Thread: Street tires at the track

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Ok, been a while since I ran a car down the drag strip, and then it was in a dedicated bracket car with slicks. Next week up at Hot August Nights the local drag strip offers a couple nights of street drags free for registered HAN participants. I am thinking about taking the Studebaker out just to see how she goes down the track. My tires are Yokohama Avid T4 235/70-15, they are fairly new so they have quite a bit of tread. Manufacturer recommended air pressure is 38 PSI. My question is, how best to prepare to launch, should I do a burnout or just a dry hop to clean the tires? I can do a pretty good dry burn out without getting them wet if thats a good way to go. I'm thinking I should stay out of the water. Do I want to lower the tire pressure some or run them at 38? I am pretty sure I am not going to be able do a hard launch without smoking them. I have a 2800 Stall converter behind an LS1 with 3.80 gears. Car weighs about 3450 without me so figure just over 3600. Track is at 4500 ft elevation.

What do you folks recommend? Hopefully I will have a chance for several passes so I can try various things. I don't expect real good track prep as this is jsut street only drags.

thanks

Pat

My understanding is that radials do not respond well to burnouts, like slicks do. I think the dry hop just to dust them would be the secret. Getting them too hot may actually hurt traction from what I hear.

Air pressure..........I would start at 38 and see how it launches and tracks. Then drop a little and see how it improved/got worse. We'll see what some of the guys who really know have to say.

Don

Street tires have a different compound than slicks and will not get sticky on a burnout. Do a little dry hop and call it good. Stay out of the water box. You'll sling water up in the wheel wells and then it will drop out onto the starting line and the starter will be pi**ed. Before you go on your trip, locate a stretch of road where you can do maybe a couple hundred feet launch and power run. Go to the grocery and get a container of white tennis shoe polish. Go to your stretch of road and paint a stripe across the tread of each rear tire about 3 inches wide. Let it dry, do your run, then stop and examine the stripe on each tire. If more of the polish is worn off in the middle of the tread, tire pressure is too high. If it's worn off at the edges, tire pressure is too low. Experiment with this until you get even wear all the way across the tread. Record the pressure of each tire at that point and keep it in the car with you. Then, just before you do the dragstrip thing, adjust tire pressure to what you have recorded. That'll be as good as it gets.

smoke the tires just a bit some were there is clean pavement look at the contack pach and drop the air pressure till you get a even patch i run mine at 30 psi you do not want to stay in the water to long if you do .i never get in the water drive round the water so it will not get up in the wheel wells and drip down on the tires i just do one dry burn out in first hit 2 and roll out and do a hop to check if there hooking up and then line up and go like hell

i take my bias ply mickeys down to 4-5 lbs heat them up for about 10-20 seconds and give it hell i have gotten them to stick better after getting them hot but with radials im not sure.

Pat, you are defeating your purpose with the dry hop. I talked with a Goodyear engineer about this. He said when you do the burnout and the tires get hot, there is a resin that comes to the surface of the tire that helps the car launch. If you do a dry hop after the burnout, you tear off the resin that was brought to the surface and the car will not hook as well.

With T-rated tires, heat is your enemy. I don't know too much about drag racing, but I know some about racing. If you drive to the track, that's all the heat those tires will need. I'd imagine with drag racing I'd drop the rear pressure to about 20psi to keep the contact patch as wide as possible, and the rpms from spinning in a straight line should balloon the tires enough to make the full patch contact, even though that low would normally only contact on the edges.

Originally Posted by techinspector1

Pat, you are defeating your purpose with the dry hop. I talked with a Goodyear engineer about this. He said when you do the burnout and the tires get hot, there is a resin that comes to the surface of the tire that helps the car launch. If you do a dry hop after the burnout, you tear off the resin that was brought to the surface and the car will not hook as well.

my car would not hook with just a dry hop has to do with what tire you using how hard of tire it is i did it this way it work for me do you may have to try different things this was with a set of grand prix tires i run this tire now and do not get them very hot and go come to think about it i should not posted on this any thing i do i can brake them lose i allways got in the lane were someone laid down a fast pass and put some hot rubber down and put heat in the track

Yup, stay out of the water, drop your tire pressure to around 28 psi, a short burn out and just drive off the converter....probably around 2200-2800 depending on the converter.... I'd brake it and run the rpm up to just where you can feel the chassis start to load...... Hot street tires on hot pavement make for a lot of wheelspin... If your lane has some good rubber down, line it up there.....

all good advice above ^^^my advice about same as Dave's... I would try 25psi short dry burn (don't power-brake it) stage shallow (just far enough to light the second stage light), stand on the brake and rev it the converter. When you see the third amber, let 'er rip!

You will have a better chance of hooking up in the groove but I know some tracks will specifically not allow street tires to run in the groove as it tears up the rubber more they want you to run outside... as said, you'll do better in the groove so run there if they let you. Most importantly... HAVE FUN!!!

Let us know how it goes...

-Chris

Thanks for all the good info folks. I finally broke down and paid for a good tune on my LS1. This was not a dyno tune, but rather the tuner rode around with me with his laptop plugged in for about two hours tweeking everything from shift points to fuel, to timing and AFR. The cars was fast and fun before, now it's even better. It's actually hooking pretty good, I need to try Techs trick with the shoe polish to get the right tire pressure. We'll see how it will do at 4500 feet next week. I know now that I need to figure out a way to get cold air to it though.

Pat

Well, I made it out to the track in Fernley during Hot August Nights. This track is at 4400 feet elevation and believe it or not it runs up hill at a noticble grade. It's actually the straightaway for a road course, but ti has a nice concrete launch pad. It's straight heads up run what ya brung and hope you brought enough. I went out there with a friend who has a 68 Camaro with an LS7 crate motor in it with a 6 speed. BOttom line is I had a blast. Best run of the night was a 14.69 backed up by a 14.71. Mph of 93. Using NHRA correction for elevation that equates to 13.89 and 98.41. And remember this track runs up hill! It took me a couple runs to get things sorted out. Hooked pretty good with tires at 30 psi, leaving off a 12-1500 rpm and rolling into the throttle. Doing that I killed everyone I raced on the start including the LS7 Camaro and a Turbo 350Z. I had some trouble with my trans popping out of 3rd gear and ended up getting passed in the lights by the 350 Z and the LS7 caught up to me a little before half track and then got loose and had to pedal it, but ended up getting around me with a 110 mph speed. Now that car hauls butt! His best time was a 13.8. I figured out how to deal with the trans problem but then ended up paired agains a couple Hondas who I really killed. All of these times are street tires, (Wide Whites even, thanks Diamond Back) through the mufflers with some junk in the trunk. I will have some video to share eventually. Anyway, thanks everyone for the tips, they worked pretty darn well. I had some younger guys come up as we were getting ready to leave, asking "What the hell is that thing? It's damn fast! You are kicking everyone's butt." I was pleased to intorduce them to the Studebaker world. There are no announcers at this outlaw track and no score boards, so the fans do not know times or really who won unless they are on the top end. We had several folks tell us they thought it was great that a couple of "Pretty Cars" came out and ran 'em instead of just sitting in a parking lot. I may try again someday down at sea level if I can find a track that will let me run. I sure love the way this thing runs.

Pat

Good stuff Pat. Thanks for the update.

Sounds like a fun time, Pat! Always fun to let the boys know that the pretty cars are fast, too! How bad was the wheelspin??? Just about going to have to find a set of slicks now when you get back home..... I think the bug bit ya again!!!!! Soon it'll be just like the good old days again! Somebody wanna help Pat find his old Chevy and the big block again??????

Dave the wheelspin was not bad once I lowered my air pressure. My first run was at regular driving pressure and it blew the tires off real bad. Once I lowerd the pressure and rolled into the throttle from 1200 or so to get it moving it would just kinda haze the tires leave pretty good. On my last run it did wheel hop a little but it did not hurt my ET much. While I was in the staging lanes with the engine off I was practicing my brake and throttle movement and that helped. Having EFI I could do that without flooding the motor. I don't want to get back into racing, too expensive in more ways than one! You should have seen my wifes face when I told her I was going to run the Stude at the track! I would like To do it again sometime though.

Pat