Home Mobile Forum News Cookbook FaceBook Us T-Shirts etc.: Europe/Worldwide. eBay Motorsport Links Advertising Live Chat  
Site Partners: SpotterGuides  
Related Sites: Your Link Here  

Go Back   TenTenths Motorsport Forum > Racing Talk > Racing Technology


Reply
 
Thread Tools Display Modes
Old 19 Nov 2008, 22:03 (Ref:2338027)   #1
jedrinck
Racer
 
Join Date: Oct 2007
Location:
Germany
Posts: 398
jedrinck should be qualifying in the top 10 on the grid
F3 tires vs F Renault tires

I need to replace the tires on my 8V F Renault which I use only for trackdays, so rules are not a problem. I could get Kumho F 3 tires at roughly the same cost as Michelin F Renault tires. The F 3 tires are a little wider and I hope to be faster with them. The fronts have 20mm more diameter but that can easily be adjusted for with the pushrods. Is there any data about the coefficient of friction of these tires accessible to help evaluate if it is worth trying them? Or, has anybody tried exactly that and is willing to talk about it?
jedrinck is offline  
Quote
Old 20 Nov 2008, 11:18 (Ref:2338275)   #2
AU N EGL
Veteran
 
AU N EGL's Avatar
 
Join Date: Jul 2006
United States
Raleigh, North Carolina
Posts: 4,418
AU N EGL should be qualifying in the top 10 on the gridAU N EGL should be qualifying in the top 10 on the grid
Michelin tires have far great grip then Kumhos. Cost more too.
AU N EGL is offline  
__________________
"When the fear of death out weighs the thrill of speed, brake." LG
Quote
Old 20 Nov 2008, 11:47 (Ref:2338284)   #3
jedrinck
Racer
 
Join Date: Oct 2007
Location:
Germany
Posts: 398
jedrinck should be qualifying in the top 10 on the grid
Are you talking about these specific racing tires or just about the general reputation of the brands? As you may know, Michelin provides spec tires for the F Renault euroseries and Kumho for the F3 euroseries.
These 13" slicks for light single seaters have absolutely nothing to do with the range of road legal tires made by these companies so no conclusions can be drawn about how well they work just buy saying that Michelin generally makes better tires.
jedrinck is offline  
Quote
Old 20 Nov 2008, 12:26 (Ref:2338300)   #4
AU N EGL
Veteran
 
AU N EGL's Avatar
 
Join Date: Jul 2006
United States
Raleigh, North Carolina
Posts: 4,418
AU N EGL should be qualifying in the top 10 on the gridAU N EGL should be qualifying in the top 10 on the grid
Quote:
Originally Posted by jedrinck
Are you talking about these specific racing tires or just about the general reputation of the brands? As you may know, Michelin provides spec tires for the F Renault euroseries and Kumho for the F3 euroseries.
These 13" slicks for light single seaters have absolutely nothing to do with the range of road legal tires made by these companies so no conclusions can be drawn about how well they work just buy saying that Michelin generally makes better tires.
Their respective race tires. If you have a spec tire then you use that.

When competitors have a choice, Kumhos are chosen more for cost benefit then for speed. Michelin are chosen for speed, up to 2 sec a lap faster, but are much more expesive.

If the price is close, go with the Michelin.
AU N EGL is offline  
__________________
"When the fear of death out weighs the thrill of speed, brake." LG
Quote
Old 20 Nov 2008, 12:41 (Ref:2338314)   #5
tristancliffe
Veteran
 
tristancliffe's Avatar
 
Join Date: Dec 2005
United Kingdom
Norwich, UK
Posts: 1,161
tristancliffe should be qualifying in the top 10 on the gridtristancliffe should be qualifying in the top 10 on the grid
It's hard to say as the F3 cars have probably never run of the spec/compound/size of FRenault tyre and vice versa.

Be aware that a taller sidewall will stiff affect suspension geometry. You can get the ride height back again, but the outboard ends of the wishbones will be higher off the ground. That could benefit, but it's more likely to make things worse (what things are a different matter though!).

I'd say stick with the Michelin spec rubber. At least then you can vaguely compare yourself with official FRenault laptimes
tristancliffe is offline  
__________________
Dallara F307 Toyota, MSV F3 Cup - Class and Team Champion 2012
Monoposto Champion 2008, 2010 & 2011.
Quote
Old 20 Nov 2008, 13:09 (Ref:2338324)   #6
jedrinck
Racer
 
Join Date: Oct 2007
Location:
Germany
Posts: 398
jedrinck should be qualifying in the top 10 on the grid
Thanks for the comments so far. Tristan, judging from your avatar you use F3 tires, are they kumhos and if yes, how many track miles do you use them for? Also, how many heat cycles can they handle before they get significantly worse, because that is really something where the Michelins shine. The 10mm ride height change necessary is the range people use to adjust for bumpier tracks, there are obviously geometry changes but I guess I won't notice them. Some classes require to run these cars at 40mm ride height and I read that costs one or two seconds a lap, most of that being attributed to the higher cg while I will have the same cg as before. So maybe MS would notice, but DC wouldn't..
jedrinck is offline  
Quote
Old 20 Nov 2008, 15:55 (Ref:2338393)   #7
tristancliffe
Veteran
 
tristancliffe's Avatar
 
Join Date: Dec 2005
United Kingdom
Norwich, UK
Posts: 1,161
tristancliffe should be qualifying in the top 10 on the gridtristancliffe should be qualifying in the top 10 on the grid
I use Avon tyres with A24 compound. They lasted all season (albeit about a second slower at the end), and my season mileage was around the 700 miles mark.

Next year I'm planning on using softer A53 tyres, and having two sets for the year. Not thought about Michelins or Kuhmos. I have no idea of the cost, sizes, compounds etc of them. I know Michelins are considered unforgiving by a rival of mine.

I don't believe in heat cycles. The only data available on them shows the effect to be miniscule, and is provided by teams that throw tyres away after one or two runs on them. Sure, rubber hardens with age, so a brand new tyre is quicker than an older one, but I don't believe using them makes that much difference until they wear out. But that's a personal feeling. I'm some still believe the unsubstantiated myths about heat cycles.
tristancliffe is offline  
__________________
Dallara F307 Toyota, MSV F3 Cup - Class and Team Champion 2012
Monoposto Champion 2008, 2010 & 2011.
Quote
Old 22 Nov 2008, 21:15 (Ref:2339782)   #8
jedrinck
Racer
 
Join Date: Oct 2007
Location:
Germany
Posts: 398
jedrinck should be qualifying in the top 10 on the grid
I haven't experienced the adverse effects of repeated heat cycles either, the FRenault club racers say the current Michelin spec tire is very durable while the one from a couple of years ago would deteriorate quickly.
One can get the Michelins or the Kumhos for about 40 Euros a piece used with about 90% of rubber left, so it would be a rather cheap experiment. I don't know about unforgiving, my 97 tatuus with the Michelin tires is an easy car to drive fast. Sizes for the Michelin FR spec tires are 16/53/13 and 23/57/13. Sizes for the F3 spec tires are 180/550/13 and 240/570/13. The front Kumhos are 10mm wider and the rear ones 20mm wider than the Michelins.
jedrinck is offline  
Quote
Old 28 Nov 2008, 20:03 (Ref:2343538)   #9
THR
Veteran
 
Join Date: Jun 1999
United Kingdom
Wolverhampton, England
Posts: 727
THR has a lot of promise if they can keep it on the circuit!
heat cycles matter!! big time
Id stick to FRen tyres tho, y change... the Fr tyres easy to come by and cheap enough really, and do seem to last pretty well.
the F3 tyres must be more expensive or the same, so y bother changing!
I know they are very different in handling! as you would expect really.
THR is offline  
Quote
Old 28 Nov 2008, 23:42 (Ref:2343625)   #10
tristancliffe
Veteran
 
tristancliffe's Avatar
 
Join Date: Dec 2005
United Kingdom
Norwich, UK
Posts: 1,161
tristancliffe should be qualifying in the top 10 on the gridtristancliffe should be qualifying in the top 10 on the grid
How did you measure the effect of heat cycles, and how did you separate those results from the effects of general wear and UV light deterioration? The professional teams can't (and don't), so I'm curious as to how you worked that out.

Tyres age and get slower, but there is no evidence that the number of heat cycles has any effect. E.g. do two test days on the same tyre of tyre. On one day do 50 two lap sprints and allow to cool to ambient between each run (i.e. 50 heat cycles). On the next day do 2 runs of 50 laps. Ignoring the effects of getting better at a circuit or car, fuel loads and all that and you'll probably find there is not much difference in lap times.
tristancliffe is offline  
__________________
Dallara F307 Toyota, MSV F3 Cup - Class and Team Champion 2012
Monoposto Champion 2008, 2010 & 2011.
Quote
Old 1 Dec 2008, 17:16 (Ref:2345089)   #11
THR
Veteran
 
Join Date: Jun 1999
United Kingdom
Wolverhampton, England
Posts: 727
THR has a lot of promise if they can keep it on the circuit!
ok i cant prove it :P
but it makes sense that every time you get the tyre hot and they turn to blu tac rather than rubber that the composition changes due to heat.
THR is offline  
Quote
Old 2 Dec 2008, 08:54 (Ref:2345514)   #12
tristancliffe
Veteran
 
tristancliffe's Avatar
 
Join Date: Dec 2005
United Kingdom
Norwich, UK
Posts: 1,161
tristancliffe should be qualifying in the top 10 on the gridtristancliffe should be qualifying in the top 10 on the grid
It only makes sense because the myth is popular. It's equally plausible that the rubber turns to blu-tac and then simply sets again, with whatever changes to the composition being negligable when it next turns to blu-tac.
tristancliffe is offline  
__________________
Dallara F307 Toyota, MSV F3 Cup - Class and Team Champion 2012
Monoposto Champion 2008, 2010 & 2011.
Quote
Old 2 Dec 2008, 12:31 (Ref:2345653)   #13
JamesH
Veteran
 
JamesH's Avatar
 
Join Date: Aug 2006
United Kingdom
Christchurch, Cambs, UK
Posts: 2,093
JamesH has a real shot at the championship!JamesH has a real shot at the championship!JamesH has a real shot at the championship!JamesH has a real shot at the championship!JamesH has a real shot at the championship!
On a related subject, is tyre softening of any help here to increase performance at lower cost?
JamesH is offline  
__________________
Locost #54 Boldly Leaping where no car has gone before. And then being T-boned. Damn.
Survivor of the 2008 2CV 24h!! 2 engines, one accident, 76mph and rain.
Quote
Old 4 Dec 2008, 09:20 (Ref:2347111)   #14
ubrben
Veteran
 
Join Date: Jun 2005
United Kingdom
Birmingham
Posts: 508
ubrben has a lot of promise if they can keep it on the circuit!
Quote:
Originally Posted by JamesH
On a related subject, is tyre softening of any help here to increase performance at lower cost?
I've only ever seen marginal benefit in improving heat cycled tyres. I know for a fact that Michelin treated MotoGP tyres to improve the initial grip of hard tyres. I don't know what they used though.

Heat cycling has a measurable effect. In the case I'm aware of the cross link density of a used tyre was higher than that of a new tyre.

I would suggest that if you can't quantify this effect it will have more to do with your test procedures/repeatability than heat cycles not being a reality.

Ben
ubrben is offline  
Quote
Old 4 Dec 2008, 09:53 (Ref:2347123)   #15
tristancliffe
Veteran
 
tristancliffe's Avatar
 
Join Date: Dec 2005
United Kingdom
Norwich, UK
Posts: 1,161
tristancliffe should be qualifying in the top 10 on the gridtristancliffe should be qualifying in the top 10 on the grid
If heat cycling is as much of a deal as most in paddocks would have you believe then procedures and repeatability don't matter, as they are dwarfed by the whole seconds per lap tyres apparently lose after three or four heat cycles.

If it does occur to any meaningful level then it's probably so tiny that I doubt most drivers bar the very best will be able to feel it.
tristancliffe is offline  
__________________
Dallara F307 Toyota, MSV F3 Cup - Class and Team Champion 2012
Monoposto Champion 2008, 2010 & 2011.
Quote
Reply

Bookmarks




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Who Tires First Tf105 Formula One 6 15 Feb 2006 14:59
Tires, tires, tires... neilap Formula One 5 30 Sep 2002 04:41
Tires Radisichrox WTCC & European Touring Car Series 2 4 Oct 2001 20:14
Tires Liz Racing Technology 2 14 Nov 2000 01:34
Tires yelwoci Racing Technology 14 6 Jul 2000 10:46


Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 19:24.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Original Website Copyright © 1998-2003 Craig Antil. All Rights Reserved.
Ten-Tenths Motorsport Forums Copyright © 2004-2018 Royalridge Computing. All Rights Reserved.