Rack and pinion steering.

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Many years ago i had a pinto rack narrowed by seven inch (!) to try and put it in with drum brakes on a 65 dart. Fast forward to 1996 and a new chassis build, and i put that same rack in with modified lower ball joints. Ackerman angle was zero, meaning the front end stays parallel from straight to a max turn angle. This supposed wrong setup had serious impact on car handling at speed . If you get sideways, the front end does not "push", trying to flip you around, because the front tires are always parallel . Three times i have gotten seriously sideways at speeds of 125, 135, and 153 mph! A quick snap of the steering wheel and my dart comes back to straight like it is on rails .
Tire scrub wear has been minimal, but pushing the car around a corner is tough. But after those three wild rides, I will live with the inconvieniance! Picture of my front suspension, using upper and lower stock control arms, etc. stable at 160 mph!

PXL_20220912_011113203.jpg
 
I shortened the lower balljoint arms and welded them back on. I did some serious strength testing to make sure they would never fail!
 
gregsdart said:
Many years ago i had a pinto rack narrowed by seven inch (!) to try and put it in with drum brakes on a 65 dart. Fast forward to 1996 and a new chassis build, and i put that same rack in with modified lower ball joints. Ackerman angle was zero, meaning the front end stays parallel from straight to a max turn angle. This supposed wrong setup had serious impact on car handling at speed . If you get sideways, the front end does not "push", trying to flip you around, because the front tires are always parallel . Three times i have gotten seriously sideways at speeds of 125, 135, and 153 mph! A quick snap of the steering wheel and my dart comes back to straight like it is on rails .
Tire scrub wear has been minimal, but pushing the car around a corner is tough. But after those three wild rides, I will live with the inconvieniance! Picture of my front suspension, using upper and lower stock control arms, etc. stable at 160 mph!

View attachment 1716348991
Click to expand...
Thanks, that's very cool Greg.
 
gregsdart said:
Many years ago i had a pinto rack narrowed by seven inch (!) to try and put it in with drum brakes on a 65 dart. Fast forward to 1996 and a new chassis build, and i put that same rack in with modified lower ball joints. Ackerman angle was zero, meaning the front end stays parallel from straight to a max turn angle. This supposed wrong setup had serious impact on car handling at speed . If you get sideways, the front end does not "push", trying to flip you around, because the front tires are always parallel . Three times i have gotten seriously sideways at speeds of 125, 135, and 153 mph! A quick snap of the steering wheel and my dart comes back to straight like it is on rails .
Tire scrub wear has been minimal, but pushing the car around a corner is tough. But after those three wild rides, I will live with the inconvieniance! Picture of my front suspension, using upper and lower stock control arms, etc. stable at 160 mph!

View attachment 1716348991
Click to expand...

Different racing genres use different levels of Ackerman. With drift cars, for example, it’s not uncommon at all to run zero Ackerman and technically negative or reverse Ackerman would be better/faster because of the slip angles involved. But even with drift cars most drivers don’t run negative Ackerman because of how different it makes the car feel compared to normal.

High speed performance is its own thing entirely because the steeing angles are reduced. Ackerman gets more important as the steering angles get more severe, so high speed maneuvers reduce the impact of Ackerman to begin with. F1 cars for example have TERRIBLE steering angles. Yeah at 200 mph they perform amazing, but navigating a parking lot would look like a scene from Austin Powers.

But those are race cars, not street cars. It’s a different bar if you’re still street driving.

gregsdart said:
I shortened the lower balljoint arms and welded them back on. I did some serious strength testing to make sure they would never fail!
Click to expand...

So you had them x-rayed? Or did destructive testing to determine the yield strength on a set of test arms?
 
72bluNblu said:
Different racing genres use different levels of Ackerman. With drift cars, for example, it’s not uncommon at all to run zero Ackerman and technically negative or reverse Ackerman would be better/faster because of the slip angles involved. But even with drift cars most drivers don’t run negative Ackerman because of how different it makes the car feel compared to normal.

High speed performance is its own thing entirely because the steeing angles are reduced. Ackerman gets more important as the steering angles get more severe, so high speed maneuvers reduce the impact of Ackerman to begin with. F1 cars for example have TERRIBLE steering angles. Yeah at 200 mph they perform amazing, but navigating a parking lot would look like a scene from Austin Powers.

But those are race cars, not street cars. It’s a different bar if you’re still street driving.



So you had them x-rayed? Or did destructive testing to determine the yield strength on a set of test arms?
Click to expand...
This thread is for my drag car.
On a 8.50 roll cage, they don't do any of that x-ray or destructive testing. they check thickness of the steel tubing.
That's legal to 150 mph.
What I'm saying with this example above is when a welder knows what they're doing they trust their welds.
Also drag race track pits have a lot of space to make wide turns.
 
MOPARMAGA said:
This thread is for my drag car.
On a 8.50 roll cage, they don't do any of that x-ray or destructive testing. they check thickness of the steel tubing.
That's legal to 150 mph.
What I'm saying with this example above is when a welder knows what they're doing they trust their welds.
Also drag race track pits have a lot of space to make wide turns.
Click to expand...

Well I guess if it will never be driven on the street you can do whatever you like, however ill advised it may be for anything else. Drag cars can get away with sketchy geometry because all they ever do is go straight, and that’s easy. Unless you get out of shape, but hey, not my problem.

As for the steering arms, he said he “did some serious strength testing to make sure they would never fail!”. For that to mean anything at all it would mean either doing destructive testing or having the welds checked beyond the “looks good to me” level. Otherwise it’s not “serious strength testing”. From an objective standpoint, you wouldn’t do “serious strength testing” on the arms you were going to use, because serious testing is destructive.

It’s already been said, but doing the front steer conversion RIGHT takes planning and custom parts. Doing it EASY means bad geometry. Drag cars in the past have largely done it with bad geometry. If it never sees any street time at all, knock yourself out. If you’re gonna put it on the street on the weekends like that, well, hopefully it’s just your funeral and not anyone else’s.
 
72bluNblu said:
Well I guess if it will never be driven on the street you can do whatever you like, however ill advised it may be for anything else. Drag cars can get away with sketchy geometry because all they ever do is go straight, and that’s easy. Unless you get out of shape, but hey, not my problem.

As for the steering arms, he said he “did some serious strength testing to make sure they would never fail!”. For that to mean anything at all it would mean either doing destructive testing or having the welds checked beyond the “looks good to me” level. Otherwise it’s not “serious strength testing”. From an objective standpoint, you wouldn’t do “serious strength testing” on the arms you were going to use, because serious testing is destructive.

It’s already been said, but doing the front steer conversion RIGHT takes planning and custom parts. Doing it EASY means bad geometry. Drag cars in the past have largely done it with bad geometry. If it never sees any street time at all, knock yourself out. If you’re gonna put it on the street on the weekends like that, well, hopefully it’s just your funeral and not anyone else’s.
Click to expand...
Thanks, I think. lol
 
MOPARMAGA said:
This thread is for my drag car.
On a 8.50 roll cage, they don't do any of that x-ray or destructive testing. they check thickness of the steel tubing.
That's legal to 150 mph.
What I'm saying with this example above is when a welder knows what they're doing they trust their welds.
Also drag race track pits have a lot of space to make wide turns.
Click to expand...
I put about a ton of force on the tierod end, and nothing moved or bent. Good enough for me. But being sure a welded steering Arm is good is about as important as it gets . A better way came about on another build i did. I used two by half inch bar stock to add the steering arm, using longer bolts. That worked well for a street car i built with rack and pinion plus coilovers.
 
gregsdart said:
I put about a ton of force on the tierod end, and nothing moved or bent. Good enough for me. But being sure a welded steering Arm is good is about as important as it gets . A better way came about on another build i did. I used two by half inch bar stock to add the steering arm, using longer bolts. That worked well for a street car i built with rack and pinion plus coilovers.
Click to expand...
Awesome Greg, thanks again.
I'll be checking with you probably next winter if & when I decide I want to tackle this.
 
Something else tht might help you out. This guy's selling a 1972 Dodge Dart with a rack & Pinion already installed. If he did it, you might get the info you need;
1972 Dodge Dart
 
Shorty Thompson said:
Something else tht might help you out. This guy's selling a 1972 Dodge Dart with a rack & Pinion already installed. If he did it, you might get the info you need;
1972 Dodge Dart
Click to expand...
that's just mustang 2 junk up front with, likely, a universal x-member on some 2x3 frame

same thing can be done, and better with RMS, hemi denny or hitting up speedway, loading a cart and melting a credit card.
 
go-fish said:
Personally, if OP has time to do this (and actually considering it) then he should never work on someone else’s car.
Any form of modification to the stock spindle (especially heating and bending) to achieve front steer r&p is slap stupid.

This should be a sticky, a list of boneheaded products and companies that are safety hazards :
  • Uni-steer or anything like it
  • Magnum Force anything
  • …..
There are other goofball products on the market but these above are actual safety hazards.
Click to expand...
I'm happy to disappoint you.
 
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