V70A compound differences

Wheels, Suspension, Brakes & Tyres questions and answers

Moderators: timk, Stu, zombie, Andrew, -alex, miata

track_addict
Fast Driver
Posts: 400
Joined: Thu Oct 15, 2009 9:12 am
Vehicle: NB SE
Location: Adelaide

V70A compound differences

Postby track_addict » Sun Jul 13, 2014 8:28 pm

Hi guys,

Ive got a set of 205/50/R15 K61 V70A's which I got a few weeks ago. Had my first event today with them, a hillclimb. The track was VERY cold all day. Temp sat at around 10deg until about 2pm when it rose slightly. I was having huge issues getting the tyres to work. I've done some googling and have come up with some differences in the spec of the tyre within each compound. What I have found is that the softs are K11's/K21's, mediums are K60/K61 and the hard is just K90. I have read that they do wet weather tyres for each compound but I haven't read anything as to which one is the wet weather tyre. Mine have K61 marked on the sidewall. Can anyone shed any light on this?

Ash.
89' Roadster - Sold
'04 SE - Sunlight Silver.

project.r.racing
Speed Racer
Posts: 3722
Joined: Sun Jan 18, 2009 10:16 pm
Vehicle: Non MX-5
Location: Glasshouse Mountains, QLD

Re: V70A compound differences

Postby project.r.racing » Mon Jul 14, 2014 6:30 pm

doubtful you were getting them hot enough if road temp was 10. a v70a is a wet/dry tyre. but if looking for a wet tyre, then W700 would be similar.

how long was the hillclimb in seconds from start to finish?

track_addict
Fast Driver
Posts: 400
Joined: Thu Oct 15, 2009 9:12 am
Vehicle: NB SE
Location: Adelaide

Re: V70A compound differences

Postby track_addict » Mon Jul 14, 2014 10:33 pm

Its definitely a case of not getting temp into them. Also was running a fast street alignment with not much camber or and crappy toe setting. This wouldn't of helped either but will definitely get a proper alignment this weekend. The car was a dog to drive. Loads of understeer unless I got the car balanced juuuussstttt right. Not looking for a wet tyres, just after some confirmation as to weather there are wet/dry variations within the V70A range.

A run is in the mid 38's for me currently. 630m with an rise of 70m from start to finish.
89' Roadster - Sold
'04 SE - Sunlight Silver.

User avatar
Charlie Brown
Speed Racer
Posts: 2623
Joined: Mon Apr 28, 2003 11:00 am
Vehicle: NC
Location: Sydney, Just out of Dragon Territory over the bridge in the "Shire"
Contact:

Re: V70A compound differences

Postby Charlie Brown » Wed Jul 16, 2014 5:04 pm

Sorry I can't help you out with a wet weather V70a compound but why not contact your state Kumho Motorsport dealer and ask?

I’ve used the mediums for a number of years on the track and they take about a lap to warm up, so for a hillclimb they would be useless. The softs would be the ones to get.

I also found the wet weather capability of brand new V70a’s is way below your normal road tyres.

You really need a dedicated set of rims and wet tyres if the budget stretches for rainy days. To give you an example, a few years ago at a wet Wakefield, one of our members who normally runs mid pack, fitted a set of 6 year old wets and was the fastest car for a number of sessions. Probably 4 seconds faster than he should have been running. A lot of chest beating went on about that. :D
Image

Wakefield 1:09.13 Eastern Creek GP 1:50.198 Ext 2:17.538 Sth 1:02.9003
Phillip Is 1:58.50 Winton Short 1:10.7 Lakeside 1:05.7711 MDTC 45.20

track_addict
Fast Driver
Posts: 400
Joined: Thu Oct 15, 2009 9:12 am
Vehicle: NB SE
Location: Adelaide

Re: V70A compound differences

Postby track_addict » Sat Jul 19, 2014 11:16 am

I didnt get the softs (could of got a set for $800!) because these tyres need to do both hill climbs and super sprints. I figured the softs would just overheat after a lap or two and I haven't seen anyone with a MX5 run softs.

Budget wont stretch for 1x set of dry semi's, 1x set of wet tyres, 1x set of road tyres. My plan is to run my R1R street tyres at the hill climb or when its wet. They're a very good tyre.
89' Roadster - Sold
'04 SE - Sunlight Silver.


Return to “MX5 Wheels, Suspension, Brakes & Tyres”

Who is online

Users browsing this forum: No registered users and 347 guests