I used to run the BFG TA R1s on the Spit and thought they were pretty good.I
then tried a set of Dunlop Racing Bias Ply tires from Charlie Gibson
(Sasco). Initially I hated them. The feel was different, you thought they
were going to toss you in the weeds, the car felt less stable, etc. Then
after about the third session I started to drive the corners differently and
they seemed suddenly better. Three sessions later I thought they were the
best improvement to the car in 4 years. They are different than steel
radials, but they do talk to you and will let you through a corner with more
of an idea of how close to the edge you are. In my realm of ignorance, I
always believed the radials gripped well and then, with little warning they
would cut loose. The bias plys give lots of warning. I suppose it's close to
"seat of the pants" driving but it works. Just with the tire change, I was
able to drop a couple of seconds from lap times on most tracks once I got
over the difference in characteristics.
Keep in mind this is in a Spitfire, which of course is a far cry from a 3
or 4, but it takes time to make the adjustment. The latest thing now with
some of the Group 1 drivers are the less expensive Hoosiers. The Dunlops are
about $130 apiece and the Hoosiers are around $85 or so. I haven't tried
them yet but I may at some point in the future. But the admission of the
Hooser sales folks at the track, they are not as well a built tire as the
Dunlop and of course their price reflects that. Another advantage of the
Dunlop is the weight. The first time I picked up one of the bias tires I was
prepared for the weight of the heavy steel radial street tire. Darn near
threw it over my shoulder. There is that much difference in weights. Seems
like less unsprung weight is a good thing. I had "Doc" try a set of these
and he prefered the Yokahama steel street radials on his GT-6. (He might not
have played with tire pressures enough, I'm not sure, and there is certainly
a factor of "change" that many of us are uneasy with.)
I am under the impression there is a general trend at this point in some
vintage racing organizations to step away from radials and return to bias
plys. Any comment from FOT? As always, many of my rantings are based on
input from the sensory organ in the seat. (It will be getting used to a new
seat soon! That broke in the crash also!)
Best regards,
Russ Moore
Spitfire #49
At 05:22 PM 6/18/97 -0700, mike jackson wrote:
>Alexander Joseph H wrote:
>
>> After putting the headlights back in and moving the cooler to the front
>> of the radiator we are running hotter...just about to the peg. Plan to
>> put Water Wetter in and fabricate a little scoop under the valance. (Any
>> ideas?)
>
>We have the oil cooler set up alongside the radiator so it's not
>blocking any of the water radiator. Also essential to have excellent
>shrouding around everything up front so the air has proper motivation to
>go thru the coolers instead of around them.
>
>a hole in the chin, below the shelf also can bring air to that bottom
>part of the radiator. Shrouding from that hole to the radiator will aid
>the motivation of those little air guys down there too.
>
>have a gutted thermostat body where the old thermo was.
>
>A modern core between the two TR header tanks finishes the cooling
>system re-engineering.
>
>Rarely run hotter than 200 deg F, even in the summer
>>
>> Dont like the Hoosiers particularly well after the BF Goodrichs.
>>
>
>Takes time to adapt to the bias tires after running on the BFGs
>comfortably. I spent many races watching the apexes well away from my
>car when I made the change. Finally started to adapt when I discovered
>cursing wasn't helping and only a modification to driving style would.
>The biggest trick was to begin turning in earlier and shallower than
>with the radials. It also takes a while to get comfortable with the
>amount of slip they will develop while still remaining attached (sort
>of).
>
>mike
>
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