Building a car for 1/8 mile drag racing
 

I'm looking at a ealry 70's Nova roller to build up for my son's first drag car. It's a really basic ride which makes it perfect for some one just starting out. I grew up running quarter mile tracks and we have been hitting some of the 1/8 mile tracks in our area just to keep the excitement level at a fever pitch. The closest quarter mile track is a bout 75 miles away and I have two 1/8 mile tracks about 30 to 35 miles away so we will be running 1/8 mile. I'm just not all that familure with what horsepower numbers translate into on the 1/8 mile, but if you take me to a 1/4 mile track I can usually come pretty close to guessing the time if I know what the HP numbers are, car, trans, the usual stuff. The car we are looking at has the interior removed, a 10 point cage, a 9 inch ford rear with leafs and slapper bars and probably guessing, 10.5 slicks around 28 to 29 inches in height. I think it's all steel except the hood. I am looking at a Scott Schaferoff 402 in/ 465hp SB engine for this car and a glide combo with the optium torque converter and rear gears for this set up. What kind of numbers (time and speed) should she put out on the 1/8? We are about 450 to 550 above seal level.

I got a 69 camaro with a 460hp 406ci SBC...Un-cut car..26x10's ET Streets
turbo 350..456 gear,,foot braking thru the mufflers and it will run 7.50's at 89/90 mph

i would say with a Glide,transbrake, and drop the mufflers put some 28x10 Slicks.i would say maybe some low 7.20's...possible high teens

i have run the qtr mile a few times and i really liked it...different ball game on the big end.

Only bad thing with the 1/8 is when you really want to start laying down some numbers,,you really have to hit it hard and run some low 60ft times or you can forgot a fast 1/8 mile et.

tougher then one thinks to break into the Mid to lower 1.20 60 ft time...in a uncut, stock suspension ,heavy , small tire car

1/8
 

I built a 360 ci flat top trw , flat tappet cam 258-266 .570 lift, steel darts 2.02-1.60 valves 1.82 PG tbrake 29 tire 84-85 camaro has run 7.18, 8" conv mabe 5.14 gear. very trouble free but this cam is 30 years old. I would build a roller today with the problems we are having with flat tappet cams. Later J.Smith 4621 racing The SledgeHammer. bjuice the zipper has seen this car run.

Mine and my wifes cars take alomst exactly 4 more seconds to make the second 1/8 mile. WE are both running 6.7-6.8 1/8 mile times. I think 1/4 mile is a waste, there is 4 seconds wasted to the day and 4 more seconds you can pop the top of a cold one,lol.

Those that can't run 1/4 mile seem to love 1/8 mile. Someday we'll be racing 60ft. LOL

Re: 1/8
 

Question for you Jimmy ?...1st off Great ET....but i am betting you coming in a little lighter then the 69 camaro i have...

My car weighs whatever a stock 69 camaro weighs from the factory, plus a 10 point cage,subframe connectors and slapper bars.....and i am 230lbs :shock:

so i am guessing i might be maybe....what ?? 3300/3400 lbs with driver ?

i would think our Gearing would be close due to the tire height difference.

oh yes i am running a flat tappet in this car also..i am very seriously thinking about running this car in a few ORSCA races this year...the 7.00 class.

gonna pick it up a little...got a 144 bm blower...also gonna look at changing to a roller, slicks, ,and a break...this should get me close enough to the index without having to be perfect every pass.. :roll:

http://www.outlawracing.com/

Love the humor parker. Any luck moving the truck?

parker just curious..what is your 1/4 et .....60ft and 330ft ?..not trying to be trivial just curious thats all.

The Ed Bigley 60ft Nationals!!!

bjuice, I don'tknow what his car weighs but ths motor ran 6.85in my sons 67 camaro @2850 14-32 and 5.83 gear,he wanted to go faster so we built a 200 dome roller cam and went 6.72 that ain't a very big improvrment for the$ spent. I am going to call previous owner of the car and ask him what it weighs the guy that has it now does not know. Later J.Smith 4621 racing

In my truck my best was 1.26 60ft, 3.66 330ft, 5.78 1/8th, and 9.08 1/4 @150.23mph. Truck weighs 2700 without driver.
In my dragster only been out one time, 1.08; 5.05; 8.05; @168mph

nuthin slack about that...the ole dragster pulls doesn't she ?

always wanted to drive one but never got the chance :cry:

but i have run a 1.14 60 in my vette

What kind of gear in the dragster? A 1.08 60' should be better than a 5.05.

4.10 gear. Its was the first time out we had 37 nozzles in the terminator and a 85 pill. The car was making heat even on the return road. I think we were a little lean. I have a 535ci with 4 1/2 stroke crank and the converter stalls 6200, may be some of the good 60ft. We're going to richen a little and move the timing up to 37-38 from 34. I'm expecting to go a little quicker. The dragster came with 34.5x17x16 slicks a 110" rollout. I ordered a set of Hoosier 33.5x17x16 with a 106" rollout. The altitude density was 5400ft with a 20mph crosswind. I'll get to see if any of these changes will help in a week or so.

We run a 4.30 gear in our 4-link Mullis. We run gasoline and have a 1.07 60' and run 4.70's. We had the 34.5's on our car and they would shake it to pieces. We went to the 33.5-17-16 Hoosiers and they are a lot better.

I ordered a set of 33.5-17-16 Hoosiers and they have 110 1/2 written on them. I set them next to a set of unmounted 34.5-17-16 and they look identical. I called Hoosier and they said the air the tire up to 20psi then check the circumference of the tire. I'm thinking they may be smaller than that at 5 psi, but I'm doubtful it will make 4 1/2 inch difference. They advertise 106" rollout. I guess I'll send them back. That part # is 18700 Hoosier, I'm thinking about ordering #18500 which is 33-17-16 with a supposed rollout of 104". I really think I need to get a shorter tire with the 4:10 gear.

We run the 33.5-17-16 CO7 and I like it a lot better than the 34.5-17-16.

weight of car
 

The 85 camaro weighted 3200 on the track , Later J.Smith 4621 racing :D

Re: weight of car
 

wow ! nothing wrong with that Jimmy..thanks for sharing. 8)

Sorry Beast, I just now saw your post. Yes, I traded it for a PSP 4link x-braced mono-shocked dragster. Car seems to work great. I'm going to try some new tires this weekend. Still miss the truck, I guess we'll find out if those wins were the truck or me. It sure is a different feeling. In the truck I just wanted to go rounds. Now I'm entering quick 8s since I can qualify. But when you running two different classes at the same race I don't know if your as focused as you are just running one class. Guess we'll see how this year goes.
Thanks for the interest Beast
dparker

1/8 mile racing
 

Go to http://www.wallaceracing.com/accel-calc.php . They have a free calculater to predict it for you. I put in 3200lbs,465hp,and a 28inch dia. tire and it said 6.99 in the 1/8 mile. Check it out and I hope it may get you close.

Re: 1/8 mile racing
 

One thing you may be failing to realize, is that, that formula is rear wheel HP, not engine HP. There's no way a 465 HP engine can put a 3200LB car thru the 1/8 mi. at 6.99. There's between 15&25% HP loss in the drive train, realistically it take about 600HP to run that ET in the 1/8 mile, and a lot of other factors are also involved, tire slippage, trans slippage, 60' times, etc.
An 465 Advertised HP motor would be lucky to run 7.80 in a 3200LB car.

Fact ot fiction

Zip.

That is a good point. Now I realize why the numbers were always off. Thanks for pointing that out.

1\8 mile racing
 

hi guy's, i'll throw my 2cents in also- i have a 68 chevelle 3385lbs w/driver-383 flat tappet -536-560 lift cam-power glide-4.56 gear -30x9 in tire -footbrake. best 1/8 good air-6.95@96mph-best 1/4 mile -good air 11.01.06.-120.85mph we guess hp to be 490-510 -w/ decent air. 5-900 ft above sea level-air up to 2000-2800 ft et falls to 7.15-20 1/8 mile-11.15-22 1/4 mile conv- stalls@low 5-s just another example to throw in the mix. thanks jim

1 horsepower= 33000 ft/lbs per minuete. or 550 ft/lbs per second. No more, no less. Just some horses make more horsepower than others.

dparker what does your s10 wiegh? i ran mine last weekend didnt run what i think it will. im going to fatten up the carb and try again it was running scary lean. i pulled the plugs and they looked like they hadnt been run. i havent had a chance to put mine on the scales yet. a 496 on 92 octane ran 6.82 at 100 mph breaking up all the way. i guess it did pretty good but i think it has more still yet

I recently traded my s-10 for a mono-shock dragster. It ran anywhere from a 9.08 151.21mph in the 1/4, and on alcohol to a 9.60 on gas at 7000ft adjusted altitude. Best 1/8 mile was 5.72. What compression are you running?

what about a 1.50 60ft 6.30 1/8 @115mph....... :lol: can anyone guess what happened??

looks like its spinning to me...a very sluggish 60ft for the mph and et

looks like its spinning to me...a very sluggish 60ft for the
 

thats what we thought to start with.. but the track was good that day and had already been 1.40 on the 60ft..just befor that, when i got back home i was looking over every thing and decided to check the throttle cable, guess what!!! the thing was not opening up all the way. it had a lokar braided cable on it which was less that 6mths old and already streached. i took it off and threw it in the trash, made me a rod with rodends and now the pedal moves half the distance but opens up every time... dont know how long it had been not opening all the way,,, just need to get it back to the track to find out the differance..

between 10:25 and 10:50 its a pump gas motor i race on 92