set up for slicks
#16
Nordschleife Master
Join Date: Oct 2004
Location: Vacuuming Cal Speedway
Posts: 7,306
Likes: 0
Received 7 Likes
on
5 Posts
Many of the IMSA cup racers are running less than 3.5 f and less than 3.0 r these days on their proprietary Yoko slicks. I'm running -3.2f and -2.7 rear on my 2600lb. w/driver 996 on either R6's, Yokes, or Hoosier slicks. They all test about the same across the tread, the slicks are 2-3 seconds per lap quicker. 700/900 springs.....
#17
Rennlist Member
I would just put them on and go from there. See what changes had to be made.
So when you say they're 2-3 secs quicker, do you mean over R6s? What length or time track?
So when you say they're 2-3 secs quicker, do you mean over R6s? What length or time track?
#18
Lifetime Rennlist Member
As far as the springs to get more heat - I understand and agree that would create more heat, but that is not the best way to go. Why would anyone want to give up grip & slide the tire to generate heat, except as a last resort? Put the right tire on the car (size / compound) with the 'right' alignment specs for the tire, and you will get the needed heat. If you need a bit more heat, I would be more inclined in increase toe (in or out) to get that additional scrub and add heat.
In regards to 'what is a slick' - they are NOT usually bias tires, at least in the context of this forum. Most of the slick used on P-Cars are radials. Most of the sports racers / formula cars in SCCA use bias slicks. Slicks have NO tread and are NOT DOT certified. The Hoosiers that are mostly discussed here are DOT tires, not slicks, but many call them slicks. Real slicks generally have less rubber depth, no thread at all and generally softer compounds than DOT R's.
Summary - IMO, there is no 'automatic' setup change appropriate to move from DOT R's to slicks.
#19
Race Car
Again, "slicks" generally means a non-DOT approved race tire that is not approved for use on public roads.
There are bias ply slicks (as noted below by va122) and there are radial slicks.
Bias ply slicks, from my understanding, need LESS camber due to their deflection, whereas radial slicks need MORE camber.
That being said, they will be better, but they may not be optimal. The added grip of the slicks will cause additional body roll and suspension deflection, which can mitigate their overall performance, and so this should be taken into account, especially in cars with rubber bushings and softer springs. If your car already has solid bushings and spring rates north of 800 lbs/in, save for optimizing the camber, you are certainly good to go for slicks, IMHO.
"slicks" are sized differently than DOT tires......DOT tires will have the traditional sizes with tread width/aspect ratio/wheel diameter;
non-DOT race tires are sized as tread width/overall tire diameter/ wheel diameter
not true. agree with jrgordonsenior
#20
Race Car
for me, being the crew chief, driver, tow rig operator, etc........it's difficult to optimize the setup by making changes between sessions or taking tire temps or whatever.
#21
Lifetime Rennlist Member
agreed. in fact, some of the top BMW club racers (B.Watts is an example) use both R6s and true slicks. I don't know how much of a setup change he does, but the best setup would involve data testing.
for me, being the crew chief, driver, tow rig operator, etc........it's difficult to optimize the setup by making changes between sessions or taking tire temps or whatever.
for me, being the crew chief, driver, tow rig operator, etc........it's difficult to optimize the setup by making changes between sessions or taking tire temps or whatever.
#22
Pro
Thread Starter
Hey Guys, thanks for the replies, just back from a weekend "culture" at Angkhor Wat" in Cambodia.
I'm with you all on the camber, but adjusting camber for me is not categorized as "changing your complete set up"
If the expression refers to camber adjustments and maybe more spring or sway due to body roll, I'm at ease, that I can figure out.
I was just taken aback by people I talk to and say aaah, you want to race slicks, you must change you the whole setup....
I'm cool now. Will let you know how it goes on the Michelin slicks....
Thanks
I'm with you all on the camber, but adjusting camber for me is not categorized as "changing your complete set up"
If the expression refers to camber adjustments and maybe more spring or sway due to body roll, I'm at ease, that I can figure out.
I was just taken aback by people I talk to and say aaah, you want to race slicks, you must change you the whole setup....
I'm cool now. Will let you know how it goes on the Michelin slicks....
Thanks
#23
Pro
Thread Starter
What is that?
That's this one http://www.deutschnine.com/mm5/merch...uning-handling
Really? That would be a dry car around 2200-2250lbs?
That's this one http://www.deutschnine.com/mm5/merch...uning-handling
Really? That would be a dry car around 2200-2250lbs?
Henk
#24
Drifting
Join Date: Jul 2006
Location: On Rennlist avoiding work
Posts: 3,065
Likes: 0
Received 2 Likes
on
2 Posts
You are absolutely right they are generalizations. I was just gong off what Hoosier told me when I started using their slicks. This thread is really educational.
Victor - I think those generalizations are just that and not necessarily true. I have seen plenty of cases where recommended camber for a given slick is equal to or less than R DOTs. You have to look at each tire. If the slick in question happens to be a bias tire, then you need far less camber - generally 1/2 to 1 degree neg camber for bias slicks.
As far as the springs to get more heat - I understand and agree that would create more heat, but that is not the best way to go. Why would anyone want to give up grip & slide the tire to generate heat, except as a last resort? Put the right tire on the car (size / compound) with the 'right' alignment specs for the tire, and you will get the needed heat. If you need a bit more heat, I would be more inclined in increase toe (in or out) to get that additional scrub and add heat.
In regards to 'what is a slick' - they are NOT usually bias tires, at least in the context of this forum. Most of the slick used on P-Cars are radials. Most of the sports racers / formula cars in SCCA use bias slicks. Slicks have NO tread and are NOT DOT certified. The Hoosiers that are mostly discussed here are DOT tires, not slicks, but many call them slicks. Real slicks generally have less rubber depth, no thread at all and generally softer compounds than DOT R's.
Summary - IMO, there is no 'automatic' setup change appropriate to move from DOT R's to slicks.
As far as the springs to get more heat - I understand and agree that would create more heat, but that is not the best way to go. Why would anyone want to give up grip & slide the tire to generate heat, except as a last resort? Put the right tire on the car (size / compound) with the 'right' alignment specs for the tire, and you will get the needed heat. If you need a bit more heat, I would be more inclined in increase toe (in or out) to get that additional scrub and add heat.
In regards to 'what is a slick' - they are NOT usually bias tires, at least in the context of this forum. Most of the slick used on P-Cars are radials. Most of the sports racers / formula cars in SCCA use bias slicks. Slicks have NO tread and are NOT DOT certified. The Hoosiers that are mostly discussed here are DOT tires, not slicks, but many call them slicks. Real slicks generally have less rubber depth, no thread at all and generally softer compounds than DOT R's.
Summary - IMO, there is no 'automatic' setup change appropriate to move from DOT R's to slicks.
#25
Nordschleife Master
Join Date: Oct 2004
Location: Vacuuming Cal Speedway
Posts: 7,306
Likes: 0
Received 7 Likes
on
5 Posts
Yes over R6's which I ran for several months when I first built the car 1 year ago. I also lightened the car by 100 lbs. and that definitely adds to the difference but power, gearing, suspension are all unchanged since the original build last summer. Laguna Seca 1:35:0 vs 1:38:0, Cal Speedway 1:45:6 vs 1:49.1, Buttonwillow 1:59:0 vs 2:02:4....
Last edited by jrgordonsenior; 09-05-2010 at 07:27 PM.
#26
Race Car
for me as an amateur that's simply not feasible from a time or cost perspective. my setup is good enough at my stage of learning, now it's just focusing on being consistent as a driver and getting the car's max performance as it is now