. You're immediately giving yourself a disadvantage by dirtying the tires and wetting them. Heating them up will take off miles that they could be used for, and will give you a negligible effect if any. Just get better tires in this case.

7. Tire pressure
How many of you have a pressure gauge in your glove box at the track? How many use it? This is HUUUUUGE when dealing with traction/top speed/etc. Check tire pressures and play with them to find your ideal spot. You want a balance between traction and top speed. Experiment! Most tracks have free air somewhere on sight ( or make buddies with someone who has an air tank!)

8. Talk to other racers
There is ALWAYS someone who knows more than you. Lanes at certain tracks can make a huge difference. At my dad's, the right lane is always faster for some reason. That could be a huge difference.

9. Analyze and PRACTICE, PRACTICE, PRACTICE!
Read the time slips at each part. Figure out what they mean if you don't. Compare with others on the board to see where you are and where your weaknesses are. This will tell you what you have to work on. MPH and 1/4 time can't be their best until your 60', 330', 660' and 1000' are perfected!

I hope this gets you started on your way to drag racing. I strongly urge anyone to try it out if you haven't before. It's safe, fun and god I love the smell of the track. Good luck!

[anavrin351]

nice write up. i plan on taking my car out for the first time this summer. It will also be the first time i ever ran a car before.

[GeezerSi]

Valuable write up! Thanks.

[ImAuthenticFTW]

nice write up man, about number 7 the tire pressure, If your on the stock tires i find it best to leave them at the normal tire pressure, these cars are not puttin down insane power and torque. If you can control the throttle and clutch right you can get a decent launch, by lower the pressure of your tires you are killing top end.........

[wallytiburon]

Originally Posted by ImAuthenticFTW

nice write up man, about number 7 the tire pressure, If your on the stock tires i find it best to leave them at the normal tire pressure, these cars are not puttin down insane power and torque. If you can control the throttle and clutch right you can get a decent launch, by lower the pressure of your tires you are killing top end.........

Won't it [lowering your tire pressure] also turn on the VSA on the 08s?

[ImAuthenticFTW]

Originally Posted by wallytiburon

Won't it [lowering your tire pressure] also turn on the VSA on the 08s?

not the VSA but the TPMS....
VSA= something like Vehicle Stability Assistance
TPMS= Tire Pressure Monitering System or something close

[mike07si]

Originally Posted by ImAuthenticFTW

nice write up man, about number 7 the tire pressure, If your on the stock tires i find it best to leave them at the normal tire pressure, these cars are not puttin down insane power and torque. If you can control the throttle and clutch right you can get a decent launch, by lower the pressure of your tires you are killing top end.........

Word, normal radials cup and lose surface area when run at below optimal pressure, which means less traction.

[mako8]

great info there. i would like to get out this summer for the first time and this is good specifics to know.

[wallytiburon]

Originally Posted by ImAuthenticFTW

not the VSA but the TPMS....
VSA= something like Vehicle Stability Assistance
TPMS= Tire Pressure Monitering System or something close

In the manual it says if TPMS is out of wack, VSA automatically turns itself on and cannot be turned off until the TPMS issue is dealt with.

[Doppler Bob]

I should add, maybe in an edit... remember that tire pressure responds to temperatures changes. I've heard estimates that a 10 degree increase in temp = 1psi gain. Air expands when its warm and contracts when its cold.

[Bboy_Burst]

Originally Posted by Doppler Bob

I should add, maybe in an edit... remember that tire pressure responds to temperatures changes. I've heard estimates that a 10 degree increase in temp = 1psi gain. Air expands when its warm and contracts when its cold.

yes, that is correct. oh and nice write up

[galaxygrey13]

Im gonna print this out and read it before i go to the track. Good info. I would rep you but it seems everyones repping powers have been jacked.

[Alpineinstaller]

I was running ~15.2 at 32 psi, I dropped the pressure down to 20 psi and was running constant 14.8-14.9.

And no the VSA did not come on when the TPMS tripped.

[Doppler Bob]

Originally Posted by Alpineinstaller

I was running ~15.2 at 32 psi, I dropped the pressure down to 20 psi and was running constant 14.8-14.9.

And no the VSA did not come on when the TPMS tripped.

No kidding. Honestly, I didn't check my tire pressure this time

I'll try a few different levels next time out though. You saw that much of a difference at the launch eh? How did it effect mph?

[ImAuthenticFTW]

Originally Posted by Doppler Bob

No kidding. Honestly, I didn't check my tire pressure this time

I'll try a few different levels next time out though. You saw that much of a difference at the launch eh? How did it effect mph?

exactly why i leave mine where they are on street tires, by lowering the pressure your killing your top end thus lowering your trap speed. i managed to still pull a 2.2x 60' time on the all seasons at that! Like said before if you can control your throttle and clutch you can still get a decent launch. these cars dont have alot of tq making it to the ground.

[SoCal07Si]

Good write-up.

+1 imaginary rep for you!

BTW, I've been doing the drag racing thing for 14 years. One thing I wanna add, we know that heat in your engine bay is a bad thing. Pop that hood open while your waiting in-between runs.

[ImAuthenticFTW]

Originally Posted by SoCal07Si

Good write-up.

+1 imaginary rep for you!

BTW, I've been doing the drag racing thing for 14 years. One thing I wanna add, we know that heat in your engine bay is a bad thing. Pop that hood open while your waiting in-between runs.

yea pop the hood, and shut the car off....but at the same time, be watchful of your temp, if it drops too low in these cars vtec wont engage. ive seen it happen a few times a tracks with long waits between runs.

[User_name:]

Need to put Barometer in your weather

[Doppler Bob]

Originally Posted by SoCal07Si

Good write-up.

+1 imaginary rep for you!

BTW, I've been doing the drag racing thing for 14 years. One thing I wanna add, we know that heat in your engine bay is a bad thing. Pop that hood open while your waiting in-between runs.

Very true... you don't want an ice cold car. But on hot days with a lot of sun, it won't cool off that quickly anyways so any heat you can get out of that bay is good!

Barometer too, but usually fair weather equals decent pressure.

[wallytiburon]

Last time I'll type this just so you guys know...

From the manual: "If the low tire pressure indicator or TPMS indicator comes on, the VSA system automatically turns on EVEN IF THE VSA SYSTEM IS TURNED OFF BY PRESSING THE VSA OFF SWITCH."

Emphasis added.