Okay, so my car- 2005 mustang gt. Procharger @9lbs, functional shaker hood scoop, 4:10 gears, its lowered 2in in front and 1 inch in the back. With 295/35/18 tires in the back. Im taking it Thursday to get dynoed. Im expecting 440 rwhp out of it. Now for the list of questions. Mostly about the launch- just messing around on the street my launches in 1st have been nothing but spinning... which is no good. Would it be to hard on my clutch and everything if i put it in 2nd and dropped clutch @2000rpm. So it'd spin little then hook and go? Just would like some advice on that subject. Also im new to 5 speeds and everything, so if some of my questions are dump that is why. Also a buddy of mine told me to shift without letting off the gas??? Is that okay to do? Or would i hurt something doing that? Oh and what do you guys think my 1/4 mile et should be with a "good" driver.
Sounds like you've picked up a pretty mean GT, congrats!
Launching in 2nd gear will definitely cause more strain on your whole Drivetrain, so I don't recommend it. Plus, flat footed shifting is risky if a shift is missed or the wrong gear is entered. Both of these techniques are pretty rough on the whole Drivetain even when they do work. If you're looking for more traction, there's a few of other ways to approach this issue.
First off all, if this car is not your daily driver, I highly suggest picking up a set of Drag Radials. With 440rwhp, you're going to need a serious tire to help plant all of that power to the ground. Picking up a set of 305/35/18 Mickey Thompson ET Street Radials
will be a night & day difference for getting traction on the street or strip.
Your rear 4.10 differential gears are very aggressive, but that's necessary not a bad thing. All this means is you're going to need more suspension mods to prevent traction loss with the fast acceleration from the 4.10's, so I wouldn't change them with your current setup, since you'll be finishing the quarter mile at the top of 4th gear.
The next step would be aftermarket Lower Control Arms
(LCA's) and Upper Control Arms
(UCA's). Most aftermarket companies will have a much stiffer than factory control arm available to help prevent dreaded wheel hop or wheel spin. Whiteline has designed one of the highest quality LCA and UCA on the market today, so needless to say- they'll help any Mustang hook up on the pavement.
Since your GT is already lowered, the suspension geometry will be off quite a bit, causing more traction issues. Whiteline resolved this issue by developing a LCA Relocation bracket
to help lowered Mustangs correct their suspension geometry for more improved traction.
As you already know, traction is key for any performance car! If you started with these 4 modifications right off the bat, you won't be nearly as worried about traction anymore. These mods should drastically help you launch your Mustang from a steady RPM in FIRST gear and cut a solid 60' at the drag strip or launch harder on the street. Of course there's several other suspension mods that will help with traction too, but these are good basics to start with. I'm sure you won't be disappointed with this route for your powerful Supercharged GT.
Let me know if I need to clarify anything or if you have any other questions!