Just did my first autox: next steps advice needed
09-12-2010, 05:50 PM
#1
Pro
Thread Starter
Just did my first autox: next steps advice needed
Hi all!
New to the vette but not new to autox. I just recently purchased an 03 z06, I absolutely love the car. I come from a Mistubishi Evo, autox prepped.
I just did my first autox today at devens in MA. If any of you know devens, it's not your typical autox location. Huge runways, our short course today was over a mile long. FTD was running 66 second, i plateaued at 78second, not bad considering it was my first day. We did managed to get 20 runs each
yes 20
The car is currently stock except for an intake, replacement valve springs i installed, all fluids replaced in the past 2k miles, and PS2 stock sized tires.
So where to go to next? I would really like to address the coolant and oil temperature, it gets way hotter than i would like. Consider a Ron Davis or Dewitt radiator/cooler.
Suspension: I loved the way the car rotated, but feel there could be some improvement in turn in response. I am considering the LGM suspension package with sways and GT2 coilovers.
Other things i am considering - still on the stock pads, stainless brake lines, NT05s for next season (don't want to run r-comps yet), half cage with harnesses, and of course new seats.
Anyway, i apologize for the long winded thread, just thinking out loud. Hope you guys can give me some suggestions.
Thanks!
Mike
New to the vette but not new to autox. I just recently purchased an 03 z06, I absolutely love the car. I come from a Mistubishi Evo, autox prepped.
I just did my first autox today at devens in MA. If any of you know devens, it's not your typical autox location. Huge runways, our short course today was over a mile long. FTD was running 66 second, i plateaued at 78second, not bad considering it was my first day. We did managed to get 20 runs each
yes 20The car is currently stock except for an intake, replacement valve springs i installed, all fluids replaced in the past 2k miles, and PS2 stock sized tires.
So where to go to next? I would really like to address the coolant and oil temperature, it gets way hotter than i would like. Consider a Ron Davis or Dewitt radiator/cooler.
Suspension: I loved the way the car rotated, but feel there could be some improvement in turn in response. I am considering the LGM suspension package with sways and GT2 coilovers.
Other things i am considering - still on the stock pads, stainless brake lines, NT05s for next season (don't want to run r-comps yet), half cage with harnesses, and of course new seats.
Anyway, i apologize for the long winded thread, just thinking out loud. Hope you guys can give me some suggestions.
Thanks!
Mike
09-12-2010, 06:58 PM
#2
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
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What kind of coolant and oil temps were you seeing? How close together were your runs? I had an 03Z and had an RD Racing with EOC radiator in the car because I saw high oil temps on a track like Watkins Glen where I was running the car hard over 10+ minutes. Before the radiator I saw 319 degree oil temps and afterwards they had dropped to 230 until I put a thermostatic bypass in the oil lines. Then the temp went to 265.
For autocross your oil temps shouldn't be anywhere near as high as I was seeing on the track. You could see 230 degree coolant temps after a run and maybe while waiting for your next run but those temps can be brought down by running the fans since the radiator has sufficient capacity for autocross duty. Even with the RD Radiator when running an autocross on hot days I would see 230 coolant temps.
You may not get what you are looking for by changing to the larger radiator and if you are looking to be competitive you may not want to add the extra weight to the front of the car.
The suspension changes would help but you could try to change the alignment first and see how that works. There is a fair amount of adjustability in the stock C5 settings and you might get what you are looking for without going to all of the extra expense of coilovers, etc.
Bill
For autocross your oil temps shouldn't be anywhere near as high as I was seeing on the track. You could see 230 degree coolant temps after a run and maybe while waiting for your next run but those temps can be brought down by running the fans since the radiator has sufficient capacity for autocross duty. Even with the RD Radiator when running an autocross on hot days I would see 230 coolant temps.
You may not get what you are looking for by changing to the larger radiator and if you are looking to be competitive you may not want to add the extra weight to the front of the car.
The suspension changes would help but you could try to change the alignment first and see how that works. There is a fair amount of adjustability in the stock C5 settings and you might get what you are looking for without going to all of the extra expense of coilovers, etc.
Bill
09-12-2010, 07:03 PM
#3
Pro
Thread Starter
Oil temps were in the 250 area, coolant in the mid 230s. Due to the low volume of people i did 3-4 hot laps. I would like to get into some road racing next season, along with autox, so i'd rather make the investment now and not have to worry about it.
Weight isn't really a concern. I don't plan to get too competitive beyond some local clubs and friends.
I will try to read more on adjusting the stock suspension. I was advised to lower the car a little bit but not sure i want to give the streets over here.
Weight isn't really a concern. I don't plan to get too competitive beyond some local clubs and friends.
I will try to read more on adjusting the stock suspension. I was advised to lower the car a little bit but not sure i want to give the streets over here.
09-12-2010, 07:20 PM
#4
Burning Brakes
C5 Z06 - Accept No Substitutes!
If you start making changes right from the start, it's easy to lose track of what really works and what doesn't. First thing I would do is baseline the Z06. Check the alignment, check the shocks, check the front/rear swaybars for condition/freedom of movement, and start keeping records of your tire pressure when hot as well as your times, ambient air temp, course air temp, and your times compared to others in the class. That will help you most in the long run in tuning the Vette.
BTW what brand and model tires are you using? (C5 Z06's did not come with EMTs.) What hot pressures did you use? A little toe out really helps turn-in on auto-x courses, but makes track cars squirrelly. Sounds like your first event at Devens was more like a low speed NCCC auto-x. Try a couple of SCCA-sanctioned events as their courses tend to emphasize control and handling rather than pure HP.
Good Luck and Have Fun!
BTW what brand and model tires are you using? (C5 Z06's did not come with EMTs.) What hot pressures did you use? A little toe out really helps turn-in on auto-x courses, but makes track cars squirrelly. Sounds like your first event at Devens was more like a low speed NCCC auto-x. Try a couple of SCCA-sanctioned events as their courses tend to emphasize control and handling rather than pure HP.
Good Luck and Have Fun!
09-12-2010, 07:28 PM
#5
Pro
Thread Starter
Tires are Pilot Sport P2s in stock size.
Pressures were 38 rear and 35 front with very even heat across. Like i said, the car rotated well, very good grip, would just a bit more turn in. Toe would be a good place to start, but I do drive on the street often so i'd rather not be stuck in a track alignment eating tires on the street if i can fix it with some parts.
I honestly have no desire to run with SCCA. The local events are crap, few runs and lots of work. We have a few groups that put on some great events that i tend to run with.
Pressures were 38 rear and 35 front with very even heat across. Like i said, the car rotated well, very good grip, would just a bit more turn in. Toe would be a good place to start, but I do drive on the street often so i'd rather not be stuck in a track alignment eating tires on the street if i can fix it with some parts.
I honestly have no desire to run with SCCA. The local events are crap, few runs and lots of work. We have a few groups that put on some great events that i tend to run with.
09-12-2010, 07:55 PM
#6
Drifting
I would suggest that you learn about all the adjustability that a C5 Z06 has. Not only can you adjust camber/caster/toe, but ride height is adjustable (as you've mentioned) . . . but that also means that you can corner balance the car and change the turn-in characteristics by adjusting rake as well. Toe is easy to change. Five or ten minutes at the beginning of the day and you can change from a "street" setting to an autocross friendly setting. Then five or ten minutes at the end of the day and you can tweak back to a street setting.
09-12-2010, 09:16 PM
#7
Advanced
The SCCA is a different game though, and the NER is very professionally run and a view into how the sport works at the national level. This season has been a steady 6 runs/day plus/minus, and as mentioned the courses are at a whole 'nother level.
Careful what you do with your mods, stick with the driver and straightforward adjustments for a while. There may come a time when a level playing field becomes important, and when that comes you may find yourself pulling stuff back off your car because you're classed with tube-frame wing cars. I guess what I'm suggesting is try not to do anything other than focus on the big nut, especially if you think you need to fix the car. If you do mod things, keep them reversible.
The SCCA recipe has some merit, after all they've been at this a while. Can't count the number of guys who co-drove my Cobra (coming from cars with all sorts of various mods) and said things like "all this has is a sway bar, shocks and brake pads???" The kool aid is admittedly an acquired taste. 10 years later things look different.
Best,
- Jeff
NER BSP #5
09-12-2010, 09:29 PM
#8
Le Mans Master
That frees you up for whatever mods you want. The temps you experienced aren't bad, but as you get faster those will climb. There are a bunch of different ways to go: I'd suggest reading through here about external oil coolers, aftermarket radiators, combo rads/EOCs, etc.
I'd frankly do those before working on suspension mods. That way you can get all the seat time you desire with peace of mind about keeping your engine temps under control.
Welcome to the insanity, and have a good one!
Mike
I'd frankly do those before working on suspension mods. That way you can get all the seat time you desire with peace of mind about keeping your engine temps under control.
Welcome to the insanity, and have a good one!
Mike
09-12-2010, 10:41 PM
#9
I run with SCCA in Super Stock class and turn some pretty decent times. Adding the seat, roll hoop, seats, and harness is a good idea. Both from a safety and ability to learn standpoint. You wont slide around, and will be able to feel the car.
My approach has been to do what lets me learn the fastest. So, I focused on my driving, and alignment. I have probably run 40 different alignment set ups all within the factory adjustments. You have to set the car up to suit your style, and you will have to adjust your setup as you improve and for different track conditions (wet, green, rubbered in, etc).
Running street tires and stock springs makes it easier to find, and stay at the limit. Even if you run a full race car, its still the same game... driving the car at the limit.
Just my two cents
Chris Shay
My approach has been to do what lets me learn the fastest. So, I focused on my driving, and alignment. I have probably run 40 different alignment set ups all within the factory adjustments. You have to set the car up to suit your style, and you will have to adjust your setup as you improve and for different track conditions (wet, green, rubbered in, etc).
Running street tires and stock springs makes it easier to find, and stay at the limit. Even if you run a full race car, its still the same game... driving the car at the limit.
Just my two cents
Chris Shay
09-13-2010, 12:26 AM
#10
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,096
Received 8,930 Likes
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5,334 Posts
Tires are Pilot Sport P2s in stock size.
Pressures were 38 rear and 35 front with very even heat across. Like i said, the car rotated well, very good grip, would just a bit more turn in. Toe would be a good place to start, but I do drive on the street often so i'd rather not be stuck in a track alignment eating tires on the street if i can fix it with some parts.
I honestly have no desire to run with SCCA. The local events are crap, few runs and lots of work. We have a few groups that put on some great events that i tend to run with.
Pressures were 38 rear and 35 front with very even heat across. Like i said, the car rotated well, very good grip, would just a bit more turn in. Toe would be a good place to start, but I do drive on the street often so i'd rather not be stuck in a track alignment eating tires on the street if i can fix it with some parts.
I honestly have no desire to run with SCCA. The local events are crap, few runs and lots of work. We have a few groups that put on some great events that i tend to run with.
As far as running high speed events in the future you could also go with a separate oil cooler and leave the radiator alone. A lot of people have success with that setup. As I said in my first post just getting the fans turned on while sitting waiting to run can bring the coolant temp down. As others have said I wouldn't jump into a lot of changes until you get to know the car better and can make informed choices based on your own observations.
Bill
09-13-2010, 06:43 AM
#11
Pro
Thread Starter
The SCCA is a different game though, and the NER is very professionally run and a view into how the sport works at the national level. This season has been a steady 6 runs/day plus/minus, and as mentioned the courses are at a whole 'nother level.
Careful what you do with your mods, stick with the driver and straightforward adjustments for a while. There may come a time when a level playing field becomes important, and when that comes you may find yourself pulling stuff back off your car because you're classed with tube-frame wing cars. I guess what I'm suggesting is try not to do anything other than focus on the big nut, especially if you think you need to fix the car. If you do mod things, keep them reversible.
Careful what you do with your mods, stick with the driver and straightforward adjustments for a while. There may come a time when a level playing field becomes important, and when that comes you may find yourself pulling stuff back off your car because you're classed with tube-frame wing cars. I guess what I'm suggesting is try not to do anything other than focus on the big nut, especially if you think you need to fix the car. If you do mod things, keep them reversible.
That frees you up for whatever mods you want. The temps you experienced aren't bad, but as you get faster those will climb. There are a bunch of different ways to go: I'd suggest reading through here about external oil coolers, aftermarket radiators, combo rads/EOCs, etc.
I'd frankly do those before working on suspension mods. That way you can get all the seat time you desire with peace of mind about keeping your engine temps under control.
I'd frankly do those before working on suspension mods. That way you can get all the seat time you desire with peace of mind about keeping your engine temps under control.
When I run my car I usually set the front tire pressure a couple of pounds more than the rear. You might want to try that at the next autocross.
As far as running high speed events in the future you could also go with a separate oil cooler and leave the radiator alone. A lot of people have success with that setup. As I said in my first post just getting the fans turned on while sitting waiting to run can bring the coolant temp down. As others have said I wouldn't jump into a lot of changes until you get to know the car better and can make informed choices based on your own observations.
Bill
As far as running high speed events in the future you could also go with a separate oil cooler and leave the radiator alone. A lot of people have success with that setup. As I said in my first post just getting the fans turned on while sitting waiting to run can bring the coolant temp down. As others have said I wouldn't jump into a lot of changes until you get to know the car better and can make informed choices based on your own observations.
Bill
Yeah, my local tuner said he does some voodoo with the fans so the car will run cooler. But if it doesn't hurt anything i'd rather just run a new radiator with an integrated cooler since i want to do a cooler anyway.
Thanks for all the input everyone!
09-14-2010, 01:30 PM
#14
Safety Car
Save your cash. Ride height/rake and alignment before you mess with anything. Corner weight it. Wheels and tires. Front swaybar. Then comes the decision between coilovers or do it in steps with fresh shocks (Bilstein, KONI or stock) and then VBP leafs.
I chased a lot of stuff on my C6 and spent a bunch of money; in retrospect I would have been way better served to do ride height + alignment + corner weights before I started throwing parts at the car...
That said, I am happy with my DRM coilovers, DRM/RD radiator w/ EOC+TOC, Pfadt poly bushings and Pfadt swaybars. The car is working pretty darn well on the road course -- I haven't had it back out at an autocross in this configuration.
I chased a lot of stuff on my C6 and spent a bunch of money; in retrospect I would have been way better served to do ride height + alignment + corner weights before I started throwing parts at the car...
That said, I am happy with my DRM coilovers, DRM/RD radiator w/ EOC+TOC, Pfadt poly bushings and Pfadt swaybars. The car is working pretty darn well on the road course -- I haven't had it back out at an autocross in this configuration.