Another Steeroids Question

[Grampy]

now what do we do?

Thanks Jim.

So we can't tell the big t-bar unit externally and we can't swap them. How best to increase the feel?

I cross check your spreadsheet big t-bar year and model against rebuilt units but it looks like it's one size fits all. Same P/N for all 2 1/2 turn units for all years and models big or little t-bar.

I also note a manual CTO unit. Do you have the stats (turns and travel) for that unit?

Any opinions on making custom steering arms with the tie rod hole location proportionally shorter to restore the turning radius. This will also reduce the mechanical advantage and (hopefully) increase the feel. You could also correct the tie rod height (bump steer) at the same time.

Grampy

 

[Sky65]

Any opinions on making custom steering arms with the tie rod hole location proportionally shorter to restore the turning radius. This will also reduce the mechanical advantage and (hopefully) increase the feel. You could also correct the tie rod height (bump steer) at the same time.

Grampy

I think if you made the steering arms any shorter you would have clearance issues between the tie rods and lower control arms.

 

[Sky65]

I have posted the table of General Motors slow c-factor center take-off power rack & pinion gears over at the Corvettefaq.com websight. Here is the address:

http://jimshea.corvettefaq.com/wp-content/uploads/2009/10/1988-94cto53rpgears.xls

If anyone is interested in the fast c-factor cto R&P gears, here is the address:
http://jimshea.corvettefaq.com/wp-content/uploads/2009/10/1988-98cto62rpgears.xls

Jim

Jim
What determines the total travel on racks that show both 144mm and 154mm travel? Is it a stop in the rack or steering stops on the vehicle it is installed in?
Thanks

 

[BBShark]

Any opinions on making custom steering arms with the tie rod hole location proportionally shorter to restore the turning radius. This will also reduce the mechanical advantage and (hopefully) increase the feel. You could also correct the tie rod height (bump steer) at the same time.

Grampy

I think if you made the steering arms any shorter you would have clearance issues between the tie rods and lower control arms.

Control arms are not in this picture obviously but you can see how long those steering arms are. I cant see where there would be any interference.

 

[Sky65]

Any opinions on making custom steering arms with the tie rod hole location proportionally shorter to restore the turning radius. This will also reduce the mechanical advantage and (hopefully) increase the feel. You could also correct the tie rod height (bump steer) at the same time.

Grampy

I think if you made the steering arms any shorter you would have clearance issues between the tie rods and lower control arms.

Control arms are not in this picture obviously but you can see how long those steering arms are. I cant see where there would be any interference.

I can only say I have a Steeroids rack on my 65 and the tie rods are very close to the tailing edge of the lower control arms with the car on the ground. The left side has even scraped at some point. I am using the p/s steering holes in the steering arms. If you move the holes even further forward I'm sure mine would hit. The car is lowered a little but I don't think that matters. Maybe someone else with a rack installed will chime in?

 

[mrvette]

Any opinions on making custom steering arms with the tie rod hole location proportionally shorter to restore the turning radius. This will also reduce the mechanical advantage and (hopefully) increase the feel. You could also correct the tie rod height (bump steer) at the same time.

Grampy

I think if you made the steering arms any shorter you would have clearance issues between the tie rods and lower control arms.

Control arms are not in this picture obviously but you can see how long those steering arms are. I cant see where there would be any interference.

Any opinions on making custom steering arms with the tie rod hole location proportionally shorter to restore the turning radius. This will also reduce the mechanical advantage and (hopefully) increase the feel. You could also correct the tie rod height (bump steer) at the same time.

Grampy

I think if you made the steering arms any shorter you would have clearance issues between the tie rods and lower control arms.

Control arms are not in this picture obviously but you can see how long those steering arms are. I cant see where there would be any interference.

I can only say I have a Steeroids rack on my 65 and the tie rods are very close to the tailing edge of the lower control arms with the car on the ground. The left side has even scraped at some point. I am using the p/s steering holes in the steering arms. If you move the holes even further forward I'm sure mine would hit. The car is lowered a little but I don't think that matters. Maybe someone else with a rack installed will chime in?

I can assure you both that any install may well have a lower control/tie rod interference problem...it obviously depends on the rack location and angle...which also affects the tie rod positions depending on your design of the rack to tie rod ends plate/block/interface....

I used a simple machined block, later cut and welded to alter the configuration...

the only install I have done is on my own SBC '72...so to say my shit would fit another engine, especially a BBC, is a stretch....but I figger headers are lots simpler to alter than steering....anyone can weld a pipe...as my exhaust guy down the street can attest...:devil::yahoo:

 

[JIML82]

The travel on a Saginaw CTO gear is determined by the size of the block that traverses inside a window in the center of the gear. The plate that attaches the tie rods to the gear attaches to it. The boot covers the block.

The Saginaw manual CTO specs:
Application: 1982 thru 1990 Cavaliar, Sunbird, Skyhawn Sport, and Firenza
C-Factor: mm/revolution 38.9 (1.53 inches)
Travel: 154 mm 6.06 inches
Input shaft turns (full lock to full lock): 4

Jim

 

[Grampy]

Jim - thanks again. The information helps me understand (I hope) the issues a little better.

I acknowledge that the tie rod - lower A arm clearance is a potential problem for a shortened steering arm. ( I've already trimmed the arms for additional room)

Jim if the short steering arm has room to work do you know if the increased force needed by reducing the moment arm length at the road wheel be translated into more feel at the steering wheel or would the resulting increase in input torque just cause tosion bar just deflect a little more to compensate and negate most of the gain?

Is pressure reduction a partial cure?

Grampy

 

[Sky65]

Jim - thanks again. The information helps me understand (I hope) the issues a little better.

I acknowledge that the tie rod - lower A arm clearance is a potential problem for a shortened steering arm. ( I've already trimmed the arms for additional room)

Jim if the short steering arm has room to work do you know if the increased force needed by reducing the moment arm length at the road wheel be translated into more feel at the steering wheel or would the resulting increase in input torque just cause tosion bar just deflect a little more to compensate and negate most of the gain?

Is pressure reduction a partial cure?

Grampy

I know your question is for Jim but if I may. I reduced the pressure and the flow rate on mine and think it helped reduce the amount of assist. This made the steering feel better to me but that is just my impression.
:beer:

 

[mrvette]

Jim - thanks again. The information helps me understand (I hope) the issues a little better.

I acknowledge that the tie rod - lower A arm clearance is a potential problem for a shortened steering arm. ( I've already trimmed the arms for additional room)

Jim if the short steering arm has room to work do you know if the increased force needed by reducing the moment arm length at the road wheel be translated into more feel at the steering wheel or would the resulting increase in input torque just cause tosion bar just deflect a little more to compensate and negate most of the gain?

Is pressure reduction a partial cure?

Grampy

I know your question is for Jim but if I may. I reduced the pressure and the flow rate on mine and think it helped reduce the amount of assist. This made the steering feel better to me but that is just my impression.
:beer:

This is where my limited experience of ONE car, mine, get into the way of semantics and 'feel' of the ass in handling, and TIRES/WHEELS.....
much less suspension and sway bars/shocks....

We ALL building our own hotrods, so to say what is 'right & rong' is kind of hard, really....

IMO the combo with the '92 Grand Am rack at 2.7 turns L-L and a supposedly stock '72 valving setup on a '88+ vette pump/drives....feels GREAT.....

sorry for lack of empirical data.....

 

[JIML82]

Reducing the flow out of the pump will cause the gear valve to be less responsive and therefore you will feel higher effort. Changing the pressure relief of the pump will only cause the steering to revert to manual efforts as you run out of power assist near full lock. It will have no affect driving down the road.

Jim

 

[Sky65]

Reducing the flow out of the pump will cause the gear valve to be less responsive and therefore you will feel higher effort. Changing the pressure relief of the pump will only cause the steering to revert to manual efforts as you run out of power assist near full lock. It will have no affect driving down the road.

Jim

Hmmmm. Interesting. Is there a way to check if I've gone too far on reducing the pressure? If I haven't, I'll leave it alone. If I have, I guess I'll pull the valve and bump it back up.
Thanks

 

[JIML82]

Very easy test. Park the car on concrete or asphalt. Hold it with the brake, slowly steer to full lock both right and left. If you have full assist until you reach full lock, you have enough pressure.

A check for sufficient flow. Find a safe, vacant parking lot. Drive at about 20 to 25 mph. Whip the steering wheel as if you were trying to avoid something that suddenly came out in front of your car. If you have full assist when making the maneuver, you have sufficient flow. If you do not have sufficient flow, when you try to whip the steering wheel, you will suddenly feel an abrupt increase in steering effort. Some people liken it to "my steering locked up." Your steering didn't lock up it just didn't have enough flow to give you full assist as you rapidly turned the steering wheel.

You can also try whipping the wheel while stopped but running out of assist when whipping the wheel while stopped has little real meaning.

Jim

 

[Sky65]

Cool. Thanks.
I'm changing over to a "slow c-factor" rack. I'll test it when I get it all back together.
:beer: