Which is Best for Auto-X Base w/ Z51 or GS?
01-05-2012, 02:39 PM
#1
Racer
Thread Starter
Which is Best for Auto-X Base w/ Z51 or GS?
Sorry to make such a vague post as I know that everyone has their preference and as such it's hard to quantify a "best car for Auto-x" but none the less I'm hoping to get some input from fellow autocrossers. This spring I'm planning on buying either an 08-09 Base Coupe w/ Z51 PKG or a 10' Grand Sport this will be my summer DD but the autocross performance is very important to me. The obvious PRO's are:
Base Coupe w/ Z51 PKG4-9K Cheaper (therefore more money for tires, wheels, brakes... down the road)
Lighter (100 - 150lbs)
Narrower
Running 9 or 9.5" Front & 10.5 or 11" Rear Aftermarket Wheels opens up a fair bit of tire choices vs. the GS/Z06 tire choices
Cheaper Tires & Brakes
GS
Wider Wheels/Tires
Bigger Brakes
Dry Sump
Slightly Better Weight Distribution (rear mounted battery)
Extra 1-2 years of factory warranty
Basically my question is; is the GS worth the extra money over the Base Coupe w/ Z51 PKG? Any help would be appreciated.
Base Coupe w/ Z51 PKG4-9K Cheaper (therefore more money for tires, wheels, brakes... down the road)
Lighter (100 - 150lbs)
Narrower
Running 9 or 9.5" Front & 10.5 or 11" Rear Aftermarket Wheels opens up a fair bit of tire choices vs. the GS/Z06 tire choices
Cheaper Tires & Brakes
GS
Wider Wheels/Tires
Bigger Brakes
Dry Sump
Slightly Better Weight Distribution (rear mounted battery)
Extra 1-2 years of factory warranty
Basically my question is; is the GS worth the extra money over the Base Coupe w/ Z51 PKG? Any help would be appreciated.
Last edited by 94boosted; 01-05-2012 at 02:56 PM.
01-05-2012, 04:30 PM
#2
Burning Brakes
Member Since: May 2001
Location: Coto de Caza CA
Posts: 1,163
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Sorry to make such a vague post as I know that everyone has their preference and as such it's hard to quantify a "best car for Auto-x" but none the less I'm hoping to get some input from fellow autocrossers. This spring I'm planning on buying either an 08-09 Base Coupe w/ Z51 PKG or a 10' Grand Sport this will be my summer DD but the autocross performance is very important to me. The obvious PRO's are:
Base Coupe w/ Z51 PKG4-9K Cheaper (therefore more money for tires, wheels, brakes... down the road)
Lighter (100 - 150lbs)
Narrower
Running 9 or 9.5" Front & 10.5 or 11" Rear Aftermarket Wheels opens up a fair bit of tire choices vs. the GS/Z06 tire choices
Cheaper Tires & Brakes
GS
Wider Wheels/Tires
Bigger Brakes
Dry Sump
Slightly Better Weight Distribution (rear mounted battery)
Extra 1-2 years of factory warranty
Basically my question is; is the GS worth the extra money over the Base Coupe w/ Z51 PKG? Any help would be appreciated.
Base Coupe w/ Z51 PKG4-9K Cheaper (therefore more money for tires, wheels, brakes... down the road)
Lighter (100 - 150lbs)
Narrower
Running 9 or 9.5" Front & 10.5 or 11" Rear Aftermarket Wheels opens up a fair bit of tire choices vs. the GS/Z06 tire choices
Cheaper Tires & Brakes
GS
Wider Wheels/Tires
Bigger Brakes
Dry Sump
Slightly Better Weight Distribution (rear mounted battery)
Extra 1-2 years of factory warranty
Basically my question is; is the GS worth the extra money over the Base Coupe w/ Z51 PKG? Any help would be appreciated.
http://www.scca.com/events/index.cfm?eid=3022
01-05-2012, 04:42 PM
#3
Melting Slicks
Member Since: Jun 2002
Location: Charleston South Carolina
Posts: 3,070
Likes: 0
Received 4 Likes
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4 Posts
The base C6 has never really proven as competitive as either the C6Z or the GS.
If I were choosing between the two, a base C6 or a GS I'd get the GS because of the wider fenders so I could put really wide rubber on it if I decided in a few years to bump up in class to street prepared. FWIW
If I were choosing between the two, a base C6 or a GS I'd get the GS because of the wider fenders so I could put really wide rubber on it if I decided in a few years to bump up in class to street prepared. FWIW
01-05-2012, 04:45 PM
#4
Le Mans Master
Look at the results from the Solo Nationals, should help clear things up.
http://www.scca.com/events/index.cfm?eid=3022
http://www.scca.com/events/index.cfm?eid=3022
01-05-2012, 04:56 PM
#5
Drifting
Before weighing in with my opinion . . . sounds like you don't want to run a Stock type class and run a class where modifications are allowed?
01-05-2012, 05:20 PM
#6
Racer
Thread Starter
01-05-2012, 05:28 PM
#7
Drifting
For Stock the GS, hands down.
When starting to modify, I don't know how big a wheel/tire size you can stick under a standard body C6, so that's what I would check out. If you're going to run a modified type class, maybe the alternate is to put a wide body kit on a standard body C6 so that you can run bigger rubber. That also depends on what type of event sites, course designs are prevalent.
Depends a lot on the rule structure where you run; I'm not familiar with Canadian organzations.
When starting to modify, I don't know how big a wheel/tire size you can stick under a standard body C6, so that's what I would check out. If you're going to run a modified type class, maybe the alternate is to put a wide body kit on a standard body C6 so that you can run bigger rubber. That also depends on what type of event sites, course designs are prevalent.
Depends a lot on the rule structure where you run; I'm not familiar with Canadian organzations.
01-05-2012, 06:50 PM
#8
Racer
Thread Starter
For Stock the GS, hands down.
When starting to modify, I don't know how big a wheel/tire size you can stick under a standard body C6, so that's what I would check out. If you're going to run a modified type class, maybe the alternate is to put a wide body kit on a standard body C6 so that you can run bigger rubber. That also depends on what type of event sites, course designs are prevalent.
Depends a lot on the rule structure where you run; I'm not familiar with Canadian organzations.
When starting to modify, I don't know how big a wheel/tire size you can stick under a standard body C6, so that's what I would check out. If you're going to run a modified type class, maybe the alternate is to put a wide body kit on a standard body C6 so that you can run bigger rubber. That also depends on what type of event sites, course designs are prevalent.
Depends a lot on the rule structure where you run; I'm not familiar with Canadian organzations.
I beleive the rules are the same, we follow SCCA Solo II Rules. i.e. both the C6 Base Coupe w/ Z51 & GS would be in either SS or ASP.
01-06-2012, 01:25 PM
#9
Racer
Thread Starter
Look at the results from the Solo Nationals, should help clear things up.
http://www.scca.com/events/index.cfm?eid=3022
http://www.scca.com/events/index.cfm?eid=3022
01-06-2012, 10:54 PM
#10
Instructor
Tough question, and lots of different and good opinions out there - but you knew that when you asked!
Having AX'd both the c6z51 (2009) and the c6z06 (2010) this past season, there are some considerations regarding the width of the car. When I run SCCA Solo events in my home area, the course is typically pretty wide and reasonbly long. Getting the wide body thru the course isn't usually a problem. However, I also run other events from local chapters (like BMW) and out of town events at small parking lots. They typically have shorter, much narrower courses with more "gymnastics" in the course. I can tell you there is a real difference when trying to get the wide body car in and out of a Chicago Box or crank any speed thru a slalom series that is spaced at less than 17 paces. With each cone costing you 2 seconds, you can knock yourself out real quick on some courses.
Brakes on both the z51 and the GS will allow you to operate at the threshold point. No advantage one way or the other for AX.
Weight of the car is not a factor. 100 lbs is negligable at a 3200 lb total with 430+ HP. (Besides, you let a passanger ride along so you can scare the bejeezes out of them, right?)
Don't fill the gas tank if you think a few pounds makes a difference.
Weight distribution on both cars is so close to even that it would not be a player in the calculations.
Dry sump not a decision player for AX or occasional track days. It is a consideration if in the future you plan to do any serious HPDE track time and use race rubber.
As far as rubber goes, you have options. Hoosier makes a set of A6's that will fit right into the narrow body without any worries and keep you in the Super Stock class. Excellent performance - go fast quickly and be ultra competitive. If you really think you need wider rubber with the narrow body, you can run the 18 inch c5z06 rear wheels on all four corners and step up the tread width a whole bunch - 305 F / 315 R. (Note that this will move you to the ASP class.)
Since this will be your DD, something very important to keep in mind is the suspension set up. If you want good AX performance, you'll need to get the car's geometry (alignment) set up for a combination of street and AX. You need something that is tolerable on tire wear for the street. Because the z51 wheels/tires are narrower, I can run a set up on the z51 that has a half degree more negative camber than I can on the wide body, and I still maintain reasonable tire wear on the street. Camber is a big player in the handling for AX. When you start pushing past neg 1.5 / neg 1.6 degrees of camber on the wide body front end, you'll use up a lot of tire on the street - and it will be the inside edge only. Expensive!
The GS and the z51 both have the preferred tranny for AX. They won't give you the 2nd gear "dead pedal" you get with the c6z06 at lower RPM's. (A lot of guys stick with the c5z because of the gear ratios as well.)
Knowing the venues you will be running (narrow/short course vs wide/long course) is something to consider.
Soooo... Just more stuff to throw on the already complicated consideration pile. Not saying one is better than the other - just pointing out my experience from driving both cars. They are both high end performers. No matter which car you choose, you are going to have a huge grin on your face when you get out there and romp down on the gas pedal!
Having AX'd both the c6z51 (2009) and the c6z06 (2010) this past season, there are some considerations regarding the width of the car. When I run SCCA Solo events in my home area, the course is typically pretty wide and reasonbly long. Getting the wide body thru the course isn't usually a problem. However, I also run other events from local chapters (like BMW) and out of town events at small parking lots. They typically have shorter, much narrower courses with more "gymnastics" in the course. I can tell you there is a real difference when trying to get the wide body car in and out of a Chicago Box or crank any speed thru a slalom series that is spaced at less than 17 paces. With each cone costing you 2 seconds, you can knock yourself out real quick on some courses.
Brakes on both the z51 and the GS will allow you to operate at the threshold point. No advantage one way or the other for AX.
Weight of the car is not a factor. 100 lbs is negligable at a 3200 lb total with 430+ HP. (Besides, you let a passanger ride along so you can scare the bejeezes out of them, right?)
Don't fill the gas tank if you think a few pounds makes a difference.Weight distribution on both cars is so close to even that it would not be a player in the calculations.
Dry sump not a decision player for AX or occasional track days. It is a consideration if in the future you plan to do any serious HPDE track time and use race rubber.
As far as rubber goes, you have options. Hoosier makes a set of A6's that will fit right into the narrow body without any worries and keep you in the Super Stock class. Excellent performance - go fast quickly and be ultra competitive. If you really think you need wider rubber with the narrow body, you can run the 18 inch c5z06 rear wheels on all four corners and step up the tread width a whole bunch - 305 F / 315 R. (Note that this will move you to the ASP class.)
Since this will be your DD, something very important to keep in mind is the suspension set up. If you want good AX performance, you'll need to get the car's geometry (alignment) set up for a combination of street and AX. You need something that is tolerable on tire wear for the street. Because the z51 wheels/tires are narrower, I can run a set up on the z51 that has a half degree more negative camber than I can on the wide body, and I still maintain reasonable tire wear on the street. Camber is a big player in the handling for AX. When you start pushing past neg 1.5 / neg 1.6 degrees of camber on the wide body front end, you'll use up a lot of tire on the street - and it will be the inside edge only. Expensive!
The GS and the z51 both have the preferred tranny for AX. They won't give you the 2nd gear "dead pedal" you get with the c6z06 at lower RPM's. (A lot of guys stick with the c5z because of the gear ratios as well.)
Knowing the venues you will be running (narrow/short course vs wide/long course) is something to consider.
Soooo... Just more stuff to throw on the already complicated consideration pile. Not saying one is better than the other - just pointing out my experience from driving both cars. They are both high end performers. No matter which car you choose, you are going to have a huge grin on your face when you get out there and romp down on the gas pedal!
01-10-2012, 10:18 AM
#11
Racer
Thread Starter
Tough question, and lots of different and good opinions out there - but you knew that when you asked!
Having AX'd both the c6z51 (2009) and the c6z06 (2010) this past season, there are some considerations regarding the width of the car. When I run SCCA Solo events in my home area, the course is typically pretty wide and reasonbly long. Getting the wide body thru the course isn't usually a problem. However, I also run other events from local chapters (like BMW) and out of town events at small parking lots. They typically have shorter, much narrower courses with more "gymnastics" in the course. I can tell you there is a real difference when trying to get the wide body car in and out of a Chicago Box or crank any speed thru a slalom series that is spaced at less than 17 paces. With each cone costing you 2 seconds, you can knock yourself out real quick on some courses.
Brakes on both the z51 and the GS will allow you to operate at the threshold point. No advantage one way or the other for AX.
Weight of the car is not a factor. 100 lbs is negligable at a 3200 lb total with 430+ HP. (Besides, you let a passanger ride along so you can scare the bejeezes out of them, right?) Don't fill the gas tank if you think a few pounds makes a difference.
Weight distribution on both cars is so close to even that it would not be a player in the calculations.
Dry sump not a decision player for AX or occasional track days. It is a consideration if in the future you plan to do any serious HPDE track time and use race rubber.
As far as rubber goes, you have options. Hoosier makes a set of A6's that will fit right into the narrow body without any worries and keep you in the Super Stock class. Excellent performance - go fast quickly and be ultra competitive. If you really think you need wider rubber with the narrow body, you can run the 18 inch c5z06 rear wheels on all four corners and step up the tread width a whole bunch - 305 F / 315 R. (Note that this will move you to the ASP class.)
Since this will be your DD, something very important to keep in mind is the suspension set up. If you want good AX performance, you'll need to get the car's geometry (alignment) set up for a combination of street and AX. You need something that is tolerable on tire wear for the street. Because the z51 wheels/tires are narrower, I can run a set up on the z51 that has a half degree more negative camber than I can on the wide body, and I still maintain reasonable tire wear on the street. Camber is a big player in the handling for AX. When you start pushing past neg 1.5 / neg 1.6 degrees of camber on the wide body front end, you'll use up a lot of tire on the street - and it will be the inside edge only. Expensive!
The GS and the z51 both have the preferred tranny for AX. They won't give you the 2nd gear "dead pedal" you get with the c6z06 at lower RPM's. (A lot of guys stick with the c5z because of the gear ratios as well.)
Knowing the venues you will be running (narrow/short course vs wide/long course) is something to consider.
Soooo... Just more stuff to throw on the already complicated consideration pile. Not saying one is better than the other - just pointing out my experience from driving both cars. They are both high end performers. No matter which car you choose, you are going to have a huge grin on your face when you get out there and romp down on the gas pedal!
Having AX'd both the c6z51 (2009) and the c6z06 (2010) this past season, there are some considerations regarding the width of the car. When I run SCCA Solo events in my home area, the course is typically pretty wide and reasonbly long. Getting the wide body thru the course isn't usually a problem. However, I also run other events from local chapters (like BMW) and out of town events at small parking lots. They typically have shorter, much narrower courses with more "gymnastics" in the course. I can tell you there is a real difference when trying to get the wide body car in and out of a Chicago Box or crank any speed thru a slalom series that is spaced at less than 17 paces. With each cone costing you 2 seconds, you can knock yourself out real quick on some courses.
Brakes on both the z51 and the GS will allow you to operate at the threshold point. No advantage one way or the other for AX.
Weight of the car is not a factor. 100 lbs is negligable at a 3200 lb total with 430+ HP. (Besides, you let a passanger ride along so you can scare the bejeezes out of them, right?)
Don't fill the gas tank if you think a few pounds makes a difference.Weight distribution on both cars is so close to even that it would not be a player in the calculations.
Dry sump not a decision player for AX or occasional track days. It is a consideration if in the future you plan to do any serious HPDE track time and use race rubber.
As far as rubber goes, you have options. Hoosier makes a set of A6's that will fit right into the narrow body without any worries and keep you in the Super Stock class. Excellent performance - go fast quickly and be ultra competitive. If you really think you need wider rubber with the narrow body, you can run the 18 inch c5z06 rear wheels on all four corners and step up the tread width a whole bunch - 305 F / 315 R. (Note that this will move you to the ASP class.)
Since this will be your DD, something very important to keep in mind is the suspension set up. If you want good AX performance, you'll need to get the car's geometry (alignment) set up for a combination of street and AX. You need something that is tolerable on tire wear for the street. Because the z51 wheels/tires are narrower, I can run a set up on the z51 that has a half degree more negative camber than I can on the wide body, and I still maintain reasonable tire wear on the street. Camber is a big player in the handling for AX. When you start pushing past neg 1.5 / neg 1.6 degrees of camber on the wide body front end, you'll use up a lot of tire on the street - and it will be the inside edge only. Expensive!
The GS and the z51 both have the preferred tranny for AX. They won't give you the 2nd gear "dead pedal" you get with the c6z06 at lower RPM's. (A lot of guys stick with the c5z because of the gear ratios as well.)
Knowing the venues you will be running (narrow/short course vs wide/long course) is something to consider.
Soooo... Just more stuff to throw on the already complicated consideration pile. Not saying one is better than the other - just pointing out my experience from driving both cars. They are both high end performers. No matter which car you choose, you are going to have a huge grin on your face when you get out there and romp down on the gas pedal!
When it comes to the venues that I race at there are really only two; one is a fairly small parking lot (benefiting the narrow body) and the other is a nice airport runway (benefiting the wide body) so no points to either car there unfortunately.
Your right that 100lbs isn't much but none the less when your going for your absolute best time 100+ lbs is still 100+ lbs (no passengers for these passes either
).I will probably only do one or two track days per season so your right about the dry sump not being a decision maker.
There seems to be more options when it comes to tires for the narrow body and more importantly the tries are a fair bit cheaper for the narrow body too. I was thinking of doing a season or maybe even two on a decent max performance summer tire such as the Hankook Ventus EVO's before getting a second set of wheels with A6's mounted.
Thats a good point regarding the camber setup, I never really thought of that with such a wide tire being street driven you have to be careful.
Thanks again for your post.
