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Re: Fast Ratio vs. standard steering gear box
Posted by: flat_six ()
Date: November 14, 2017 01:13PM

MtnVairMike Wrote:
-------------------------------------------------------
> This is an interesting thread for sure. I am not
> alignment expert but I thought I read somewhere
> that using only the shorter arms and not the QS
> box messed with the Ackermann angle?
>
> Maybe I'm dreaming, maybe I'm not...
>
>
> [corvaircenter.com]
>
> Thanks
>
> Mike

Only the standard arms provide the correct Ackermann geometry. The box has nothing to do with it. The factory quick steering option shortened the arms a little bit, preserving most of the correct Ackermann, and getting the rest of the gains in the box. Not sure why they didn't make all of the change in the box, but perhaps it was not possible for some reason.

So yes, the stubby aftermarket quick arms are terrible near full lock. Lots of tire scrub and under steer.

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Re: Fast Ratio vs. standard steering gear box
Posted by: thewolfe ()
Date: November 14, 2017 01:17PM

Yes quick steer arms of any type(even with the quick steer box) mess with the ackerman angle unless they have been modified to move the tie points out towards the wheels. The shorter the arm, the worse the ackerman. The GM quick steer arms, being longer than all the other quick arms, would have the least amount of increased ackerman. Only problem with modifying the arms is that the drum brake backing plates get in the way. Possible with disc brakes though. But then you change the bump steer characteristics since the tie rod is now lengthened. This could probably be lessened by lengthening the drag link and/or using bump steer adapters. Everything has tradeoffs!

Nate Wolfe
Portland OR
65 Corsa 180

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Re: Fast Ratio vs. standard steering gear box
Posted by: davemotohead ()
Date: November 14, 2017 01:40PM

For road racing I am using a quick box with standard arms, for autocross a quick box with fast GM arms, My car now has a fast box with the short arms and a posi, 2 1/4 turns lock to lock bicept builder and yes is scrubs the front tires and pushes the front end exiting a corner under power. going to change that!





Email me at: Dave Motohead

1960 4dr sedan caveman car
1961 Rampside (Chetside)
1962 Rampside (Barnside)
1962 Short Rampside (Shortside)
1962 Monza 700 Wagon
1963 Monza 900 coup (General Nader)




Sign my guest book!
[motoheadmall.com]
-----------------------------------
Rust Free Lancaster Ca

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Re: Fast Ratio vs. standard steering gear box
Posted by: MtnVairMike ()
Date: November 15, 2017 09:29AM

Cool thread. I love getting skooled on a subject.

Thanks,

Mike

1966 Monza Convertible, 140HP-4 speed, Ermine White

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Re: Fast Ratio vs. standard steering gear box
Posted by: rnch ()
Date: November 15, 2017 01:09PM

Now I'm starting to wonder if the one I briefly owned had the fast ratio box, quick steering arms...or both?

The previous owner had done a lot of add ons and parts swaps (nothing wrong with that!); so only he would know.

I do know that the darn thing steered hard when backing out of my driveway and parallel parking it....and that was back when I was still weight lifting three times a week!


confused smiley

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Re: Fast Ratio vs. standard steering gear box
Posted by: PGVair ()
Date: November 15, 2017 01:14PM

That's a possibility. I had those short aftermarket steering arms on a Corvair years ago when I was much younger and it was harder to turn the steering wheel than the Corvair I have now with factory QS box & arms.

Wade Lanning

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Re: Fast Ratio vs. standard steering gear box
Posted by: BobV66Vair ()
Date: November 16, 2017 09:25AM

I may as well ask this question here. Sorry if it's too far off topic. I am sending my stock arms to M Leveque to have them shortened and pushed out into the wheel to save some problems with the Ackerman. Does anyone know if that can gain enough to cut the L to L down significantly? Wondering what to do now that the quick boxes are not available any longer. Waiting a year or two is not going to work. I'll still buy one or two if they are ever built.

Bob Vinnacombe
Sandy, Oregon
1965 Corsa 140 stock
1966 Monza Soon to be race car
1968 Monza Parts for now

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Re: Fast Ratio vs. standard steering gear box
Posted by: flat_six ()
Date: November 16, 2017 10:02AM

BobV66Vair Wrote:
-------------------------------------------------------
> I may as well ask this question here. Sorry if
> it's too far off topic. I am sending my stock arms
> to M Leveque to have them shortened and pushed out
> into the wheel to save some problems with the
> Ackerman. Does anyone know if that can gain enough
> to cut the L to L down significantly? Wondering
> what to do now that the quick boxes are not
> available any longer. Waiting a year or two is not
> going to work. I'll still buy one or two if they
> are ever built.


The objective of all of these mods is to quicken the steering ratio. The number of turns lock-to-lock is simply a convenient way to measure that, assuming other factors (like changing location of the stops) don't come in to play.

When you shorten the arms, the ratio gets quicker, but the front wheels also move more parallel to each other when you turn, which is away from the ideal Ackermann (wheels theoretically turn around the same center point).

That said, most of us just buy the short arms and live with the less than ideal geometry because that is SO much better than living with Queen Mary steering.

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Re: Fast Ratio vs. standard steering gear box
Posted by: thewolfe ()
Date: November 16, 2017 11:09AM

The car is also twitchier on the highway with short arms. Any slop in the steering box or linkage will get amplified by the faster ratio arms. Moving the tie points out will help with ackerman but doesn't change the ratio. Leveque modified my arms that way and I'm at about 3.5 turns lock to lock. I don't notice any tire scrubbing unlike when I had Clark's quick steer arms in my car.

Nate Wolfe
Portland OR
65 Corsa 180

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Re: Fast Ratio vs. standard steering gear box
Posted by: jmaechtlen ()
Date: November 16, 2017 01:40PM

To alleviate steering effort, has anyone gone to reduced caster?

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Re: Fast Ratio vs. standard steering gear box
Posted by: PGVair ()
Date: November 16, 2017 02:52PM

Reduced caster probably doesn't help when parking, but should at higher speeds. However at higher speeds the short arms usually aren't a problem.

Wade

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Re: Fast Ratio vs. standard steering gear box
Posted by: UGLYTRUK ()
Date: November 16, 2017 06:26PM

What exactly does Leveque do to the arms?

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Re: Fast Ratio vs. standard steering gear box
Posted by: MattNall ()
Date: November 16, 2017 06:38PM

Cut and reweld to duplicate Factory Quick arms.





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Re: Fast Ratio vs. standard steering gear box
Posted by: 180sret ()
Date: November 17, 2017 03:56PM

Anybody have the actual measurements on the length of the arms from start of inside bend to end of arm? Don't know a whole lot about these, measured mine on the V8 car at 3.25". The car is 2.5 turns lock to lock and has power R & P. A sneeze will change lanes pretty quick. I have the same arms on my stock Corsa but don't recall much effort to steer it.
Gord

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Re: Fast Ratio vs. standard steering gear box
Posted by: UGLYTRUK ()
Date: November 17, 2017 06:22PM

Where and when's that pic from Matt?

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Re: Fast Ratio vs. standard steering gear box
Posted by: MattNall ()
Date: November 17, 2017 06:28PM

That'll be Rick Loving... meant to respond earlier!





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Fast Ratio vs. standard steering gear box
Posted by: Mike Stillwell ()
Date: November 17, 2017 06:31PM

Pic is of the late Mike Harrison's display. Mike passed away shortly after the 40th Yenko Reunion in 2006. So the pic is older than that. Mike was one of my longest Corvair buddies. One of the best.

Mike
YS-117

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Re: Fast Ratio vs. standard steering gear box
Posted by: MattNall ()
Date: November 17, 2017 07:25PM

Mike do you have an arm to measure? If not it seems Motohead and someone else have one arm each! gg





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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