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E body Fast ratio arms ?

Posted By: Lee446

E body Fast ratio arms ? - 07/12/19 12:03 AM

I just discovered that both my pittman arm and idler arm on my 70 barracuda are well worn. Since I have to replace them anyway, I wondered about going to the fast ratio arms. I have power steering and a gen 2 hemi with TTI headers. What problems would I run into to use these components? Would changing to them affect the alignment job that I just had done? I can replace them with stock if it is going to turn into a problem. PST seems to be reasonably priced, are they a good choice? Thanks!
Posted By: Pacnorthcuda

Re: E body Fast ratio arms ? - 07/12/19 01:58 AM

It’s going to affect the toe setting as the tie rods will have to adjusted to accommodate the new pitman and idler.
It will not affect caster or camber.

You will like it, it makes for a much more responsive set up.
Posted By: Kern Dog

Re: E body Fast ratio arms ? - 07/12/19 03:59 AM

Originally Posted by Pacnorthcuda
It’s going to affect the toe setting as the tie rods will have to adjusted to accommodate the new pitman and idler.
It will not affect caster or camber.

You will like it, it makes for a much more responsive set up.


Oddly, when I installed mine, the alignment guy said it only moved my toe setting from zero to 1/8" out.
The F/R arms are about 3/4" to 7/8" longer. If you have more than 1 1/4" of clearance with the stock stuff, you should clear just fine.
Posted By: Lee446

Re: E body Fast ratio arms ? - 07/12/19 05:31 PM

Thanks for the info! I measured my header clearance and it is a no go on the drivers side. Thanks for giving me a heads up and keeping me from having to return them!
Posted By: Kern Dog

Re: E body Fast ratio arms ? - 07/13/19 02:22 AM

Sure thing!
Posted By: Grizzly

Re: E body Fast ratio arms ? - 07/14/19 04:02 AM

Since this is in the handling forum, it's worthy to add that modifying your exhaust is a worthwhile thing to do to get modern day 16:1 ratio.....especially if you are running a smaller diameter steering wheel such as the Tuff Wheel. twocents

I have the Fast Ratio in a few E bodies and would never go back. I have 24:1 power and manual steering in a few others and they will eventually go into the scrap metal pile along with my space saver tires/rims, 450 wheels, frame tie down brackets, and bumper jacks/j-hooks.
Posted By: GoodysGotaCuda

Re: E body Fast ratio arms ? - 07/14/19 03:21 PM

I've got a new Pro Forged small sector pitman I can't use, if you're interested. I have the big sector shaft box. callme
Posted By: Sniper

Re: E body Fast ratio arms ? - 07/14/19 04:12 PM

Originally Posted by Grizzly
Since this is in the handling forum, it's worthy to add that modifying your exhaust is a worthwhile thing to do to get modern day 16:1 ratio.....especially if you are running a smaller diameter steering wheel such as the Tuff Wheel. twocents

I have the Fast Ratio in a few E bodies and would never go back. I have 24:1 power and manual steering in a few others and they will eventually go into the scrap metal pile along with my space saver tires/rims, 450 wheels, frame tie down brackets, and bumper jacks/j-hooks.


Not sure why you think you have a 24:1 power steering box. 15.7:1 is the spec for power steering in the 67 thru 73 fsm, 65 and 66 don't say.

So if you have power steering you have to do nothing to get "modern day 16:1 ratio" it been 15.7:1 since at least 1967.

Not to mention that a 16:1 ratio manual box, with normal length arms, has been available since the early 60's. So I am really at a quandary wondering where you get the idea that a 16:1 ratio is modern, unless you were around when the model T was new.
Posted By: Grizzly

Re: E body Fast ratio arms ? - 07/15/19 01:57 AM

Okay, it's been a really long time since I messed with these.

I Have the regular power as you say in 3 cars, have power with Fast Ratio in another, have manual with Fast Ratio in another, all E bodies.

I was of the understanding that the Fast Ratio power arms brought the steering to 16:1?

So, does the Fast Ratio arms actually bring the power box higher? Say, 14, or 12:1?

Have other vehicles that have 16:1 ratios and they steer faster than my Mopars?

What am I missing here other than a Firm Feel? up
Posted By: Sniper

Re: E body Fast ratio arms ? - 07/15/19 02:12 AM

Regular power steering is 15.7:1.

Fast ratio arm on it obviously makes it less than that. On cars that came with the fast ratio arm had a steering box with different stops, same ratio though. According to Firm Feel the p/s ratio with the longer arm is 12:1.

Manual boxes can be 24:1, 20:1 or 16:1, the 24:1 and 16:1 ratios are available new at RockAuto.

I don't know what your other vehicles are, much less what their actual ratio is.
Posted By: Mopar Mitch

Re: E body Fast ratio arms ? - 07/18/19 11:36 PM

I thought the T/A Fast Ratio made it 12.7:1?

Yes... the internal PS box ratios are actually all the same... the difference comes from the longer arms.

The factor screwed up on the E-bodies and didn't install the correct matching longer Idler arm (~70-C-Body.... aka Fast Ratio Idler)... to match the longer "FAST RATIO" Pitman Arm.

Regardless, add a smaller diameter steering wheel and you'll experience quicker steering yet!... and have the PS box rebuilt to tighter specs (IE: FF Stage 2 or preferably Stag-3).
Posted By: Kern Dog

Re: E body Fast ratio arms ? - 07/19/19 12:54 AM

So it is true? The Fast Ratio idler arm really is just a C body part?
I recently parted out a '70 Polara and saved the Idler arm and bigger tie rod assemblies!
Posted By: moparpollack

Re: E body Fast ratio arms ? - 07/19/19 07:06 PM

Originally Posted by Frankenduster
So it is true? The Fast Ratio idler arm really is just a C body part?
I recently parted out a '70 Polara and saved the Idler arm and bigger tie rod assemblies!


Yes, but the clocking I believe is splined differently.
Posted By: Sniper

Re: E body Fast ratio arms ? - 07/19/19 07:11 PM

Originally Posted by Mopar Mitch
I thought the T/A Fast Ratio made it 12.7:1?


I don't know and I can't find any documentation saying what it is, from the factory.

Firm Feel's statement is based on their arm, which may or may not be identical to the factory arm and that's the only thing I could find that gave a ratio with a longer arm.
Posted By: Kern Dog

Re: E body Fast ratio arms ? - 07/21/19 02:00 AM

Originally Posted by moparpollack
Originally Posted by Frankenduster
So it is true? The Fast Ratio idler arm really is just a C body part?
I recently parted out a '70 Polara and saved the Idler arm and bigger tie rod assemblies!


Yes, but the clocking I believe is splined differently.


I mentioned the idler....No splines on the idler. I figure the Pitman would be different.
Thanks.
Posted By: Sniper

Re: E body Fast ratio arms ? - 07/21/19 02:05 AM

Reclocking the spline isn't rocket science.
Posted By: myduster360

Re: E body Fast ratio arms ? - 07/21/19 05:29 AM

The C body Idler and Pitman has a larger diameter tapered stud too, at least compared to an A-body it is. So the drag link would need drilled and reamed to the proper size.

I've had a set of brand new Moog C-body pitman and idler arms in the garage for close to 20 years and never have got around to modifying a drag link to fit them. The cost of the tapered reamer never made economical sense unless i was doing a half dozen or so.

Posted By: Kern Dog

Re: E body Fast ratio arms ? - 07/21/19 07:04 AM

The C body Pitman arm I have looks to have the same size stud.
Posted By: DGS

Re: E body Fast ratio arms ? - 07/22/19 07:13 AM

Originally Posted by myduster360
The C body Idler and Pitman has a larger diameter tapered stud too, at least compared to an A-body it is. So the drag link would need drilled and reamed to the proper size.

I've had a set of brand new Moog C-body pitman and idler arms in the garage for close to 20 years and never have got around to modifying a drag link to fit them. The cost of the tapered reamer never made economical sense unless i was doing a half dozen or so.



I think the idler stud is the same size as A,B,E but the pitman arm stud is larger (which is definitely true for 69+ C-bodies - don't know about the earlier ones).
Posted By: Mopar Mitch

Re: E body Fast ratio arms ? - 07/23/19 06:23 PM

Correct! The dubbed "Fast Ratio Idler arm" is nothing more than a standard C-body idler are (~1970 ish). It always has been, and always will be. No-one ever "invented", created or designed the "fast ratio idler arm". Those who advertise it is simply selling the C-body idler arm and tagging the marketplace dubbed name onto it ("fast-ratio idler arm"). The factory overlooked installing it on the assembly line of the e-bodies when the Fast Ratio PS box was offered in late 70... and carried on for a brief time into 71 for the e-bodies with 340 engine options only. They knew it and determined the added cost and details to get it onto the assembly line were not worth the hassles as the option was soon to be discontinued. I'd spoken with Chrysler personnel in the late 70s about this and that's what they told me. There are no splines to be concerned of when installing the idler arm. The "Fast Ratio Pitman Arm" has splines that require proper one-way-only alignment to the gear box.
Posted By: myduster360

Re: E body Fast ratio arms ? - 07/25/19 02:44 AM

Originally Posted by DGS
Originally Posted by myduster360
The C body Idler and Pitman has a larger diameter tapered stud too, at least compared to an A-body it is. So the drag link would need drilled and reamed to the proper size.

I've had a set of brand new Moog C-body pitman and idler arms in the garage for close to 20 years and never have got around to modifying a drag link to fit them. The cost of the tapered reamer never made economical sense unless i was doing a half dozen or so.



I think the idler stud is the same size as A,B,E but the pitman arm stud is larger (which is definitely true for 69+ C-bodies - don't know about the earlier ones).


You're correct. it's just the Pitman arm that's larger diameter. I dug out mine to be sure.
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