The formula for a 12 second Mustang GT/Bullitt.....
OK, I see so many people having big problems with their cars at the track, while my quest for the 12's was pretty easy and uneventful. While the majority on here are good guys, I think 75% of our younger crowd who are building their first fast car have no clue whatsoever. It's not all about horsepower guys. I have a bone stock engine, the valve covers have never even been off. I don't have a supercharger or nitrous, and I drive my car 70 miles a day back and forth to work. So for the younger guys, I'm going to save you a ton of money to get into the 12 second range and be a serious contender. In my opinion 12 second cars are where you start to get fast, so take that for what it's worth.
#1: Track Time, Track Time, Track Time......You have to do it to get better at it. Don't worry about your car being slow, or what other people think, you're on there for one reason: To work on YOUR driving. Go to a test and tune every other week, or at least once a month. I started at a 14.1, and got down to a 13.9 without doing any changes to my car, I just learned how the car wanted to be driven. Shifting at redline on a stock 4.6 will slow you down also. Play with your shift points, but I've found 5600 to be a good starting point.
#2: Tires, Tires, Tires.......Unless you've got a fairly stock automatic, you'll never be consistant on street tires. Even a stock 5 speed is hard to launch and get anywhere near decent 60ft times on street tires. My 60ft times on stock tires was a 2.2. Upgrading to BFG Drag Radials got me a 1.8. That's .4 second gain right off the starting line, and equated to a .6 gain at the stripe. There's no other mod you can do right off the get-go that will net you that type of gain without a power adder.
#3: Control Arms....... Let's face it, the factory Mustang rear suspension is horrible. Horrible for handling, Horrible for drag racing, so do something about it. There's 2 different ways to do this, and it really depends on what your goals are with the car. Lower control arms are not an option, you have to have them. I went a bit aggressive on mine, and have HPM Megabite SRs with adjustable heim joints in them. You don't have to get that serious, but you do need something better than stock with some good stiff bushings. With the upper control arms, you have to make a decision. How much money do you want to spend, and how 1/4 mile focused are you vs. handling? I went the expensive route, because I want my car to handle like it's on rails, not just be a 1/4 mile queen. I went with FRPP upper control arms and the Maximum Motorsports Panhard bar to keep the rear end centered under the car. I adjusted my pinion angle using the lower control arms to -2 degrees. However, the cheap way if you just want to make 1/4 mile blasts is to buy a set of double adjustable upper control arms, and set your pinion angle using them. The only drawback to this is that because of the geometry of the rear end, using poly bushings in the upper control arms induces some bind in the rear suspension. If you're just a casual driver, and 1/4 mile junkie, you'll never experience it though. Only if you get into hard cornering will it happen.
#4: Weight Reduction........Seriously, did you really need that double 1/4 pounder with cheese for lunch? Seriously though, it's been said that for every 100lbs you can cut off your car, you gain around .1 in the 1/4 mile, and I'd say that's pretty close to begin with on a street car. How crazy you get with this is up to you. Like I said, I drive my car 70 miles a day, so just gutting my car isn't an option. Before I go to the track, I take everything out of the trunk, including the spare tire, and I take the passenger and rear seats out, and make sure that all my crap is out of the center console. That's as far as I go, and probably 150-200lbs lighter, I would guess.
#5: Gears and Tune.....I always suggest doing these two at the same time, it just makes sense. I chose 4.10's because most of my driving is down back country roads, and road with speed limits of 55mph or less. My GPS tells me average speed for however long I want, and I've been letting it go for 2 months, and my average is 40.2mph. 4.10's in a naturally aspirated car is the perfect gear for blasting down the 1/4 mile. It will take you to the limits in 4th gear, and provide the max torque multiplication you can get. I've calculated that 4.10's on a 26" tire will be good until I'm running high 11's, then I'll have to switch to a 28" tire in order to not run out of gear. No problem. As far as the tune, at this stage, I don't think it's completely necessary to go spend $400 plus the cost of the tuner for a custom dynotune. I bought an SF3 from Holcomb Motorsports with the canned tunes in it, but never used the canned tunes at the track. To be honest, my car ran like crap with the canned tunes, because they were GT specific. I think the best deal for the money is to contact VMP, Brookspeed, or another company that will do remote tuning. They send you a base tune, which you load into your car for fairly cheap, $50-75. You then take your car to a local dyno, and datalog on the SF3 or X3 and get the air/fuel readings from the dyno operator. Then you take all that information and email to them, and they adjust your tune for you to be as close to perfect as you can get it. I think that's one of the best deals going.
#4: Bolt Ons....... Make them count. Don't waste money, period. I did buy a CAI for my car, mainly because my car didn't have a stock airbox on it when I bought it, it had a cheap Spectre filter bolted onto the back half of the factory airbox. GHETTO!!!! But honestly, you don't need one. A good paper filter kept clean flows as well as any K&N or oiled gauze filter. I know you don't want to hear that, but it's true. Dyno Proven. I would take snorkel off of the airbox, and possible open the hole up a little, and take your passenger's side headlight out while you're at the track, and the air blows straight into the filter. It's only 2 slide clips, and unplug the bulbs, not a huge task for anyone. An aftermarket shifter is one of the best purchases you can make, honestly. It will allow you to become very good at shifting your car, and the factory one is very very sloppy. Highly recommended. You can do underdrive pulleys if you want, but I made it into the 12's without them, they're still sitting in my office in the box. The only other mod I made to my car is weld in mufflers, which aren't worth any power, and I went with an off-road X pipe from UPR. That's it!!!!!!!! That's the secret, or lack of it. Because mine is a Bullitt, I do have a different intake and throttle body, but at this horsepower level, a simple plenum and throttle body combination on your stock GT intake is plenty to make up the difference. How do I know?
A friend of mine with similar mods, (different brands, but the same mods) in a GT with plenum and throttle body and I made a side by side pass down the 1/4 mile, the differences being only .04 seconds. Now that's a good run!!!!!!
My only disclaimer to this list is that I have been drag racing for 18 years, and my track is close to sea level. Different altitudes and barometric pressures will effect your times significantly. There are quite a few online calculators that will allow you to adjust your times to sea level to account for those. I do not condone using those times as "your times", but it does help you compare your times to others, such as mine that are more near sea level to see if your driving and your mods are making the difference they should.
Now, get to the track and start practicing!!!!!!
2001 Dark Highland Green Bullitt
12.25@110 naturally aspirated on a bone stock 2V longblock
Under Reconstruction for RS275 Drag Radial Class
Pushrods and Powerglide Coming Soon
If it weren't for physics and law enforcement, I'd be unstoppable.