High speed stability with 3rd gen steering box swap? - Team Camaro Tech
Brakes, Suspension & Steering Conversion questions, Steering & Handling

 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old Dec 28th, 11, 07:59 PM Thread Starter
Senior Tech
Greg
 
Join Date: Jan 2004
Location: Winston Salem, NC
Posts: 1,500
High speed stability with 3rd gen steering box swap?

I have done a ton of reading and see that lots of people have done the 3rd gen swap. My question is about high speed stability with the quick ratio box?

Today i have the "pinkie steer" factory power steering. Now that I am going 115 at the top end of the track I am looking for stability. With the easy steering a little bump in the track quickly turns into a sway. My first thought is to go to a factory manual box. It's slower ratio means that if I hit a bump and move the wheel an inch or two it unsettles the car less.

The 3rd gen box requires more effor to move, but a 1" move will "turn" the car a lot more right? Just wondering how that will be on the top end.

69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, 9:1, 10 PSI, Water/Meth injection
1.325 60', 5.988 @ 115.4 (carb)
Switched to Super Sniper EFI 2019
Greg O is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old Dec 29th, 11, 08:59 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,591
Garage
Re: High speed stability with 3rd gen steering box swap?

Yes, it will to some degree, maybe not as much as you anticipate, and you will learn the new effort required.
Add more caster for high speed stability.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - maybe this year, 2019 ...
Everett#2390 is offline  
post #3 of 10 (permalink) Old Dec 29th, 11, 02:07 PM
Senior Tech
 
Join Date: Jan 2004
Location: Saginaw, Michigan
Posts: 1,122
Thumbs up Re: High speed stability with 3rd gen steering box swap?

The fastest ratio available in Gen III Camaros were power steering gears with 12.4:1 gear sets. If you are concerned that it might be too fast, there was an intermediate fast ratio gear with a 14:1 ratio during the Gen III years that might be a better fit for your race car.

I have a listing of all these 14:1 power steering gears that were used in production in the Gen III Camaros.
1982, 83, 84 Level IV suspension 14:1 ratio 27 inch-lb valve effort 70 degree output
1985 Level II suspension 14:1 ratio 27 inch-lb valve effort 70 degree output
1986 thru 93 Base Camaro 14:1 ratio 23 inch-lb valve effort 70 degree output

Now the problem is whether or not the aftermarket rebuilders have these exact gears available. I sometimes have doubts that the rebuilders take a lot of care in trying to match the actual production gears. (I shouldn't just complain about the aftermarket people, I am sure that the General Motors Service Parts people restrict the actual number of gear boxes that they make available as well.)

I think the best thing to do is to actually check the ratio of a gear that you might purchase from a rebuilder. Go out and purchase a cheap plastic protractor and carefully tape it to the output shaft of a new remanufactured gear. Carefully measure the total sweep of the output (pitman) shaft. The total sweep should be 70 degrees. Now measure the rotation of the input shaft as you turn the gear from full lock to full lock. You should rotate the input shaft 2 3/4 turns (actually 2.7222 turns). That would be a 14:1 ratio.

BTW here is the calculation for steering gear ratio:

Pitman sweep (70 degrees) X gear ratio (14) / 360 = input shaft rotation
70 X 980/360 = 2.7222

Now the bad news. As much as you can actually measure the sweep and ratio, you will not be able to check the valve effort built into the gear. Certainly the effort should not be "pinky finger" light. A 23 or 27 inch-lb valve should provide moderate steering effort. I don't know how to quantify it any better than to say moderate. Gen I gears had valves that were in the 18 inch-lb range. Valves in the 23 to 27 inch-lb range should feel to have significantly higher effort.

There was a Gen III power gear for the Berlinetta (1982-85) that had a variable ratio (15:1 on center and 13:1 near full lock.) Unfortunately, this gear box went back to the "pinky finger" (17 inch-lb) effort found in the early Gen I years. So I don't think your really want this one.

Good luck,
Jim
JIML82 is offline  
 
post #4 of 10 (permalink) Old Dec 29th, 11, 07:32 PM Thread Starter
Senior Tech
Greg
 
Join Date: Jan 2004
Location: Winston Salem, NC
Posts: 1,500
Re: High speed stability with 3rd gen steering box swap?

Thanks for the valuable info. I see your location....did you work for Saginaw by chance?

I did some looking at O'rielys as they cary the Cardone brand. It looks like the 27-6550 is the 12.4 high performance one. That is the one most people go for but they are looking for handling feel and performance. i am more straight line.

The other part number they list is a 27-6530 for the "soft ride" option on the same year Camaro. Should that be the 14:1? I dont see a separate part number for the 27 vs. 23 inch-lb 14:1 box looking at the different years. they may have combined the part numbers. I think i will go for the 14:1

69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, 9:1, 10 PSI, Water/Meth injection
1.325 60', 5.988 @ 115.4 (carb)
Switched to Super Sniper EFI 2019
Greg O is offline  
post #5 of 10 (permalink) Old Dec 30th, 11, 04:24 AM
Senior Tech
 
Join Date: Jan 2004
Location: Saginaw, Michigan
Posts: 1,122
Re: High speed stability with 3rd gen steering box swap?

Yes, I worked in the engineering department (steering section) for 39 years before retiring in 2001.

I don't know what Cardone calls their various Camaro gears. I am not sure what "soft ride" means. If it is the Berlinetta gear then the steering may feel very light. (But you won't know that until you bolt the gear into your Camaro. I would order what you think is the 14:1 gear and check the ratio by rotating the input shaft and measuring the output as described.

Wish that I was of more help,
Jim
JIML82 is offline  
post #6 of 10 (permalink) Old Dec 30th, 11, 06:22 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,591
Garage
Re: High speed stability with 3rd gen steering box swap?

Old school trick was taking a fish scale and attaching to the spoke and rim, farthest point from the s/wheel center, and measure the 'pull' needed to turn the wheel in both directions?

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - maybe this year, 2019 ...
Everett#2390 is offline  
post #7 of 10 (permalink) Old Dec 31st, 11, 11:57 AM
Moderator
David Pozzi
 
davidpozzi's Avatar
 
Join Date: Nov 1999
Location: Central California, USA
Posts: 10,064
Re: High speed stability with 3rd gen steering box swap?

I'm pretty sure a 1979 Z/28 used a stiff feel 14 to 1 box, that was the first year GM stopped offering variable ratio steering.
If you want to get a couple more MPH at the end of a quarter mile, correct the bumpsteer. When the front comes up at speed, the wheels toe-out.

Check my web page for First Gen Camaro suspension info:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

67 RS 327 original owner. 1965 Lola T-70

Last edited by davidpozzi; Dec 31st, 11 at 03:06 PM.
davidpozzi is offline  
post #8 of 10 (permalink) Old Dec 31st, 11, 09:21 PM Thread Starter
Senior Tech
Greg
 
Join Date: Jan 2004
Location: Winston Salem, NC
Posts: 1,500
Re: High speed stability with 3rd gen steering box swap?

Man this stuff will drive you nuts when dealing with the aftermarket. i looked at every different 1982 Camaro part number at O'Rielly's to see if there was a separate part number for a Berlinetta and there is not. Cardone 27-6530 is the part listed for all 82 Camaros AND the 79 Camaro AND the 85 Z/28 without the special suspension. So i guess it is a bit of pot luck as to what you might get in the box. Might be the VR 'pinky steer' berlineta box or the one i want...the 14:1 higher effort piece. i guess the only way to be sure I get a stiff feel box is to get the special suspension piece. It is 27-6550.

69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, 9:1, 10 PSI, Water/Meth injection
1.325 60', 5.988 @ 115.4 (carb)
Switched to Super Sniper EFI 2019
Greg O is offline  
post #9 of 10 (permalink) Old Jan 1st, 12, 12:28 PM
Moderator
David Pozzi
 
davidpozzi's Avatar
 
Join Date: Nov 1999
Location: Central California, USA
Posts: 10,064
Re: High speed stability with 3rd gen steering box swap?

I would contact a rebuilder & get specifically what you want. I have concerns a Cardine box would actually be what the listing says it is.
I would buy a box from AGR, they make other ratios than 12.7 with stiff valving if you contact them. Also a 12.7 box can be slowed down by using a short 5.25" pitman arm, & longer outer steering arms will slow it more. I drove the One Lap Camaro 155 mph at Road America last year with great stability & it has the fast ratio box with fastest combo of steering arms. I do think for a drag only Camaro slowing the steering with the short pitman is a good plan.

Check my web page for First Gen Camaro suspension info:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

67 RS 327 original owner. 1965 Lola T-70
davidpozzi is offline  
post #10 of 10 (permalink) Old Jan 1st, 12, 02:50 PM Thread Starter
Senior Tech
Greg
 
Join Date: Jan 2004
Location: Winston Salem, NC
Posts: 1,500
Re: High speed stability with 3rd gen steering box swap?

Getting Lee's to rebuild it is $300+ as is the AGR box. You can get a Cardone piece for $116. I guess it is the balance of "you get what you pay for" but i can't see paying triple. I appreciate the feedback on the 155 MPH with the high ratio box. I think I will go that route. If i am unhappy with it i'll be much happier if i only invested $120 vs. $350.

69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, 9:1, 10 PSI, Water/Meth injection
1.325 60', 5.988 @ 115.4 (carb)
Switched to Super Sniper EFI 2019
Greg O is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome