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Model A front suspension

7K views 11 replies 4 participants last post by  Alecigio 
#1 ·
Hello everyone,
I am currently building a 1931 Ford Tudor (Sedan 2 doors). I am looking to buy a front suspension for it. First of all I am making a hot rod out of it so I want a IFS. I will have a 302 as the engine with around 300 horse power and I also have an aftermarket frame but I don't know from which company it comes.

I searched the boards for which suspension would fit correctly but I didn't find much about it. I would like to have 13" cross drilled brakes but It doesn't need to have any chrome on it exept on the brake calipers.

I don't want to modify the front fenders to make fit the crossmember. I don't really care about the price, I can go up to 5000$ CAN (3000$ US) for it. What are your suggestions for a suspension for my car?
 
#4 ·
Alecigio said:
First of all I am making a hot rod out of it so I want a IFS.

I don't want to modify the front fenders to make fit the crossmember.

You mean you are making a Street Rod out of it.......not a HotRod.....

For a A Arm suspension to work best......both arms need to be parallel to the ground..........this is not going to happen a Model A with fenders.

A lot of folks here have had a ongoing debate about Heidts stuff and some of the MustangII/Pinto front ends and kits.

:D
 
#6 ·
Alecigio said:


What do you mean by it is not going to happen to a Model A with fenders??
http://www.totalcostinvolved.com/assets/pdf/02-03.pdf


Go look at the photos on the TCI Model A page.
The ones with a IFS.........the lower and upper A arms are not parallel.......:D

The upper runs upward and the lower one runs downward.


Just a fact of life........and they are unequal length too.

Many years ago, before the MustangII/Pinto front ends were even made........people were putting Jag stuff under the front and the rear of Model A's and Deuces. The main issue with the front was/is that the A arms need to be parallel to work properly. On a fenderless car......no problem to achieve (but they are UGLY :( )

Most decent kits with IRS are 2 - 3 grand
Frames with the IRS suspension and the rear done.................twice.at least.

:D
 
#7 ·
What Duece is saying is the Mustang II front suspension has to be "flattened out" to run under a pre- '32 front fender. The Model A's front fenders have a much flatter shape, as they come out from the frame rail, then a '32-'34 front fender. This necessitates the upper control arm to be pushed down into rebound which upsets all of the designed in geometry from Ford. Upsetting the geometry makes for some questionable high speed handling problems and causes bump steer and ackerman issues. As far as I know none of these problems have been redesigned out of a "Model A" IRS.
I have a '31 Tudor myself and I have decided to go with a straight axle in the front. I have talked to a lot of rodders that have both straight axles and IFS units and it has been my concensus that the straight axle is preferred and can out handle the IFS due to the problems I've listed above... This is just my opinion though so I would suggest talking to a few rodders, as I did, and make your own informed decision.
Mark
 
#8 ·
Thanks to both of you. I see what you were saying about the A-arms being not parallel. I will probably go talk to some people around here who have model and ask them their opinions on that. I will also go talk to someone who sold me my frame, he is restoring cars as a living.
 
#9 ·
:D



Lots of folks have IFS under their cars..........;)

A good bit of it is " Monkey see.......Monkey do.........."

They do NOT understand the WAY of IRS and the engineering behind it. IFS in a everyday production car rides, drives and handles well. It was designed to do so. The big Three spend millions and millions of dollars designing IFS. The rodders with IFS want these same things in their modified ride.

When something is adapted.....that's exactly what happens.....it is adapted to...NOT engineered for the vehicle. Pinto/MustangII front ends are 56 inches wide.........wheel mounting flange (WMF) to wheel mounting flange (WMF)........If you shorten the A arm......you must shorten the rack or bump steer will happen. 56 inches is too wide for most early cars.



On my 32 Ford (above)..........my straight axle (with a 4 bar suspension) is 48 inches kingpin to kingpin ....or 54 inches wide WMF to WMF..........two inches more narrow than a Pinto/MustangII. .......and a Model A 's front fenders are almost 2 inches more narrow than a 32 :D :D ..............RUB ??? I think so....if not narrowed or modified.


NOT trying to give you a bunch of grief..........just trying to let you be well informed and THEN make your decision.

DEUCE....General Rodding Tech Moderator.

.
 
#10 ·
If I understand right, the mustang II suspension is too wide for the model A fenders? So I would have to cut the A-arms. I don't want to buy a suspension from a mustang or a pinto, i would like to buy one made for the frame I have. Should not it have the right size to not rub on the fenders?

The suspension I was really looking at is this one.

Does it count as a Mustang II suspension or goes in another category? What I consider as a Mustang II one is

I would not like the second one because I think it looks ugly and too big.

Sorry if I ask a lot of questions, it is just that I want to have the most informations before I make a choice on what to get and not regret it later.
 
#11 ·
:D



This one has the rack behind the crossmember. That's good ..........or you would have to modify the splash apron on your 31 :( . What happens when the upper A arm moves a good bit? The lower will move the same amount but the spindle will change it's angle and the tire patch on the road will decrease.

If the suspension goes up........the upper ball joint moves closer to the frame and the center of the tire patch moves to the inside area of the tire. If the suspension moves down......the upper ball joint moves away from the frame and the center of the tire patch moves to the outside area of the tire.

This is reduced SOME by using a shorter upper A arm.


As a general rule, when the kit makers narrow a Pinto/MustangII.........they narrow the crossmember, not the arms.

Look at the above photo and you can see that the rack arms are the same length (pivot points) as the the lower A arm. If NOT.........bump steer will occur.
Not on the one above :D and that's good.



This is correct geometry.......

Heidts will not make a Pinto/MustangII kit for the Model A or 32's. I took the above photo from their on-line catalog.

http://www.heidts.com./heiford.htm

:D
 
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