Tramlining
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Tramlining
I have now put over 1000 miles on my new 406 SBC and upgraded wheels (17 inch wheels with 255/50/R17 Nitto G555 tires). The 406 is absolutely fantastic, and is everything I wanted and needed in torque / power. The Corvette is happy!!!
As for the wheels, I sense there is more traction, and minor better handling overall. Its hard to compare directly, but I suspect I would have been spinning tire with my 15 Coopers (8 inch tread) when the Nitto's (10 inch tread) are not, on the many hard launches I seem to do now!!! (its addicting).
BUT......what I do notice with these tires is "tramlining". Tire America has a good description of this on their website, and causes for it, but it is essentially that with the wider / stiffer tires, there is more a tendency for the car to seek out the low spots / valleys in the road. That has become very obvious with these tires versus my previous 225/70/R15 tires that only had 8 inches of tread. I also had the problem with my first set of tires, which were also wider Goodrich Radial TA 225/60/R15.....same problem. When I went with the narrower tires, the problem went away for the most part. PA roads are notorious for this problem, and on the worst roads, the car is hunting all over the place. On better roads, its not doing this and is solid. On good sweeper roads.....I can dial in the turns with just pressure on the steering wheel and go as fast as I can dare.....solid..
Right now I am willing to live with it, and realize that the pros exceed the cons. But my question to the forum is.......is there anything I can do about it? Or is it just the nature of the wider / stiffer tires.
As for the wheels, I sense there is more traction, and minor better handling overall. Its hard to compare directly, but I suspect I would have been spinning tire with my 15 Coopers (8 inch tread) when the Nitto's (10 inch tread) are not, on the many hard launches I seem to do now!!! (its addicting).
BUT......what I do notice with these tires is "tramlining". Tire America has a good description of this on their website, and causes for it, but it is essentially that with the wider / stiffer tires, there is more a tendency for the car to seek out the low spots / valleys in the road. That has become very obvious with these tires versus my previous 225/70/R15 tires that only had 8 inches of tread. I also had the problem with my first set of tires, which were also wider Goodrich Radial TA 225/60/R15.....same problem. When I went with the narrower tires, the problem went away for the most part. PA roads are notorious for this problem, and on the worst roads, the car is hunting all over the place. On better roads, its not doing this and is solid. On good sweeper roads.....I can dial in the turns with just pressure on the steering wheel and go as fast as I can dare.....solid..
Right now I am willing to live with it, and realize that the pros exceed the cons. But my question to the forum is.......is there anything I can do about it? Or is it just the nature of the wider / stiffer tires.
Last edited by Shovels and Vettes; May 22, 2021 at 08:41 PM.
Popular Reply
Jun 13, 2021, 09:27 AM
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Update.......I have put over 2000 miles on the 17 inch tires these last few months. With all the associated tramlining issues, I decided to reinstall my original YJ8 wheels, with 225/70/R15 Cooper tires, and drive it for comparison. Attempting to avoid any intentional bias / opinion, here are the notable differences I have perceived, starting with most significant to least significant. I also want to qualify that all of this is based on taking lots of curvy Pennsylvania two lanes roads at 50 - 70 mph. These are the speeds that I drive regularly and on these roads anything faster is just dangerous, and irresponsible, and 10-15 mph above the posted speed limits. Nothing I write below applies to speeds above these speeds as it is irrelevant to me.
- Tramlining and bump steering is now completely non-existent with the 15 inch tires. On many Pennsylvania roads I drive on regularly, the ruts / grooves moved the car dramatically with the wider 17 inch tires, and it caused a significant and bothersome movement of the car, requiring more driving attention and reactions. The bump steer was also very annoying and more noticeable. The tramlining and increased bump steer caused by these 17, 10 inch wide tires, made the experience of driving the car borderline unacceptable to me, and made the car feel less controllable. It is THE #1 reason I will not continue using these 17 inch / wider tires. FYI - I had the same experience with the first tires I had on the car, which were 255/60/R15 Goodrich Radial TA tires. So, IMO, this tramlining is a result of the wider 10 inch tread on the ground versus the 8 inch tread of the 225/70/R15 tires, not the diameter or speed ratings or any alignment specs.
- Ride comfort is better with the 15 inch tires. Bumps, ruts, etc. feel slightly less harsh with the 15 inch tires. But....the difference between the 15 inch and 17 inch tires is not significant, and I would be content with the ride of the 17 inch tires.
- Handling is better with the 17 inch tires. As predictable, have 10 inches of rubber on the ground, versus 8 inch, as well as the lower height sidewall, and better rubber, makes the 17 inch tires perform better in faster turns. With the same movement of the steering wheel, the 17 inch tires respond immediately, whereas there is a slight feel of sidewall flex on the 15 inch tires. The initial dive into the turn comes with a slight sense of body movement on the 15 inch tires, but then once that is passed, the 15 inch tires have no problem gripping and making the turns. With the 17 inch tires, the car is capable of faster entry and faster speeds in turns. However.......this is not to suggest that the 15 inch tires are reaching their limits, or is bordering on loss of control. I powered through many tight turns with the 15 inch tires, and the car handled it perfectly, and I never felt I was on the verge of spinning out.
- The 15 inch tires handled the torque of the 406 without spinning the tires, at the power launches that I am going to make. I had concerns about this when I installed the torquey 406, and was one main reason I decided to buy the 17 inch tires. I have no doubt I could spin the 15 inch tires in multiple gears, and I have no doubt that the 17 inch 10 inch tread tires would handle that torque better.....BUT, I simply am not interested in high power, clutch dump maneuvers. I will never do burnouts.....I consider that abuse, and I don't abuse my machines. My goal with the 406 is focused on smooth, high torque acceleration, not burning rubber......and it turns out the 15 inch tires handle that more than adequately. The other bonus is that the 15 inch tires protect the driveline from abuse....as they will spin before they apply the loads to the hardware.
- The last issue is "the look", and this is purely a personal taste choice. As much as I like the look of the American Racing Torq Thrust wheels, the factory YJ8 aluminum wheels look absolutely perfect on the car. Secondly, the white letters also add a detail that the 17 inch tires were missing, and made the car look more plain. Lastly, the fat sidewall look of the 15 inch tires look "right" for a C3......its what they came with, and that look is the look I fell in love with as a teenager. I would NEVER install 18 inch wheels because IMO, they just take away the look. The 17 inch wheels were an acceptable compromise, but still not the look of the 15's.
In summary, the word that comes to mind is "compromise". This experiment proved to me that there is no perfect solution, both 15 and 17 inch tires had good things, and bad. Ultimately, the 15 inch tires are my choice. I give up a small amount of handling capacity, which I admit is a significant factor in a sports car. But truth is, at the speeds and roads I drive, this small compromise in handling capacity does not offset the downsides of excessive tramlining. On better roads, and higher speeds in turns, the 17 inch tires do perform better, and if I lived in a place with better roads, maybe I would stick with 17's. But given the 15 inch tires provide 100% of my handling needs........this compromise is irrelevant. I think I notice it now, with the sudden switch of tires,.....but as I drive more, it will just be the handling that I get used to.
The tramlining and bump steering was really annoying and took alot of fun out of the car for me. It felt less controllable, as the car was being driving by the ruts, and that was unacceptable to me. Now, with the 15 inch tires, the car tracks perfectly on all the roads I drive on, and I can relax and enjoy it. In the end, the goal is to have an enjoyable experience driving the car, and the 15 inch tires do that better, for me. Big bonus is that it looks perfect. So.....I will be selling the 17 inches / Torq Thrust wheels.
And when I build the 69 with the big block.....it will have 15 inch Rallye wheels....decision done, no further experimentation required.
- Tramlining and bump steering is now completely non-existent with the 15 inch tires. On many Pennsylvania roads I drive on regularly, the ruts / grooves moved the car dramatically with the wider 17 inch tires, and it caused a significant and bothersome movement of the car, requiring more driving attention and reactions. The bump steer was also very annoying and more noticeable. The tramlining and increased bump steer caused by these 17, 10 inch wide tires, made the experience of driving the car borderline unacceptable to me, and made the car feel less controllable. It is THE #1 reason I will not continue using these 17 inch / wider tires. FYI - I had the same experience with the first tires I had on the car, which were 255/60/R15 Goodrich Radial TA tires. So, IMO, this tramlining is a result of the wider 10 inch tread on the ground versus the 8 inch tread of the 225/70/R15 tires, not the diameter or speed ratings or any alignment specs.
- Ride comfort is better with the 15 inch tires. Bumps, ruts, etc. feel slightly less harsh with the 15 inch tires. But....the difference between the 15 inch and 17 inch tires is not significant, and I would be content with the ride of the 17 inch tires.
- Handling is better with the 17 inch tires. As predictable, have 10 inches of rubber on the ground, versus 8 inch, as well as the lower height sidewall, and better rubber, makes the 17 inch tires perform better in faster turns. With the same movement of the steering wheel, the 17 inch tires respond immediately, whereas there is a slight feel of sidewall flex on the 15 inch tires. The initial dive into the turn comes with a slight sense of body movement on the 15 inch tires, but then once that is passed, the 15 inch tires have no problem gripping and making the turns. With the 17 inch tires, the car is capable of faster entry and faster speeds in turns. However.......this is not to suggest that the 15 inch tires are reaching their limits, or is bordering on loss of control. I powered through many tight turns with the 15 inch tires, and the car handled it perfectly, and I never felt I was on the verge of spinning out.
- The 15 inch tires handled the torque of the 406 without spinning the tires, at the power launches that I am going to make. I had concerns about this when I installed the torquey 406, and was one main reason I decided to buy the 17 inch tires. I have no doubt I could spin the 15 inch tires in multiple gears, and I have no doubt that the 17 inch 10 inch tread tires would handle that torque better.....BUT, I simply am not interested in high power, clutch dump maneuvers. I will never do burnouts.....I consider that abuse, and I don't abuse my machines. My goal with the 406 is focused on smooth, high torque acceleration, not burning rubber......and it turns out the 15 inch tires handle that more than adequately. The other bonus is that the 15 inch tires protect the driveline from abuse....as they will spin before they apply the loads to the hardware.
- The last issue is "the look", and this is purely a personal taste choice. As much as I like the look of the American Racing Torq Thrust wheels, the factory YJ8 aluminum wheels look absolutely perfect on the car. Secondly, the white letters also add a detail that the 17 inch tires were missing, and made the car look more plain. Lastly, the fat sidewall look of the 15 inch tires look "right" for a C3......its what they came with, and that look is the look I fell in love with as a teenager. I would NEVER install 18 inch wheels because IMO, they just take away the look. The 17 inch wheels were an acceptable compromise, but still not the look of the 15's.
In summary, the word that comes to mind is "compromise". This experiment proved to me that there is no perfect solution, both 15 and 17 inch tires had good things, and bad. Ultimately, the 15 inch tires are my choice. I give up a small amount of handling capacity, which I admit is a significant factor in a sports car. But truth is, at the speeds and roads I drive, this small compromise in handling capacity does not offset the downsides of excessive tramlining. On better roads, and higher speeds in turns, the 17 inch tires do perform better, and if I lived in a place with better roads, maybe I would stick with 17's. But given the 15 inch tires provide 100% of my handling needs........this compromise is irrelevant. I think I notice it now, with the sudden switch of tires,.....but as I drive more, it will just be the handling that I get used to.
The tramlining and bump steering was really annoying and took alot of fun out of the car for me. It felt less controllable, as the car was being driving by the ruts, and that was unacceptable to me. Now, with the 15 inch tires, the car tracks perfectly on all the roads I drive on, and I can relax and enjoy it. In the end, the goal is to have an enjoyable experience driving the car, and the 15 inch tires do that better, for me. Big bonus is that it looks perfect. So.....I will be selling the 17 inches / Torq Thrust wheels.
And when I build the 69 with the big block.....it will have 15 inch Rallye wheels....decision done, no further experimentation required.
Burning Brakes
Joined: Jul 2018
Posts: 875
Likes: 289
From: LaFayette Georgia
C3 of Year Finalist (performance mods) 2019
St. Jude Donor '19
I used Global West upper control arms to gain the caster desired.
Last edited by 74_stingray; May 19, 2021 at 07:15 AM.
Racer
Joined: Oct 2001
Posts: 474
Likes: 64
From: Portage La Prairie Manitoba
Had the same problem on my 81...steered straight and tracked good at lower speeds but became a challenge above 90 mph.Wider tires will amplify the problem.
Never did resolve it sold the car.Let us know if the wheel alignment resolves it... until then be careful!
Never did resolve it sold the car.Let us know if the wheel alignment resolves it... until then be careful!
Race Director
Joined: Nov 2006
Posts: 13,197
Likes: 7,795
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Agreed, with stock control arms shimmed right out, your lucky to get 3.5 -3.7 caster. offset upper control arm shafts or after market arms. you want to get out to about 6 caster.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,181
Likes: 9,317
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
sounds like driving with old bias ply tires
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Caster
So....solution, more caster and go back to power steering. Yeah.....not going back to power steering. I love the feel of the manual steering, and if I have to live with road ruts, I guess I will.....OR, I will put my 15 inch tires back on the car if it bugs me that much. Everything is a compromise.
Last edited by Shovels and Vettes; May 19, 2021 at 08:06 AM.
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
90 mph
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Not Going to Happen
What I do know is that with the Cooper 225/70/R15 tires, the car was noticeably more comfortable on the PA roads, and the tramlining essentially went away. And I still could take ALL the curves at speeds that I was content with. Truth is, with those tires, the car was more enjoyable to drive......which is the point. Theoretical performance on a race track is irrelevant. I have tried these big wheel, modern rubber tires, and now I have this tramlining. So.....not sure now. Time will tell what I do. But there will be no power steering conversions, and not really interested in cranking up caster so high that the steering effort is uncomfortable. Right now, the steering effort is almost unnoticeable.
Last edited by Shovels and Vettes; May 19, 2021 at 08:02 AM.
Race Director
Joined: Jul 2018
Posts: 10,558
Likes: 8,356
From: San Antonio, TX/Mahopac, NY
2024 Corvette of the Year Finalist - Modified
2024 Corvette of the Year Finalist - Unmodified
2023 C7 of the Year Winner - Modified
So, you ask for solutions to adjust your car to accommodate crappy road conditions and then reject every solution including good suggestions to help your cause. Based on this, just go back to the narrow 15” radials you were running before and be happy.
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Meany
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Another thing to consider is the toe.....excessive toe out will make one wheel always hunt for straight and this will swap a thousand times going down the road.....this feels like the car is "hunting"....and is amplified by wide, low profile tires......
Going to the max camber (3.5 to 3.7) as stated above will not increase the steering effort that much........if it does then hit the gym.
If the car hunts with the 17's and not with the 15's then using the 15's isn't solving the problem...it is just crutching it....
I drove a 2018 Dodge Demon on PA roads last October. 0-100 MPH in 5 seconds......and 5 seconds is about all you want to do because there is not a stretch of straight, flat road to save your *** within a 100 mile radius.......I was getting nervous and this is on of the most capable street cars on the planet......so I know what you are saying there.
Also....do not overlook the rear.....whacked out rear alignment can make the car seem like the front is bad........and again, it is amplified by flat, wide tires......it is easy to get the camber at 0 but not so to get the rear wheels pointing straight, and this is OFTEN overlooked.......
Jebby
Jebby
Going to the max camber (3.5 to 3.7) as stated above will not increase the steering effort that much........if it does then hit the gym.
If the car hunts with the 17's and not with the 15's then using the 15's isn't solving the problem...it is just crutching it....
I drove a 2018 Dodge Demon on PA roads last October. 0-100 MPH in 5 seconds......and 5 seconds is about all you want to do because there is not a stretch of straight, flat road to save your *** within a 100 mile radius.......I was getting nervous and this is on of the most capable street cars on the planet......so I know what you are saying there.
Also....do not overlook the rear.....whacked out rear alignment can make the car seem like the front is bad........and again, it is amplified by flat, wide tires......it is easy to get the camber at 0 but not so to get the rear wheels pointing straight, and this is OFTEN overlooked.......
Jebby
Jebby
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
Zero scrub radius.... with the wider tires and rims the 'scrub radius' is OUTSIDE of the centerline of the wheel bearing center.. This causes tramlining. This also contributes to bump steer.
Unkahal
Unkahal
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 971
From: Tennessee/Rhode Island
Some good suggestions above about alignment and making sure that ALL suspension components are in top shape, no room for worn suspension or steering components with ultra high performance 17 inch tires, which will magnify bad suspension components and poor alignment. Highly recommend a front spreader bar as well. Aftermarket control arms with poly upper and lower control arm bushings will help as well.
Sent you a PM
Sent you a PM
Last edited by jb78L-82; May 21, 2021 at 06:04 PM.
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
I have a Speed Direct spreader bar. All control arm bushings were new rubber when I rebuilt the car four years ago, so they have about 18,000 miles on them. Idler arms, ball joints, tie rod bushings were also new rubber when I rebuilt the car. You suggested to me several years ago I switch my front sway bar bushings to poly, and I did, when I added the factory 7/16 rear sway bar on the car. So....unless this stuff is too old or worn out, I have already done what you suggested. I really am not interested in completely rebushing everything right now. It was all Moog stuff, and I hope its not worn out in 18,000 miles.
Frankly,on nice roads, i.e. not the worst roads I drive on in PA, the car tracks perfectly. Its only on very rutted or rough roads that I get much hunting. Its not enough of an issue for me to start making major repairs or major rebuild work. Summer has just begun......I lost all last summer with the new engine build, so whatever it is, I am running it. I might consider poly bushings on the control arms this coming winter.....maybe.
As for alignment, I have had enough of paying people who really don't want to spend the time to do it right. I am going to start collecting the equipment Cagotzman uses, and will do my own alignments. If I can do minor tweaks now, experimenting, I might do that. It tracks straight most of the time, with any pulling. Tough again to tell on the roads of PA.....the never ending pitch and slope changes, as well as curves, potholes, ruts, and genuinely bad roads.
I actually got a decent alignment two years ago....and had to tweak it a little after the fact. With the 15 inch wheels and tires, it was tracking perfectly, it rode well, and did NOT tramline at all. One reason I like the 225/70R15 Cooper tires.....no matter what people want to say about them, the car rode well, tracked well, and handled every single curve I took at the speeds I can comfortably drive in PA. Sometimes I think that people try to build race cars, and never actually put them on the track.....so it all for nothing. I am having mixed feelings now about spending the money on these 17 inch wheels and tires. If the 17 inch wheels with Nitto G555 tires is better at handling......its only by a small margin.
My biggest concern with the 15 inch tires was not handling......it was the torque / traction with the 406.
Thanks for the suggestions.
Frankly,on nice roads, i.e. not the worst roads I drive on in PA, the car tracks perfectly. Its only on very rutted or rough roads that I get much hunting. Its not enough of an issue for me to start making major repairs or major rebuild work. Summer has just begun......I lost all last summer with the new engine build, so whatever it is, I am running it. I might consider poly bushings on the control arms this coming winter.....maybe.
As for alignment, I have had enough of paying people who really don't want to spend the time to do it right. I am going to start collecting the equipment Cagotzman uses, and will do my own alignments. If I can do minor tweaks now, experimenting, I might do that. It tracks straight most of the time, with any pulling. Tough again to tell on the roads of PA.....the never ending pitch and slope changes, as well as curves, potholes, ruts, and genuinely bad roads.
I actually got a decent alignment two years ago....and had to tweak it a little after the fact. With the 15 inch wheels and tires, it was tracking perfectly, it rode well, and did NOT tramline at all. One reason I like the 225/70R15 Cooper tires.....no matter what people want to say about them, the car rode well, tracked well, and handled every single curve I took at the speeds I can comfortably drive in PA. Sometimes I think that people try to build race cars, and never actually put them on the track.....so it all for nothing. I am having mixed feelings now about spending the money on these 17 inch wheels and tires. If the 17 inch wheels with Nitto G555 tires is better at handling......its only by a small margin.
My biggest concern with the 15 inch tires was not handling......it was the torque / traction with the 406.
Thanks for the suggestions.
Last edited by Shovels and Vettes; May 21, 2021 at 09:21 PM.
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 971
From: Tennessee/Rhode Island
Thanks for the details on what you have done. One area you did not mention is the rear suspension?
Are your rear trailing arm bushings new and do your rear wheel bearings have the factory runout or less? Are you running adjustable heim jointed competition type rear struts which allow zero rear camber changes from that part of the rear suspension. Also, are you 100% sure about the condition of the manual steering box and associated links (rag joint?) and check your lower front ball joints for wear since that part can and will wear out early since it absorbs tremendous forces (made worse by poor quality roads). If your suspension is not in 100% tip top shape (or better with additional modern parts), a 255/45-50/17-18 inch ultra high performance summer only tire will expose any and all weaknesses!
Something seems not correct if your Cooper 225/70/15 tires gave you most of the grip of a 255/45/17 ultra high performance tire although I must say there are big differences with certain tires on cars, meaning I have no experience with Nitto tires at all, much less Nitto 17 ultra high performance tires on a C3. Other Examples, Michelin Pilot Sport 4S Ultra high performance summer only tires transformed my 2012 Lexus IS 350 F Sport's handling, ride and steering response versus the factory, Bridgestone similar tire, and the same transformation occurs with the C6Z06 going from Goodyear run flats to Michelin Super Sports, same size tires.
If you drive a ultra high performance summer only tire way below its handling/steering potential, you are correct that a mass market passenger car cooper 225/70/15 tire will appear to offer the same characteristics. Push either tire to 8/10's+ their potentials, and glaring differences will appear... VERY quickly......
Are your rear trailing arm bushings new and do your rear wheel bearings have the factory runout or less? Are you running adjustable heim jointed competition type rear struts which allow zero rear camber changes from that part of the rear suspension. Also, are you 100% sure about the condition of the manual steering box and associated links (rag joint?) and check your lower front ball joints for wear since that part can and will wear out early since it absorbs tremendous forces (made worse by poor quality roads). If your suspension is not in 100% tip top shape (or better with additional modern parts), a 255/45-50/17-18 inch ultra high performance summer only tire will expose any and all weaknesses!
Something seems not correct if your Cooper 225/70/15 tires gave you most of the grip of a 255/45/17 ultra high performance tire although I must say there are big differences with certain tires on cars, meaning I have no experience with Nitto tires at all, much less Nitto 17 ultra high performance tires on a C3. Other Examples, Michelin Pilot Sport 4S Ultra high performance summer only tires transformed my 2012 Lexus IS 350 F Sport's handling, ride and steering response versus the factory, Bridgestone similar tire, and the same transformation occurs with the C6Z06 going from Goodyear run flats to Michelin Super Sports, same size tires.
If you drive a ultra high performance summer only tire way below its handling/steering potential, you are correct that a mass market passenger car cooper 225/70/15 tire will appear to offer the same characteristics. Push either tire to 8/10's+ their potentials, and glaring differences will appear... VERY quickly......
Last edited by jb78L-82; May 22, 2021 at 06:14 AM.
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
Reality
Thanks for the details on what you have done. One area you did not mention is the rear suspension?
Are your rear trailing arm bushings new and do your rear wheel bearings have the factory runout or less? Are you running adjustable heim jointed competition type rear struts which allow zero rear camber changes from that part of the rear suspension. Also, are you 100% sure about the condition of the manual steering box and associated links (rag joint?) and check your lower front ball joints for wear since that part can and will wear out early since it absorbs tremendous forces (made worse by poor quality roads). If your suspension is not in 100% tip top shape (or better with additional modern parts), a 255/45-50/17-18 inch ultra high performance summer only tire will expose any and all weaknesses!
Something seems not correct if your Cooper 225/70/15 tires gave you most of the grip of a 255/45/17 ultra high performance tire although I must say there are big differences with certain tires on cars, meaning I have no experience with Nitto tires at all, much less Nitto 17 ultra high performance tires on a C3. Other Examples, Michelin Pilot Sport 4S Ultra high performance summer only tires transformed my 2012 Lexus IS 350 F Sport's handling, ride and steering response versus the factory, Bridgestone similar tire, and the same transformation occurs with the C6Z06 going from Goodyear run flats to Michelin Super Sports, same size tires.
If you drive a ultra high performance summer only tire way below its handling/steering potential, you are correct that a mass market passenger car cooper 225/70/15 tire will appear to offer the same characteristics. Push either tire to 8/10's+ their potentials, and glaring differences will appear... VERY quickly......
Are your rear trailing arm bushings new and do your rear wheel bearings have the factory runout or less? Are you running adjustable heim jointed competition type rear struts which allow zero rear camber changes from that part of the rear suspension. Also, are you 100% sure about the condition of the manual steering box and associated links (rag joint?) and check your lower front ball joints for wear since that part can and will wear out early since it absorbs tremendous forces (made worse by poor quality roads). If your suspension is not in 100% tip top shape (or better with additional modern parts), a 255/45-50/17-18 inch ultra high performance summer only tire will expose any and all weaknesses!
Something seems not correct if your Cooper 225/70/15 tires gave you most of the grip of a 255/45/17 ultra high performance tire although I must say there are big differences with certain tires on cars, meaning I have no experience with Nitto tires at all, much less Nitto 17 ultra high performance tires on a C3. Other Examples, Michelin Pilot Sport 4S Ultra high performance summer only tires transformed my 2012 Lexus IS 350 F Sport's handling, ride and steering response versus the factory, Bridgestone similar tire, and the same transformation occurs with the C6Z06 going from Goodyear run flats to Michelin Super Sports, same size tires.
If you drive a ultra high performance summer only tire way below its handling/steering potential, you are correct that a mass market passenger car cooper 225/70/15 tire will appear to offer the same characteristics. Push either tire to 8/10's+ their potentials, and glaring differences will appear... VERY quickly......
When it comes to the relative performance of these tires versus my 15 inch tires, I think you have revealed the truth of the matter, and one that applies to so many things we do on these cars. I drive my car alot, on Pennsylvania two lane roads. I enjoy finding particular routes through the beautiful hill country. These roads are very curvy, but again, not the best surfaces. Routinely I am driving 55-60 mph, which is many times a little fast for the road and above posted speed limit....but the car easily does it. Going above 60 is a very rare occasion, on the very rare straight portion of a road, and only for a very short distance. The Cooper 15 inch tires did this very well, never feeling that I was sliding or losing any control, I sensed no tire flex or wallowing.
So point is......I don't push the tires to 8/10's of their potential. Who honestly does on the street? And where? For how long? Maybe in places in the country with way better roads. There are lots of Youtube video's of fools losing control of their Corvettes and Mustangs on the street.....all in very short distances. I am NOT interested in any of that nonsense in my C3 Corvette. I do NOT want to find out the limit of ANY tire, as that results in loss of control So, call me an old man.....but this is not a contest or a race.
This has revealed to me, once again, the reality of "improvements". I bought in to many many things I have read and learned in the forum. I think in retrospect, many "improvements" made only had very marginal gains.....when they were claimed to make a BIG difference. I say this to bring some reality to this, and maybe to help others make decisions based not on the hype, marketing and fantasy, but on the reality of HOW they use their car in the real world. On my 69 Convertible Corvette project.....I am NOT making the same mistakes again. The car will be very stock, and I will save all that money spent for other things.....like gasoline to drive it.
My biggest reason for wanting wider tires was primarily to put more rubber under the rear tires, thinking that the greatly enhanced torque of the 406 SBC I just installed would prevent alot of unnecessary tire spinning. I thought the bonus would be better handling on the roads, but I honestly think it was a marginal gain in handling. I may throw the YJ8 wheels with Cooper 15's back on the car and drive it. Maybe I will find out the difference is more noticeable than I remember given it was a year between driving it with the new tires and wheels. Otherwise, its still a joy to drive, and the tramlining is limited to very poor roads (there are plenty of those in PA).
I spent over $1300 on these 17 inch wheels and tires, with the expectation, based on the "hype" on this forum over how much better these bigger wheels and low profile tires would be,. and the truth is,.......they are not that much better in my real world, and in fact, come with tramlining. My alignment specs are very much in line with what has been suggested on this thread, virtually new suspension components, with best rebuilds on steering box and trailing arms. Its okay. It is not unbearable, or even that hard to deal with. I am just disappointed in once again spending alot of money for a marginal gain at best. Lesson learned.
Last edited by Shovels and Vettes; Jun 13, 2021 at 10:17 AM.
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 971
From: Tennessee/Rhode Island
Understand...thanks for the reply.
At this point, my thought is make sure the alignment is correct with the addition of the recommendations for more negative toe in front and see if you are happy with the changes. Otherwise, I would say that going back to your old tires and rims is probably best for your driving style and roads..........I am sure you are disappointed that after all your work, you feel much of it was not worth the journey.
At this point, my thought is make sure the alignment is correct with the addition of the recommendations for more negative toe in front and see if you are happy with the changes. Otherwise, I would say that going back to your old tires and rims is probably best for your driving style and roads..........I am sure you are disappointed that after all your work, you feel much of it was not worth the journey.
Last edited by jb78L-82; May 22, 2021 at 07:28 AM.