Drag Racing Results - How much MPH increase is "normal" from 1/8 to 1/4 mile?

Is there a rule of thumb for 1/8 mph to 1/4 mile trap mph that is the norm?

15 mph, 20 mph, 25 mph, 30 mph+..?

Just curious..

Depends on power level, and transmission type.

Stock-Bolton Autos generally gain 21-22mph.

I think the M6 cars usually gain 23-25mph. (Bolton/Stock)

bolt on my m6 gained 23.5
cammed 23.88, but my clutch was slippin bad, put in a spec3f and it pulls like crazy in 3rd and 4th, never went back to the track with that setup.

I think how hard you launch has an effect too. I run drag radials and have never been able to leave really hard. I normally run 94-95 in the eigth (best being 96.0) and typically run 121 -123 mph in the quarter.

A couple of weeks ago I was suprised to see a stock ZO6 run 99 mph in the eigth with factory tires. He was barely hitting 127 in the quarter. That was the first that I realized that a stock ZO6 is quicker than my car with a good driver.

A good rule of thumb is that your 1/8 mile trap speed should be about 80% of your 1/4 mile trap speed. If your 660' mph is less than 80%, that can indicate a weak launch, poor traction, poor low end engine performance, converter too tight, or being under geared. If your 660' mph is greater than 80%, that can indicate an exceptional launch, too much tire, weak top end engine performance, converter too loose or too much gear.

My car gains 30 mph from the 1/8th to the 1/4.

.

depends on power, no general answer.

fuel cars ~60 MPH, Pro-Mod's ~40 MPH, down to 10-20 for stock 4 cylinder girlie cars.

.

I pick up about 25.5 mph with 423RWHP, 4.11s, 26" tall drag radials, M6.

Mine is usually around 24-25mph with the cam.

27MPH here on motor and I have picked up a best of 30MPH on the spray.

318 to the tires unlocked. 333 to the tires locked. 2000 Camaro A4 w/PT4000 converter. 3600 pound raceweight. I picked up 21-22 MPH with the converter unlocked and 23-24 MPH when I locked the converter at the 1/8th mile mark. This was when I was SI and not much weight reduction. 88.xx MPH 660' trap speed all the time but 110 out the end unlocked and 112 locked. I'm hoping to pick up a few more MPH out the end now that I've gotten substantially more power to work with.

Theres no real way to tell given all the variables but generally a high 10 sec na car picks up 24 to 27 from the 1/8 to the 1/4....

math is generally Mph X 1.26

[QUOTE=RAACCR]A good rule of thumb is that your 1/8 mile trap speed should be about 80% of your 1/4 mile trap speed. If your 660' mph is less than 80%, that can indicate a weak launch, poor traction, poor low end engine performance, converter too tight, or being under geared. If your 660' mph is greater than 80%, that can indicate an exceptional launch, too much tire, weak top end engine performance, converter too loose or too much gear.[/QUOTe

I never heard of the 80% rule before, mine runs about 79.40 to 79.50. This very interesting. Gives me something to you look at. My car SI with boltons averages 23 to 25 MPH from the 1/8th to the 1/4 quarter mark. :drive:

I picked up 29-30 mph with the setup below. My car was never geared properly for the clutch setup i was using, my best 60' was a 1.54. It goes without saying, if your car makes killer power but has a poor launch, you will pick up a higher percentage mph on the top end. A perfect example is my car. Making 450-460 at the tires i would trap 94-95 in the 1/8th and 124 in the 1/4 with a 3625 raceweight...

Shane

Alright some helpful info in here. What is a good trap speed in the 1/8 for an A4 car stock? Bc i trapped 84mph stock but never ran it in the 1/4..

My car traps just under 98mph in the 1/8 and just above 123 in the 1/4. So a few tenths above 25 mph. 80% would be accurate in my case.

when i was SI i gained between 24-30mph.

cam only now the 2 days ive ran it at the end of last year was 23-25mph.

-brandon

I'm good for 22mph from the 1/8th to 1/4, w/ 3:23's.

I'm installing an S60 w/ 3:73's .. hopefully that will move me along a little better.

my bolt-on auto went 87 in the 1/8 and 110 in the 1/4. i gained 22-23 mph on average regardless of the weather conditions.

on street tires, my gf's lid only m6 99 t/a went 81 in the 1/8 and 108 in the 1/4 (with her driving..). she had nice 1.96 60', but hit 2nd gear and hazed the tires...i was suprised to see it pull that hard and produce a 108 trap. lid only full weight 99 car with 70k on the clock - runs good. :D

mine gains 22-23mph

I'm good for 26. I average a high 95.xx mph in the 1/8 and my 1/4 mph is usually in the 121-122 range. This is a cam only 6 speed

Mine is running 100 in the 1/8th and 126 in the 1/4... 80% rule sounds about right.

I'm going from mid 103's in the 1/8 to mid 131's in the 1/4 at my best, so that is ~27MPH but my car is a stick.

Yea, 25-26 MPH seems to be the norm..

There are some variables but generally speaking, the faster a car is, the greater the difference between the 1/8 and 1/4 mph. When I was running high 10's, I picked up 24-25 mph. Now that I am running low 10's, I am picking up 27-29 mph.

Mine lid and cutout only ran 81 in the 1/8 and 101 in the 1/4 so exactly 20mph its an A4 and the DA was 4500 feet that day