Need advice for traction

[THUMPN68]

Hello, I have a 68 C10 2wd with a well built 355sbc, granny low 4spd, 3.73 gears & running 255/60/15 rear tires. I built this in high school as a uptown stop light to stop light racer but it is literally impossible to hook up . Any suggestions on traction bars or ladder bars ? Im sporting a flatbed too so that probably doesnt help matters . Thanks !
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[GASoline71]

How is it a stoplight to stoplight racer with a wide ratio granny 4 speed? Ditch the granny low 4 speed, and cram a TH350 or TH400 in there with a stall converter. If you still want a 4 speed... look at a close ratio car 4 speed like an M21 or an M22. Some cats have swapped T5's or T56's in their trucks.

Is this a coil or leaf sprung truck?

Gary

[SS Tim]

Ok, so we have addressed the trans choice.

There is so little information given its hard to know where to begin.
LWB or SWB?
Coil or leaf rear springs?
What kind of shocks are you running?
Stock, lowered or raised?
Open, posi, locker or hopefully not, a spool rear differential.
Brand of tires and how old are they?
How wide are your wheels?
How much tire pressure, hint not the max printed on the sidewall?
Flatbed, so how big and what is it made of?
How heavy is the bed?
How about a picture or two?

Finally welcome to the board, everybody learns here whether they want to or not. ;-)

[THUMPN68]

GASoline71....it has coil springs with factory leaf over load . Would a 4spd from a 79 Z28 work?
Thanks.
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[TBONE1964]

"Finally welcome to the board, everybody learns here whether they want to or not. ;-)"

I concur with that

Let me educate you on another not so often considered element of traction. It is called the tire foot print. It is what the tread pattern looks like when applied to pavement. It can tell you a lot about how the tire is contacting the road.

For example, if you have a 10 inch tire with 9 inches of tread and your foot print is only showing a 2 inch strip of rubber in the middle, then you have too much air. If your foot print is showing one strip on each side of the tire, then it does not have enough air. Follow where I am going here?

Ideally you want your tire foot print to show as much of the tread on the road as possible which will require playing with air pressure until you get it correct.

With all of this in mind, keep in mind that although you have a nice foot print does not mean you will have good air pressure for normal driving.

If you want to fix your traction problem, put some good street legal drag slicks on it. You know the ones with only 2 grooves in them so they are considered legal. If you still have a traction problem then your drive train has way to much HP for your truck.

[THUMPN68]

SS Tim...wow im getting educated quick,cool & thanks ! Well the shocks are all new but factory spec . Truck is factory ride height . Rear tires are 12" wide & GoodYears Eagle i believe. It is a true posi rear end . The flatbed is aluminum & i guess around 300-400pounds . I run 30 lbs of air pressure in rears . Hope that helps alittle . Thanks !
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[jocko]

If worried about traction, T5 not the right choice. If still want a 4-speed, then have to consider stick placement - and car 4-speeds don't make that easy as the shifter is mounted near the end of the tailshaft.

If $$ not an issue, then T56 with adjustable stick location (you'd want the fwd location) is a great choice. And O/D to boot. Sounds like mileage, however, might not be at the top of your list of concerns if you're asking about traction.

[SS Tim]

We are getting closer
LWB or SWB? It makes a difference
Coil or leaf rear springs? coils and leafs
What kind of shocks are you running? stock replacemen
Stock, lowered or raised?
Open, posi, locker or hopefully not, a spool rear differential. Have you rebuilt or tested the posi per the manual?
Brand of tires and how old are they? Actually they are about 10" wide and about an 8" tread x 27" tall right?
How wide are your wheels?
How much tire pressure, hint not the max printed on the sidewall? 30 psig
Flatbed, so how big and what is it made of? _____ x _____ aluminum
How heavy is the bed? 300-400lbs
How about a picture or two?

Added
Are you running a rear mounted spare or even a rear bumper?
Have you weighed the truck? total____ , front axle____ rear axle____

[THUMPN68]

jocko...i am on a budget but your right im not really concerned about MPG . I just take it out on weekends right now . Im 18 so this is really a learning process for me . I know the granny low was over kill but it was in the truck & will brake your neck when the clutch is dropped at 5000rpm lol . Ive even tried starting out in 3rd at 3500rpm & it still goes up in smoke . Thanks !
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[GASoline71]

Sounds like you need better tires. If all you're getting is wheel spin... then you need wider tires with a better contact patch. After you do that... we can talk about wheel hop... that will be next.

Gary

[THUMPN68]

SS Tim....yeah i think your right on the tire size . I know the rims are 10"& the guy who sold me the tires said they were 12" but he was probably wrong . The tires WERE in good shape but getting smooth now . I can get the bed size for you tomorrow. Sorry i dont know what LWB is ?. Never had the posi per manual checked . Thanks!
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[THUMPN68]

Oh & yes it has a aluminum tube bumper but no spare . Thanks !
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[GASoline71]

LWB... Long Wheel Base (long bed).

Gary

[THUMPN68]

Yes was originally a long bed . Had a 250 6cyl . Was a forestry truck its whole life .
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[SS Tim]

Sounds like your wheels are too wide for the tires depending on the tire.
If your tires are not up to the task, sidestepping a clutch at 5k isn't helping and if they are your driveshaft probably isn't going to last long.
The posi has a service spec to measure the amount of clutch preload there is for engagement. A clutch posi can wear and if it does not have the friction modifier in the axle oil it may not work at all. If you don't have manuals they can be downloaded here.
http://67-72chevytrucks.com/vboard/s...d.php?t=558016

From your description of the bed it is probably a fair bit lighter than a stock fleetside bed which is about 500lbs plus another 95lbs or so for a step bumper, plus a spare.
Be interesting to see the scale numbers. I'd say you are running about 2300 up front and 1300 out back. That would be about a 70/30 weight distribution. Maybe a little more rake than stock too. Have you tried it with about 500lbs of hay or feed on the back?

[TBONE1964]

This is getting interesting and bringing back some memories of my street racing days. I once had a friend with a 71 GTO that has your same problem. No matter what he did he could not get traction. His car was a tire fryer for sure and it was so cool watching him do burn outs between the stop lights. The problem for him is that I had a BB Camaro at the time with some nice illegal drag tires and all the other components built for the HP the car had. My friend would get so mad because he could never beat me in a drag race.

He went and bought himself some drag slicks just like mine and put then on his GTO. He still could not beat me and started breaking parts left and right. This week it was a rear axle, next week, drive shaft, week after that, transmission. He eventually put his street tires back on and gave up on traction.

Moral of this story is a little tire spin can be your friend. If your drive train is not up to it, getting good traction is most likely going to start breaking parts.

[special-K]

You're ass-end light. A four banger will smoke 'em with no bed weight. I don't see how it snaps you neck dumping the clutch in granny @5g. Doesn't it just sit and spin?

I'm afraid I can be of no assistance. I have similar issues as well:

[THUMPN68]

Special-K....sometimes when i heat my tires up beyond belief lol , it will just for a milli-second hook when i take off but 99.9% of the time your right , it just breaks loose . Even starting out in 3rd ! I have access to a 4spd out of a 79 Z28. Is that a better option if it fits ? Can i get rid of that middle bearing that splits the driveshaft ? Its new but i heard they are a problem . What year of straight driveshaft should i look for . Thanks!
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[TBONE1964]

I think you are correct with your thinking about a 4 speed from a 79 Z-28. I think you should use it. You may have to drill a hole in your seat for the shifter.

As far as a 1 piece drive shaft, you will want to have one made up at a shop. Have them make it up out of 4 inch aluminum tube and fill it with lead. Your traction problems will be over.

I have a 1964 Chevy SWB (short wheel base) with a 292 straight 6 , granny low 4spd, 3.73 gears with 255/60/15 rear tires and I have the same problem. At 5K it will just haze the rear tire. I have to wear a HANS devise when I drive it hard.

It does not matter what trans you put in your truck you will have the same problem. Two things will fix your problem, more weight on the rear axle or better tires.

[special-K]

Nothing wrong with 2pc driveshafts. The one in your truck has lasted over 40 years...even with your abuse after all this time. Carrier bearings are like any wear part. They wear out in time...especially when no properly maintained.

[THUMPN68]

I really appreciate everyones advice im NOT taking any of it with a grain of salt for i know squat about these types of issues. I never had any adult help in this process & worked for every nut & bolt . I had a classmate that has a wicked 76 dodge 150 2wd. That his daddy had built for him. Has a 451big block Chrysler stroker , 4link suspension, you name it,it has it .He destroys everybody . He ran my buddies 66 chevelle with a 377sbc stroker & that dodge truck handed his ass to him ! He was running 11.98 1/4mile times at the high school shoot out . I want to beat him ! Lol . Thanks!
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[WIDESIDE72]

1. Ditch the granny 4 spd
2. Get some weight in back. My dad was a pipefitter/ welder and always added a 4x8 sheet of 1/4 plate in his pickups. He would swap it from one to the other.
3. Drag radials
4. Air bags in rear coils. Experiment with air peessure. Usually a little more in pass side to counter driveshaft rotation.

All of this still wont get you high 11's with your current engine. Youre gonna need more power. You need either:
1. More cubes
2. Nitrous
3. Supercharge
4. Turbo(s)
"Speed costs money. How fast do you wanna go?"
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[TBONE1964]

Originally Posted by THUMPN68

I really appreciate everyones advice im NOT taking any of it with a grain of salt for i know squat about these types of issues. I never had any adult help in this process & worked for every nut & bolt . I had a classmate that has a wicked 76 dodge 150 2wd. That his daddy had built for him. Has a 451big block Chrysler stroker , 4link suspension, you name it,it has it .He destroys everybody . He ran my buddies 66 chevelle with a 377sbc stroker & that dodge truck handed his ass to him ! He was running 11.98 1/4mile times at the high school shoot out . I want to beat him ! Lol . Thanks!
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You will be fine and excuse my sarcasm. I think you need to set a goal list for what you want to achieve and stick to it. This is a list that you will write down with your goals. Be realistic and your goals will be achievable.

Most of us have been in your shoes and had a car/truck we wanted to go just a little faster. I know I did and there was always someone who was just a little faster than me.

Don't worry about more horse power if you can't get what you have to hook up.

There is always good people and help here. Most of all I will say, enjoy and have fun.

[THUMPN68]

WIDESIDE72...Great tips! Well i want to be quick not fast if that even makes since? That's why i thought the granny low would be good for quick launches ....Man i was wrong ! I honestly won't be running 1/4mile that often mostly 1block sprints lol . Even my buddies with "normal" 4spds are lucky to pull the 3rd gear when we run light to light. Thanks!
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[THUMPN68]

TBONE1964....Thanks, with age comes wisdom & i totally respect that . Maybe someday i can give advice . Thanks!
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