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Tighter steering ratio, tighter on center steering rack for C5/C6?

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Old 12-12-2015, 12:07 AM
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RC000E
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Default Tighter steering ratio, tighter on center steering rack for C5/C6?

Any rack options out there to get quicker, less mushy steering out of this car? Thought I recalled there being a "racing rack" that made it into some racing examples in scca or some other form. Anyone know of any such thing? Any companies making a modded steering gear to go inside the rack...custom machined?
Old 12-12-2015, 11:14 AM
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c5racr1
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Try "turn one" they should be able to point you in the right direction.
Old 12-12-2015, 02:17 PM
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RC000E
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thanks...googling...
Old 12-15-2015, 09:27 AM
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RC000E
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Turn one says they can't help....

I know there are some GT cars out there with quicker racks...they had to come from somewhere. Search continues!
Old 12-15-2015, 11:00 AM
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RX-Ben
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I think you will need to adapt a Woodward rack.
I would be interested to hear what they say if you call them.
FWIW, the GM propaganda about the C6 race car said they used "production steering racks"
Old 12-15-2015, 02:47 PM
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SouthernSon
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Turn one rebuild, solid bushing mounts and R7 tires will absolutely jerk you to the side of the track without much turn of the wheel.
Old 12-17-2015, 07:28 PM
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This is for my street car/canyon runner, etc. I don't use this Z06 on track anymore, just mountain roads, exhibition stuff, etc. I could do plenty of "mods" so to speak, to gain steering feel, stiffness, etc. I was simply curious if anyone had a faster ratio rack option. My M3, BMW used some pretty interchangeable racks over the years...I was able to get rid of the numb on center "high speed stability" rack, to something much faster and it simply transformed the behavior of the car. Corvettes sped up the ratios over the years, going to the variable...sucks there isn't anything out there. I got amazing steering in the bmw for under 300 bucks!
Old 12-17-2015, 07:33 PM
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Originally Posted by RX-Ben
I think you will need to adapt a Woodward rack.
I would be interested to hear what they say if you call them.
FWIW, the GM propaganda about the C6 race car said they used "production steering racks"
I'm looking into this...I'm interested. I'll post when I know something...
Old 12-19-2015, 04:31 PM
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AND0
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Have you tried the DRM solid steering rack bushing yet?
What about control arm bushings?

I installed the VBP poly control arm bushings custom drilled and zerked to be greasable, and my C5Z was transformed definitely a must do. Steering feedback is better but not great, or even good.....
DRM rack bushing seems to get mixed reviews....
I'd really like to hear from some one with good control arm bushings that the DRM was final step to good steering response
Old 12-19-2015, 04:57 PM
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Matt_27
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Originally Posted by AND0
Have you tried the DRM solid steering rack bushing yet?
What about control arm bushings?

I installed the VBP poly control arm bushings custom drilled and zerked to be greasable, and my C5Z was transformed definitely a must do. Steering feedback is better but not great, or even good.....
DRM rack bushing seems to get mixed reviews....
I'd really like to hear from some one with good control arm bushings that the DRM was final step to good steering response
I have full Delrin CA bushings and plan to do the DRM delrin rack bushing in the next two months so I will let you know. Agree that CA bushings improved steering feel a lot but it is still not good. It seems like now that the CA bushings aren't deflecting you can feel the compliance in the rack itself and also feel how crappy the power steering valve response time is. In a big sweeper with the suspension loaded up and when you move the wheel back and forth there is a big dead zone you have to move through.

I have a Solstice as well and the rack ratio and steering feel is quite a bit better than the C5's. Stock bushings.
Old 12-20-2015, 10:42 AM
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In to hear the results for sure. I've had a number of cars after getting my C5Z (a keeper car for me) and while my C5Z has always kept my interest, the steering has really stood out to me more and more. My S2000 has some fantastically quick and nimble steering, tons of feel, and my M3 is fantastic these days, with the mods available. If my C5Z could feel anywhere near those cars it'd be incredible.
Old 12-20-2015, 01:47 PM
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Louis Gigliotti
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The Factory GM cars, and even the whelen cars near the end of their life, used a very purpose built race rack. We failed many steering racks in Rolex, and Whelen switched to a modified cadillac rack, and then coerced GM into providing them with a GT2 rack.

IIRC, the rack was in the 10k+ range.
Old 12-22-2015, 02:35 PM
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Originally Posted by AND0
......I'd really like to hear from some one with good control arm bushings that the DRM was final step to good steering response
Good point. I don't remember which mods I did first but I am running the poly rack bushing, poly suspension, turn one rack/pump and R7's. Also, we mustn't forget the alignment, springs and shocks. My car turns quick, sets quick, stays true and is about as predictable as one could want.
Old 12-22-2015, 04:31 PM
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Originally Posted by SouthernSon
Good point. I don't remember which mods I did first but I am running the poly rack bushing, poly suspension, turn one rack/pump and R7's. Also, we mustn't forget the alignment, springs and shocks. My car turns quick, sets quick, stays true and is about as predictable as one could want.
I said this a little bit wrong I think....
My car's (C5Z) steering response with the poly bushings, good alignment, good shocks, OEM springs, bars, and good street tires is good. Sets quick, stays true, and is predictable, BUT it is really the steering FEEDBACK that is lacking compared to some other cars in the class.
Some cars just have that connected to the road steering communication, GM just didn't do it for us....
Old 12-22-2015, 06:17 PM
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Originally Posted by AND0
....Some cars just have that connected to the road steering communication, GM just didn't do it for us....
I realize we all have some difference in our feel and inputs to the vehicle while on the track but I find it sufficient to counter steer and correct very easily. I wish I understood what kind of feel you find lacking. I really enjoy instructing and strive to understand exactly what my drivers are trying to tell me. Perhaps we can hook up at a track someday. For what it's worth, a Pro hot shoe in the continental tire series was in my car several times this past summer. He thought it to be the best handling C5 he has driven.
Old 12-26-2015, 09:58 AM
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To me the difference is hard to describe. I don't have any issue driving the Corvette, I think it's a fantastic car. It's just compared to other vehicles in the German and even Japanese sector, the steering just feels....muddy, not to mention the ratio is just too slow. It's one of those mods that would wake the car up a lot, if selected properly. It's certainly an issue of "stiffness" and I think bushings, even going heim joints would make a huge impact, but I feel starting at the rack...if possible, would be a hell of a nice mod.
Old 12-26-2015, 09:58 AM
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Originally Posted by Louis Gigliotti
IIRC, the rack was in the 10k+ range.
That's certainly out...

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Old 12-27-2015, 01:24 PM
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Install a smaller steering wheel
Old 12-28-2015, 09:42 AM
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I actually did it backwards, installed the DRM rack bushing first when I built the car, then did Prothane bushings 1.5 years later. That said, the steering has been very responsive from day one with that solid rack bushing, and it only improved with the new control arm bushings.

My teammates have everything from M3's and DSM's to a Ferrari and multiple 911 turbos, and they have always been really happy with how the car drives & responds. I would say that if you do the DRM rack bushing and poly suspension bushings and are still not satisfied, you either need different tires or you're being too harsh a critic of the car.
Old 12-28-2015, 10:05 AM
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LateBreak
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Originally Posted by RC000E
To me the difference is hard to describe. I don't have any issue driving the Corvette, I think it's a fantastic car. It's just compared to other vehicles in the German and even Japanese sector, the steering just feels....muddy, not to mention the ratio is just too slow. It's one of those mods that would wake the car up a lot, if selected properly. It's certainly an issue of "stiffness" and I think bushings, even going heim joints would make a huge impact, but I feel starting at the rack...if possible, would be a hell of a nice mod.
E36 M3 Variable around 15.4:1
E36 96-99 M3 Variable around 17.8:1
BMW E46 M3 15.4:1
2014 911 12.25-15.02 Variable
Ferrari 458 11.9:1
Ferrari 430 16.9:1
C7 Corvette 12.0 - 16.4 Variable
Nissan GTR 14:1
Nissan 240sx HICAS 14.9:1; Non-HICAS: 17.0:1
Nissan 350z 15.9:1
C63 AMG 13.5:1
C5 Z06 16.1:1

So is it a bit slow compared to some newer cars? Sure. But not so much that you could tell a difference. It's more about the feel than the actual steering ratio. Do the bushings and you'll be happy.

Also make sure that your tires aren't too wide for your rims, that will kill turn-in feel. While you don't want to look like a 'stance bro' with 215's on a 9" wheel, a slight stretch in the tire helps with steering feel, versus too wide of a tire for the wheel which lets the tread move more in relation to the wheel.

Last edited by LateBreak; 12-28-2015 at 10:09 AM.


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