Drag Racing Fastest Truck List inside, sortable for any make/model/engine listed.
TIME SLIP DATABASE

What do you need to race?

Thread Tools
 
Search this Thread
 
Old 08-01-2017, 10:02 PM
  #11  
TECH Junkie
 
ZO6Ted's Avatar
 
Join Date: Jan 2007
Location: Arlington, TX
Posts: 3,294
Received 252 Likes on 164 Posts
Default

That was pricy imo. Lift the rear with a jack on the center of the diff. Put the valve stem at the bottom with trans in neutral and have someone rotate the tire exactly once while you are under and count the rotations of the driveshaft. That will tell you your ratio. It was a huge difference on mine but I was 4l60. I went from 9.54 with 3.42's to 8.90 with 4.10's at 5 lbs and a very mild tune. Same weather and everything. It should be dramatic.
Old 08-01-2017, 10:59 PM
  #12  
TECH Resident
Thread Starter
iTrader: (1)
 
crashmymax's Avatar
 
Join Date: Sep 2010
Posts: 759
Received 21 Likes on 19 Posts
Default

Originally Posted by ZO6Ted
That was pricy imo. Lift the rear with a jack on the center of the diff. Put the valve stem at the bottom with trans in neutral and have someone rotate the tire exactly once while you are under and count the rotations of the driveshaft. That will tell you your ratio. It was a huge difference on mine but I was 4l60. I went from 9.54 with 3.42's to 8.90 with 4.10's at 5 lbs and a very mild tune. Same weather and everything. It should be dramatic.
Going to try this when I get back home next week. Gears and true trac where just under a grand and $1300 for installation.
Old 08-02-2017, 10:51 AM
  #13  
TECH Senior Member
iTrader: (26)
 
kbracing96's Avatar
 
Join Date: Jul 2004
Location: Oakland, OR
Posts: 9,485
Received 30 Likes on 28 Posts
Default

You guys have to remember, he was in Denver CO. That track is a mile high to start with and I'm sure it was hot that day! lol. It's hard to make boost when you're at 9000'+ DA. And you have to make about 2.5lbs of boost just to get to sea level air pressure. I think he did pretty good considering the air conditions. Take that thing to sea level on a cool day and you'll be amazed at the difference!

I wouldn't spend too much effort on getting the tune dialed in up there unless you're going to be there a while. Because it should really be dialed in at a lower elevation if that's where your going to run it the most. The gears probably don't feel like they added that much because of the elevation your at right now killing power. It's huge!! I grew up in Wyo about 2.5 hours from there so I'm all to familiar with what a hp robber is from elevation. When I would got to Phoenix to "winter", it was amazing how much better my truck ran down there.
Old 08-02-2017, 12:36 PM
  #14  
TECH Resident
Thread Starter
iTrader: (1)
 
crashmymax's Avatar
 
Join Date: Sep 2010
Posts: 759
Received 21 Likes on 19 Posts
Default

Originally Posted by kbracing96
You guys have to remember, he was in Denver CO. That track is a mile high to start with and I'm sure it was hot that day! lol. It's hard to make boost when you're at 9000'+ DA. And you have to make about 2.5lbs of boost just to get to sea level air pressure. I think he did pretty good considering the air conditions. Take that thing to sea level on a cool day and you'll be amazed at the difference!

I wouldn't spend too much effort on getting the tune dialed in up there unless you're going to be there a while. Because it should really be dialed in at a lower elevation if that's where your going to run it the most. The gears probably don't feel like they added that much because of the elevation your at right now killing power. It's huge!! I grew up in Wyo about 2.5 hours from there so I'm all to familiar with what a hp robber is from elevation. When I would got to Phoenix to "winter", it was amazing how much better my truck ran down there.
Im at 3,400' in rapid city and driving around the black hills gets up to 5,100' so I figured tuning in denver would be ok. Wont the computer compensate for the elevation change? There are no competent tuner/dyno operators near me so dont have many options. You no any good ones in Wyoming? I spent a few years in Lander Wy.
Old 08-02-2017, 06:18 PM
  #15  
TECH Senior Member
iTrader: (26)
 
kbracing96's Avatar
 
Join Date: Jul 2004
Location: Oakland, OR
Posts: 9,485
Received 30 Likes on 28 Posts
Default

Originally Posted by crashmymax
Im at 3,400' in rapid city and driving around the black hills gets up to 5,100' so I figured tuning in denver would be ok. Wont the computer compensate for the elevation change? There are no competent tuner/dyno operators near me so dont have many options. You no any good ones in Wyoming? I spent a few years in Lander Wy.
The computer will adjust to a degree. Atomic should be able to keep you pretty good with some back and forth logs.

I forget you're out of Rapid, was thinking back east for some reason. Wouldn't hurt to have a Denver shop check it out. Look up J&S Performance and Tuning and tell them I sent you. They are pretty good guys in Arvada.



All times are GMT -5. The time now is 04:15 AM.