Board logo

RACE SLICKS.
boosted - 10/5/14 at 08:39 AM

Hi after some advice on tyre choice for racing for 18 mins at castle combe in a westfield with 250 bhp live axle.

Need slicks as currently using 888 but never used before...need to be 15 " as got big brakes and 3 set of wheels.

poss looking at 195 50 15 fr and 205 50 15 rear in the slick equivalent sizes...

questions are

1. what makes
2. what compounds
3.How many laps will they last

where to get?

many thanks

Jon


f750sgr - 10/5/14 at 12:32 PM

There are already 2 slick shod kit cars in the races you want to enter. have a chat with them. I was there at the Easter race weekend and watched them battling with a variety of makes and models.

Sean


CNHSS1 - 10/5/14 at 01:03 PM

19/57-15 is a close equivalent


boosted - 12/5/14 at 06:18 PM

going down to 13 "....my wilwood dynalite 11 app. fit under 13" wheels....gonna borrow a wheel of a mate.


daniel mason - 12/5/14 at 06:30 PM

pm sent


boosted - 15/5/14 at 12:33 PM

Advice needed.

Tried a 13 " wheel on front and does not clear caliper....Have Wilwood Dynalite calipers and 285mm discs....so getting expensive to convert to 13 ".

Heres the question....is this a no no?

15" on front 13" on rear? That way can get nice wide rear wheels and slicks on back where the grip is needed and use soft 888's or ao48s on front in 15".....

F1 do it can i?


boosted - 15/5/14 at 12:38 PM

quote:
Originally posted by CNHSS1
19/57-15 is a close equivalent


caterham csr on 13" wheels....8 j front 10 j rear avon slicks.

caterham c400 on 13" wheels 6j front 8 j rear michelin slicks.

Not sure what power these guys are putting out. but they are both 7 secs a lap quicker than me ! :


CNHSS1 - 15/5/14 at 12:38 PM

mix and matching wheel diameters is OK, but mixing and matching tyre TYPES is a big no-no for me.
List 1B tyres such as A048Rs, R888s, Kumho V70s, are essentially rod tyre carcasses, usually with extra sidewall steel and softer rubber, but still road tyres and they behave like a road tyre but better on track. Slicks are a different concept. very little steel in them, much lighter and thinner carcass, they deliver the grip in a much different way. Slicks like a greater slip angle to activate the compound, that road tyres don't like.

stick to same tyre type F&R imho


CNHSS1 - 15/5/14 at 12:43 PM

quote:
Originally posted by boosted
quote:
Originally posted by CNHSS1
<a href='dial:19/57-15' style='text-decoration: underline'>19/57-15</a> is a close equivalent


caterham csr on 13" wheels....8 j front 10 j rear avon slicks.

caterham c400 on 13" wheels 6j front 8 j rear michelin slicks.

Not sure what power these guys are putting out. but they are both 7 secs a lap quicker than me ! :


given a generic car, and a lap length of say 60s on decent road tyres, id say 1Bs would be 4-8 secs quicker dependant on venue and with a little increase on spring rate and damping rate.
decent slicks would see a further 3-6seconds off that time, but would generally need more setup work as the tyres will generate greater load requirements for the springs and dampers and the camber/toe at least.

a road car swapped from road tyres to slicks would only be 4-5 secs quicker, simply due to the extra traction, but it would handle 'orrible, without addressing the extra grip


boosted - 15/5/14 at 06:58 PM

Thanks for all your help guys...been tracking for 15 years and made the next step into racing...dont wanna stay at the back.

doing all right on 888's at 1.19 round combe. but ...it gets under your skin

Cars got procomp shocks wide track etc has the potential with plenty of power.

When i spoke to Avon Motorsport tyres he said nothing available in 15 " for a westfield racing car.


CNHSS1 - 15/5/14 at 07:40 PM

If you want a List 1B for circuit racing in 15" Avon ACB10s in 7" & 8" would be ideal I would have thought. As they are based on a slick carcass with moulded tread pattern they weigh approx half what a R888 or Kumho V70 would.

If going for slicks, Avon do plenty of 15" tyres, guess you would need to do some homework on compounds though, guessing it depends on race lengths and cars overall weight. I used to use A15 but thats way too soft ffor circuit racing.

[Edited on 16/5/14 by CNHSS1]


boosted - 16/5/14 at 12:41 PM

Thanks mate,

That's what i thought he said he wouldnt sell me any 15 " slicks as these are all for saloon cars and not suitable for lightweight kitcar?

Ill check out the acb's

I have 3 sets of team dynamics 15" wheels


CNHSS1 - 16/5/14 at 12:47 PM

did you speak to BMTR in Birmingham? they are the big Avon Motorsport dealer and hugely helpful

the weight of the car is a factor to be fair, my hillclimber was 800kg on 15" 21.5" diameter, 8.7" fronts A15 compound and 10" rears iirc. if your cars circa 500kg then that may well be the issue.


CNHSS1 - 16/5/14 at 01:11 PM

http://bmtrracing.com/

http://bmtrracing.com/avon-compounds/
http://bmtrracing.com/avon-dimensions/
http://bmtrracing.com/competition-tyre-prices/

they list ACB10s in 15" in A24 and ZZRs in 15" A24 btw


boosted - 16/5/14 at 07:11 PM

Thanks Guys big time. Ill ring them Monday ! I rang head office Melksham Avon Motorsport ! Its 20 mins away and a couple of my mates work in the factory! ( Cooper tyres).

Not sure on weight of car its a narrow SE circa 600kg weighing it is on my todo list.


Guys thanks alot !


boosted - 19/5/14 at 10:35 AM

Spoke with BMTR and 13" way to go....as he said if you want to compete 13's forget 15's! Thanks guys for your help

plan now convert dynalite to 165mm with caliper mounts and discs.

get some wheels n slicks...


boosted - 19/5/14 at 10:59 AM

edit convert to 260 ish ....but my dynalite wont convert with mounts so looks like new brakes for the front boo hiss.


boosted - 30/5/14 at 07:42 PM

right! ready to ring up and buy! but few q's and offsets widths etc confusing me!

car is westfield se narrow body...i want to go 13" 6j front 8j rear...is this possible to fit 8" in rear?

and sorry but want offsets?

looking at compo cxr or caterham7 500 wheels. car has over 200bhp

whats best offset will they fit! ?


boosted - 31/5/14 at 05:56 PM

worked out my offsets by measuring existing and using an online calculator....cant find any prices for the Compomotive cxrs? read there in administration? doh!


boosted - 2/6/14 at 01:20 PM

Boo hiss!!! Compomotive only have 6j in stock sold out of 7 and 8j ! changing casting supplier so 8-12 weeks before any available! Need these for there choice on offsets so i could get a 8j in rear! Team dynamics only do 7j so looks like im stuck with my combo for this season.....Avon zzr's seem the best way togo on my 15" wheels.