Thats a 28" tall tire, and that is a LOT of tire for the stock 3.31 gear You would do better with a 275/50/15 (26" tall). My car will bog with 3.73s and a 275/60/15 tire if I don't launch above 4K, and it makes 740 ft/lbs.

Work on the launch technique, SLIP the clutch to keep the rpms up, and go to the floor with the gas when you start releasing the clutch. That will help some, but I honestly don't think you will ever get it to NOT bog without a gear or tire change.

 

I agree with Steve. A 28" tire is a lot of tire for your set-up and is hurting your gearing a good bit.

 

I feel that you have a few things against you. Tires are too big (for the lack of gear), too low of tire pressure, not a big enough burn out either, and you're launching too low.

If you're gonna stick with the 3.31 gears for now I'd try reving the motor 5000-6000 and quickly slip the clutch no dumping it. That should bring your 60' down a good bit and get you closer to the 11's like you should be.

 

I don't really want to swap gears because the way the trans is geared the final drive is actually steeper than the 3.31 lets on. When I'm slipping the clutch should it be just as fast as pressing the accelerator down?

 

Then move to a smaller tire, thats really the only other option. A 275/50/15 will be 26" tall and will be more suited to your combo. And yes, the foot should go to the floor while the clutch is being slipped. That way the rpm's will stay up and get the car under power faster.

 

Indeed.

5000+ rpm launch, slip the clutch, and it'll leave hard. Hard enough that you'll want to upgrade to some control arms like these as soon as you can afford them.

http://www.uprproducts.com/mustang-c...ushing-05.html

 

I'm getting those as soon as I get back from Ireland next month.

I've been working on launching this week with just the street tires and am getting even those to hook up a lot better than I could before. What I'm doing is holding the rpm's up high and letting the clutch out until I feel the car move. Then I just stand on the gas and slip/dump the clutch the rest of the way. Is that how it's supposed to be done?

 

For the most part yes but I've always gradually got on the gas as i slip the clutch insread of standing on it but if this is working for you then roll with it man!!

 

I kind of like the larger tires because I can stay in 3rd longer which pulls a lot harder than 4th. I'm not having to shift into 4th until I'm just about to cross the line. Maybe it evens itself out?

 

Definitely learning a lot on this thread. We gonna find out tomorrow if the learnin' I've been getting pays off.