VF2 SSV advice on moving to smaller diameter wheel size

[Kdawg78]

I’ve got a VF2 SSV Commodore with the standard 245/40R19 wheels on all corners. I’ve got some 18 inch wheels I want to put rubber on just for track days, and wanted to know of peoples experience in moving to 245/45R18 or 245/40R18… what’s better and what’s tyres do you recommend

 

[Forg]

For track days (and you don’t care about speedo accuracy) the 40-series would have to be better; stiffer firewall & less weight, also lower … I’ve forgotten the correct term, rotational momentum (ie. the car’s fighting the tyres less when accelerating as the bulk of the tyre’s mass is closer to the axle).

Check around for available tyres though, you may find that it’s hard to find good tyres in the right size. That might end-up dictating what you go with.

*edit*
Just had a look at the Jax site; interestingly they don’t have any Michelin tyres in 245mm & 40-aspect for an 18” wheel, but they DO have a 35-series Pilot Sport Cup 2 Connect … I don’t know what the Connect part is, but the Cup 2 is a very good road+track tyre, almost a semi-slick and probably the style of tyre you’d want if the track isn’t dry. Dunno if a 35 is too small for some reason, nor if you want to focus solely on dry days & stick to slicks …

 

[rambunctious]

Fitting smaller diameter wheels will get you off the line a little quicker but drop your top end speed
meaning higher revs or less speed at the top end.
I would guess at around 5% difference
But you probably already know this.

 

[Ginger Beer]

Hankook Z221 for track days

245/40 18

https://www.garysmotorsporttyres.com.au/products/hankook-z221?variant=39401020162231

Your better of using "real" semi-slicks for dedicated track rims for multiple reasons

 

[Kdawg78]

For track days (and you don’t care about speedo accuracy) the 40-series would have to be better; stiffer firewall & less weight, also lower … I’ve forgotten the correct term, rotational momentum (ie. the car’s fighting the tyres less when accelerating as the bulk of the tyre’s mass is closer to the axle).

Check around for available tyres though, you may find that it’s hard to find good tyres in the right size. That might end-up dictating what you go with.

*edit*
Just had a look at the Jax site; interestingly they don’t have any Michelin tyres in 245mm & 40-aspect for an 18” wheel, but they DO have a 35-series Pilot Sport Cup 2 Connect … I don’t know what the Connect part is, but the Cup 2 is a very good road+track tyre, almost a semi-slick and probably the style of tyre you’d want if the track isn’t dry. Dunno if a 35 is too small for some reason, nor if you want to focus solely on dry days & stick to slicks …

I’ll have to look into 35, but I was reading that I shouldn’t go any further than an inch from manufacturing specs.

 

[Kdawg78]

Hankook Z221 for track days

245/40 18

https://www.garysmotorsporttyres.com.au/products/hankook-z221?variant=39401020162231

Your better of using "real" semi-slicks for dedicated track rims for multiple reasons

Thanks for that, I was finding it hard to find more real racing tyres other than the ones you can get from your average tyre joint. I’ll look into these. Someone I know mentions Federals??? As a cheaper option but not sure what people think about those.

 

[Ginger Beer]

Thanks for that, I was finding it hard to find more real racing tyres other than the ones you can get from your average tyre joint. I’ll look into these. Someone I know mentions Federals??? As a cheaper option but not sure what people think about those.

Real semi-slicks will improve times by "alot"

Don't use them on the street as you will heat cycle them to death, strictly track days

Do some googling on setting up your track tyres, invest in a temp gauge, it will help with setting up your tyre pressure and alignment settings, a "probe" type is best, but a cheap IR one will be better than nothing

For your first few outings only do 1 or 2 warm up laps followed by 3 hot laps, then pull in and check your tyre temps and pressures, you need to do this quickly, as you will lose heat fairly quickly

Look at where the tyre is wearing, and adjust from there

Once setup correctly you should get a few sessions out of a set of tyres, if they aren't set up correctly, you can kill a set in 1 session

Get a note book.
When I was "playing" racecar driver, a friend who has quite a few shiny trophies recommended that I get a note book and keep info from every track, tyre types, alignment settings, cold temp, hot temp and ambient temp

This ended up increasing tyre life and decreased lap times considerably

For an example, I'm thinking back a bit now......for either my MX5 or R33, during a club day at Wakefield Park with the "southern sporting car club" (SCC), that called for a 200tw tyre ( Hankook RS3) to be eligible to run in the street class supersprint, IIRC my cold tyre pressures were LF 28 RF 34 LR 30 RR 32 (or something like that), after 2 warm up laps all tyres were around 36-38°c

Dunlop DZ03G's were about 3 seconds a lap faster than the RS3's, I cannot remember what pressures I used but I think they liked low 30's????

Taking notes and playing around was half the fun really, well playing amateur race car driver and amateur mad scientist

I miss those days, but I've got other things that take up my time and money now

Track days are addictive and can be expensive

Enjoy

 

[Ginger Beer]

Cheap, and in your size

Mixed reviews

https://www.tempetyres.com.au/tyres?Brand=Toyo&TyreWidth=&TyreProfile=&TyreDiameter=18&TyreLoad=&TyreSpeed=&TyrePattern=Proxes R888R&RunFlat=

 

[harrop.senator]

Had a lot of luck with zestino grudges myself. I can get 265 35 18 for $120 or so at my wholesale price. Probably $160 retail maybe $180.

The nankangs and good rides were good too , but availability and price was too good to say no to.

It's been a long time since I ran something high end like an r888 to compare to. But there's plenty of 4-600 whp drift cars transitioning on the cheapies at 160k an hour lol , they do the job.

 

[RevNev]

I’ve got a VF2 SSV Commodore with the standard 245/40R19 wheels on all corners. I’ve got some 18 inch wheels I want to put rubber on just for track days, and wanted to know of peoples experience in moving to 245/45R18 or 245/40R18… what’s better and what’s tyres do you recommend

245/40x18 "R" Spec tyres for the track. Don't waste your time with road tyres, they're all junk compared with an "R" Spec. Top end "R" Spec's like Dunlop, Michelin, Yokohama aren't cheap, but there's few in the cheaper brands that are pretty good. The grip of an "R Spec" tyre is massively, I'll repeat that "massively" better and faster than the best road tyre available!