Please help- straight axle or A-arms

We are building a 33 ford coupe for drag racing.
I'm not sure what style front end to use.
I love the straight axle but I'm concerned its design may not be strong enough.
We expect to run 140 mph with big wheelies.
What would you guy use?

 

They've used straight axles since the start. I'm a straight axle guy. Traditional is the way to go. Find a nice 36 axle and put about 7-9 degrees in it.

 

I really want to run a straight axle, I just wanted to make sure I'm making the best decision

 

Straight axle! Lots of guys with current wheel standers use them.

 

This car has a straight axle and Ford style suspension , and it runs low tens leaving on the bumper.

Meltdown Drags 2013 July 19-21

 

Straight axle......or a Straight axle!

 

Straight!!!!

 

You might want to look into some of the altereds and FEDs as to what's sturdy enough. I would think that wheels up launches on straight axles have been happening for decades, but the real deal is the control on the way down. If it were a near static drop you're gonna break even the stoutest of OEM A-arm set ups. Just find some youtube vids of wheelie contests to see what I mean. I'm thinking also that some of the purpose built straight axle stuff for drag racing has a weight limit as part of the specs.

Just for fun, tell us more about your car.

 

Seems to me that the energy used to wheel stand could be better spent on a flat line run down the track.
Just sayin'

 

We have a fiberglass 33 ford 3 window.
We used stock frame rails to build our custom frame. We narrowed the rear 6" on each side.
Going with a 15" wide slick, 5 speed trans & 76mm turbo. Radiator in the trunk, no fenders or hood.
We race with a stick shift class ( www.umtrnorthcom ).
I really hope to get a straight axle front end, they look amazing o. These old coups.

 

Straight axle is the only way to go. HRP

 

Straight axle for sure

 

Launched at 6500 . Ran 11.80's @ 120mph. Pulled 3 foot wheelies. And ran as straight as an arrow.

Posted using the Full Custom H.A.M.B. App!

 

Very nice

 

Can anyone tell me with a straight axle front end if it will handle smoothly at a high speed?
We are looking at 140-150 mph.

 

have you heard the speeds they run at Bonneville with a straight axle?

 

Nope.
When someone tells me why I shouldn't use a straight axle, I ask the question here because I know many of you have experience with straight axles. I've been told its a loose ride at high speeds. But I also know 100% of the dragsters are using straight axles and those boys are flyin.

 

The higher the speeds, the more inclination you might want on the kingpins. Some of those rails and funny cars going 200-300 mph have as much as 20 degrees inclination. Most street cars are around 5-10 degrees. 7 degrees seems to be what most shoot for on the street.

 

Its all in the degrees. On the street you run the axle at around 5-7 degrees back angle. The faster you go the more angle. I run mine at around 8-10. Have you seen in the old pics of dragster when they turn the wheels look like they are laying over? Some of them run 20+ degrees.

 

Walk around some of Mazooma's fine pics. There's only one IFS, all others are straight axles. http://www.jalopyjournal.com/forum/showthread.php?t=639058

 

Nothing wrong with a modern, up to date tube axle.
Just remember to design a proper Panhard rod to keep the axle centered. The bar should be level (to the ground) at full weighted ride height.
Also as some have said, 6 or 7 degrees caster is a good place to start.

I ran a dropped tube axle in my Anglia years back with no regrets. Ran 9.80's at 132/134.

Mike

 

Shakey Puddin runs a straight axle and it seems to do just fine.

http://www.youtube.com/watch?v=7x68ZHe0hM4

Don

 

You haven't said if the A-arm option will have suspension.If not BIG wheel stands wil cause chassis damage.If you would like to win rounds,Big wheel stands won't help to win.
You said you will run in a specific class.Find out what the others will be running,and follow the majority.That way you will be competitive,and not round one fodder.
Big wheel stands while looking cool for the spectators,will not win you races.
In my Altered ,I have run 139 mph but only after removing 39"wheelies bars and installing 68".The straight axle has 12degrees caster adjustable shocks,and a steering damner to stop the "Funky Chicken"dance that can be common with straight axles.Hope this helps

 

Personally I love straight axles

 

Straight axle but make sure it's done properly. The Marcellus, Borsch and Boyd AA/FA had a crash a few years back when an improperly welded kingpin boss sheared off the main tube at 180 mph. It was a gift from a so.cal. fabricator and looked fine at the weldments to the naked eye, but had no penetration and a poor weldment prep. I will not divulge the fabricator as he is not in the business any longer. Fortunatly big Mike Boyd got the chutes out and the car scrubbed the rail till the end , it then hooked some of the old K-rail and did a slow roll, Boyd was un-injured but the body work was plenty messed up, The Roo-man stepped up and built them a new chassis and axle.

 

I forgot to ask what your planned wheelbase will be?

 

Wow. Thanks for all the helpfully info.
We will have a front suspension.
I think the old coups ran a 106" & 112" wheel base.
I do not have a firm direction yet on wheel base. I need to ask around and learn some "do's & don'ts" on this.
I'm all ears if anyone has any suggestions.

 

My 1968 era Altered is 96".Since you won't have front fenders,112" would be a good choice.I've seen straight axles and A-arm on that wheelbase.

 

Straight axle or not , I would build something remiscent of the Moonyham/Sharp#554 coupe and smoke 'em the full 1/4 mile !

 

something along the lines of cliff hansens car.....

stick with a stock wheelbase and go with a narrower tire. its kinda clowny/pro street looking with big big big tires...a 33x10.5 would be plenty ...look for pics of the 554 coupe

as for caster, I was told around 8 degrees