Gears and Tune
 

I am planning on adding: Bottle heater, dyno tune with a flip chip, and 3.90 gears. My trap speed right now is about 110mph in the 1/4 mile at 800psi. What kind of a trap speed should I expect from these changes? Ill have the bottle pressure at about 1000-1100psi. Gears do increase the speed dont they?

Your trap is already pretty strong if you ask me for your setup. I would have normally expected about a 106 - 108. I assume you have a 100 shot.

I think you may be able to pull a 115 + with that heater and gears. You could run even higher if you start loosing more traction down low which I suspect may be your problem.

Keep in mind, you trap speed is a function of two things: how much power you are making and how much traction you are loosing at launch. Cars that slip down low will typically trap higher because they are spinning through the gears sooner. Remember in the end, your actually trap speed will depend on what gear you are in and at what rpm. Cars that have traction problems, will be running at higher rpms when they cross the finnish line.

So, changing gears, could result in a large traction issue especially on the spray.

genearly speaking you lose MPH with gears almost always this is true. but with the bottle heater and a tune that should compinsate for it i would say you will trap the same or slightly high with a lower et.

Spike is right! but your also gettin a tune, that should help a bit and pick up some MPH :confused: With the bottle heater what you will get is consistency by running the same pressure ;)