NHRA
Jim Underdahl Atlanta preview
Atlanta Dragway
Edited: May 12, 2011, 11:53 PM
Copy link
Share on Viber

Underdahl works to control effects of Atlanta's humidity; PSM rider relies on engine changes and data to get down the track

Jim Underdahl competes against Steve Johnson during round 1
Photo by: Ted Rossino
ATLANTA, Ga. - When a meteorologist talks about humidity, he is usually referring to the amount of water vapor in the air and how that makes us feel. When NHRA Pro Stock Motorcycle rider Jim Underdahl talks about it, however, he is referring to the density of the air, the number of grains of water, and how that affects his motor's combustion and his on-track performance. This weekend, at the Summit Racing Equipment NHRA Southern Nationals at Atlanta Dragway, Underdahl and his crew chiefs will be keeping a close eye on the water in the air - and on the ground.
"Last year in Atlanta it was hot and humid, and we struggled to get down the track. We qualified, but not with the numbers we thought we should have been running," Underdahl said. "This year, the forecast is calling for humidity and rain, so we'll have to pull from the data we got last year to adjust our tune up."
Friday's forecast in the greater Atlanta area calls for a high of 85 degrees and a 40 percent chance of rain, followed Saturday with a forecast high of 79 degrees and a 70 percent chance of rain. Sunday's forecast calls for a 20 percent chance of rain with a high of only 72 degrees.
"I'm not a weather man, so I can't tell you what's going to happen, but with Saturday looking bad, it makes any chance we get on Friday that much more important to get down the track and into the show.
We'll take it one lap at a time, and not worry about the weather or anything else we can't control.
Jim Underdahl
Water on the track will stop racing; water in the air stops combustion, and modern science has proven it. NASA engineers reported: "water vapor reduces engine power in proportion to the amount of vapor present, and power is directly related to the consumption of oxygen." According to Underdahl and his crew chiefs Greg Underdahl and Ben Kriegsfeld, the team has already taken steps to give them more control over that mix so they can keep the power production up and the elapsed times down.
"Over the past week, we worked on our carburetors to give us a more open tuning range. That means we should have more control over the fuel-to-air mixture that is especially important when we're fighting water in the air. Those changes combined with what we learned last year and our performance advancements this year should give us a boost getting down the track," Underdahl said.
"Really, though, I'm just excited to be working at getting our Suzuki Extended Protection bike down the track and into the show on Sunday so we can win some rounds and move up in the points. We'll take it one lap at a time, and not worry about the weather or anything else we can't control," he said.
-source: jim underdahl PR
We want your opinion!
What would you like to see on Motorsport.com?
Take our 5 minute survey.
- The Motorsport.com Team
Read and post comments
Read also :
Share Or Save This Story
Copy link
Share on Viber
Previous article Shawn Langdon Atlanta preview
Next article Don Schumacher Racing works on cockpit saftey
Top Comments
There are no comments at the moment. Would you like to write one?
View More & Comment
More from
Greg Underdahl

Jim Underdahl Seeks To Maintain Momentum At Norwalk
NHRA
NHRA
Jim Underdahl Seeks To Maintain Momentum At Norwalk

Jim Underdahl Englishtown Final Report
NHRA
NHRA
Jim Underdahl Englishtown Final Report

Jim Underdahl Looks For Win At Englishtown
NHRA
NHRA
Jim Underdahl Looks For Win At Englishtown
Latest news

Spire claims Joe Gibbs Racing is now seeking nearly $150m in damages
NASCAR Cup
NAS NASCAR Cup 1 min
Spire claims Joe Gibbs Racing is now seeking nearly $150m in damages

Inception Racing switches to Corvette for 2027 IMSA GTD season
IMSA
IMSA IMSA 5 min
Inception Racing switches to Corvette for 2027 IMSA GTD season

Cadillac reveals date for F1 engine factory debut, thanks drivers for being “patient”
Formula 1
F1 Formula 1
United States GP
7 min
Cadillac reveals date for F1 engine factory debut, thanks drivers for being “patient”
Subscribe and access Motorsport.com with your ad-blocker.
From Formula 1 to MotoGP we report straight from the paddock because we love our sport, just like you. In order to keep delivering our expert journalism, our website uses advertising. Still, we want to give you the opportunity to enjoy an ad-free and tracker-free website and to continue using your adblocker.
You have 2 options:
- Become a subscriber.
- Disable your adblocker.
Subscribe now Already subscribed? Sign in here
Already disabled your adblocker?
Reload page
Manage Alerts
Subscribe
