Radical PR6 setup for hillclimb / sprints

[noodle1]

stiglet said:

I've been out of Radicals for a few years but from memory, whilst A92 front A15 rear would be fine for Hillclimbs, even though most sprints are short in Scotland they are very twisty and hard on the front tyres.

Boyndie/Kames/Golspie cooks A92 fronts (esp n/s) and you end up heat gunning/ rasping all the time IIRC

So if you've got plenty rims a set of sep. Hillclimb fronts with A92s and sprint A15s may be a good shout.

As for tyre pressures, I used to run Crossplies so can't help there.

Angus, looks likeat least 3-4 Radicals in C1 next year...........fancy coming back -where's your old one?

Thanks
So does that mean i can run differnt compounds on each axle? Theres quite a lot I need to get upto speed on. Whats the pro's/ cons of runing crossplies against radials?
It sounds likle it could be a busy weekend at those tracks but im sure itll be worht it overall.
Be good to see a few others in the class and im more than happy to prop up the bottom of the timesheets

[noodle1]

scooby151 said:

Hi, I run a 1300 PR6 for hillclimbs in Malta (where the roads aren't so good) , which last for a max of 60sec. I use A92 front and rear, since I don't have the power. Found them to be very good. I also run 8inch front and 10rear. Weight loss is my passion in life :-p the car's weight not mine ;-). I have mine down to 431 kgs (excluding fuel). If I could be of any help, let me know :-)
P.s. This is a video to show you what I mean when I say our roads are crap ;-)
https://m.youtube.com/watch?v=ikWSJj5jby0

Very fast up some interseting roads there, Thanks for that Ill be sure to get in touch to get some info from you on weightloss and setup I need all the help i can get.

[scooby151]

My e mail is [e-mail] ;-)
James

[stiglet]

Yes there's nothing to prevent you running softer compounds on the front, the theory being that you can warm your rear tyres before the start of a hillclimb but there's not a lot you can are permitted to do re the fronts.

I ran A92 (or the equiv. then) front and A15 (or eqiv.) rear. Great for Fintray hillclimb and Alford sprint but fronts used to take a hammering at Golspie/Boyndie so my sons were no strangers to the wood plane /rasp

Crossply v radial is a topic of its own and there are one or two old threads already on this you can look at. However worth checking that the info. is current (eg ability of earlier front suspension to adjust to correct camber etc)

The theory was that CPs whilst having less ultimate grip were more progressive and forgiving but things seem to have moved on and many hillclimbers have changed from CPs to radials. This may be due to improvements in tyre technology/more availability of the softer compounds in radial format - others will confirm. Also radials used to be a bit dearer.

There are several threads on "uphill racers" which are worth a read

I still run CPs on my Reynard because that's what it came with and I haven't got round to changing yet

[SportsLibre]

stiglet said:

Yes there's nothing to prevent you running softer compounds on the front, the theory being that you can warm your rear tyres before the start of a hillclimb but there's not a lot you can are permitted to do re the fronts.

I ran A92 (or the equiv. then) front and A15 (or eqiv.) rear. Great for Fintray hillclimb and Alford sprint but fronts used to take a hammering at Golspie/Boyndie so my sons were no strangers to the wood plane /rasp

Crossply v radial is a topic of its own and there are one or two old threads already on this you can look at. However worth checking that the info. is current (eg ability of earlier front suspension to adjust to correct camber etc)

The theory was that CPs whilst having less ultimate grip were more progressive and forgiving but things seem to have moved on and many hillclimbers have changed from CPs to radials. This may be due to improvements in tyre technology/more availability of the softer compounds in radial format - others will confirm. Also radials used to be a bit dearer.

There are several threads on "uphill racers" which are worth a read

I still run CPs on my Reynard because that's what it came with and I haven't got round to changing yet

Anoyingly, that just about sums it up,

I always ran CPs and still would, but then my old Clubsport didn't have the adjustment to run Radials (and they were cheaper) The PR6 should be set up for Radials, however they will be Dunlops? and the characteristics and profile are different to the Avons as you should find in the previous threads.

[AJWSNR]

The problem on pr6 is to go crossply you may need to change to less camber and will run out of threads on rose joints when lengthened.We ran car in kirkstown at UAC sprint on sat and 2nd fastest behind pilbeam/milling ton ( 2.33 sec down) but ahead Reynard lotus. The radials run at 21 lb front and 22 rear. Make sure you bring temp oil/water before run. Werun elf wrf fuel as we. Cannot get 100oct in irl. Have fun!

[noodle1]

scooby151 said:

My e mail is [e-mail] ;-)
James

Cheers Ill get in touch soon once I've picked her up had a some time to get familiar.

[noodle1]

stiglet said:

Yes there's nothing to prevent you running softer compounds on the front, the theory being that you can warm your rear tyres before the start of a hillclimb but there's not a lot you can are permitted to do re the fronts.

I ran A92 (or the equiv. then) front and A15 (or eqiv.) rear. Great for Fintray hillclimb and Alford sprint but fronts used to take a hammering at Golspie/Boyndie so my sons were no strangers to the wood plane /rasp

Crossply v radial is a topic of its own and there are one or two old threads already on this you can look at. However worth checking that the info. is current (eg ability of earlier front suspension to adjust to correct camber etc)

The theory was that CPs whilst having less ultimate grip were more progressive and forgiving but things seem to have moved on and many hillclimbers have changed from CPs to radials. This may be due to improvements in tyre technology/more availability of the softer compounds in radial format - others will confirm. Also radials used to be a bit dearer.

There are several threads on "uphill racers" which are worth a read

I still run CPs on my Reynard because that's what it came with and I haven't got round to changing yet

That's some great advice, Id never considered different compounds front to rear, but it makes complete sense.
I'm starting to think the race weekend might get quite busy prepping tyres etc between runs, do you have any advice on this/tools to use etc? Something I've never dealt with
I've read various forums opinions on the CP vs radials and it seems like a tough choice, Ill check out uphill racers see what there opinions are, first season will prob be with the simplest setup for track nights with the Dunlop's to familiarise myself with the car and onto Avon's for the weekends

[noodle1]

SportsLibre said:

Anoyingly, that just about sums it up,

I always ran CPs and still would, but then my old Clubsport didn't have the adjustment to run Radials (and they were cheaper) The PR6 should be set up for Radials, however they will be Dunlops? and the characteristics and profile are different to the Avons as you should find in the previous threads.

Cool I think radials will be the way forward

[noodle1]

AJWSNR said:

The problem on pr6 is to go crossply you may need to change to less camber and will run out of threads on rose joints when lengthened.We ran car in kirkstown at UAC sprint on sat and 2nd fastest behind pilbeam/milling ton ( 2.33 sec down) but ahead Reynard lotus. The radials run at 21 lb front and 22 rear. Make sure you bring temp oil/water before run. Werun elf wrf fuel as we. Cannot get 100oct in irl. Have fun!

On average how long/ do you find it take to warm her up properly?

what temps am looking to be above for running?

is there Maximums I shouldn't exceed?

[mnrvortxf20c]

Your coolant will probably boil before you have any heat In the oil!
A pre heater would be great as engine hours are logged even if idle so of you spend 2 hours per event warming oil then That's 2 more hours off warranty.

[stiglet]

noodle1 said:

I'm starting to think the race weekend might get quite busy prepping tyres etc between runs, do you have any advice on this/tools to use etc? Something I've never dealt with

Rasp/Wood plane (ie manual) v Hot air gun

This is another topic on its own, and again there are threads about this on Uphill racers. My take on this (which may be wrong) :-

Manual

Pros - cheap , compact equipment, doesn't put tyre through extra heat cycle
Cons - Bl**dy hard work, takes longer

Air gun

Pros - Less effort, quicker, does a great job if the tyre has not gone too far.
Cons - Puts the tyre through a heat cycle (so I'm told) Needs a heat gun and 2kw generator (more stuff to lug to a hillclimb/sprint). Will not work too well if tyre has rippled ( you'll find out........!)

The secret to the manual option is to use a smallish plane (silverline No 2?) but keep it sharp. I take an oilstone to events. Also use plenty of soapy water. My sons used to do my tyres for me this way, but they have since mutinied.

I used to use the hot air gun at home only but have since got a generator so I can do this at events. A lot of folk running slicks carry 2kw gens. in their vans so there's no need to buy one straight away - you'll easily get a shottie of someone else's (mine?).

The secret to warming the engine is to do it two or three times first thing ( and after lunch) and not just once. As has been said it takes longer to get the oil warm than the coolant so run it up to modest temp. switch off for 10 mins and do it again. Modern oil is pretty clever stuff these days though and doesn't have to be boiling hot to do its job.

Good idea to use the harder tyres at Knockhill - I destroyed a set of fronts there at a private track session, but then I let anyone who wanted a shot of my Radical have a few laps

.....and it wasn't even for sale then

[andylaurence]

You've forgotten option 3 for tyre prep - don't bother! I'm too lazy to bother, so I just run the tyres as they are. I'm not sure what difference the tyre prep makes as I've never seen data showing it's quicker.