CLASS RACER FORUM

CLASS RACER FORUM (https://www.classracer.com/classforum/index.php)
-   Bracket Racing (https://www.classracer.com/classforum/forumdisplay.php?f=19)
-   -   altitude change problem (https://www.classracer.com/classforum/showthread.php?t=71363)

Sam Ehret 10-29-2018 12:02 PM

altitude change problem
 
When I race at Tuscon, el. 3300 ft and DA of 5000 ft I can hook the car and am consistent with 60 ft times. 10.8's at 125 mph(5200 da)
I'm having a problem blowing tires off in Phoenix that is 1200 ft and usually has a DA of 2500-3000 ft. best 10.68 at 125 mph(2200 da).
What should I do different in Phoenix?

Jeff Stout 10-29-2018 04:12 PM

Re: altitude change problem
 
I'm guessing your tune up is set for Tucson? Im usually .25 to .28 faster in Phx. and about 3.5 MPH faster also. Im the opposite and set up for Phx air Sounds like its lean and excessive timing in Phx altitude in which helps bottom end power but hurts the rest of the pass. Just guessing

Jeff Stout 10-29-2018 04:24 PM

Re: altitude change problem
 
Looked up in my log book and found similar DA numbers and at 3000 difference I was .22 faster in Phx. I have changed timing and opened valve lash to compensate when its really bad in Tucson.
Also converter acts different and track prep will come into play.

Sam Ehret 10-29-2018 04:34 PM

Re: altitude change problem
 
Thanks Jeff, I was considering adding a carb spacer in Phoenix, along with a couple thou tighter lash. Tire pressure and shock adjustment don't seem to help. I think the track is worse at WHP.......just guessing....Ill try a bit less timing also

RobbieRacer 11-06-2018 03:16 PM

Re: altitude change problem
 
If your there for Drag and Drift night, it's the track. At Team races and big events it hooks pretty good.


All times are GMT -5. The time now is 05:10 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Copyright Class Racer.com. All Rights Reserved. Designated trademarks and brands are the property of their respective owners.Ad Management plugin by RedTyger