What ratio steering box?

[71maroesteban]

What ratio should I use for a street and occasional track car? 21.7 or 10.1?
Car is a 1969 Camaro
ridetech suspension with tru turn

[Motobrewmaster]

It really depends on what you like. That said most people seem to prefer the 12.7:1 box. I have had one in my Camaro and it worked great.
However I am now running an 8:1 and really like it. However I personally like a very responsive car, so this would most likely be too quick for most.

David Pozzi who is a member here (Hi Dave!) has done a ton of testing and has compiled it into a great reference website. Read the info on his site and you will learn so much and it will probably answer most or all of your questions. Here is the link
http://www.pozziracing.com/first_gen_suspension.htm

[Josh@Ridetech]

Hey Esteban,

I believe I've been emailing you actually! Like he said above, a lot of it is preference. I have the 12.7:1 box going on my car now. After driving some of the test cars here, that helped make my decision, they were just great all around. If you're wanting something more track oriented, then you might want to look at something a little faster.

[TheBandit]

I recently put a 12.7:1 box in my Nova with a heavy 235 t-bar. 12.7:1 is only a tad faster than the variable ratio box that was in my car before; its barely a noticeable difference. Around town and on the freeway it works great. I think for autocross, especially on tighter courses, I'll be wishing for something faster. But I also haven't tried a faster box, so I don't know if it would be "twitchy" feeling. One reason I did not look for a faster ratio box is that I know my wife will occasionally drive my car and I don't want her to overcorrect with a faster ratio. I imagine I would get used to it and do fine, but she might not expect the sensitivity and end up changing lanes when she doesn't mean to.

With regard to the heavy 235 t-bar, the more I drive it the more I like it. It requires more muscle for parking maneuvers, but at any kind of speed it's just a ton more engaging to drive the car. I really enjoy it.

I mostly street drive my car, but I occasionally autocross also. If I was doing more autocross I would spring for a faster ratio.

[SPG]

I'd be interested to know how a 10:1 box feels on the road, some people says it's fine, others say it's way too fast.
The video Lee made says the 9:1 feels fine, but it's marketing and I want to hear from an actual user.

[Motobrewmaster]

I'd be interested to know how a 10:1 box feels on the road, some people says it's fine, others say it's way too fast.
The video Lee made says the 9:1 feels fine, but it's marketing and I want to hear from an actual user.

I am running a 8:1 in my car and so far it feels fine to me. In fact I actually like it. However I have just put the car on the road with it and need to put more miles on it to truly give a better impression.

The box I am running is a Turn One 600 with a .210 T-bar, I am using the ridetech TruTurn up front on 245/40 18's. It is also important to note that Turn One also rebuilt the power steering pump to match the box. The feel is very good and is certainly quick but does not feel "twitchy" to me. I will be doing track time and some autocross which is why I opted for the faster box.

I am also experimenting with alignment spec's to find what feels good and hopefully find a combination that works for me. The current alignment is intentionally biased to see if a reasonable street driving mode is possible with the 8:1.

They are:
STREET
Camber -0.9°
Caster 6.8° (yes this is the aggressive experiment part)
Toe 0 (so far for me feels fine and tracks well down the road, highway requires attentive driving but I expected that.)

I did it this way so all I have to do is add a 1/8" spacer on both sides to push it to the track spec's:
Camber -1.5°
Caster 6.8°
Toe 0, but I might try out 1/16"

This is all to be determined and will certainly learn what works or doesn't, but hey it is all for fun anyway!

Cheers, Steve

[TheBandit]

Good info Steve. Thanks for sharing your impressions. For reference I have stock based suspension and spindle with the Guldstrand mod. I have mine at 6.5deg caster and 2deg camber with 1/16 toe in. This is my street setting for now. I usually run 1deg camber but I have been rubbing the top inside lip of the fender and this gets it to clear.

[David Pozzi]

I've found if you have a 12.7 box, with shortest outer steering arms, then the short power steer pitman arm is the best. If you use the long pitman with short outer arms the steering will be so fast you have trouble coming close to cones where you might hit them because you can't precisely steer the car. Less than two turns lock to lock. If you ran the heck out of the car maybe you could get used to it but I've run first gen Camaros a whole lot and once we got rid of the understeer and got the car handling neutral, it was just too quick, even with stiff valving. If the front pushes a lot, then it's hard to make the steering too fast.

[79T/Aman]

there is more to steering than the gear ratio, as David pointed out the length of the other steering components affect the steering speed, bump steer and Ackerman will also affect the speed and feel, this in turn will also affect the size torsion bar is used
You will also get answers based on experiences with other cars that have complete different steering links and geometry, I would not compare a 2nd gen F-body and A-bodies to a 1st gen.

[TheBandit]

All great points. The devil is in the details!

[anguilla1980]

I went with a TurnOne SB2 10:1 with the 235 t-bar, Lee PS pump w/external reservoir setup for hydroboost psi, and I added the Lee PS filter and a Derale PS cooler w/fan. Everything is -6AN.

I'm still installing everything (doing the hydroboost at the same time along with a serpentine belt conversion) so I haven't driven it yet. My entire suspension is brand new/upgraded as of last summer. I'm hoping I'll be happy with my choice.