Who's running 600 Series steering boxes & what ratio?

[Motobrewmaster]

Ok, who is running 600 series steering boxes and what ratio are you running?

Why did you choose the ratio?
What is your car used for mostly?
How do you like it?

[Typhoon1015]

I have a 12-1 670 box. Was found 2nd hand at a good price. Used for Autocross, road course, and street. Works great, but due to upgrading, I plan to purchase a 10-1 since I run smaller courses and hand over hand action limits me some. Turn one can set you up with a 12/10/8 depending on what your doing with it. 90% of consumers will do a 12-1 but if your getting serious with good-guys type courses and other high angle cornering duties you will benefit from a 10-1 unit.

They are lighter boxes than 800 series as well and have rack and pinion valving. You can also tailor the torsion bar to your liking to either increase or decrease steering effort at the wheel. Steering wheel diameters also play a factor, so going smaller in diameter there would also effect hand effort.

[stab6902]

To make the results more meaningful, you should specify what platform. I'm assuming 1st gen F-body? Wheelbase has a direct affect on how quick the steering feels to the driver. What feels great in a Chevelle may feel nervous in a Camaro.

Additionally, the lengths of the pitman/idler arms vs the steering arms (at the spindle) directly affects steering ratio. For 1st gen F-bodies, there are at least 3 different pitman/idler lengths and 3 different steering arm lengths (between different model years, power/manual/quick ratio steering options, plus some Pontiacs were different). In short, there are a ton of different combinations, so getting accurate data and feedback will require some diligence.

For my 1968 Firebird, I chose a couple of new cars that had a steering ratio that felt good to me and did the math to choose a ratio to make my Firebird feel the same. For my combination of pitman/idler and steering arms, it turned out to be 14:1. I would not want to go any quicker or higher effort. It feels great at speed (35+ mph), but it feels under-assisted at lower speeds compared to my target new car (C7 Corvette). The new cars have speed dependent variable assist that's tough to duplicate in an old car. I drive the car on the street but I built it with autocross in mind.

Despite what some people seem to think, quicker steering isn't necessarily better. Think about it in terms of the other controls of the car. Would a quicker ratio throttle be more desirable? Not to me. When I have the traction to support 40% throttle, I have a better chance of nailing 40% with a long pedal stroke than a short one. Same idea goes for braking and steering.

I like all the controls to match in terms of effort and travel. I don't want a long, high effort manual brake pedal with a jumpy, soft electronic throttle and twitchy, under-assisted steering. Every driver appreciates a car that's easy to drive fast and consistently.

[dontlifttoshift]

Good post!

[UMI Tech]

At UMI we run the Turn One 8:1's on our auto-x cars (LeMans, 71 Camaro and Green Machine G-Body). The 8:1 is pretty crisp for street driving but you only live once. They are beyond awesome for Good Guys and make road racing feel like a fighter pilot. For a car like Justin's as mentioned above I think a 10:1 would be just about perfect.

[rchaskin]

I had LEE build me a 12:1. I think it is awesome.
If I had it to do over, I would have got a 10:1.

[Motobrewmaster]

Glad to get some good replies to my thread. Thanks for the info and input I really appreciate it. I am talking to Turn One and need to make a decision between the 10:1 and the 8:1. The cost gap is pretty big between the two. They are currently rebuilding my power steering pump for my LS.

I have the pitman arm length but need to measure the idler and steering arms. The idler is a ProForged and the same length as the original PS one only much BEEFER. I have a Ridetech Tru-Turn setup on it but will need to measure the steering arms too. I will measure them up tonight after work.

The pitman = 5.8" Idler = 5.25" ????? will verify

I WILL be using this car for trackdays on a couple of the tighter tracks in my area. Others when time and $ allow.
http://www.clubmotorsports.com/course My closest and favorite local
http://palmermotorsportspark.com/trackinfo.aspx My next favorite track locally
http://nyst.com A little drive but a fun track.

160688
160689

[Motobrewmaster]

So my idler arm is confirmed as 5.25".
The steering arms are 5.625"

[UMI Tech]

Just heard from Turn One that 12.7:1 housings are back in stock for now. Get 'em while they exist!

[chevelletiger]

I have a turn one silver ceramic coated one in 12 to 1 ratio that I would like to sell so I can get the 10 to 1

[D-Man]

Bumping the thread.

I need opinions on the 10-1 ratio for normal highway driving at 70-80 mph.

Back story -- I was just offered a 10-1 steering gear (670) for a very good price. I'm more into track days than auto cross, but mostly drive on the highways and 2 lane rural roads. 1970 Camaro. Can run a bigger, say 14", steering wheel.

[pitts64]

To make the results more meaningful, you should specify what platform. I'm assuming 1st gen F-body? Wheelbase has a direct affect on how quick the steering feels to the driver. What feels great in a Chevelle may feel nervous in a Camaro.

Additionally, the lengths of the pitman/idler arms vs the steering arms (at the spindle) directly affects steering ratio. For 1st gen F-bodies, there are at least 3 different pitman/idler lengths and 3 different steering arm lengths (between different model years, power/manual/quick ratio steering options, plus some Pontiacs were different). In short, there are a ton of different combinations, so getting accurate data and feedback will require some diligence.

For my 1968 Firebird, I chose a couple of new cars that had a steering ratio that felt good to me and did the math to choose a ratio to make my Firebird feel the same. For my combination of pitman/idler and steering arms, it turned out to be 14:1. I would not want to go any quicker or higher effort. It feels great at speed (35+ mph), but it feels under-assisted at lower speeds compared to my target new car (C7 Corvette). The new cars have speed dependent variable assist that's tough to duplicate in an old car. I drive the car on the street but I built it with autocross in mind.

Despite what some people seem to think, quicker steering isn't necessarily better. Think about it in terms of the other controls of the car. Would a quicker ratio throttle be more desirable? Not to me. When I have the traction to support 40% throttle, I have a better chance of nailing 40% with a long pedal stroke than a short one. Same idea goes for braking and steering.

I like all the controls to match in terms of effort and travel. I don't want a long, high effort manual brake pedal with a jumpy, soft electronic throttle and twitchy, under-assisted steering. Every driver appreciates a car that's easy to drive fast and consistently.


Front steer vs rear steer also make a big difference. I find rear steer will be more sensitive and faster then front steer. Also steering wheel diameter play into this as well. I have a Lee 14:1 with a 30 lb valve and a 13" steering wheel in a 69 el Camino front steer, its a nice street set up..