: Size and feel: A title that ought to get everyone's attention!



Trionalaw
12-06-12, 10:49 AM
Car and Driver magazine in its January, 2013, issue noted in an article entitled AUTOMOTIVE SINS AND VIRTUES under the sin category:

overly wide tires: now I am become Death, the destroyer of steering feel.
It had a footnote which read “See BM WX 5, every Cadillac Escalade in orange County, California. Conversely, Subaru BRC, Scion FR-S, 1997 Acura Integra type-R. Apologies to the Bhagavad Gita.

This is my question: I am thinking about going to wider tires both front and back. Have any of you experienced loss of steering feel when using wider front tires? I have had an E 36, E 46 and E 90 M3 and find the steering feel in my 2012 CTS V Coupe to equal if not exceed those vehicles. Particularly, when running in competition mode, I really like the steering feel. I would not want to do anything to diminish it.

On the other hand, if I stayed at 255/40/19 on the front to “preserve” the steering feel and went wider on the back, would my problem then be oversteer?

Thanks so much.

Happy holidays,

Jim

Smokin80
12-06-12, 05:26 PM
Somebody correct me if I am wrong but I would suspect that with wider rear and stock front you will exacerbate the under steer on these cars.

I haven't done it yet but I am going to run 265 35 19 fronts and 305 30 19 rears.

Just my .02.

Dr. Design
12-06-12, 10:12 PM
Hello,
Actually it would be quite the opposite. The car would want to understeer. On our track cars and setups we run a square setup and run a 295 in the front. The front end grip is amazing and the initial turn in feel is direct. Granted our combinations might be a little different than your typical CTSV with just tire mods (i.e. if you have sway bars, etc..). With our sways we can dial in under or over steer regardless of tire selection and size.

Are you just looking for a setup for street or are you planning on a little track action?

Thank you,

Dr. Design
D3 Cadillac



On the other hand, if I stayed at 255/40/19 on the front to “preserve” the steering feel and went wider on the back, would my problem then be oversteer?

Thanks so much.

Happy holidays,

Jim

Trionalaw
12-07-12, 09:52 AM
Dr. Design:

Your comments are much appreciated. I go to high-performance driving schools with my beast – my CTS V Coupe, not my wife. I would like to stay with my stock wheels and go as wide as I can. I may lower the car with some springs, but am concerned about the effect upon the magnetic ride control suspension. I assume it would still work. However, if something went wrong with it I suppose my warranty would be toast.

Do you have any thoughts about how why one can go at each end for my car?

Again, thanks so much for your input.

Happy holidays,

Jim

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Feedback much appreciated.

Happy holidays,

Jim

Smokin80
12-07-12, 11:55 AM
D3

Do you guys run 9.5 inch rims all the way around? And then 295 35 19s? Or are you running different rims all together.

To the original poster....not trying to hijack your thread. I think this is still on topic with what you are asking.

Cheers

Dr. Design
12-07-12, 03:55 PM
Hello,
Okay sounds good. So if you are hitting the driving schools and getting the car on tracks then you have a few options. Since you are running a OEM wheel setup then you will be limited on the tire you can run for that size/width wheel. The fronts will be based on the approved rim width of the tire manufacturer. However if you can find a set of rear sedan wheels and use our spacer kit you can run a square setup and get the 295 combo. Most of our customers that track will try a 265 & 305 RE11 combo, only to eventually switch to the square setup. The grip of the RE11 combo would still be better than the factory setup on the track.

As for the lowering spring setup. No problem with the mag ride as our system is the only one on the market designed to work in conjunction with the MR system and keep it working properly. Anything regarding warranty, we would recommend checking with your service department first as every dealership handles warranty differently. We will say this however. We have installed and sold MANY lowering springs to MANY dealerships without and issue. But to be safe you should check with your dealership.

In terms of my thoughts, I guess we would need to start with yours. What do YOU feel the car is doing. I have driven enough of these cars at speed and know that Coupes/Wagons/Sedans all handle differently when on track. So if you get feedback from a Sedan driver, it might not apply 100% for your setup. In your original post you mentioned that you want to preserve your front end feel. Are you looking for more rotation to get the back end to track the front better? Given that you are dealing with OEM suspension, I would venture to say that your are looking to increase turn in and increase vehicle rotation and at least get the chassis neutral. Please advise.

Happy Holidays to you as well! =)

Thank you,

Dr. Design
D3 Cadillac



Dr. Design:

Your comments are much appreciated. I go to high-performance driving schools with my beast – my CTS V Coupe, not my wife. I would like to stay with my stock wheels and go as wide as I can. I may lower the car with some springs, but am concerned about the effect upon the magnetic ride control suspension. I assume it would still work. However, if something went wrong with it I suppose my warranty would be toast.

Do you have any thoughts about how why one can go at each end for my car?

Again, thanks so much for your input.

Happy holidays,

Jim

----------

Feedback much appreciated.

Happy holidays,

Jim

----------

Hello,
Yes that is one the combinations we run on the track cars. That is also the correct tire size for the Sedans. On the Coupes we run the 305 R888 on the 10" rim. Here is a picture of our track setup.

http://www.d3cadillac.com/graphics/d3_showcars/legionnaire/Forgeline%20Race%20Wheels%20-%20Gold/Legionnaire%20Gold%20Forgeline%20%281%29.JPG
http://www.d3cadillac.com/graphics/d3_showcars/legionnaire/Forgeline%20Race%20Wheels%20-%20Gold/_I4A0101.jpg


Let us know if there are any questions.

Thank you,

Dr. Design
D3 Cadillac


D3

Do you guys run 9.5 inch rims all the way around? And then 295 35 19s? Or are you running different rims all together.

To the original poster....not trying to hijack your thread. I think this is still on topic with what you are asking.

Cheers

Trionalaw
12-07-12, 05:19 PM
D3

Do you guys run 9.5 inch rims all the way around? And then 295 35 19s? Or are you running different rims all together.

To the original poster....not trying to hijack your thread. I think this is still on topic with what you are asking.

Cheers

No problem with the hijack. Can I send you my address and when my wife is usually home?

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Yes that is one the combinations we run on the track cars. That is also the correct tire size for the Sedans. On the Coupes we run the 305 R888 on the 10" rim. Here is a picture of our track setup.

I quoted your comment about the photo. If I understand what you are saying you are running the same size wheels and tires all the way around. I'm assuming that's what you mean by square.

I would venture to say that your are looking to increase turn in and increase vehicle rotation and at least get the chassis neutral.

I quoted you again. That is what I am looking for.

By the way, is the coupe in the picture female? If so, is she dating anyone?

Thanks again.

Happy holidays to you and yours,

Jim

----------

Yes that is one the combinations we run on the track cars. That is also the correct tire size for the Sedans. On the Coupes we run the 305 R888 on the 10" rim. Here is a picture of our track setup.

I quoted your comment about the photo. If I understand what you are saying you are running the same size wheels and tires all the way around. I'm assuming that's what you mean by square.

I would venture to say that your are looking to increase turn in and increase vehicle rotation and at least get the chassis neutral.

I quoted you again. That is what I am looking for.

By the way, is the coupe in the picture female? If so, is she dating anyone?

Thanks again.

Happy holidays to you and yours,

Jim