[GunMetalGrey]

Originally Posted by glamcem

I should've looked again and told you the exact sizes, my bad

Toyo RRs have 285-315-325/30/20 sizes so I would consider 285 front and 315 in the rear, if you want to be able to use them on OEM wheels. It's only marginally taller than the OEM tires (27.2" vs 27.5") ..I personally wouldn't mind adding a slight bit of rake as our cars are prone to understeer and as I'd be already adding more rubber in the rear it would definitely take care of that slight oversteer concerns because of that marginal addition of a rake (if any)

https://trackdaytire.com/product/toyo-proxes-rr/

My friends and I have been using RRs on summer/track season (April to October) here in PNW to drive around town and go to and come back from track. They don't HC out with street/highway driving and that's the beauty of them. My friend who used in his GS says he was able to get 4-5 events and 4-5k miles street driving. For track use we typically get 20-25 HCs and then the performance degrades and we retire tires. So they don't cord before they HC out. ormance degrades and we retire tires. So they don't cord before they HC out.

No worries, but where are you seeing these sizes? At Toyos website, I didn’t see 315/30’s for the rear...
Thanks for clarifying and give more details on the performance longevity.
I wonder how they stack up to the SC3R’s in terms of performance...Not longevity bust just pure grip and lap time?)

I didn’t know you could legally use these tires on the street?

[TrackClub]

Originally Posted by Norm Peterson

On the matter of 'rake' . . . I suspect that it's not the rake per se that's affecting the understeer-oversteer handling balance, but changes in the front vs rear geometric roll center heights that necessarily accompany any changes in rake (or just ride height, for that matter). A higher geo-RC will transfer more load than a lower one, and RC load transfer happens much more quickly than load transfer developed through chassis roll. The roll moment would remain the same because no adjustment is being made between the geo-RCs and the chassis/its CG, and with an increase in rake caused by taller tires you're getting a little more rear LLT from the unsprung mass effect.

Rake would be a visual indication of sorts regarding what might have been done to the Geo-RCs.


Norm

Norm, you always add so much valuable info in your comments. Indeed, it is not the rake itself, but the change *caused* by the rake. Well explained. Thanks!

[TrackClub]

Originally Posted by glamcem

I should've looked again and told you the exact sizes, my bad

Toyo RRs have 285-315-325/30/20 sizes so I would consider 285 front and 315 in the rear, if you want to be able to use them on OEM wheels. It's only marginally taller than the OEM tires (27.2" vs 27.5") ..I personally wouldn't mind adding a slight bit of rake as our cars are prone to understeer and as I'd be already adding more rubber in the rear it would definitely take care of that slight oversteer concerns because of that marginal addition of a rake (if any)

https://trackdaytire.com/product/toyo-proxes-rr/

My friends and I have been using RRs on summer/track season (April to October) here in PNW to drive around town and go to and come back from track. They don't HC out with street/highway driving and that's the beauty of them. My friend who used in his GS says he was able to get 4-5 events and 4-5k miles street driving. For track use we typically get 20-25 HCs and then the performance degrades and we retire tires. So they don't cord before they HC out.

I wouldn't hesitate to use 285F with 315R myself. Agree fully with all your comments. The gearing will be a tad taller, but not much. 5 to 6 DAYS (20-25 heat cycles) and no cords would be tremendous. But street driving? Seriously? These are not street legal, but besides that point, any rain and one would be in a lot of trouble...
I would be ok driving them short distance to/from, but not any track road trips further away. I got caught in a passing shower on a secondary highway once on used up NT01s and almost ended up in a ditch a few times.
Plus made everyone following me totally furious i am sure: "here's a guy in a Vette and he can't bloody drive!". Lol!

[glamcem]

Originally Posted by GunMetalGrey

No worries, but where are you seeing these sizes? At Toyos website, I didn’t see 315/30’s for the rear...
Thanks for clarifying and give more details on the performance longevity.
I wonder how they stack up to the SC3R’s in terms of performance...Not longevity bust just pure grip and lap time?)

I didn’t know you could legally use these tires on the street?

Have you clicked on the link? You can see them in that drop down menu. 285/30/20 and 315/30/20 RRs are also on Toyo's website. It also says "DOT COMPETITION TIRE" on those links too

https://www.toyotires.com/tire/patte...ires-proxes-rr

Also why don't you like the R888Rs? They're great tires if you ask me and should be the longest lasting out of the bunch. Yes they're about 1.5-2 seconds behind the RRs or even maybe even 3 seconds compared to R7s etc ..but they're great for mixed street/track use, for those who want longevity with still a bit more grip than RE71R or NT01, it's a great alternative IMO.

If the performance of the R888Rs are very similar to OEM SS 1LE tires, that still doesn't mean they're equal in performance but that's probably because we cannot fully utilize the added grip (because we don't have the suspension or sway bar to eliminate the body roll caused by the added grip). Here's hoping, my sway bars will take care of that body roll I previously experienced with more aggressive tires.

I haven't tried the SC3Rs but from what I can tell they're pretty close to Cup 2 when they provide ultimate grip (a couple laps maybe) and/or Toyo RR, Trofeo Rs.. Nasa also puts them in the same classification

From fastest the slowest the ultimate performance of the tires can be listed as this:
R7s >Z214-R1>TD221- RR-Cup2-Trofeo R-SC3R (RRs and SC3Rs should be more consistent throughout the session) > Nankang AR1>R888R>NT01-RE71R-R888 (old compound)> RS4-Goodyear Supercars (SS 1LE tires)

Longevity and resistance to HCs is another important thing of course . It really all comes down to your expectations and track experience I believe. I don't think with the stock suspension setup (on the SS1LE) we can see the full benefits of the extra grip but that shouldn't be an issue for ZLE since it's already tuned up for much grippy tires

[TrackClub]

Originally Posted by glamcem

Man that's a lot of reading, I thought I was too descriptive

Edit: I noticed that I didn't pay attention to the rake numbers, when calculating rake, we don't compare the overall diameters of say 18 vs 19" tires, for the actual ride height difference we use radius, in other words half the difference so the rake itself would be affected about .4 not .8"..that's very negligible in you think about in grand scheme of things, after a few sessions the weight in the gas tank would also affect some ride height difference too for instance

Keep in mind there are two things that are important if we're speaking Corvettes:
1- They're front and rear height adjustable and I have no doubt they neglected the consider all these factors and adjust the rake if it causes any issue. The guy in the video below (C7 Z07) is OCD about those details and would probably spend much more time than any of us, trust me
2- 345 RR tires in the back especially on a 13" wide wheels is quite a bit of tire. They swear their cars are very balanced not "piggy oversteer" or anything, adding some rake to a factory car wouldn't add tons of oversteer but maybe light oversteer which can be addressed with some alignment, height, tire pressure adjustments. For the reference, OEM C7 Z07 wheels and tires are 19x10 and 20x12 (vs 19x11 and 19x13" on their cars).


The guy in the first video (C7 GS) is the fastest among all of us, he's the local go kart champ, races with Miata and many other cars and has been tracking with his Lotus and Corvettes for years... They race with a Miata and shared stints with Randy Pobst too ..and guess what, they're lap times were identical at the Ridge.. that's not to say, they're in the same league with one and only Randy Pobst of course, just to give you an idea how much time they spent on that track and experience on different cars


Yes, I am aware of those lap times too but like I said above. In those tests GT2RS had Michelin Pilot Sport Cup 2 R N0 tires. However, when they use same Cup2 tires that lap time difference is smaller (so 5 seconds of difference would be maybe 2-3 seconds which also aligns with his data) . Of course GT2RS will always be faster but I think you missed the part when I said the guy who drove the GT2RS was a pro racer (they say Aussie Stig IIRC) not just some random dude on youtube and more importantly was on regular Cup2s not on those cheater tires I know, achieving the car's full or (9/10ths of potential) takes a lot of time for drivers like us but for a pro racer it only takes half a day maybe.

My friend was still 3 seconds behind that GT2RS. That wouldn't make him a pro driver but since this is our home track and he's also an instructor with tons of seat time on this track (including races), I think they're lap times would be pretty consistent. Lap times prove that too.

This is him doing the 1:48 at the ORP with RRs. The pro racer who did the 1:45 in a GT2RS was driving in 43F Ambient temps which is very close to his conditions (45F)





Please see above post for my correction of the tire sizes, 285/315.. not 325..it's still is also available but I agree it would be a bit too tall for being 20" I guess




You know, it's a never ending process

Thanks Cem! Ok a few things here that made me go down a wrong rat hole: apart from 315 vs 325 i thought your Vette buds run 18/19 combo vs 19/19. Obviously the latter wont affect the rake that much (and you're right re rake calc, albeit i took a quick and dirty comparo between OD of 19/20 stockers vs 18/19. Since they run 19s all around they are proly good (obviously based on the results).

Thanks for posting the vid, always fun to watch! Ya, i kinda figured your bud was not just an average amateur hpde guy and hence my comment that he could really wheel the car. That was quite obvious rather quickly. And yes, agree with your GT2 comparos now especially given regular cup2 vs RR. A no brainer.

I would say even top pros really work to nail a new venue. Half a day will hardly make them competitive. They usually spend days on sims, do detailed track walks, take notes, get intel, then log as many hrs as they can (even if not in an actual race car).
But, of course, they will become faster much quicker than an average amateur - zero question. One reason why is that they are already one with a car and can adjust their driving by what the car is telling them (to max the pace). An average amateur hardly understands that a car is actually trying to tell them something. And frankly most dont log sufficient seat time to learn the "language" to communicate with the car. But enough about that as for us it is mostly about having bags of fun!

PS Too bad RRs dont make 305/30/19. A real pity!

PSS +1 your last comment!

[TrackClub]

Originally Posted by glamcem

Have you clicked on the link? You can see them in that drop down menu. 285/30/20 and 315/30/20 RRs are also on Toyo's website. It also says "DOT COMPETITION TIRE" on those links too

https://www.toyotires.com/tire/patte...ires-proxes-rr

Also why don't you like the R888Rs? They're great tires if you ask me and should be the longest lasting out of the bunch. Yes they're about 1.5-2 seconds behind the RRs or even maybe even 3 seconds compared to R7s etc ..but they're great for mixed street/track use, for those who want longevity with still a bit more grip than RE71R or NT01, it's a great alternative IMO.

If the performance of the R888Rs are very similar to OEM SS 1LE tires, that still doesn't mean they're equal in performance but that's probably because we cannot fully utilize the added grip (because we don't have the suspension or sway bar to eliminate the body roll caused by the added grip). Here's hoping, my sway bars will take care of that body roll I previously experienced with more aggressive tires.

I haven't tried the SC3Rs but from what I can tell they're pretty close to Cup 2 when they provide ultimate grip (a couple laps maybe) and/or Toyo RR, Trofeo Rs.. Nasa also puts them in the same classification

From fastest the slowest the ultimate performance of the tires can be listed as this:
R7s >Z214-R1>TD221- RR-Cup2-Trofeo R-SC3R (RRs and SC3Rs should be more consistent throughout the session) > Nankang AR1>R888R>NT01-RE71R-R888 (old compound)> RS4-Goodyear Supercars (SS 1LE tires)

Longevity and resistance to HCs is another important thing of course . It really all comes down to your expectations and track experience I believe. I don't think with the stock suspension setup (on the SS1LE) we can see the full benefits of the extra grip but that shouldn't be an issue for ZLE since it's already tuned up for much grippy tires

Cem, for the record (and to continue to entertain the audience lol!) I disagree with your ultimate tire list. Plus ya forgot about A7 There is no way Cup2 is faster than G3R for one. There are others but i will keep them to myself

I also disagree that an SS (or ZL1) doesn't respond well to sticky tires. Take a look at fastest laps thread. Many folks have zero suspension mods and successfully run dot and even full slicks on otherwise stock cars. And id say some of the laptimes are stunning.

Lastly, if ya think softly sprung car cant take advantage of grippy tires, watch Nascar CUP race on a road course.

Cheers!

[glamcem]

Originally Posted by TrackClub

Thanks Cem! Ok a few things here that made me go down a wrong rat hole: apart from 315 vs 325 i thought your Vette buds run 18/19 combo vs 19/19. Obviously the latter wont affect the rake that much (and you're right re rake calc, albeit i took a quick and dirty comparo between OD of 19/20 stockers vs 18/19. Since they run 19s all around they are proly good (obviously based on the results).

Thanks for posting the vid, always fun to watch! Ya, i kinda figured your bud was not just an average amateur hpde guy and hence my comment that he could really wheel the car. That was quite obvious rather quickly. And yes, agree with your GT2 comparos now especially given regular cup2 vs RR. A no brainer.

I would say even top pros really work to nail a new venue. Half a day will hardly make them competitive. They usually spend days on sims, do detailed track walks, take notes, get intel, then log as many hrs as they can (even if not in an actual race car).
But, of course, they will become faster much quicker than an average amateur - zero question. One reason why is that they are already one with a car and can adjust their driving by what the car is telling them (to max the pace). An average amateur hardly understands that a car is actually trying to tell them something. And frankly most dont log sufficient seat time to learn the "language" to communicate with the car. But enough about that as for us it is mostly about having bags of fun!

PS Too bad RRs dont make 305/30/19. A real pity!

PSS +1 your last comment!

You're very welcome but I made another typo ahah ..sorry man, my kids were pushing by buttons when typing (fighting, screaming) and I accidentally said 19x11 ..it should be 18x11" . They have 18x11" F and 19X13" R with 315/30/18 and 345/30/19 respectively (both have RRs and R7s on the same sizes) .. With R7 the rake is smaller because the overall rear diameter is smaller than the RRs.. However, like I said the effect of the rake is still about .4" which is very small. On top of that, they also both decreased the front ride height about 5mm so when you add that it becomes about 15mm rake.

One would think it would add some oversteer but that wasn't the case for them. My friend with the GS is a bit faster than all of us and so his driving style also requires some corrections as he pushes the car to its very limits. At the ridge (same day) GS was still faster than the Z07 by about 1 second.The Z07 driver ,however, is smoother and much more seat time at the ORP so his 1:48 at there is very very competitive and much faster than the GS at the moment. We are all planning to go to the ORP (Viper, Z07, GS and my SS 1LE with all of us running Toyo RR tires) it would be a nice opportunity to get tons of data points

I agree with pro driver comments btw

[glamcem]

Originally Posted by TrackClub

Cem, for the record (and to continue to entertain the audience lol!) I disagree with your ultimate tire list. Plus ya forgot about A7 There is no way Cup2 is faster than G3R for one. There are others but i will keep them to myself

I also disagree that an SS (or ZL1) doesn't respond well to sticky tires. Take a look at fastest laps thread. Many folks have zero suspension mods and successfully run dot and even full slicks on otherwise stock cars. And id say some of the laptimes are stunning.

Lastly, if ya think softly sprung car cant take advantage of grippy tires, watch Nascar CUP race on a road course.

Cheers!

You are correct about the A6 tires they're definitely faster but so are the BFG R1S tires too since they're both sprint/autox tires I didn't think about them listing but yeah you can put them at the beginning (along with some good condition slicks maybe, they performed similar to fresh R7s in our experience)

Also, I should've mentioned that the ones with dashes between are the same category, similar "ultimate" lap time tires..my bad (I say ultimate because their characteristics and longevity may differ) so just ignore the order of them ..you may just use the greater sign as a reference. Within the same group (NASA point classification) they should be within few tenths to each other since the difference between RR and R7 is already about 1-1.5 seconds ...and the difference between RRs and R888Rs are maybe another 1-1.5 seconds, the margins are very tight between them so they're not cumulative ..in other words R7s are not a whole 5-6 seconds faster than say R888Rs or NT01s, they overlap each other .

Like I said I have no first hand experience with the SC3R tires but I am willing to test them some time, the only thing that keeps me getting a 19" ZLE spec set is, those are the only available tires that makes sense to me for size, performance, price.. I don't see any good option with say 315 or 325/30/19 "..on 18" sizes however there are tons of options for 295/315/30/18 sizes.

Since they introduced the SC3Rs as direct competitors of Cup2s and magazines and some online forums repeat the same I figured they would fall somewhere between R888R and R7s just like the RR, TD221, Cup2s, Trofero Rs..maybe marginally faster than others in the group I don't know.

Btw, the lap times will be faster but we cannot make sure if it's the tire compound only, unless they're used on the very same wheels and tire sizes, since most of the time we opt for smaller, lighter wheels .they also greatly affect the overall lap time even with that my lap times were only about 2 seconds faster with. For instance I did a better lap time with both used slicks and Trofeo Rs but car's feel sucked .. I knew that it was because of the added grip and body roll, I am surprised you never experienced that. Ryephelie for instance improved his lap times after switching to sway bars when he started using those SC3Rs which makes sense that alone tells me our softer setup is specifically designed to work with OEM tires and it needs more sway/spring when we add more tire. It was the case for any other car, I think Camaro is no different.

[GunMetalGrey]

Thanks Cem, I’m not sure what Toyo site I was looking at! Must have been the Canadian version, and this is the American version, but it looks like I’d still have to find a distributor to get these since it doesn’t look like they sell directly from this website. Know anyone?

The instructors at my local track say the Trofeo R is 1.5 seconds faster per lap than the Cup 2; that’s on a tight technical track that takes about 1:20 to 1:30 to complete per lap.

I’d be surprised if the SCR3 isnt faster than the cup 2 as well with grip level more like the Trofeo R.

I just installed YYZ performance springs in my car to help with the body roll but haven’t touched the sway bars yet.
Likely going to try those Spherical bushings for the radius bars, I’m surprised no one else has yet!

[TrackClub]

Originally Posted by glamcem

You are correct about the A6 tires they're definitely faster but so are the BFG R1S tires too since they're both sprint/autox tires I didn't think about them listing but yeah you can put them at the beginning (along with some good condition slicks maybe, they performed similar to fresh R7s in our experience)

Also, I should've mentioned that the ones with dashes between are the same category, similar "ultimate" lap time tires..my bad (I say ultimate because their characteristics and longevity may differ) so just ignore the order of them ..you may just use the greater sign as a reference. Within the same group (NASA point classification) they should be within few tenths to each other since the difference between RR and R7 is already about 1-1.5 seconds ...and the difference between RRs and R888Rs are maybe another 1-1.5 seconds, the margins are very tight between them so they're not cumulative ..in other words R7s are not a whole 5-6 seconds faster than say R888Rs or NT01s, they overlap each other .

Like I said I have no first hand experience with the SC3R tires but I am willing to test them some time, the only thing that keeps me getting a 19" ZLE spec set is, those are the only available tires that makes sense to me for size, performance, price.. I don't see any good option with say 315 or 325/30/19 "..on 18" sizes however there are tons of options for 295/315/30/18 sizes.

Since they introduced the SC3Rs as direct competitors of Cup2s and magazines and some online forums repeat the same I figured they would fall somewhere between R888R and R7s just like the RR, TD221, Cup2s, Trofero Rs..maybe marginally faster than others in the group I don't know.

Btw, the lap times will be faster but we cannot make sure if it's the tire compound only, unless they're used on the very same wheels and tire sizes, since most of the time we opt for smaller, lighter wheels .they also greatly affect the overall lap time even with that my lap times were only about 2 seconds faster with. For instance I did a better lap time with both used slicks and Trofeo Rs but car's feel sucked .. I knew that it was because of the added grip and body roll, I am surprised you never experienced that. Ryephelie for instance improved his lap times after switching to sway bars when he started using those SC3Rs which makes sense that alone tells me our softer setup is specifically designed to work with OEM tires and it needs more sway/spring when we add more tire. It was the case for any other car, I think Camaro is no different.

Zero question imo that G3R are head and shoulders above Cup2s. While i haven't tried the former i have tried the latter and the car wasnt any faster than stock G3s.

Can't recall exact details of Ryephile's set up, but suspect it had much to do with the car's balance and tire wear, as the aftermarket wheels have different offsets. But wont speculate here.

2 seconds per average lap is a terrific result. Dont forget GM put Trofeos on Gen5 Z28 and they were largely responsible for its fantastic pace. Yet Gen6 SS 1LE beat it at Laguna on G3s and less power...

As far as stock SS 1LE (or ZL1) suspension and sticky tires...there is plenty of recorded evidence of the fact that nothing else has to be changed to gain tons of pace as long as the driver can push the car to its new (much higher) limits. Provoste is the best example of that, but there are plenty of others running DOT slicks with great results on stock cars. Sure, smaller wheels will reduce the weight a bit and lower thr gearing, but largely it is the rubber that makes the difference where it counts: in the corners...

I do have experience running sticky tires on my c5z and when i went with stiffer sways my outside front tire got pulvarized in a day as weight transfer was occuring way too quickly. On advice of my mechanic (a Grand Am champion with a record 37 wins, who was sponsored by GM), i went back to softer sways and everything was peachy. Many race cars are set up for softer compliance, yet they all run uber slicks.

Speaking of sways and springs: your C7 buds...you said they run stock cars. Do they? Or did they mod their suspensions to run R7 and RR?

Cheers!

[TrackClub]

Originally Posted by GunMetalGrey

Thanks Cem, I’m not sure what Toyo site I was looking at! Must have been the Canadian version, and this is the American version, but it looks like I’d still have to find a distributor to get these since it doesn’t look like they sell directly from this website. Know anyone?

The instructors at my local track say the Trofeo R is 1.5 seconds faster per lap than the Cup 2; that’s on a tight technical track that takes about 1:20 to 1:30 to complete per lap.

I’d be surprised if the SCR3 isnt faster than the cup 2 as well with grip level more like the Trofeo R.

I just installed YYZ performance springs in my car to help with the body roll but haven’t touched the sway bars yet.
Likely going to try those Spherical bushings for the radius bars, I’m surprised no one else has yet!

Ditto here on the RR stock sizes in 20s. There seems none offered on the websites i visited and our Canadian Toyo website only lists 285 as the only choice offered. So that is proly a no go. Also, they seem much more $ vs G3Rs. Perhaps on par with Trofeos? Damn sure i wont be spending that kind of coin just to go faster, especially that i am already pretty happy with my pace.

Fyi there is zero evidence that yyz springs help with pace on a track and I recall somebody posting a test result here that suggested to the contrary and they swapped them out. Apart from the sways to fine tune balance (such as with different wheel offsets), switching up a single suspension component is not a good idea, as they are all calibrated to work in concert. When serious folks mod suspensions they buy springs AND dampers that are designed to work together, as the latter's job is to control the former. Folks that just lower the cars, do so mostly for cars and coffee visual effect. That's perfectly fine for the street, but not track, were balance is key.

Lastly, given you have 5 (or so?) track days behind your belt, please trust me (and please dont get offended) it really is way too early to be messing with one of the best platforms ever engineered (bar none). No matter what tires you run, you have one of the best handling cars ever produced. Spend your money on seat time and coaching. It will produce the biggest gains in your pace. Guaranteed. Cheers!

[TrackClub]

Here's a 6min vid from best pros, describing how suspension works in a nutshell.
They have a great YouTube channel and ive been subscribing for years: highly recommended.
They also have other, more indepth vids on the subject, should you desire to study it further.

Note their comments about all the components needing to work together. With your new springs you'll be changing not only the rates, but also balance F vs R, including ride height and possibly rake. This will have a direct effect on the car's balance. In addition, the effectiveness of your excellent MRC shocks, which have been developed for specific spring rates and ride height will certainly be affected as well. As i said earlier, it is a bad idea to switch up either springs, or shocks in isolation and that's why any top shelf racing shop sells them as sets, specifically designed to work together.
Of course, adjustable shocks are yet another choice, albeit one has to be schooled in what such adjustments do for both bump and rebound functions and at either end of the car - to dial them up right. Books have been written on this complex subject by highly accomplished crew chiefs. Lastly, note the very last comments in the vid re rubber stops.

Anyhow, here's the link. Cheers!

[glamcem]

Originally Posted by GunMetalGrey

Thanks Cem, I’m not sure what Toyo site I was looking at! Must have been the Canadian version, and this is the American version, but it looks like I’d still have to find a distributor to get these since it doesn’t look like they sell directly from this website. Know anyone?

The instructors at my local track say the Trofeo R is 1.5 seconds faster per lap than the Cup 2; that’s on a tight technical track that takes about 1:20 to 1:30 to complete per lap.

I’d be surprised if the SCR3 isnt faster than the cup 2 as well with grip level more like the Trofeo R.

I just installed YYZ performance springs in my car to help with the body roll but haven’t touched the sway bars yet.
Likely going to try those Spherical bushings for the radius bars, I’m surprised no one else has yet!

Are you able to see this below link and order from them? With the 8% coupon 315/30/20 RRs are even cheaper than the stockers

https://trackdaytire.com/product/toyo-proxes-rr/



Speaking of Cup2 vs G3R tires lap times, it tells me something is off. 1.5 seconds on a short track like that is huge and it would put them in RR or Z214 league which I doubt. Keep in mind I was referring to ultimate lap time not average lap time. Cup2s have pretty steep performance curve when they reach the optimal temps you have 2 or so laps to put it down the PB and then the performance falls. That's the reason why in magazine tests it's not an issue, they can easily put the good performance metrics and lap times since they typically do a couple hot laps but for normal track use, real world conditions they/re not desirable. Also, Cup 2 tires are about 1.5 seconds faster than the previous cup tires. Additional 2 seconds on top of that would put them in R6, Z214s territory which I highly doubt .Maybe those tires didn't work well for the given setup and conditions or they're already HC'd out?

Some good info for NASA Time Trial Class Rules and tire pointing system:

https://www.camaro5.com/forums/showthread.php?t=393436

[glamcem]

Originally Posted by TrackClub

Zero question imo that G3R are head and shoulders above Cup2s. While i haven't tried the former i have tried the latter and the car wasnt any faster than stock G3s.

Can't recall exact details of Ryephile's set up, but suspect it had much to do with the car's balance and tire wear, as the aftermarket wheels have different offsets. But wont speculate here.

2 seconds per average lap is a terrific result. Dont forget GM put Trofeos on Gen5 Z28 and they were largely responsible for its fantastic pace. Yet Gen6 SS 1LE beat it at Laguna on G3s and less power...

As far as stock SS 1LE (or ZL1) suspension and sticky tires...there is plenty of recorded evidence of the fact that nothing else has to be changed to gain tons of pace as long as the driver can push the car to its new (much higher) limits. Provoste is the best example of that, but there are plenty of others running DOT slicks with great results on stock cars. Sure, smaller wheels will reduce the weight a bit and lower thr gearing, but largely it is the rubber that makes the difference where it counts: in the corners...

I do have experience running sticky tires on my c5z and when i went with stiffer sways my outside front tire got pulvarized in a day as weight transfer was occuring way too quickly. On advice of my mechanic (a Grand Am champion with a record 37 wins, who was sponsored by GM), i went back to softer sways and everything was peachy. Many race cars are set up for softer compliance, yet they all run uber slicks.

Speaking of sways and springs: your C7 buds...you said they run stock cars. Do they? Or did they mod their suspensions to run R7 and RR?

Cheers!

Yes they run stock cars but with Z07 package spring rates, sway bars and MRC tune (as well as the ABS programming) change dramatically compared to non-Z07 cars as they're already tuned to run with Cup 2s.

I am surprised the fact that you experienced outside front tire wear after the sway bar install. The whole purpose of sway bar install is to eliminate that outer wear caused by the body roll and to defeat the slower weight transfer. Maybe with the amount of confidence (more flat feel) you ended up driving harder? or somehow your alignment changed during that (not enough camber or whacked toe)? I am pretty sure something was not right.

Sway bars are more of a necessity on regular Z51 cars as they don't have stiffer suspension. My friend who switched to sway bars and LG coils ended up shaving his lap times by 6 seconds when had a Z51 (before the Z06 Z07)!! that's a lot and his outer tire wear definitely improved since less roll on them. I have to add though that huge lap time difference also happened since he increased the front tire size to 315 feom 245 and he replaced the leaf suspensions with LG coils.. the effect would be much smaller on our cars of course. With the 315s his car also felt like a boat haha

Take a look at this photo , the only difference is LG sways



Ryephile also mentions that his lap times improved but he didn't like the G3Rs as much ..

take a look at below:

https://www.camaro6.com/forums/showp...&postcount=125

and

https://www.camaro6.com/forums/showp...&postcount=139

Like I said, better lap times don't always translate to better car feel. Gearing and rotational mass changes greatly improve the trap speeds and overall acceleration that also shaves seconds