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Discussion Starter · #1 · (Edited)
Drag radials-street VS track behavior?

I have BFG 275/60-15 drag radials on my 75' ranchero with a fairly stout 400, edelbrock heads and intake, hooker headers ect...its torquey, and i can spin it to 6k with out much worry...

When "cold",From a stop without the brakes, i can put the drag radials up in smoke if i floor it. If i finess the pedal a little they hook a little better. This is on the street of course. When warm, its much the same, but they hook more quickly in both scenarios. If i stall it up a little(1500-1800 max before tires spin) and pedal down when i let off the brake, it spins hard, hot or cold doesnt matter.

I havent been to a track in years, and never in a fast car with drag radials. How should i treat them at the track? Short burn out, long burn out?

The other big problem i have is a stock convertor currently. Should i stall up the engine at all? Or just ease off the line? I am aware that every car and track is different and you cant give me EXACTLY correct info, and practice will be the best way to find out.

Just looking for advice and best guesses. Thanks in advance.
 

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Well, in a nutshell, nothing works as well on the street as it's un-prepped pavement. Drag radials are better than common street tires, and bias slicks are better than drag radials. Depending on the track, DRs will hook rather well with a good setup, but requires the handlers (starting line crew) do good prep. Even then, high-powered cars can lose it at the 1-2 or even 3-4 shift as you're back to mostly plain pavement again. Offhand, my general tips are to:


  • Run the right pressure for a good launch footprint, but not lower to where it squirms at launch or loses top-end stability (do a search on testing for correct tire pressure).
  • Check nut torques beforehand and after the first few runs.
  • Drive around the water and back up into it so the fronts don't carry water with them for the rears to roll through or sit in.
  • Back just into the damp area so the treaded DRs don't fling wet water onto your wheel well and later drip onto them at the line.
  • Spin them up in 2nd or 3rd gear until you haze them over (more is usually a waste), and drive out of the water, backing-off the throttle as you go so you don't shock-load the trans too bad. You are only cleaning and heating the surface of the tread.
  • Have a buddy use an IR thermo gun to read the surface temp when you stage to get the temp right. Proper burnouts for traction are not very impressive and only heat the tire to a few degrees above pavement temp. Take readings the exact same way each time for best consistency. Properly, use a tire pyrometer - but they are quite expensive.
  • Don't wait for the other guy - stage fully and let your tread sink into the sticky goo as long as possible without moving. It's better to do a burn and wait (and better traction while you do) than to stage late, even if your tires cool a bit.
  • Inspect your tires on all surfaces for rubbing, as tire shake and high-mph growth can be more than you expect.
  • Video the launches if possible (motionless, framing just 3 car lengths of the launch, on a tripod) for chassis tuning diagnostics. If you can video, chalk your tires to make it easier to see tire action.
  • If pulling the DRs for the season, store them the same way as slicks.
  • Buy fresh slicks for the strip as soon as your budget allows. Do not buy used slicks (even with lots of rubber left) unless you know their history, age, and exactly how they were stored.
David
 

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I ran BFG drag radials for a while. They seemed to actually be worse on the street than regular street tires. They only worked better after a burn out at the track and with 13 or 14 pounds of air. I put the ET Drag's back on my car for now. I don't know what sort of tire I'm going to run once my car is back in street trim for good.
 

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Discussion Starter · #4 ·
Thanks fellas! Im pretty stoked about hitting the track. I have visions of going fast in my big boat chero, but worry about doing what my buddy did in his chevelle...15.5 @98 mph...street tires on a stout4-speed 396.Kinda funny. Id rather put down a good time though than burn rubber for half the track.

What slick do you recomend when i can swing it? I hear good things about mickey thompsons, and hoosier, and goodyear...How about a more specific question- How much should i spend on a slick for a rig that may only go occasionally to the track?
 

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I feel your pain. My Falcon only went 13.5 @ 107 on street tires, and they're big and in good condition. Slicks are all but manditory on the drag strip with higher HP cars in my opinion. I couldn't get into it fully until around 1/3 track.

I know a few guys that run MT Drag Radials and love them. At about $200 each they're not cheap though. Regardless, if you plan on making passes I'd pony up for some. They'll last 2-3 years from what I understand - unless you race a lot more than you plan to. It's an age thing I've been told.

Correct me if I'm wrong guys. :bow:

John
 

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I have been told that Micky Thompson ET Streets are the closest thing to a slick in a "street" tire. Some places will hassle you running those on the street though and they won't last long if you start putting miles on your car.

I have a set of BFG drag radials that didn't last any time at all. Not sure exactly why. I didn't put very many miles on my car. I was doing some big burnouts at the track with them to get them hot though.

I will probably run ET Streets once I get my vintage plate and can drive my car around.
 

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The bias ET streets are similar to my beloved stiff wall bias drag slicks--even uses the same compound. There is also a radial version of the ET streets, which is not the same.
 

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Best thing to do is have two sets of tires/wheels. Run slicks at the drag strip and standard radials on the street. Anything else is a compromise.

Having two sets of wheels/tires saves money in the long run. Street radials are better street tires. They last FAR longer, are FAR more resistant to getting sliced/cut, work FAR better in the rain, you aren't afraid to do the occasional burnout... and are FAR less expensive than drag radials.

Drag slicks work FAR better at the track than drag radials. Drag radials require perfect track prep, and once they do start to spin, they don't recover. They don't do well with shock loads, and are pretty much not an option for a stick shift.

If you drive your car much at all on the street, do yourself a favor and buy an extra set of wheels/slicks for drag strip use. Used sparingly, the slicks will last several years or more. You can buy cheap steel wheels made for dirt circle track racing for around $50 each.

Good Luck!
 

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What Mike posted is right on the money.
 

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Discussion Starter · #11 ·
Thanks guys. I like the two sets approach, once i can swing it.
 

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Here is my car spinning radials and recovering with out lifting. incar track - YouTube

IF you have a clutch, bias is the only way to go. I love my Mickey Thompson radials with an auto and transbrake...even foot braking. If you are making much power regular radials are useless and sometimes dangerous. Drag radials are all my car ever has on it. It makes trips to the track much nicer not having to change tires.
 
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