Thread: Straight Front Axle or IFS

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I plan to build a 32 3w coupe. I plan on driving it to and from work which is 100 miles of highway driving per day. I like the look of a Straight Front Axle but will I be better off with IFS for drivability?

Set up correctly, a straight axle will ride and handle just fine. Youre only a few miles from me; look me up and I'll give you a ride in my coupe...

Jim is right. I have a '32 3W coupe with a pinched frame and a Heidt Superide independent front suspension. There is not a lot of difference between the two. Since you like the look of a straight front axle, go with it. To me, it all depends on the style of the car. I built mine as a slick, modern highboy so the IFS was the right choice. My previous car was more traditional, and I used a straight front axle under it.

Straight axle gets my vote every time. All things being equal IFS might have a slight edge, but I just like the look of a dropped straight axle a whole lot more.

Don

For just a driver, straight axle works.... When you want to build in some serious handling with good adjustability, then IFS gets my vote!!!! Just me, but I'd never even consider a straight axle again, but then I'm more concerned about the handling then about "the look".... Just depends on what you want.

I'm concerned with "the look" as much as driveablity, but you can have both. If its a hi-tech style car and/or if it's got fenders to hide the ugly, IFS is ok, but if it's a traditional style car or a fenderless car I wouldn't consider anything but a solid axle.

FWIW I drive mine everywhere (and I do mean everywhere!) with a 4" dropped axle here in PA, with potholes big enough to lose a kid in... no problems.

Originally Posted by Dave Severson

For just a driver, straight axle works.... When you want to build in some serious handling with good adjustability, then IFS gets my vote!!!! Just me, but I'd never even consider a straight axle again, but then I'm more concerned about the handling then about "the look".... Just depends on what you want.

Can a 32 handle well? What is the steering ratio of a traditional setup vs a IFS with a rack?

Originally Posted by 32driver

Can a 32 handle well? What is the steering ratio of a traditional setup vs a IFS with a rack?

IF you are hung up on a rack and pinion setup ... you can buy a rack and pinion setup for a straight axle 32. I have the Uni-Steer setup under my 32 3W ...



They list for $385. Go here to see more http://www.streetrodstuff.com/Products/2039/

Here is my 3W

Depends on what ratio rack you put in it...

Can it handle well with a straight axle??? Depends on your definition of handling....It will go down the road straight, turn ok at reasonable speeds, and have a tolerable ride if the correct spring is installed...

Will it handle as well as an IFS in the windy-twisties at high speed???? No. But it's not fair to compare a design based on 1920's technology to a quality, well designed IFS.... Two entirely different concepts. With an IFS, caster and camber adjustments can be made easily, bump steer is a non-issue if the system is set up correctly, etc. Spring rates are easily changed, single and double adjustable shocks are available.

I'm not going to argue which is better, it's all dependent on your driving style...FOR ME, the IFS is the only way to go for the way I like to be able to drive a car.... Comparing IFS to a straight axle is not an apples to apples comparison.....

Like Dave says ...

For road racing, competitive events and such ... IFS is considered better ... by most. I am old school ... and prefer the look of a straight axle.



I drive my 32 Roadster a good bit. I have driven it from my home to Louisville KY ( 500 plus miles ) in one day ... quite a few times. It does not ride and drive as well as my 2008 Cadillac DTS but I find the ride and drive very acceptable ... for a 2500 pound vehicle.

If you are planning fenders and such ... the IFS is not quite as ugly ... but for a fenderless 32 ... for my money ... it HAS TO BE a straight axle.

I agree with almost everything said above so far. If straight axles were the absolute "cat's meow" in handling, they would be the hot setup for Formula One. Obviously, they aren't...

On the other hand, a straight axle can be made to handle pretty well. I think my coupe could hold its own against any stock Camaro, Firebird, or Mustang on a twisty course. A lot depends on the springs, shocks, radius rod configuration, etc. My coupe has a dropped axle up front suspended on adjustable torsion bars instead of a buggy spring. The rear is sitting on coil springs with NASCAR style weight-jackers. We drove this thing on a 2400 mile trip up through the midwest and back through the Carolinas in 2006. It was fun to drive in the hills of east Tennessee and North Carolina...

Bottom line is, if this is your first build a straight axle may be a lot easier to set up.

IFS looks fine on a highboy as long as you pinch he frame. Otherwise the IFS looks clunky, IMO. Compare the photo of my car at the Nats earlier this month and the orange flamed deuce posted previously. The orange deuce is a beautiful car, I've seen it, but it is not my taste in frame/front suspension design.

I have basically the same rear end setup that you have ... BUT my springs are in front of the rear end ... and mine is connected with 4 bars instead of a pair of trailing arms





It rides very good IMHO ... and handles well also.

Deuce,
Do you have any problems with the upper locating arms hitting the exhaust when the rear end drops? I have a set up similar yours in the 34 3 W I am re doing and have concerns over the upper arms hitting the exhaust. Also, are any of your locating arms adjustable? I am making all 4 of mine adjustable to make up for any inaccuracies in my measuring for axle location and pinion angle.

Jack.

All of my bars ( front and rear ) are adjustable. When I ran the exhaust, I removed the shocks and the coil springs and let the frame sit down as far as it would drop. Then I ran the tail pipes.

The pipes do not hit ... but are very close when in the no shock/no coil mode. With the springs in and the shocks on ... I have enough clearance. My battery box is on the right side ... thru the floor ... under the seat and it did rub on a good bump. I discovered that after I installed the body for the last time.

I did have to bend the exhaust a little on the right side where it interfered with the battery box.



The 32 sits pretty low ... but nothing hangs down past the running boards.