Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Beginner Tire Recommendations

 
Post new topic   Reply to topic    924Board.org Forum Index -> 924 Racing Today
View previous topic :: View next topic  
Author Message
MikeJinCO  



Joined: 08 Jun 2010
Posts: 733
Location: Maysville, Colorado

PostPosted: Tue May 15, 2018 2:10 pm    Post subject: Beginner Tire Recommendations Reply with quote

The car is finally beginning to come together. I need to get some tires for a beginner driver. I have both the 6" spiderwebs and 7" cookie cutters for wheels. I have fender flares rear and front and the coil overs have about 2-1/2" springs so fender and clearance shouldn't be an issue. I figure I need a pretty forgiving tire that lasts well and a couple or reports recommended a BFG Rival over the Toyo R888R or Kumho RS4. They will be used track only for vintage use. I will probably have about 140HP(10-1, mild port, 264 deg cam,MSDS) and weight of 2100b(guess). I figured on a tire size of 205/50 but could go to 225. I cannot legally go below the 50 section. I'm not even considering Hoosiers at this time.

Among the local vintage group Hoosiers are recognized fastest, the RS-4 good for longevity and some use Toyo's.

Which tires would be recommended?
_________________
Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com
Back to top
View user's profile Send private message Visit poster's website
CÚdric  



Joined: 27 Aug 2004
Posts: 1752
Location: Sweden

PostPosted: Tue May 15, 2018 10:20 pm    Post subject: Reply with quote

Is it for racing or just track days? For a track day NA i would stay on 205s on 7" wheels, i really like that setup, but all tyres are not the same width, even though they are sold as the same size.

All tyres i have been running have been very progressive on my cars, even aggressive compunds, though its a bit heavier than yours which of course affects the car response. My NA was very nice aswell, even with aggressive Rcomps. But of course, when stuff happens it happens at a higher speed level, which can get you into troubble. I didnt like the old R888s, way to sloppy sidewalls, couldnt handle heat that good aswell, but the R888r seemt to be much better at those points. What was nice with them though was the short warm up time, more aggressive tyres could be very sketchy until they reached a good heat level, the toyos were almost good from the start, not completely unimportant factor.

A more street oriented tyre will most likely be a bit more slippery at a lower limit, and thus making it easier to learn how to manage the traction in the best way. With that weight i think you will have quite some margin for tyre overheating and thus could chose tyre more freely, otherwise that is mostly the drive to have more tyre width.
_________________
┤80 924 Turbo
Back to top
View user's profile Send private message MSN Messenger
924RACR  



Joined: 29 Jul 2001
Posts: 8114
Location: Royal Oak, MI, USA

PostPosted: Tue May 15, 2018 10:51 pm    Post subject: Reply with quote

Can't speak to those tire choices, since I'm only running on Ho-ho's, but size-wise I'd be inclined to use the 205's on the 6's, not 7's - save the weight/rotational inertia...
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
CÚdric  



Joined: 27 Aug 2004
Posts: 1752
Location: Sweden

PostPosted: Wed May 16, 2018 4:29 am    Post subject: Reply with quote

I don't know if there is any weight differences between those wheels, the spider webs are no lightweights. The 7'' cookies are 6.9kg if i remember correctly, a really good track wheel.
_________________
┤80 924 Turbo
Back to top
View user's profile Send private message MSN Messenger
924RACR  



Joined: 29 Jul 2001
Posts: 8114
Location: Royal Oak, MI, USA

PostPosted: Wed May 16, 2018 5:29 am    Post subject: Reply with quote

Even if they weighed the same, a 6" wide rim should have a little less rotational inertia due to less wheel flange.

But I'm pretty sure once upon a time I weighed them and confirmed they were lighter.
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
CÚdric  



Joined: 27 Aug 2004
Posts: 1752
Location: Sweden

PostPosted: Wed May 16, 2018 5:49 am    Post subject: Reply with quote

924RACR wrote:
Even if they weighed the same, a 6" wide rim should have a little less rotational inertia due to less wheel flange.

But I'm pretty sure once upon a time I weighed them and confirmed they were lighter.



I guess it might be very dependent on what kind of tracks you drive on, ours are pretty short and twisty in general, thus quite hard on the tyres. But here the 7'' and 205 combination is by far the most common on cars with similar power to weight ratios like miatas, the reduced sloppyness and better tyre wear seems to outweigh the added inertia quite easily, but different tracks have different optimums.
_________________
┤80 924 Turbo
Back to top
View user's profile Send private message MSN Messenger
MikeJinCO  



Joined: 08 Jun 2010
Posts: 733
Location: Maysville, Colorado

PostPosted: Wed May 16, 2018 8:34 am    Post subject: Reply with quote

The car is track only although it might get a couple of illegal test drives if it can clear the driveway rocks. I weighed both wheels on bathroom balance scale and the cookie is about 3/4 lb lighter than the spiderweb. I think Ill probably go with the 205 Toyos on the 7" cookies as the increase in track should help a bit.
_________________
Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 924 Racing Today All times are GMT + 11 Hours
Page 1 of 1

 
Jump to:  
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 vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group