Technical 1/8th mile and 1/4mile time

Back in the day my club founders boasted of having a 100mph car in the quarter. No small feat in 1953. Would my car go 100 in the quarter if I just ran 10.94@ 63mph in the 1/8th?

 

No. Use this calculator: Wallace Racing - Convert ET's For 1/4 Mile and 1/8th Mile

 

Casual 6 beat me to it. Wallace Racing's website has a LOT of additional calculators you might find helpful as well.

Lynn

 

There is always nitrous....

-Abone

 

What do you have for a transmission and final drive?
What gear were you in at the end of the 1/8?
Would you say the start was gentle, too much wheelspin, an off the line bog or ??

0-60 in about 10 seconds? Sounds like a 1955 T-bird.
https://simanaitissays.com/wp-content/uploads/2024/02/dp-2.jpg?w=459

 

255ci flathead 2 carbs, ford 3 speed, 3.78 banjo, 7.50x16 rear tires in a 29 roadster. Was just wondering how difficult it was back in the late 40s-early 50s to go 100mph in the quarter

 

If you ran 63 in the eighth it is not going to pick up another 37 mph in the final eighth.

You didn't specifically ask about the e.t.s but you woud have likely run a 17 sec. quarter - not fast enough to run 100.

A general rule of thumb is 64%
To get a quarter mile time from an eighth mile e.t. divide eighth e.t. by .64
To get an eighth mile time from a quarter mile e.t. multiply quarter e.t. by .64.

 

So, I just used the Wallace calculator and I am stunned. 17.28et and almost 78mph in the quarter. I thought I was flying, hahahahaha

 

A good rule is your 1/4 mile ET will be 1.57 to 1.58 times your 1/8 mile.
So 1.57 times 10.94 comes out to 17.17 and change.
Much depends on how your car reacts in the first 60 feet.

 

Maybe in the second quarter of the mile. Definitely not in the first........

 

I figure 100 MPH in the quarter could be in the mid to high 13's.
your flathead is just slightly faster than my old HOT ROD Datsun pickup. 17.70 @77 MPH @Fremont

 

I have never ran the Olds on the 1/4. Sanctioned tracks have a limit of 13.5 I think for convertibles without roll bars. Using this slip in the jockey box, which wasn't my best time but in there (lightening fast reaction time ...I think I was finishing a burger on the line). 530G

your calculator spit out this

Which would make sense I guess as it a second below their cutoff. A reliable calculation?

Not bad for a grocery getter with an 8 track. Like @wheeldog57 said, it felt faster. My 60 footers were never good. The announcer always laughed at me, "let's see if that Olds can get off the line this time without frying the tires". I tried spiking the converter, water trap, driving around the water trap, MT DOT Drag tires, WOT off the gate, holding it, lineloc vs brake pedal. Lousy 60 footers and only one 000 light to my credit. It's still a ton of fun.

It wasn't purpose built to drag race, more of a boulevard cruiser and stop light brawler.

 

That right there. That's the whole point. If it ain't fun there better be a payoff, 'cause that's work.

 

Run a quarter mile track and get the time slip. It will tell you. Lippy

 

Lippy, I can usually count on you for good experienced info. You are one of the good guys here.
Pull up a map of Kansas and search for dragstrip.
Pull up a map of M***. and search for dragstrip.

 

And they have to let you. I ran one time, too fast for my car, didn't even get a time slip. Just had to report to the tower. Like going to the principal's office. They said do it again and I'd get the boot. I thought about it, but I had a beer and hit the stands. 1/8th mile cutoff for a convert with no roll bar is 8.25 I think (don't quote me)! They only gave me a warning and told me to slow it down or get complaint. I have a handfull of sub 8's.

 

What is the weight and estimated HP of your vehicle.

Everytime you 2 x the speed you need 4 x the power to overcome resistance.

So there is more advantages gained in the first 1/8 than the 2nd 1/8. If your car ran on the limiter [not recommended] at the end, it would have little effect on the ET or terminal speed.
You need as much mechanical advantage off the line !
If your engine is limited to 5000 rpm you would need 4.61 gears to peg at 100 mph through the traps [with your tyre size]

To get 100 mph through the traps ,you need to cut a 13.5 ET
If your Flattie produced 200 hp at the flywheel, you would need a weight of 2500 lbs [total including driver]

The secret to the "stock eliminator" racers is mechanical leverage.
They use heavy flywheels, high rpm, and 5.2:1 to 6.5:1 gears to leap frog these cars out of the hole.
These cars have a short life expectancy of engines and drive train.

 

My sediments exactly.

I've ran everything from 8-second O/T Mustangs and REDs to 13 second Willys and Anglia g***ers to 17 second streeters. and every time I get behind the wheel to race, my adrenalin kicks in. If my own Mom was in the next lane I'd want to kick her ever-loving ***.
Its all exhilarating fun to me.
If my car were to run a 17-flat, like yours, I wouldn't dwell on how slow it is. I'd start thinking "How can we get 'er down into the 16s?" That is how you should look at racing your hot rod. What can you do to make it go faster.
Sometimes going faster means spending more money. But sometimes it just means optimizing your tuning skills and driving technique.

Another observation: I've heard other racers say they can't watch drag racing - it bores them. Especially handicap bracket racing.
Not me.
If I hear a garbage truck is going to race a street sweeper I'm in. I wanna watch. Its the thrill of the hunt, not the caliber of the gun.

 

I've always subscribed to the general theory that whatever you turned in the 1/8th mile add 50% to it and that will be close to your 1/4 mile time and speed. So your 63 mph 1/8 would be around 94-95 mph in the 1/4.

 

Back to you original query. In one of Don Montgomery's excellent books about the golden age of all things hot rodding he posed the question, "Just how fast were the old dry lakes and drag racers?"
And he went on to explain that a built flattie in a lightened up '30s era ch***is could indeed equal the performance of most of the muscle car era performance cars yet to come.
So your club founders were no doubt remembering correctly. Some hot rods in the '50s could probably run 100 mph with ease.

 

My 33 pickup is one of the ones that breaks the formula as it would run faster and pickup up speed from the the 1/8 to the 1/4, but that was due to lack of traction for the first 1/8th mile.

It would run low 7s in the 1/8 and then mid to high 12s in the 1/4 as around the 1/8 mark is where it would finally start gripping and put power down. It would trap just over 100mph and then be a handful shutting down due to the fenders causing lift.

Then for a reference, my new O/T muscle car has a best time of 12.18 in the 1/4 at 113 and that is pretty much showroom stock.

 

Nice post of the calculator...

Hello,

Our fastest time for our stock 348/280 hp 58 Impala was 14.98 seconds E.T. and 98.05 mph in the quarter mile at Lion’s Dragstrip. I was driving the 98 mph speed in a time trial run. My brother got the 14.98 E.T in an elimination race. So, we were both happy campers. Bragging rights split down the middle always works for compe***ion between brothers… ha!

For a long time, that little print out was in my possession, then in my desk and finally, bit the dust somewhere in those many moves from our old Westside of Long Beach house to apartment to various different small houses over the years.

It was always funny to hear others that did not race at Lion's Dragstrip tell the stories that they went 100 mph in the quarter mile at the local Bixby Knolls' Cherry Avenue Drags location. Their comment was that while driving, the speedometer registered over a 100 mph and that is how fast they were going.
At the start of any race, our speedometer was registering 120 and pegged the needle to the right. So much for top speed reliability of a stock speedometer.


SOUND

At Lion's Dragstrip, the average speed for the quarter mile was usually during the eliminations and other factors played in lower times… nervousness, slower reaction times, other cars in the lane(s) next to you… etc. But, there were times that everything comes together, while a run after run is made with a bunch of timing slips and a nice shiny trophy at the end of the day was the result. Yes!


Jnaki

For our custom 292 c.i. 671 SBC build in our 1940 Willys Coupe, our fastest time was 112 mph. But, the quickest E.T. was set on the last day of compe***ion for us. 12.60 e.t. so in the comparison chart:

12:40 E.T. was the National Record in C/Gas at the time and we were heading for that goal.

Not that it matters, but the 1/8th mile was non existent at the time, with some local dragstrips trying various length dragstrip timing set ups. The Riverside Raceway ½ mile track racing was also, very popular. YRMV

 

Don't feel alone. I have spanked a lot of "10 second street cars".....
10 second street cars usually end up running 15.50's.

 

I think that's actually slower than expected 1/4 mile times. Mid 7's in the 1/8 would usually mean an 11 sec. 1/4 mile time. So it's actually slower in the 1/4 mile than I'd expect. Maybe too low a rear gear to achieve higher MPH or lower ET?

 

At that point in time it had 4:11's when it was running at PIR every Wed. I have a VHS tape somewhere of the truck making a p*** and you can hear it squealing almost the whole p***. The traction problem was the buggy rear spring and BFG radials. It never ran on slicks. If it had traction for the 60ft and 1/8th mile it would have probably made a 11 second p***. It was just horribly inconsistent for bracket racing with the traction issues.

Even with the lack of traction at Woodburn, it was still fast enough for the officials to kick it out until it got a roll cage for 1/4 mile. That is what ended it racing career because my grandpa wasnt going to cut the truck up to add that.

 

My last ever kind of a drag car< Of my own/not one I just helped buddy on in later years, was a Fixed up by me, Studebaker Lark { F-Stock}/Home built headers,Supercharged V8 2D HT,w-TT Rear. 1/4 mile, in 14 sec flat,102 mph. in early 1967.
I didn't do any drags my self after 1969,sold the LARK. Was having way too much fun stockcar n sports car racing.

 

I was sitting here trying to remember the speeds I ran at Little River in my 69 Cutl*** in 1969 when I was running 14.25 there but I don't think I ever broke 100. Most of us never ran it out for the mph clocks there anyhow shutting it down right after we crossed the 1/4 mile mark. Not much for shut off area in those days especially with drum brakes when you were heading right back for another p*** in your cl***.

 

My shoebox [around 3400# with me in it] 289-4spd-5.14 gear-Det-locker ran 14.00 @ 100.00 on street tires. With an ***ortment of borrowed slicks I eventually got to 13.41 @ 102.3x. Back then no 1/8 mile or 60ft.

 

That's a respectable time.

The actual ET was slightly too slow for the Terminal Speed.
So it could do with some mechanical leverage [deeper gears] or it wasn't hooking off the line
----------------------------------------------------------------------------------------------------------
Back in the early 80's I owned an O/T 1971 Fastback Mustang
This was powered by a healthy 302 Windsor that had a Holley 2 Barrel , Headers, Unknown Mild Cam, C4 Trans
2.79 rear.
The car weighed 3250 lbs with me sitting in it [I was skinny back then] and on a rolling road dyno produced 206 hp at the wheels [estimate 240hp]



On the 1/4 it got mid 15's at 98 mph with unhooked headers etc. I tried everything possible.
The best time was when I held the trans back in 2nd at the top end.

The next time out , I swapped the diff centre for 4.3:1 ratio [nothing else] and did all the usual unhook the headers ,remove the spare etc etc.
4.30 gears in 3rd was slightly lower than the 2.78 gears in 2nd

This one modification got the car into 14.17 seconds [best time] and 98 mph [consistently]
That was a 1.3 second gain from a rear end swap.

For the terminal speed it should've got high 13's but this was in the days of running "Firestone Formula 1 Superstock" tyres

[with modern know-how ,a set of 4.88 gears and hotter cam , 3500 stall, Hoosiers, Cal-Tracs, 90/10 shocks should get that same car into the low 13's with the same terminal speed. And leave people scratching their heads when they spy the 2 barrel under the hood]

 

Jere Sheehan got his 100mph patch in a 34 roadster with junkyard 4.44 gears early to mid fifties. He used to love to tell that story