Homepage Garage Wiki Register Social Groups Calendar Search Today's Posts Mark Forums Read
#Camaro6
Go Back   CAMARO6 > Technical Camaro Topics > Road Course/Track and Autocross


BeckyD @ James Martin Chevy


Post Reply
 
Thread Tools
Old 04-12-2021, 10:23 PM   #85
DaveC113

 
DaveC113's Avatar
 
Drives: 2018 Camaro 1SS 1LE
Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
Quote:
Originally Posted by Msquared View Post
In stock form, the limiting factor on rear negative camber is the toe link adjustment range. Past a certain amount of negative camber (-1.9 on my car), the toe links run out of adjustment and more negative camber causes toe out. I agree with your guy: we don't want toe out, especially in the rear! That's why if I were running in a class that allowed mods, like CAM C, one of the first mods I'd do would be to install aftermarket toe links with threaded rod ends that allow more range of adjustment. That would allow more rear negative camber. AFAIK, in the front the toe is not a limiting factor in getting negative camber: you just run out of adjustment range at the slotted knuckle attachment. You need camber plates up front to get more negative camber.
Gotcha, the issue is it's a street car too, I put ~8k miles/year on it.

If I got camber plates and ran ~1.5 degrees w/ ~1/8" toe in for street, when I set it to ~3 deg for autox I'll end up with 1/8 to 1/4" toe out.

The owner of the race shop thinks that much toe out is excessive. He thinks I'll get better tire wear and the steering will be better with my current ~2.3 deg camber with zero toe... He said maintaining zero toe is more important than getting more camber so it's best not to use camber plates to change alignment between street and track use. He also thinks the preference for a little toe out is outdated and doesn't apply to most modern cars.

So, I was planning on using camber plates and changing camber settings from street to autox/track but now I'm thinking I might follow his advise and leave it static.
__________________
DaveC113 is online now   Reply With Quote
Old 04-12-2021, 10:49 PM   #86
VR Baron
SoCal Camaro5 Race Team
 
VR Baron's Avatar
 
Drives: 2021 Shadow Grey Camaro 2SS 1LE
Join Date: Mar 2010
Location: SO CAL
Posts: 14,283
Quote:
Originally Posted by DaveC113 View Post
Gotcha, the issue is it's a street car too, I put ~8k miles/year on it.

If I got camber plates and ran ~1.5 degrees w/ ~1/8" toe in for street, when I set it to ~3 deg for autox I'll end up with 1/8 to 1/4" toe out.

The owner of the race shop thinks that much toe out is excessive. He thinks I'll get better tire wear and the steering will be better with my current ~2.3 deg camber with zero toe... He said maintaining zero toe is more important than getting more camber so it's best not to use camber plates to change alignment between street and track use. He also thinks the preference for a little toe out is outdated and doesn't apply to most modern cars.

So, I was planning on using camber plates and changing camber settings from street to autox/track but now I'm thinking I might follow his advise and leave it static.
I agree with him. All my race friends who are top drivers and or performance shop owners say same. As does my alignment guy. And other pro’s in the business. I maxed out -2.6 front camber and do 0 toe. That is max for me on camber, and what I have always run. Good handling and pretty even wear on the street. Also to much negative camber opens the door to ice mode(?) potentially.
VR Baron is online now   Reply With Quote
Old 04-13-2021, 12:07 AM   #87
DaveC113

 
DaveC113's Avatar
 
Drives: 2018 Camaro 1SS 1LE
Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
Quote:
Originally Posted by VR Baron View Post
I agree with him. All my race friends who are top drivers and or performance shop owners say same. As does my alignment guy. And other pro’s in the business. I maxed out -2.6 front camber and do 0 toe. That is max for me on camber, and what I have always run. Good handling and pretty even wear on the street. Also to much negative camber opens the door to ice mode(?) potentially.
Thanks for your input!
__________________
DaveC113 is online now   Reply With Quote
Old 04-13-2021, 07:39 AM   #88
Msquared

 
Msquared's Avatar
 
Drives: Chevrolet SS 1LE
Join Date: Oct 2019
Location: St. Charles, MO
Posts: 1,438
Quote:
Originally Posted by DaveC113 View Post
If I got camber plates and ran ~1.5 degrees w/ ~1/8" toe in for street, when I set it to ~3 deg for autox I'll end up with 1/8 to 1/4" toe out.

The owner of the race shop thinks that much toe out is excessive. He thinks I'll get better tire wear and the steering will be better with my current ~2.3 deg camber with zero toe... He said maintaining zero toe is more important than getting more camber so it's best not to use camber plates to change alignment between street and track use. He also thinks the preference for a little toe out is outdated and doesn't apply to most modern cars.
While I think zero toe is probably ideal, I don't think a little toe out is going to hurt performance on a stop watch. I've driven mine on the OE GYs with 5/32 and there was no obvious difference to me in the way it felt or on comparative times. That will wear the inside of the tire more, though. Depending on the tire, giving up -0.7 of camber is going to show up on the timer, though. I'm not sure the GY SC3s need -3 camber, but I think the Yoks or Rivals would want that much, and I'm sure the Yoks would like even more. It's tough to compromise - no question.
__________________
Matt Miller
2020 SS 1LE
Msquared is offline   Reply With Quote
Old 04-13-2021, 10:14 AM   #89
VR Baron
SoCal Camaro5 Race Team
 
VR Baron's Avatar
 
Drives: 2021 Shadow Grey Camaro 2SS 1LE
Join Date: Mar 2010
Location: SO CAL
Posts: 14,283
Quote:
Originally Posted by Msquared View Post
While I think zero toe is probably ideal, I don't think a little toe out is going to hurt performance on a stop watch. I've driven mine on the OE GYs with 5/32 and there was no obvious difference to me in the way it felt or on comparative times. That will wear the inside of the tire more, though. Depending on the tire, giving up -0.7 of camber is going to show up on the timer, though. I'm not sure the GY SC3s need -3 camber, but I think the Yoks or Rivals would want that much, and I'm sure the Yoks would like even more. It's tough to compromise - no question.
Yeah, you don’t want to go to like a 1/4” toe out or more. Chevy is +- even but just a little, which is fine. My zle friends run -2.8 to 3 because they can , I would like to but I don’t want to mod car that much with plates.
VR Baron is online now   Reply With Quote
Old 04-13-2021, 10:48 AM   #90
DaveC113

 
DaveC113's Avatar
 
Drives: 2018 Camaro 1SS 1LE
Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
Quote:
Originally Posted by Msquared View Post
While I think zero toe is probably ideal, I don't think a little toe out is going to hurt performance on a stop watch. I've driven mine on the OE GYs with 5/32 and there was no obvious difference to me in the way it felt or on comparative times. That will wear the inside of the tire more, though. Depending on the tire, giving up -0.7 of camber is going to show up on the timer, though. I'm not sure the GY SC3s need -3 camber, but I think the Yoks or Rivals would want that much, and I'm sure the Yoks would like even more. It's tough to compromise - no question.
Seems like I'll be giving up a couple tenths on a typical autox course in exchange for better tire wear, better steering feel, and not buying, installing, adjusting or possibly having a dealer tech see camber plates.

I might revisit the idea if I get another vehicle so I don't drive the Camaro as much.

Another possibility is running more like 2 deg on the street w/ 1/8 toe in and adding only 1 degree at the track, where I should end up with nearly zero toe or just a tiny bit of toe out... seems like too much $ and effort though!
__________________
DaveC113 is online now   Reply With Quote
Old 04-13-2021, 11:34 AM   #91
rotis
 
rotis's Avatar
 
Drives: 2019 ZL1 1LE
Join Date: Sep 2010
Location: Bastrop, TX
Posts: 438
Adjusting front toe when changing camber is very easy, as long as the camber is changing by a predictable/known amount. I have camber plates marked for street camber and track camber. It's 3 flats on each front tie rod when changing between the two, it is easy to verify with toe plates, I use these- https://www.longacreracing.com/produ...-Magnets-(pair)
rotis is offline   Reply With Quote
Old 04-13-2021, 12:36 PM   #92
DaveC113

 
DaveC113's Avatar
 
Drives: 2018 Camaro 1SS 1LE
Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
Quote:
Originally Posted by rotis View Post
Adjusting front toe when changing camber is very easy, as long as the camber is changing by a predictable/known amount. I have camber plates marked for street camber and track camber. It's 3 flats on each front tie rod when changing between the two, it is easy to verify with toe plates, I use these- https://www.longacreracing.com/produ...-Magnets-(pair)
Ha, I was just looking at that!

More work, but I do think it's possible to mark 2 positions on the toe adjustment and switch between the two.
__________________
DaveC113 is online now   Reply With Quote
Old 04-13-2021, 05:42 PM   #93
funked1
 
funked1's Avatar
 
Drives: '23 Hyundai Kona N, '24 VW GTI
Join Date: Aug 2019
Location: Sacramento, CA
Posts: 402
Quote:
Originally Posted by AustinTXracer View Post
YAY! I'm at 48 runs and 1000 miles to/from events across the last 6 weeks, and they still have 5-6/32 left across all tires. I haven't noticed any loss of performance yet, but be aware that they are on galactic backorder in the 305 size. I just placed an order with TR and estimated shipping is 7/2.
Yeah I gave up on the backorder. 295/35/19 square it is then.
funked1 is offline   Reply With Quote
Old 04-13-2021, 07:31 PM   #94
Mountain

 
Mountain's Avatar
 
Drives: 2017 SS 1LE, 2016 1SS (previous)
Join Date: Apr 2016
Location: Metro-Detroit
Posts: 1,863
Quote:
Originally Posted by Msquared View Post
I finally got to drive on the Falkens yesterday. First, I chickened out of my 305/315 plan (in B Street, so stickling with 10/11 wheels) and switched over to 275/305. Word on the street has been that "Falkens don't like to be pinched," and that concerned me a bit trying the 305 on the front 10" wheels. I don't know if this was a mistake or not. The upsides to the smaller fitment are: not a pinched fit, and shorter tires lower the CG and roll centers for less weight transfer. Obvious downside is less contact patch compared to the bigger tires. As a comparison, I used the stock Goodyears last year.

Well, to say the RT660s are different then the GYs is understatement! First impression was that they have so much more forward grip that I bogged the car off the line on the first start. Holy crap! These feel better in acceleration than the GYs by a wide margin, and also far better than Rivals. I think they are better than the RE71s that I drove on a friends 6th-gen Camaro, too. Also, they have significantly more lateral grip than the GYs. The rear-end step-out that seems to be caused by the eLSD disappeared. I didn't feel it once, and it wasn't for lack of pushing the car on corner exit. Crazy!

The one negative is that ice mode reared its head, which never happened with the GYs. I'm not sure if that's a product of the increased grip or the slightly bigger difference in front:rear diameter. If the latter, then maybe the 305/315 fitment would avoid this. It was easy enough to avoid with a more gradual brake application.

I tried keeping pressures at 35f/33r, which is a bit higher than I ran the GYs. This seems to be about right based on edge wear. I am running my car at -2.7 camber front and -1.9 rear (basically all I can get), and zero toe front and rear. So far I'm impressed. Temps were about 70F when I ran, with lots of sun and strong breeze, so not very stressful on the rubber compound. The two big questions will be how many runs they are good for, and how greasy will they be when it gets hot? For the latter, I don't mind using a sprayer, and I don't usually have a codriver, so I think it'll be okay.
"Ice mode" is going to be most affected by tire compound and brake pads/brake force changes from OE. Messing with the F:R tire diameter (or revs) can also do that, especially if you go to an extreme.

275/30R19 front and 305/30R19 rear, or 275/35R19 front and 295/35R19 rear, will yield the same/similar F:R split to the OE GY SC3 setup as far as revs. With the 35-series, you a right there in diameter, too.

I have a feeling that running tires that are more sticky than the GY SC3 and in a square setup on the SS 1LE has the potential to allow "Ice mode" to become more likely of an occurrence in autox (not necessarily track, though, due to the nature of autox driving). It may also play into the eLSD. Why? Think about what the tire revs/wheel speeds are doing and than think about how the car is probably [optimally] programmed.
Mountain is offline   Reply With Quote
Old 05-28-2021, 06:14 PM   #95
mecorn
 
Drives: 2020 Camaro SS 1LE
Join Date: Apr 2020
Location: Salt Lake City
Posts: 10
I have just taken delivery of a set of 305/30 fronts and 315/30 rears. I will be mounting them on 19s with stock widths. Any more input on how the 305s respond to being pinched???
mecorn is offline   Reply With Quote
Old 05-28-2021, 09:27 PM   #96
joelster

 
joelster's Avatar
 
Drives: '94 Z28+ '15 Z/28
Join Date: Jun 2009
Location: Cheektowaga, NY
Posts: 1,275
I noticed a big difference in tire pressures on the 660's. The sweet spot for me is 30lbs. I ran them for 2 events at 31-32lbs. On the 3rd event I had a decent lead so I tried lowering them. OMG what a difference. Took them to 30 and the front end was noticeably better. Lowered my time by 1.1 seconds. Went to 4th event and ran them at 30 for the whole event and set top pax. I run 19x11, 19x11.5, and 315/30/19 square. Car is roughly 3650lbs.
__________________
1973 Mach 1, 351C cruiser
'15 Z/28 Red Hot, A/C
1980 Z28- resto-mod project
1979 Y84 Trans Am
1986 IROC-Z
joelster is offline   Reply With Quote
Old 05-29-2021, 08:05 AM   #97
TrackClub


 
TrackClub's Avatar
 
Drives: 2020 SS 1LE (previous: 2017 SS 1LE)
Join Date: Mar 2012
Location: Canada, eh!
Posts: 5,091
Quote:
Originally Posted by mecorn View Post
I have just taken delivery of a set of 305/30 fronts and 315/30 rears. I will be mounting them on 19s with stock widths. Any more input on how the 305s respond to being pinched???
I dont like to exceed max manufacturer allowed tire width on a given rim size. Besides the obvious possible safety aspect, a turn in may feel sloppy due to extra tire flex - which is never a good thing. Note that race cars go the other way: max allowed rim width for a given tire, to max front end responsiveness.
Cheers!
TrackClub is offline   Reply With Quote
Old 05-29-2021, 04:06 PM   #98
funked1
 
funked1's Avatar
 
Drives: '23 Hyundai Kona N, '24 VW GTI
Join Date: Aug 2019
Location: Sacramento, CA
Posts: 402
Quote:
Originally Posted by joelster View Post
I noticed a big difference in tire pressures on the 660's. The sweet spot for me is 30lbs. I ran them for 2 events at 31-32lbs. On the 3rd event I had a decent lead so I tried lowering them. OMG what a difference. Took them to 30 and the front end was noticeably better. Lowered my time by 1.1 seconds. Went to 4th event and ran them at 30 for the whole event and set top pax. I run 19x11, 19x11.5, and 315/30/19 square. Car is roughly 3650lbs.
Thanks for the data point! I started at 32 cold last time and let them drift up to about 37, and it definitely did not help. I'm going to start at 30 cold tomorrow and hold them there.
funked1 is offline   Reply With Quote
 
Post Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:58 PM.


Powered by vBulletin® Version 3.8.9 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.