Unofficial SCCA Production Racing Forum
It is currently Wed May 23, 2018 9:50 pm

All times are UTC - 8 hours

Post new topic Reply to topic  [ 22 posts ]  Go to page Previous  1, 2, 3
Author Message
PostPosted: Tue Feb 20, 2018 5:51 am 
User avatar

Joined: Fri Nov 13, 2009 9:12 pm
Posts: 1140
Location: SA, TX
As I've documented here several times, I had to make rather large setup and driving style changes with my 2300lbs FWD car when going from the bias-ply tires to the radial tires. Mostly it was to calm down the rear of the car, as it became scary loose, finally ending with rear springs down 25%, rear bar down two sizes, and camber increased from 1.25-0.75 to 3.5-3.0 all the way around. Once I got it dialed in though, they're just awesome. I'm still not 100% sure that with all things being equal, having the perfect setup on the car for each tire, that I would necessarily be automatically faster on the radial. The difference is that on the bias-ply, I'll be fast on laps 1-3 and then be pedaling the car to the finish as I burn the front tires down, while on the radial, I'll click off fast and consistent laps from like lap 4 until the checkered flag.

You have to think about what you're dealing with here. The bias-ply is 1950's technology, which was designed to be used on lightweight, well balanced, mostly open wheel cars, which is the realm that continues to best utilize that technology today. It's also, in my opinion, why so many of the more traditional Prod cars continue to have great success on them, as they're lightweight and don't abuse any one corner of the car more than another. Conversely, on a FWD nose-heavy car like mine, that technology just doesn't work. They're just not designed to handle the heavy loading and multi-directional moments that I'm going to ask from it. They're more efficient at handling energy, putting it to the road, managing the heat, and reducing drag.

Like I said, it does not surprise me at all that the lighterwight, more balanced cars continue to use the bias-ply very successfully in Prod. Their suspension design really limits what they can get out of the radial, and the bias-ply isn't really hindering them, so they both remain very viable options. But if you have a heavier car, a FWD car, or a RWD car with quite a bit of power, then it's a no-brainer to me that you should working with the radial slicks on your car. Once you get the setup and driving style down (which is absolutely different!), you're car will be faster and more consistent than what the bias-ply can give you.***

***Disclaimer: All of this means nothing if the driver just flat-out prefers the feel of one construction over the other. A comfortable driver who's confident in his machine, without that, the rest of this is a moot point. If you've been driving on bias-plys for 25 years, I'm not going to be shocked that you don't like the feel of the radial. Me, I'm the opposite case. I drove on DOT radials for 10 years in IT before moving to Prod and bias-plys, and I just did not mesh well with them. When the radial slick came out, it was like putting on my favorite pair of old tennis shoes....once I got the setup right and the car calmed down.


ruckracing honda's:
'15 & '10 Runoffs FP Champion
'10, '09, & '08 ARRC ITA/ITB Champion

PostPosted: Tue Feb 20, 2018 5:12 pm 
User avatar

Joined: Sun Aug 18, 2002 6:16 pm
Posts: 5302
Location: Oregon City, Or.
Thanks Kevin, Great Feed back. Thanks to everyone that responded...

Joe Harlan Member #175515

Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 22 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 8 hours

Who is online

Users browsing this forum: No registered users and 2 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group