Whats up, Just ran my 71 on the track last night. I need help determining times, The track was just running the 1/8 mile so just wondering what my 1/4 time might be like. ET was 10.2 at 72.8 MPH. I could not get my tires to hook up till half track, sould run a softer tire. I have a SB 400 with a 12bolt posi I think to be a 2:73 rear. Factory code. migth have different gears in it. Anyone know what my 1/4 time might be and if the 2:73's sound right. Thanks.

Conversion: 10.2 x 1.57 = 16.04 1/4 mile e.t. 72.8 x 1.26 = 91.73 mph in 1/4 mile. To check on probable differential gear ratio I need to know tire diameter and rpms and if in second or third gear at the 1/8th. That is a lot of mph for a 16 second pass, for sure you were spinning for some distance. Also, what altitude is your track at, and do you have any idea what the corrected distance altitude was while you were racing.

Thomas

Thanks, the tires are 255 60 15 and 26 inchs tall, i am in 2 gear at the 1/8 mile. The trans is a 350 turbo and looking at the tape I spun well past the 60 foot mark. I had 15 LBS of pressure.

That tire size should be 27" tall. What was your rpm through the lights? 2.73's or 3.07's were common gears.

Airing down is fine for slicks and other purpose made drag tires, you actually decreased your available traction by airing down your street radials. You will probably find that they get the best bite somewhere between 29-32 psi. Also with street tire you will want to avoid the burnout box as much as possible. Do not do a big smokey burnout with street tires, just burn them enough to clean them up. Street tread tires tend to slurp up water out of the burnout box and bring wetness to the starting line - further hampering your clean getaway. If you were
powerbraking it off the line - don't. Try your launch at just off idle. If much more than one turn of the tires off the line then try this: at launch stab the accelerator 1/2 way down, then quickly ROLL the throttle all the way down.

Thomas

I think that is great advice from Bomber67. I have a '71 and when I first got the car and made my very first pass ever, I ran 16.07, I think. I was new to drag racing, so I thought you either hammer down when the green light comes on, or you powerbrake while giving it some gas. Well, after some practice, I have found that my best 60 ft times are when I footbrake with the left foot, and then "roll" my right foot into the gas pedal from idle to WOT. On my BFG radials, I average right around a 2.0 60ft without too much spin. Basically, practice will help you with developing a good rollout.