I think there are several reasons and I'll put them out there for consumption:
Houston Raceway Park is at like 7ft of elevation. We have dense air here almost all year long. This is the main reason, IMO, why I can run these times.
I stage shallow. Which is to say that I stop as soon as the second staging light comes on. This means I get a very, very short rolling start before the timers start to help get a good time. If it's a heads-up race, then I tend to stage deeper so as to shorten the length of the track. This doesn't sound like much, I'm sure, but it is the sum of the parts that add up.
I don't run with the tailgate, spare tire, front metal shield under the engine (because I have to remove it anyway to route my nitrous line), floor mats, jack, tools, nada - I even take out my CDs. However, I do usually leave the baby seat in just for effect.
I have a lot of runs and know what it takes to get the best 60' times on my particular truck.
I only run with an 1/8 tank of gas or less. Most of the time I have the low fuel light on when I get to the track. For reference, I weight about 180#.
Immediately after passing through the end of the 1/4 mile, I turn on my heater full blast. It is always on full blast unless I am in the burnout area and making a pass. The heater is just another radiator so I use it to cool down. I pop the hood whenever I'm stopped to let the heat out. I have not used ice on the intake yet because it gets a little messy and I don't want to have to deal with it.
I do run the throttle bypass mod for the cooling hoses. This has been subject to debate but I believe in it for a few reasons.
I run the front tires at 50psi.
All utility bed items are removed.
That's everything I can think of that I do at the track.
My mods:
Stock airbox with the inner tube cut out with a K&N drop-in air filter.
Banks cat-back exhaust.
Resonator mid-pipes replaced with custom made mid-pipes. These are stepped 2" coming out of the cats to 2.5" for the slight bends and then 3" to the Moroso Spiral flow mufflers (3") and then 3" to the Banks.
17" off-road wheels with P275/60-17s on them for about 3" less tire height and better gearing.
And the small wet nitrous system.
Remember when I first started out I was running 15.4s. I got 15.3s when I figured out how to launch it. 15.2s with the weight removal. 15.1s with the Banks. 14.9s with the mid pipes. 14.8s(14.79) with the shorter tires.
By the way, a Volant will be on the way shortly. I chose it mainly due to the fact it was "fixed" with a second generation box to make it better and the fact the engine breather lines are downstream of the mass air sensor and not in front of it like the K&N CAI does. I don't necessarily agree that it is the oil in the K&N filters that ruins the sensors (as I have run several on other FI cars with MA meters), but the oil vapor being sucked in from the engine intake vacuum is definitely not helping, IMO. I will most likely put individual breathers on the valve covers and plug the lines on the intake tube just to keep things "cleaner" going into the engine.
I have yet to dyno the engine. I made my hp calculations off of a performance calculator by inputting the weight of the truck and the MPH from the timeslips.
