Go Back  CorvetteForum - Chevrolet Corvette Forum Discussion > General Corvette Topics > Autocrossing & Roadracing
Reload this Page >

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

Notices
Autocrossing & Roadracing Suspension Setup for Track Corvettes, Camber/Caster Adjustments, R-Compound Tires, Race Slicks, Tips on Driving Technique, Events, Results
Sponsored by:
Sponsored by:

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

 
Old 12-28-2015, 12:02 PM
  #21  
SouthernSon
CF Senior Member
Support Corvetteforum!
 
SouthernSon's Avatar
 
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 11,808
Received 192 Likes on 147 Posts
Default

Originally Posted by LateBreak View Post
....... 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.
In a nutshell!
SouthernSon is offline  
Old 12-28-2015, 12:18 PM
  #22  
RC000E
CF Senior Member
Thread Starter
 
Member Since: Sep 2009
Location: My interests are mobile
Posts: 6,941
Received 333 Likes on 202 Posts
Default

Get out of an S2000 and a Porsche C4S, or a ZHP 330ci and drive your C5Z...then get back to me...lol.

I love the car, but the steering is mush and slightly slow, lacks feel. My S2000 steering in my Z06 would be like heaven...lol. My car is well maintained, properly sized tires for the wheels, corner balanced, cambered and aligned in my own shop...it handles fantastically well, but when you get out of certain machines, you can immediately feel the lack of steering precision. I have a ZHP rack with some spherical bearing components on my M3...good lord it feels amazing.

I am quite certain the bushings will help, and I fully intend to do them (if I keep this rack). My coilovers are off getting rebuilt at the moment, so the "winter" build will involve some steering mods as well. This thread was merely intended to explore what my options are and what people have discovered available thus far so I can form an action plan. I know there is a myriad of "typical" modifications available...I just wasn't sure if a rack was or not...hence why the thread.

Appreciate the responses, but the thread didn't ask for a "workaround", it simply asked...is there a faster rack out there? My best direction is on the last page...and I have an inquiry out. We'll see.
RC000E is offline  
Old 12-28-2015, 01:28 PM
  #23  
LateBreak
CF Senior Member
 
LateBreak's Avatar
 
Member Since: Jan 2010
Posts: 667
Likes: 0
Received 11 Likes on 11 Posts
Default

I know you weren't asking for a workaround, just suggesting that upgrading the rack bushing will likely solve a lot of what you're feeling. I DD a stock C5Z on the street and race a C5 non-z with the suspension gone through. The car with a solid rack bushing has much tighter steering and crisper response than the one without. It has more of that connected feel that you're looking for. The stock rubber rack and control arm bushings can easily account for play in the wheel.

If that doesn't cover it, a steering quickener would be much easier and cheaper than finding a faster rack that will fit.
LateBreak is online now  
Old 12-28-2015, 02:36 PM
  #24  
SouthernSon
CF Senior Member
Support Corvetteforum!
 
SouthernSon's Avatar
 
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 11,808
Received 192 Likes on 147 Posts
Default

Originally Posted by RC000E View Post
.....
Appreciate the responses, but the thread didn't ask for a "workaround", it simply asked...is there a faster rack out there? My best direction is on the last page...and I have an inquiry out. We'll see.
Sorry, I guess we thought you were looking for a way to address what you characterized as 'muddy' feel. Lots of people really don't understand how to address what they consider an issue. We figured you might be one of them since you have an issue with steering response on a vehicle that many top level drivers and champions are content with after making the mods that were suggested.
SouthernSon is offline  
Old 12-28-2015, 04:33 PM
  #25  
RC000E
CF Senior Member
Thread Starter
 
Member Since: Sep 2009
Location: My interests are mobile
Posts: 6,941
Received 333 Likes on 202 Posts
Default

Sigh....we always gotta do this online....pm sent...
RC000E is offline  
Old 12-29-2015, 01:25 PM
  #26  
SouthernSon
CF Senior Member
Support Corvetteforum!
 
SouthernSon's Avatar
 
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 11,808
Received 192 Likes on 147 Posts
Default

Originally Posted by RC000E View Post
Sigh....we always gotta do this online....pm sent...
No problem, PM replied.
SouthernSon is offline  
Old 12-29-2015, 01:40 PM
  #27  
RC000E
CF Senior Member
Thread Starter
 
Member Since: Sep 2009
Location: My interests are mobile
Posts: 6,941
Received 333 Likes on 202 Posts
Default

Waiting to hear back from Woodward after Jan 5 when they reopen. From there I'll determine what direction I will go with this. Stay tuned..
RC000E is offline  
Old 12-29-2015, 04:31 PM
  #28  
parsonsj
CF Senior Member
 
parsonsj's Avatar
 
Member Since: Sep 2009
Location: Winter Springs FL
Posts: 429
Received 6 Likes on 4 Posts
Default

I've run Woodward racks in other cars, and they feel amazing compared to the C6Z. In fact, the car I had before my Z06 was a Woodward-racked tube chassis street car, and I remember the disappointment about steering feel when I first took my new-to-me Z06 for its first test drive.

Anyway, that's a long way of indicating I'd love to hear what Woodward has to say.

Last edited by parsonsj; 12-29-2015 at 04:31 PM.
parsonsj is offline  
Old 12-29-2015, 05:01 PM
  #29  
Ludeaem
CF Senior Member
 
Ludeaem's Avatar
 
Member Since: May 2004
Location: Indianapolis IN
Posts: 426
Received 14 Likes on 13 Posts
Default

Another possible work around is a smaller diameter steering wheel.
Ludeaem is offline  
Old 04-12-2018, 10:41 PM
  #30  
JJwins
Junior Member
 
Member Since: Jul 2017
Posts: 17
Received 0 Likes on 0 Posts
Default

Bumping a really old thread but this is the closest thread to what I'm hoping to find out. Anyone make a "high performance" rack for the c5/c6? I'm coming from an Evo and the "numb" steering feel is driving me nuts! Id do pretty much anything to get a sharper feel/feedback from the steering wheel.
JJwins is offline  
Old 04-13-2018, 04:04 PM
  #31  
John B
CF Senior Member
 
John B's Avatar
 
Member Since: Feb 2001
Location: Zimmerman MN
Posts: 598
Received 13 Likes on 12 Posts
Default

I agree. Its slow & numb steering. Many are taking this the wrong way. Yes they can be great handling cars with the stock rack. My car is a set up proven fast car with all the tricks. It would be so much better with a quicker rack with better feel. My old C4 track car had much quicker rack 1.6 turns lock to lock. Just changed my ice racer from 2.5 turns to 1.2 turns. Single best improvement. When you are confident that you can catch a car with the flick of a wrist you can push harder. My C5 rack is out now. Unaware of any bolt in answer. Looking into options besides prerack quickener. Effort will go up.
John B is offline  
Old 04-19-2018, 12:02 PM
  #32  
SouthernSon
CF Senior Member
Support Corvetteforum!
 
SouthernSon's Avatar
 
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 11,808
Received 192 Likes on 147 Posts
Default

I might add that some of us have replaced the transverse springs with coil overs and shaved seconds off of times. Perhaps this might give you a better steering response, too.
SouthernSon is offline  
Old 04-19-2018, 12:35 PM
  #33  
c5racr1
CF Senior Member
 
Member Since: Feb 2000
Location: new orleans
Posts: 2,015
Received 70 Likes on 64 Posts
Default Steering

put a smaller steering wheel, and spherical bushings, and coilovers. Also try solid bushings on the rack. Works wonders
c5racr1 is offline  
Old 10-30-2018, 10:38 AM
  #34  
peanut
Junior Member
 
Member Since: Jul 2006
Location: Louisville KY
Posts: 17
Received 1 Like on 1 Post
Default

*** Another bump for an old thread .... ***

Anything new on the quicker ratio racks in the past 6 months? Anyone made/modified anything?
peanut is offline  
Old 10-30-2018, 11:39 AM
  #35  
Quickshift_C5
CF Senior Member
 
Member Since: Sep 2006
Location: Iowa
Posts: 2,615
Received 111 Likes on 101 Posts
Default

I think there is a lot of confusion on what the thread creator is talking about regarding steering feel and how quick the rack is. No amount of bushing changes or adjustments anywhere is going to fix it.

Its extremely difficult to understand what he's talking about if you haven't had the chance to drive an S2000 or BRZ/FRS. The difference is immediately and blatantly obvious and getting back in a C5Z after feels like driving a school bus.

Last edited by Quickshift_C5; 10-30-2018 at 11:40 AM.
Quickshift_C5 is offline  
Old 10-31-2018, 02:18 AM
  #36  
K.I.T.T.
CF Senior Member
 
K.I.T.T.'s Avatar
 
Member Since: Dec 2016
Location: Lookin over Hoover Dam
Posts: 2,093
Received 734 Likes on 403 Posts
Default

^Indeed.

I will say, since I started the thread, I've changed the car a bit. My Z06 is running the square setup with 18x11's and 295 Michelins. I've added a smaller diameter Nardi dish and NRG hub. The steering feel definitely improved, as did the rate of turn and the turn in from the front end rubber I've added. The overall balance is much better. Still isn't where I want it to be, but it's closer. I've read the 09+ steering rack is pretty much a swap in, so I'm likely going that route. I'm also going to do the rack bushing and am doing solid tie rod ends for more feel, which I've purchased and will be installing shortly.

I will say, vs my gf's 09 6spd, my car feels sharper and the driving position is now definitely better. I'm getting there but...it's still no S2k, that's for sure. It's not even an E46 M3, but it's getting very close. Definitely doesn't feel like a school bus anymore...because they definitely do, when stock.
K.I.T.T. is online now  
Old 11-06-2018, 11:16 PM
  #37  
rad63
Junior Member
 
Member Since: May 2016
Posts: 15
Likes: 0
Received 1 Like on 1 Post
Default

Steering rack started leaking in my 2008 Z51. I need either a new one, or rebuild mine.

I know that GM was changing racks over time. Does it make sense to put 2009+ part to get better(?) steering feel? What is common wisdom?

Car pretty much lives on autocross course, so it's very important for me.
rad63 is offline  
Old 11-07-2018, 02:44 PM
  #38  
K.I.T.T.
CF Senior Member
 
K.I.T.T.'s Avatar
 
Member Since: Dec 2016
Location: Lookin over Hoover Dam
Posts: 2,093
Received 734 Likes on 403 Posts
Default

Originally Posted by rad63 View Post
Steering rack started leaking in my 2008 Z51. I need either a new one, or rebuild mine.

I know that GM was changing racks over time. Does it make sense to put 2009+ part to get better(?) steering feel? What is common wisdom?

Car pretty much lives on autocross course, so it's very important for me.
The 2008 had steering rack improvements, but 2009 did also. 2008 was focused improving on center feel, something the c5 definitely lacks...thats the big difference of c5 vs s2k or later bmw. On center precision...well...there is none. Its not just about ratio...the s2k does come close to twitchy due to the rate, but fast ratio with the right assist/feel compromise, makes a car feel lighter and smaller.

Below is a lengthy but detailed explanation of the 2008 improvements, then the subsequent 2009 improvements, from the engineers themselves. Read below if you wish:

----------------------------------------

“Last year [2008], we added a premium steering gear in response to owners who felt that Corvettes could benefit from improved on-center feel and precision,” adds Juechter.

For 2009, we found another means of making Corvette steering even better.
Quicker steering ratios make a car feel nimble and responsive. But if the ratio is too quick, the car is nervous at highway speeds. Juechter’s ‘even better’ development is a variable-ratio rack-and-pinion steering gear that provides the best of both worlds.

Terrel Johnson, a Corvette engineering team member for five years, is the lead steering design engineer.

Johnson explains:

“The new variable-ratio steering provides the same 17.1 to 1 on-center ratio that we’ve used successfully for years. But when the steering wheel angle exceeds 15 degrees of left or right turning, the ratio begins speeding up.
The change is so gradual that the driver notices nothing unusual, but after a little more than half a turn of the steering wheel, the ratio has changed to 14.6 to 1. This trims the number of turns lock-to-lock from 2.78 to only 2.54, a 9-percent improvement.

“With multiple ratios in one steering gear, we’re able to tune the on-center zone for excellent stability and reduced sensitivity at highway speeds without making Corvettes feel sluggish around town. The quicker off-center ratio helps the car feel more nimble and highly maneuverable while parking or negotiating a U-turn.”

Asked exactly how the variable-ratio gearing is achieved, Johnson answered with two words: helix angles. Some digging revealed what he was talking about.

Inside the rack-and-pinion steering system, the pinion gear teeth encircle their shaft in a spiral called a helix. This configuration increases the number of pinion teeth in contact with rack teeth.
The greater the gear-to-gear contact area (more teeth engaged), the less the likelihood of lash when the rack-and-pinion assembly is under load. Lash is steering precision’s bitter enemy.

Pinion gear teeth must be evenly spaced because each tooth contacts the rack at least twice during the two-plus turns lock-to-lock.
But, since each rack tooth is engaged only once throughout the rack’s full travel, how the rack teeth are configured can vary.

At the center of the steering rack, the teeth are cut at a 14-degree helix angle. This causes the rack teeth to engage the pinion teeth at their roots, yielding minimal rack motion for each increment of pinion rotation.

At the end of the rack, the teeth are cut at an 18-degree helix angle. Now the rack teeth engage the pinion gear teeth near their outmost tips. That larger-radius point of contact causes the rack to move substantially more for each increment of pinion rotation. Presto: a faster steering ratio.

Variable-ratio steering is another example of a seemingly miniscule change that yields a noticeable improvement in the Corvette’s daily-driving behavior.

From the engineer’s perspective, the Corvette is a Rubik’s cube of interlocking, interacting systems.
A small change here can inflict major consequences there. Corralling an additional 36 horses under the hood for 2008 sent transmission engineers scurrying to make sure their chunks of the cube could take the gaff.

Design release engineer Dave Howe, who’s responsible for the Corvette’s six-speed manual transaxle, explains, “Our objective was to provide the necessary torque capacity without major disturbances to the basic design. But while we were at it, we seized the opportunity to install improvements every customer will appreciate.”
K.I.T.T. is online now  
Old 11-12-2018, 04:03 PM
  #39  
Torch FRC
CF Senior Member
 
Torch FRC's Avatar
 
Member Since: Oct 2007
Location: San Diego Ca
Posts: 3,991
Received 32 Likes on 27 Posts
Default

The Sparco 330mm wheel I put in my C5 was worth every penny.
Torch FRC is offline  
Old 11-13-2018, 03:46 PM
  #40  
K.I.T.T.
CF Senior Member
 
K.I.T.T.'s Avatar
 
Member Since: Dec 2016
Location: Lookin over Hoover Dam
Posts: 2,093
Received 734 Likes on 403 Posts
Default

^ I agree...I did a 350mm and smaller diameter immediately accentuates responsiveness and makes the car feel like it's tighter on center. I imagine 330 definitely takes it a step further, but with the way the magnasteer gets heavy at high speed, I worry about effort over a 20min session with a smaller wheel. Fatigue leads to a lack of precision so i tried to strike a balance.

Right now I feel the rate of steer is pretty good, I just think there needs to be more feel and I wish it were more precise on center even still. It's tighter, but it's still sloppy vs s2k and bmw standards. That on-center is all rack design. I'm adding the bushing and solid outer/bump steer correction to the front here momentarily, so I am hoping I get more feel to the tire.

I'm working hard to remove compliance in some areas, but then add it back in others. I think taking away compliance in bushings and ends, but then adding it back in with a little softer spring rate on the pfadts might get me to where I am aiming...so that's the plan. Right now I think the pfadts are oversprung slightly for street duty and high frequency surfaces. The roads where I am are smooth though, so I feel I can give away some bushing compliance, etc.
K.I.T.T. is online now  

Thread Tools
Search this Thread
Quick Reply: Tighter steering ratio, tighter on center steering rack for C5/C6?


Sponsored Ads
Vendor Directory

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: