quick lift jacks and Sprint tyres
Discussion
Just bought a used SR3 from Radical with hydraulic jacks, as i am only using it for track days and sprints i have been told not to bother with it, even to take the system out, my question is what quick jack do i need and where is the best place to buy one. Any advise on sprint tyres would be very helpfull.
I use the "Long" Quick lift Jack fom Demon Tweeks (no 4 on P383 of the 2010 catalogue). I've seen a small producer advertising them for direct sale (cheaper than DTs) but can't for the life of me remember where. However, as I've had one for yonks, why should I upset myself by remembering where I could have got one cheaper?
As for sprint tyres, most of us use Avon Radials in A91 front and A15 rear compound or A15 all round. (See here for the full range of Avon compounds: http://www.avonracing.com/compounds_page.aspx.)
BUT A91 is very very soft and goes off very quickly even on the smaller, lighter Radicals (Clubsport, Prosport, SR4) that most of us use on sprints and hillclimbs. So, as the SR3 is heavier, I'd suggest that you start with A15 all round but keep in mind the possibility of moving 1 step harder to A49 if you're destroying tyres too quickly.
If you've not used Avon's before, you will find that they need to run with less negative camber than Dunlops, so the suspension settings in the Radical Owners Manual won't give the best results. You'll need to be careful if you wind out the rose joints to reduce the camber and ensure that there is enough thread left in the wishbone to be safe. If you hit this problem, PM me and I'll send you some helpful hints.
The other issue you might have is with the availability of sticky slicks in the 15" & 16" sizes that SR3s use. Unless you have a friendly Avon motorsport dealer in your area then it's best to phone BMTR: http://www.racecarnewmedia.com/bmtr/intro.asp and seek their advice.
Soft slicks pick up "dead" rubber and "roll-off" on their surface at a pretty rapid rate. So, to get best results on the track you'll need to keep the tyre surface clean. The conventional way to do this is by wet Surforming (a tiring, filthy and dispiriting process) but some use a heat gun on a scraper (not on the tyre as it hardens them) to clean up the surface. There is a very good discusion of the pros and cons here: http://www.uphillracers.com/showthread.php/cleanin...
Whichever method you use it is something to be faced every 2-3 events.
Any other Qs just ask.
Good Luck!
As for sprint tyres, most of us use Avon Radials in A91 front and A15 rear compound or A15 all round. (See here for the full range of Avon compounds: http://www.avonracing.com/compounds_page.aspx.)
BUT A91 is very very soft and goes off very quickly even on the smaller, lighter Radicals (Clubsport, Prosport, SR4) that most of us use on sprints and hillclimbs. So, as the SR3 is heavier, I'd suggest that you start with A15 all round but keep in mind the possibility of moving 1 step harder to A49 if you're destroying tyres too quickly.
If you've not used Avon's before, you will find that they need to run with less negative camber than Dunlops, so the suspension settings in the Radical Owners Manual won't give the best results. You'll need to be careful if you wind out the rose joints to reduce the camber and ensure that there is enough thread left in the wishbone to be safe. If you hit this problem, PM me and I'll send you some helpful hints.
The other issue you might have is with the availability of sticky slicks in the 15" & 16" sizes that SR3s use. Unless you have a friendly Avon motorsport dealer in your area then it's best to phone BMTR: http://www.racecarnewmedia.com/bmtr/intro.asp and seek their advice.
Soft slicks pick up "dead" rubber and "roll-off" on their surface at a pretty rapid rate. So, to get best results on the track you'll need to keep the tyre surface clean. The conventional way to do this is by wet Surforming (a tiring, filthy and dispiriting process) but some use a heat gun on a scraper (not on the tyre as it hardens them) to clean up the surface. There is a very good discusion of the pros and cons here: http://www.uphillracers.com/showthread.php/cleanin...
Whichever method you use it is something to be faced every 2-3 events.
Any other Qs just ask.
Good Luck!
joesacco said:
Just bought a used SR3 from Radical with hydraulic jacks, as i am only using it for track days and sprints i have been told not to bother with it, even to take the system out, my question is what quick jack do i need and where is the best place to buy one. Any advise on sprint tyres would be very helpfull.
Joe,I have a long quick jack in my garage that I used when I run my SR3 that is now sold, so its available for sale if interested.
Tony.
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