what RPM should i lauch at?
03-31-2015, 11:22 PM
#1
Le Mans Master
Thread Starter
what RPM should i lauch at?
Ok guys, the drag strip is going to open tomorrow(wensday) here in Indy. Reckon I am gonna try and make it and see what the 86 will do. heck, its only 20 bucks for the "test and tune" day. Its a auto, Z-51, with the 307 rear end. 1986. Whats the best RPM to launch ? Aint much of a driver but want to set a base line b4 putting on the stuff I have bought to make it go faster. Its stone stock. At some point, I want it to be into the 13s. Got the headers, vortec heads, eldelbrock manifold and their runners waiting in the cob webs of the garage. Hoping for at least a low 14 as a baseline.
03-31-2015, 11:29 PM
#2
Le Mans Master
Your limited by the converter in the automatic. I believe stock is 1400 RPM. So you want your foot on the brake and the other on the gas to bring up the RPM's to about 1200+. Release the brake and hit the gas on the LAST yellow light. Don't wait for the green. Your reaction time will be right on if you hit it at the last yellow.
Leave the auto in Drive..not over. Add air to front tires...about 40 psi and drop rear tires to about 30 psi to start.
You will probably be in the mid 14's if your stock.
Leave the auto in Drive..not over. Add air to front tires...about 40 psi and drop rear tires to about 30 psi to start.
You will probably be in the mid 14's if your stock.
04-01-2015, 09:11 AM
#3
Le Mans Master
...... Just go from idle ... that way you will flash stall the converter as far as it will go ... leave on the last yellow ... practice , practice , practice .............
04-01-2015, 10:27 AM
#4
Team Owner
Pro Mechanic
Unless you're racing someone else, leave the line when you want to....when you are ready. Timer start when your front tires clear the beam, so if you're going for best ET, leave after the green, when you are ready and focused.
04-01-2015, 11:30 AM
#5
Le Mans Master
It also depends on what tires your running, street tires will break loose pretty easy if you launch while running up the rpms and locking the brakes , with my car if I do this I'll just sit there and spin......If your running slicks it won't matter ...For street tires I would say go from an idle like mentioned above...Go find an empty parking lot this afternoon and practice a little before you go to the track tomorrow....
..Also , do like Tom says above, you just want to see what times your running ,nothing worse then jumping the light.....WW
..Also , do like Tom says above, you just want to see what times your running ,nothing worse then jumping the light.....WW
Last edited by WW7; 04-01-2015 at 11:40 AM.
04-01-2015, 09:41 PM
#6
Le Mans Master
Thread Starter
is some good advice here, thanks guys. Just got back from Lucas oil Raceway @ Indy. Did 4 runs. Best launch was off idle with NO burnout. You guys ever get wheel hop? felt like it on two of the runs.
04-01-2015, 09:53 PM
#7
Team Owner
Pro Mechanic
I've never gotten wheel hop with my C4. Used to get it ALL THE TIME in my C6. Irritating as ***. Never in the C4. Very easy car to burn out, and launch.
04-01-2015, 10:02 PM
#9
Team Owner
Pro Mechanic
Well can you post the numbers? hard to give any advice with little to no info. All we know is you may have gotten wheel hop.
For example, if you pulled a 1.8 sixty foot time, you can't very well improve on that (in a stockish car on street tire). Don't know what you did or what happened.
For example, if you pulled a 1.8 sixty foot time, you can't very well improve on that (in a stockish car on street tire). Don't know what you did or what happened.