weight in trunk

[turbochallenger]

Anyone running real street tires put weight in the trunk for traction, and what tire pressure you run?

[sst3193]

I welded blocks of scrap to the inside of the bumper of my 74 Cuda and soon found out , that it made traction more difficult to find. Friend bought a motorhome and removed a ballast bar out from under the back of it, turns out it fit perfectly, in the back seat area of my car. Putting the weight in front of the rear axle helped mine a lot more than it being behind. Car was super close to being 50/50 weight distribution and it sure made for some smooth wheelstands!!!!!!!!!!!

[Capt Jack]

Ive run sand bags, batteries, free weights, tool boxes etc in the search for moveable/removable traction.  old school trick thats still around cuz it works.  just be sure its secured well, as Ive had those items slide back and knock lights out, dent inner fenders, or slide forward and beat other stuff up.

as far as the street tires, you really dont want to vary too much from the intended tire pressure.  unlike slicks or drag radials, street tires lose their grip pretty quickly when the pressure varies from the intended set point, either up or down.  this is because they either bulge out the center (too much pressure) or collapse the center causing it to run on the edges only (too little pressure).  race tires are designed to keep that footprint flat moreso than street tires, so I would recommend keeping it close to manufacturer recommended and not varying more than 2 or 3 lbs in either direction.  (IMO)  that'll also help the tires last longer.  if youre going to race it a lot, get some DOT drag radials or actual slicks

[turbochallenger]

Well the problem is the class for king of street I run requires those tires 275/60/15 . On drag radials 275/60/15 with 3.23 gears I ran 6.64 @109 mph in the 1/8th. ON these street tires the best I could muster was 7.30 @ 105 mph and that pass was with 2.94 gears. I have installed a tighter converter and the 3.23 gears back. I have cal-tracs. qa1 shocks up front. Everything I can think of. Right now on the street I can almost do a half throttle take off.

[krabysniper]

street tires lose their grip pretty quickly when the pressure varies from the intended set point, either up or down.  this is because they either bulge out the center (too much pressure) or collapse the center causing it to run on the edges only (too little pressure).

And a good (old school trick) way to know if your tires a set to the correct pressure (not neccesarily the tire or vehicle manufacturers recomendation either), for any given weight (load) or vehicle, and is true far all tires bias or radial, is go somewhere where you can drive in a nice straight line on clean pavement or concrete, stop and rub a chunk of chalk (like the kind kids use to draw on sidewalks and stuff) across the face of the tread, then drive forward for a hundred yards, stop get out and check the line. The goal is to have the line wear off evenly, if it rubs chalk off the center faster, then your over inflated, rubs chalk off edges faster, under inflatted.

[turbochallenger]

Was at the track sunday and I managed a 1.68 60 ft time the rest were low 1.70s. I had 19 lbs tire pressure. Battery in the back, 130 lbs of weight lifting weights back there. Full tank of gas. I also raised the front end up 1 inch . The back is pretty much stock height. This gave me more initial weight on the tires. That pass was a 7.12 @ 106 mph. best pass so far on these tires.