[Firebob]

So I was out for a putt today to see how the new alignment specs feel and decided to run by the Jr high and heat her up a bit. Absolutely no traction what so ever through first and second. So I began to wonder what kind of 1/4 mile time is possible to run with an early Fbody car on street tires? I know rubber compounds and suspension and other stuff makes a difference but generally speaking I wonder if 12 seconds is possible using just enough juice to hold traction with street tires?

[RocktimusPryme]

Definitely possible. I ran an 8.7 88 mile eighth last week on for real street tires. Not drag radials. That was with a 2.2 60. I broke the tires loose at the 1-2 shift. After that it hooked and booked.

I also had a 1.9 60 foot earlier on an aborted run. Put that 1.9 in a full run and I think I would have been in 12 second territory all day.

That said? What’s the point? Just buy a set of drag radials.

[Firebob]

Im wondering how you can do that. You ( and I not saying specifically you, just anyone) must have to feather the throttle just enough to hold the tires from spinning. That could be considered an art form I would think. I've always been an all or nothing kind of guy. I'm sure if I ever did get traction the rear end would explode. At the very least the u joint would give up...again. NOT fun. I'm trying to avoid spending $2500 on new parts if I can help it.

[RocktimusPryme]

Yeah I did the 8.5 swap. Consequently that narrowed nova rear gave me more room for tires too. It’s still a 1310 but it’s a good solid joint. I’m at least partially confident it will be okay.

It would for sure be an art. I’ve made three runs with this car. Two were aborted due to a fuel pressure issue.

I made two 2.1+ 60s and had that one 1.9. So I know it’s possible but it takes far more skill to do it consistently than just having good tires. Hell its probably possible to be lower than the 1.9. Just maybe not repeatable.

[Firebob]

Drag racing is not really my thing but I've made a few runs down the strip through the years. Only had what I would consider a couple decent runs. I think the best 60 for me was a 2.2. It would definitely take an amount of patience I do not possess to only throttle up to the point of grip on a given set of tires.

[JLMounce]

Part of it is knowing your car, where it does and does not have traction and specific to street tires, not shocking them and pounding them into submission. The compounds used on modern street tires are quite good. However, the tire construction doesn't allow for much if any flex in the sidewall and the compound itself can't overcome being shocked.

Once the wheel is spinning, it gets hot and greasy and easier to spin. This is the primary reason you don't do a burnout before you stage on street tires. Give them a scuff to clean them up, then start your staging procedure.

Knowing how your car loads itself and where the converter flashes or where the clutch engages can help you ride the edge of traction without shocking the tire and turning it into smoke. For my car, I know that if I give a quick throttle blip off idle to about half throttle, then immediately back it off a bit, that'll give me a decent hit without smoking the tires, then as the car is in motion, I can quickly roll into the throttle and it'll hold traction through the rest of 1st gear. I slam second and the car will get momentarily upset and recover.

Like anything else, practice makes perfect. The problem is practice at the drag strip gets expensive and practice on the street can also turn expensive.

[Lee]

The '67 Firebird in my signature first came into my possession around '96. With 3.31 gears, a stock torque converter, and generic cheap 275/60-15 radials, I got it to run 12.3's @ 113mph. It would not do that every run though, I had to work the throttle juuuuust right off the line to keep from blowing the tires away. Even spinning, it would still typically be in the 12.7-.9 range.

I got one of the first sets of BFG Drag Radials soon after that. You had to be a member of BFG's "Team T/A" and have the membership card in order to buy the tires at that time. With those, it broke into the 11.9's. Soon after that, the torque converter blew up...

[Firebob]

That's pretty impressive Lee. I wouldve bet against being able to do that on street tires. Maybe I try and rein in my need for speed and try to see if it's possible for me to get rolling without blowing up the rubber. I know I've got more power than I can use at this point. Just have to figure out how to control my bad behavior.

[AG]

If you are spinning that bad now I wouldn't bother going racing unless you got a set of drag radials, you wouldn't need big ones. Racing my '72 LeMans vert with a 455, TH350 and 3.55 gears with 275/60/15 street tires was difficult at the line. Had to feather it out which is hard to do when you are at the line and want to just put the gas pedal through the floor. It went 13.55 at 106 mph with a 2.4 60'.

[TAQuest]

Originally Posted by Firebob

So I was out for a putt today to see how the new alignment specs feel and decided to run by the Jr high and heat her up a bit. Absolutely no traction what so ever through first and second. So I began to wonder what kind of 1/4 mile time is possible to run with an early Fbody car on street tires? I know rubber compounds and suspension and other stuff makes a difference but generally speaking I wonder if 12 seconds is possible using just enough juice to hold traction with street tires?

1969 Firebird. 11.90 on street tires. BFG street drag radials.
428 with 6x heads. Low compression. Single stage nitrous kit.
Usually ran mid 12's until the magic happened one cool night at Mid Michigan Motorplex. Broke into the 11s on a grudge match with a 5.0 Mustang. 1992.

[Lee]

Originally Posted by Firebob

That's pretty impressive Lee. I wouldve bet against being able to do that on street tires. Maybe I try and rein in my need for speed and try to see if it's possible for me to get rolling without blowing up the rubber. I know I've got more power than I can use at this point. Just have to figure out how to control my bad behavior.

Robert, thanks! To keep my self honest, I did some research. Memories tend to blur with time and age. It turns out mine blurs towards the conservative side, as here is some info I posted back in 2004 about the car:

https://forums.maxperformanceinc.com...d.php?t=403193

[ponyakr]

Lots of suspension tricks required to go quick with hard, narrow tires.

If you can talk to somebody who is going quick, in the F.A.S.T. racing series, you may be able to learn some of those tricks.

https://www.fastdrags.com/

When I first started racing my '69 GTO, in '73, soft tires were not legal. I ran the biggest hard rubber, street legal M&H tires that would fit. Best it ran was 13.90's. I popped the clutch at 3000rpm, then went to WOT, just before the tries quit spinning. 3.90 gears, close ratio Muncie

In '74, they allowed a special, soft rubber, "cheater" tire. It was basically a slick with some very small grooves. Ran 13.50's with those. Popped the clutch at 3500 & nailed it. VERY little spin. Anything under 3500 would produce a bog. Had original RA3 400 engine. Only change was a replacement timing set.

9" slicks were legal in '75. Had engine rebuilt, with Lunati cheater cam. Switched to 4.56 gears. Ran 12.90's. I know these are not quick times. But, we were beginners, and I'll admit I knew VERY little. We did OK at local tracks.

Anyhow, from my experience, soft sticky tires are at least 1/2 sec quicker than hard street tires.

[RocktimusPryme]

Originally Posted by ponyakr

Lots of suspension tricks required to go quick with hard, narrow tires.

If you can talk to somebody who is going quick, in the F.A.S.T. racing series, you may be able to learn some of those tricks.

https://www.fastdrags.com/

When I first started racing my '69 GTO, in '73, soft tires were not legal. I ran the biggest hard rubber, street legal M&H tires that would fit. Best it ran was 13.90's. I popped the clutch at 3000rpm, then went to WOT, just before the tries quit spinning. 3.90 gears, close ratio Muncie

In '74, they allowed a special, soft rubber, "cheater" tire. It was basically a slick with some very small grooves. Ran 13.50's with those. Popped the clutch at 3500 & nailed it. VERY little spin. Anything under 3500 would produce a bog. Had original RA3 400 engine. Only change was a replacement timing set.

9" slicks were legal in '75. Had engine rebuilt, with Lunati cheater cam. Switched to 4.56 gears. Ran 12.90's. I know these are not quick times. But, we were beginners, and I'll admit I knew VERY little. We did OK at local tracks.

Anyhow, from my experience, soft sticky tires are at least 1/2 sec quicker than hard street tires.

Those FAST guys put up some insane numbers. Its been a minute since I looked, but I remember an article that talked specifically about tires in FAST. Some of the Hemi guys were running low 10s or even single digits on skinny bias plys. One of the drivers said his speed secret with the bias tires was to buy bald ones. I guess they act closer to a slick. He would go around to factory stock enthusiasts and buy their used up factory correct tires.

That said I think the fastest times still go to like the CJ mustangs that came factory with wider radials. So Im not sure what their secrets are.

Also, Ive heard it said by many a racer of your era that if they could just go back in time with a few sets of modern tires that they would be national champions lol.

[XLR8STEVE]

I was stuck in the 13s until I put Drag Radials and Caltracs on the rear. Caltracs worked awesome. Best in the convertible 68 FB was 12.59 after that. The caltracs also help on the street. Cheap. $300.00