Steering ratio doubler advice.

[tcanin00]

I have a '71 Dart Swinger and am in the process of replacing my front suspension with QA1 and PST parts. The car originally had power steering and I'm swapping it out for a 24:1 manual steering box.
The plan was to convert to electric power steering and get a 16:1 manual steering box from PST.
My question is, can you run a 2:1 doubler on a street driven car? That would effectively make my 24:1 box a 12:1. I know doublers tend to be race car only parts, and don't want to create an unsafe or dangerous car to drive on the street. I would like to autocross occasionally, but this will be a daily driver when the weather is nice.

 

[pishta]

16:1 is like 3.75 lock to lock? 12:1 would be like a 2.8? That would be like go cart steering....maybe a little sketchy on the interstate.

 

[tcanin00]

That was my concern, being too responsive.

 

[72bluNblu]

So you’re talking about making the 24:1 manual steering box a 12:1 with a quickener? I run a 16:1 manual box on my duster with 275/35/18’s up front and I think that with a manual box the 16:1 ratio is about as much as you’re going to want. A 12:1 will require a ton of steering effort at low speeds, in an AutoX setting it would likely slow down your steering response in slow corners because of your ability to come around on the wheel fast enough.

Now, if you’re going to an EPAS it would work. I’m actually considering doing exactly that on my Duster, EPAS and a 1.5:1 quickener for a 12:1 ratio. You have to adapt the column anyway to add the EPAS so adding the quickener as part of that process would make sense.

The T/A and AAR E-bodies ran 12:1 steering ratio’s, they used the 16:1 power steering box and an extended pitman arm to get the ratio. So running a 12:1 ratio is not unheard of at all, but with power assist.

The Hotchkis Challenger used a 1.5:1 steering quickener set up instead of the longer pitman arm on a standard 16:1 power steering box. It's a Coleman unit that's mounted under the dash. It's a little hard to see it, but these are the only pictures I've found of it. There's a thread over at moparts on it where @autoxcuda talks about it, maybe he'll chime in here. They're his pictures

Hotchkis Challenger

 

[Commando66]

Have you driven your car with manual steering? A-bodies in my opinion don't need power steering. My go-to manual steering is the 20:1. It's one full turn faster than the 24:1 but not as "heavy" feeling as the 16:1. Electric power steering? Why? Are you planning to upgrade your electrical system at the same time? Keep it simple. These cars in nearly stock form with new suspension and steering parts are great performing cars. Add heavier torsion bars, good performance shocks and sway bar to make it drive more modern.

 

[72bluNblu]

Have you driven your car with manual steering? A-bodies in my opinion don't need power steering. My go-to manual steering is the 20:1. It's one full turn faster than the 24:1 but not as "heavy" feeling as the 16:1. Electric power steering? Why? Are you planning to upgrade your electrical system at the same time? Keep it simple. These cars in nearly stock form with new suspension and steering parts are great performing cars. Add heavier torsion bars, good performance shocks and sway bar to make it drive more modern.

Have you driven an A-body with 16:1 manual steering and 275mm wide tires in the front with a good amount of positive caster? Because that’s exactly what I’ve been doing for the last 10 years with my Duster, using it as a daily driver with 1.12” torsion bars, Hotchkis shocks, Hellwig sway bars, etc. I’m well aware of how it steers and handles.

20:1 is still too lazy a ratio for AutoX IMO, you’d be sawing away at that steering wheel on a tighter course. 16:1 is good, but with wide, sticky tires on the front and good alignment settings the steering effort in tighter courses gets pretty high.

The Hotchkis Challenger, while a larger Ebody, had great success on AutoX courses using the 12:1 ratio power steering. Although an early A may be significantly lighter, the 67-76 A’s are not ridiculously lighter than an E.

EPAS is a great way to add a power assist, most are available with potentiometers so that you can adjust the amount of assist with the turn of a knob. You’re already driving an alternator, and depending on your engine, radiator, fan and accessories adding the additional belts and pulleys for standard power steering can be a significant headache. Plus the EPAS will be lighter- no power steering pump, no heavy power steering box, no hydraulic lines. Just an alternator you already have to run and the EPAS itself.

Not sure about the OP’s car, but I have a completely new American Autowire harness and a 160A alternator. So EPAS is a no-brainer for power assist steering. And I could dial it up for AutoX and then dial it back down for the highway.

 

[autoxcuda]

So you’re talking about making the 24:1 manual steering box a 12:1 with a quickener? I run a 16:1 manual box on my duster with 275/35/18’s up front and I think that with a manual box the 16:1 ratio is about as much as you’re going to want. A 12:1 will require a ton of steering effort at low speeds, in an AutoX setting it would likely slow down your steering response in slow corners because of your ability to come around on the wheel fast enough.

Now, if you’re going to an EPAS it would work. I’m actually considering doing exactly that on my Duster, EPAS and a 1.5:1 quickener for a 12:1 ratio. You have to adapt the column anyway to add the EPAS so adding the quickener as part of that process would make sense.

The T/A and AAR E-bodies ran 12:1 steering ratio’s, they used the 16:1 power steering box and an extended pitman arm to get the ratio. So running a 12:1 ratio is not unheard of at all, but with power assist.

The Hotchkis Challenger used a 1.5:1 steering quickener set up instead of the longer pitman arm on a standard 16:1 power steering box. It's a Coleman unit that's mounted under the dash. It's a little hard to see it, but these are the only pictures I've found of it. There's a thread over at moparts on it where @autoxcuda talks about it, maybe he'll chime in here. They're his pictures

View attachment 1716225684

View attachment 1716225685

Hotchkis Challenger

I don’t have much to add to that. I just took the pictures when I had the opportunity. It just had a nicely fabricated support bracket.

 

[tcanin00]

So you’re talking about making the 24:1 manual steering box a 12:1 with a quickener? I run a 16:1 manual box on my duster with 275/35/18’s up front and I think that with a manual box the 16:1 ratio is about as much as you’re going to want. A 12:1 will require a ton of steering effort at low speeds, in an AutoX setting it would likely slow down your steering response in slow corners because of your ability to come around on the wheel fast enough.

Now, if you’re going to an EPAS it would work. I’m actually considering doing exactly that on my Duster, EPAS and a 1.5:1 quickener for a 12:1 ratio. You have to adapt the column anyway to add the EPAS so adding the quickener as part of that process would make sense.

The T/A and AAR E-bodies ran 12:1 steering ratio’s, they used the 16:1 power steering box and an extended pitman arm to get the ratio. So running a 12:1 ratio is not unheard of at all, but with power assist.

The Hotchkis Challenger used a 1.5:1 steering quickener set up instead of the longer pitman arm on a standard 16:1 power steering box. It's a Coleman unit that's mounted under the dash. It's a little hard to see it, but these are the only pictures I've found of it. There's a thread over at moparts on it where @autoxcuda talks about it, maybe he'll chime in here. They're his pictures

View attachment 1716225684

View attachment 1716225685

Hotchkis Challenger

Thanks for posting this. I had read your post about having a 16:1 box with larger tires in a different thread and I understand the amount of effort that would require. I plan on using a Toyota Prius EPAS unit. I haven't had time to make the parts and modifications to my steering column yet.
I'll read the thread you linked to get more information about running the doubler. I would assume that if Hotchkiss is successfully using a doubler, it's not a terrible idea. Just a different way of getting to 12:1 like the T/A cars that were mentioned.

 

[tcanin00]

Have you driven your car with manual steering? A-bodies in my opinion don't need power steering. My go-to manual steering is the 20:1. It's one full turn faster than the 24:1 but not as "heavy" feeling as the 16:1. Electric power steering? Why? Are you planning to upgrade your electrical system at the same time? Keep it simple. These cars in nearly stock form with new suspension and steering parts are great performing cars. Add heavier torsion bars, good performance shocks and sway bar to make it drive more modern.

Yes, years ago I manual steering swapped a '73 Scamp with a 318. I used 24:1 and the column from a Duster. The Scamp drove fine, and I don't remember it being it being to difficult to maneuver or park.
I am upgrading the electrical system with a complete harness and charging system from a '94 Dakota, along with the Magnum 5.2 from that truck. I'm also replacing the torsion bars with much heavier rate PST bars and KYB shocks.

 

[tcanin00]

Thanks for all of the discussion and advice on this. I found the quickener on Facebook Marketplace in upstate NY. The guy is shipping it Monday and that saves me a 6 hour round trip from Harrisburg, PA.
My next question would be, should the quickener be before the EPAS unit or after?
I wanted to post pictures of my car and the suspension set up earlier, but didn't have enough signal. I should be able to upload them now.

That new k-member sure makes a beat up core support look worse than it actually is.

I wasn't impressed by the quality of fasteners that QA1 supplies with the k-member. I've changed the washers for some thicker, higher grade ones.

The new PST torsion bar is on the right, it's 1.140" in diameter compared to the stock bar's .890" diameter. I do think the powder coating adds .015" to both bars.

Boxed in LCA's with Proforged greasable pivot pins.

Mostly completed right side suspension with a set of used PST tubular UCA's. I had already converted to disc brakes and big bolt pattern with M body knuckles, rotors, and brakes.

I know it has been discussed on here that long tie rod sleeves are needed, but I can't remember which ones will work. E body sleeves are the same as A bodies from PST. I have solid aluminum sleeves on it now, but there is a lot of tie rod end thread sticking out of the sleeve.

 

[Commando66]

Have you driven an A-body with 16:1 manual steering and 275mm wide tires in the front with a good amount of positive caster? Because that’s exactly what I’ve been doing for the last 10 years with my Duster, using it as a daily driver with 1.12” torsion bars, Hotchkis shocks, Hellwig sway bars, etc. I’m well aware of how it steers and handles.

View attachment 1716225801

20:1 is still too lazy a ratio for AutoX IMO, you’d be sawing away at that steering wheel on a tighter course. 16:1 is good, but with wide, sticky tires on the front and good alignment settings the steering effort in tighter courses gets pretty high.

The Hotchkis Challenger, while a larger Ebody, had great success on AutoX courses using the 12:1 ratio power steering. Although an early A may be significantly lighter, the 67-76 A’s are not ridiculously lighter than an E.

EPAS is a great way to add a power assist, most are available with potentiometers so that you can adjust the amount of assist with the turn of a knob. You’re already driving an alternator, and depending on your engine, radiator, fan and accessories adding the additional belts and pulleys for standard power steering can be a significant headache. Plus the EPAS will be lighter- no power steering pump, no heavy power steering box, no hydraulic lines. Just an alternator you already have to run and the EPAS itself.

Not sure about the OP’s car, but I have a completely new American Autowire harness and a 160A alternator. So EPAS is a no-brainer for power assist steering. And I could dial it up for AutoX and then dial it back down for the highway.

No

 

[clementine]

that long tie rod sleeves are needed,

@BergmanAutoCraft

 

[72bluNblu]

Thanks for posting this. I had read your post about having a 16:1 box with larger tires in a different thread and I understand the amount of effort that would require. I plan on using a Toyota Prius EPAS unit. I haven't had time to make the parts and modifications to my steering column yet.
I'll read the thread you linked to get more information about running the doubler. I would assume that if Hotchkiss is successfully using a doubler, it's not a terrible idea. Just a different way of getting to 12:1 like the T/A cars that were mentioned.

Exactly, just a way to get the 12:1 ratio without having to deal with the longer pitman arm and the header and oil pan clearance issues that those bring. Especially on an A-body.

I really like the 16:1 manual box, even with the 275's up front. Heck I even have a tuff steering wheel on it which is a smaller diameter. It's fine at anything above 20 mph or so. It gets pretty heavy in parking lots, and I expect it will be a lot for tight AutoX courses. The EPAS is the best of both worlds.

12:1 isn't super crazy either, my Austin Healey 100 had 12.6:1 manual steering and it was fine on the street, I daily drove that for a few years without any issues from the steering ratio being too fast. It wasn't heavy either, but that's a 2,000 lb car with narrower tires. But it wasn't too twitchy at all, and I'm sure it didn't have anywhere near the caster I run on my Duster either.

As for where to put the quickener, I'm not sure it really matters. It might be under a little bit less load if it were between the EPAS and the steering wheel? It would depend on how the EPAS loads the steering shaft. Realistically I think you'll have to put it wherever it actually fits.

Yes, years ago I manual steering swapped a '73 Scamp with a 318. I used 24:1 and the column from a Duster. The Scamp drove fine, and I don't remember it being it being to difficult to maneuver or park.
I am upgrading the electrical system with a complete harness and charging system from a '94 Dakota, along with the Magnum 5.2 from that truck. I'm also replacing the torsion bars with much heavier rate PST bars and KYB shocks.

Looks great except for the KYB's. Those will be absolutely atrocious with 1.14" bars if that's what you've got there, I thought PST only made 1.03's. Either way the KYB's are awful. I ran them on my Challenger with 1.12" bars and when I swapped them out for Bilsteins it was like a whole new car. KYB's are hot garbage, especially for larger torsion bars.

No

Well, there you go.

I like the 16:1 manual steering on the street even with 275's and +6.5° of caster. But for slow autoX courses the amount of effort required will probably be too much. The EPAS, especially one with a potentiometer, would be awesome as you could adjust it. Having run the 16:1 and done a good amount of driving in my Healey on the street and for autoX with a 12.6:1 ratio I would much rather have a 12:1 or 16:1 ratio vs a 20:1, you'd always be turning the wheel.

 

[tcanin00]

"Looks great except for the KYB's. Those will be absolutely atrocious with 1.14" bars if that's what you've got there, I thought PST only made 1.03's. Either way the KYB's are awful. I ran them on my Challenger with 1.12" bars and when I swapped them out for Bilsteins it was like a whole new car."

Thanks for taking the time to respond and give your advice. I measured the outside diameter of the torsion bars with a dial caliper, which is by no means accurate. But it will get you in the ball park. I made the assumption of that the powder coating adds .015" to the diameter because if that is subtracted from the diameter of both bars, you get nominal numbers. The stock bars being .875" or 7/8th and the PST bars being 1.125" or 1 and an 1/8th.
I don't remember what the largest size bar PST sells. I bought them at least four years ago. I do remember coming to a decision on size after reading several threads on this and other forums.
I'm running KYB's all the way around the car with Super Stock springs on the rear. It doesn't seem to bad, but I haven't really driven it aggressively before taking apart the front end. The decision on shocks was more of a price point, since QA1's and Afco's are a bit out of my price range. What is the part number of the Bilsteins?

 

[Killer6]

If You've got power assist that keeps up with the steering gear controls, there is simply no such thing as 'too fast', unless You're running rallies etc. where You're getting bounced around....that is last thing I would be worried about. The last years of the Shelby Daytona/Z's were barely over 2 turns lock to lock, & My 1st 'hotrod' 7hp B&S homemade go-kart was 1/3 turn lock to lock....yeah..no power assist there.....

 

[junkyardhero]

I'm running KYB's all the way around the car with Super Stock springs on the rear. It doesn't seem to bad, but I haven't really driven it aggressively before taking apart the front end. The decision on shocks was more of a price point, since QA1's and Afco's are a bit out of my price range. What is the part number of the Bilsteins?

super stock springs are not conducive to good handling or a great ride.

mos def recommend upgrade on the shocks. with the big bars you really need a good shock to tame them and kyb's are not that.

 

[Commando66]

@72bluNblu, My 66 Valiant wagon had a factory installed 16:1 steering box and 245/60/14 tires. It was very heavy but responsive driving down the road. It just wasn’t for me.

 

[Jeremiah (jd)]

I ran a 16:1 box with fast ratio pitman idler for a few summers. I think it was 12 something to one. It wasn't horrible with skinny front tires and a big block under the hood.

For reference a fast ratio p/s box is 14:1.

 

[tcanin00]

super stock springs are not conducive to good handling or a great ride.

mos def recommend upgrade on the shocks. with the big bars you really need a good shock to tame them and kyb's are not that.

The car didn't ride too bad on the super stocks. You could tell the spring rate was higher on the rear compared to the stock front torsion bars. I took the first, shortest leaf out of the spring pack before I put the springs on the car. It looks like it sits level, haven't measured the rear ride height yet.
What shocks would you recommend?

 

[72bluNblu]

"Looks great except for the KYB's. Those will be absolutely atrocious with 1.14" bars if that's what you've got there, I thought PST only made 1.03's. Either way the KYB's are awful. I ran them on my Challenger with 1.12" bars and when I swapped them out for Bilsteins it was like a whole new car."

Thanks for taking the time to respond and give your advice. I measured the outside diameter of the torsion bars with a dial caliper, which is by no means accurate. But it will get you in the ball park. I made the assumption of that the powder coating adds .015" to the diameter because if that is subtracted from the diameter of both bars, you get nominal numbers. The stock bars being .875" or 7/8th and the PST bars being 1.125" or 1 and an 1/8th.
I don't remember what the largest size bar PST sells. I bought them at least four years ago. I do remember coming to a decision on size after reading several threads on this and other forums.
I'm running KYB's all the way around the car with Super Stock springs on the rear. It doesn't seem to bad, but I haven't really driven it aggressively before taking apart the front end. The decision on shocks was more of a price point, since QA1's and Afco's are a bit out of my price range. What is the part number of the Bilsteins?

As far as I know the only bars PST has sold in that timeframe were 1.03's. Firm Feel, Sway Away and BergmanAutocraft sell larger bars, and MP used to sell larger bars like that.

KYB's with factory torsion bars don't feel terrible, because you're experiencing the combination of too soft a spring with a really stiff shock. As far has handling goes its not ideal, but the stiff shocks band aid the soft torsion bars. When you combine them with stiffer springs, their cheap internal construction just gives a really harsh ride. I ran my Challenger with KYB's for most of the 70k miles I put on it, with 1.12" bars, blaming the bars for the stiff ride. The bars are fine, the KYB's are trash.

For large torsion bars, the RCD Bilsteins are probably the best bang for the buck. There are better shocks, but the price goes up fast. They worked well with the 1.12" bars on my Challenger, as I said earlier the comparison between the ride with the KYB's and the ride with the Bilsteins was night and day, a massive improvement with the Bilsteins.

Bilstein Shocks - Front - A Mopar Body - Bergman Auto Craft

Bilstein Shocks - Mopar - A Body Rear - Bergman Auto Craft

@72bluNblu, My 66 Valiant wagon had a factory installed 16:1 steering box and 245/60/14 tires. It was very heavy but responsive driving down the road. It just wasn’t for me.

I totally understand that not everyone wants to run 16:1 manual steering, that's fine. Where you lost me is when you're saying that A-bodies don't need power steering, than also say that 16:1 manual steering on an A is too heavy. Seems like power steering would be the solution to that problem without sacrificing steering ratio don't you think?

I ran a 16:1 box with fast ratio pitman idler for a few summers. I think it was 12 something to one. It wasn't horrible with skinny front tires and a big block under the hood.

For reference a fast ratio p/s box is 14:1.

A 16:1 box with the fast ratio pitman and idlers out there would be 12:1.

But the fast ratio power steering box itself is 16:1, then uses fast ratio pitman and idler arms to get to 12:1. The box itself for the T/A and AAR cars was still 16:1, they were different because the inner stops were reset to match the travel of the longer steering arms. All of the factory power steering boxes for these cars were 16:1, if you put a standard pitman arm on a T/A box the ratio is the same as the standard power steering boxes.

The aftermarket Borgeson power steering box conversion gives a 14:1 ratio, but that's not Mopar parts.

 

[junkyardhero]

The car didn't ride too bad on the super stocks. You could tell the spring rate was higher on the rear compared to the stock front torsion bars. I took the first, shortest leaf out of the spring pack before I put the springs on the car. It looks like it sits level, haven't measured the rear ride height yet.
What shocks would you recommend?

bilstein RCD. those are about the best priced "good" shocks you can get. from there the price goes up rapidly.

 

[tcanin00]

As far as I know the only bars PST has sold in that timeframe were 1.03's. Firm Feel, Sway Away and BergmanAutocraft sell larger bars, and MP used to sell larger bars like that.

KYB's with factory torsion bars don't feel terrible, because you're experiencing the combination of too soft a spring with a really stiff shock. As far has handling goes its not ideal, but the stiff shocks band aid the soft torsion bars. When you combine them with stiffer springs, their cheap internal construction just gives a really harsh ride. I ran my Challenger with KYB's for most of the 70k miles I put on it, with 1.12" bars, blaming the bars for the stiff ride. The bars are fine, the KYB's are trash.

For large torsion bars, the RCD Bilsteins are probably the best bang for the buck. There are better shocks, but the price goes up fast. They worked well with the 1.12" bars on my Challenger, as I said earlier the comparison between the ride with the KYB's and the ride with the Bilsteins was night and day, a massive improvement with the Bilsteins.

Bilstein Shocks - Front - A Mopar Body - Bergman Auto Craft

Bilstein Shocks - Mopar - A Body Rear - Bergman Auto Craft


I totally understand that not everyone wants to run 16:1 manual steering, that's fine. Where you lost me is when you're saying that A-bodies don't need power steering, than also say that 16:1 manual steering on an A is too heavy. Seems like power steering would be the solution to that problem without sacrificing steering ratio don't you think?



A 16:1 box with the fast ratio pitman and idlers out there would be 12:1.

But the fast ratio power steering box itself is 16:1, then uses fast ratio pitman and idler arms to get to 12:1. The box itself for the T/A and AAR cars was still 16:1, they were different because the inner stops were reset to match the travel of the longer steering arms. All of the factory power steering boxes for these cars were 16:1, if you put a standard pitman arm on a T/A box the ratio is the same as the standard power steering boxes.

The aftermarket Borgeson power steering box conversion gives a 14:1 ratio, but that's not Mopar parts.

Thanks for the information. To be honest, I don't remember what website or company I bought the torsion bars from, and the box wasn't marked. Google shows that PST makes 1.12" bars for A bodies, and that's probably what these are with 0.020" of powder coating.
I looked on BAC's site at the RCD Bilsteins, they're within my pain threshold. I hate when being cheap makes me spend more money on better parts.
I initially looked at the Borgeson power steering boxes, but decided an EPAS system would work be for my car.

 

[72bluNblu]

Thanks for the information. To be honest, I don't remember what website or company I bought the torsion bars from, and the box wasn't marked. Google shows that PST makes 1.12" bars for A bodies, and that's probably what these are with 0.020" of powder coating.
I looked on BAC's site at the RCD Bilsteins, they're within my pain threshold. I hate when being cheap makes me spend more money on better parts.
I initially looked at the Borgeson power steering boxes, but decided an EPAS system would work be for my car.

PST makes 1.12" torsion bars for C-bodies. Not A-bodies. What is stamped on the end of the torsion bar? PST and FFI both have their stamps on the ends of the hexes.

 

[tcanin00]

PST makes 1.12" torsion bars for C-bodies. Not A-bodies. What is stamped on the end of the torsion bar? PST and FFI both have their stamps on the ends of the hexes.

I'll have to look. I'll let you know.

 

[tcanin00]

Had a few minutes to get a picture of the torsion bar end. Here's what is on it.

I also looked up my PST order from April 2020. The are 1.03" bars. I have a hard time believing they measured .110" bigger in diameter than advertised. Maybe they're rated by spring rate equivalent to a 1.03" bar?