Dunlop Racing Tires

driller

driller

El Presidente
Staff member
In the search for front tires to run at the track, I found these...

http://photos.imageevent.com/driller/cdchanger/mini-DSC01352.JPG

I picked these up from www.rogerkrausracing.com

http://photos.imageevent.com/driller/cdchanger/mini-DSC01354.JPG

They are vintage Dunlop Racing 550-16 tires. They have a diameter if 27.1 inches and a tread width of 4.2 inches. I weighed them at 16 pounds each. They are a Dunlop "204" compound which is very hard and should result in minimum rolling resistance.

http://photos.imageevent.com/driller/cdchanger/mini-DSC01355.JPG

They are marked 175-80/16 and 68H which implies a speed rating of 130 mph and a load index of 68 which correlates to only 694 lbs. However, Roger assured me that for my intended use the load index would be of no consequence.

http://photos.imageevent.com/driller/cdchanger/mini-DSC01356.JPG

These tires retail for $328 each and he had them 'used' for $50 each. Used means they were most likely 'used once' in a race application. The tires are marked LF and RF and the tread block wear on the right side indicates they were used in circle track racing application.

The downside is they are tube type tires and consequently that will add a couple pounds to the wheel/tire combo.
 
RE: Dunlop Racing Tires

[div class="dcquote"][strong]Quote[/strong]
Cool. Are you going to mount them on a set of snowflakes?
[/div]

Nope, they will be mounted on a pair of rare 16" dia. x 4" wide 'spare tire' aluminum rims. I'm looking to get them mounted today and weigh the package. I'm hoping for 24-26 lbs each vs. about 50 pounds each for the Kumho radials on the chrome 10spokes. This should go real well with the Hoosier QuickTime Pro DOT drag tires on the snowflakes in the rear. That combo in the rear tips the scales at 35 pounds each without tubes. ;)

I was told to get the aluminum rims bead blasted and powder coated to match the Blue Flame. That may happen later, but for now they'll remain OEM black. ::uh::
 
RE: Dunlop Racing Tires

John, I don't want to rain on your parade, but those tires look hard
as rocks. If you need to haul it down fast will you have any braking?
The 1/4 mi track I go to (Tristate - IA) has 3 turn-outs to the
return road and I usually just coast out to the last one. I had
my stock front tires pumped up to 40+ lbs and I decided to brake
harder and take the second turn-out. I was shocked - with just
slightly more than average braking the anti-lock kicked in!
The smaller footprint made a big difference.
I'm re-thinking skinnies (call me chicken schist) due to a track
accident a week ago Sunday.
The son of one of our club guys was running a quick fox mustang (10-
11 sec) and at about 1000' something in the rear susp. broke.
He crossed the other lane, t-boned the guard rail, got airbourn
and a light pole t-boned him behind the driver door.
The car had slicks and skinnies, which left skinny little skid marks
from where he broke, all the way to the guard rail.
The roll cage held, but the impact broke his back in 3 places.
Spinal cord was not cut, but beat up bad enough that he is paralized.
Makes me think that some decent tires might have slowed him down
enough that he might have come out better, but we'll never know.
From now on, for me, stock fronts at normal pressure.

Mel C.
93 garnet/grey
Garage Queen
 
RE: Dunlop Racing Tires

[div class="dcquote"][strong]Quote[/strong]
John, I don't want to rain on your parade, but those tires look hardas rocks. If you need to haul it down fast will you have any braking?The 1/4 mi track I go to (Tristate - IA) has 3 turn-outs to thereturn road and I usually just coast out to the last one. I hadmy stock front tires pumped up to 40+ lbs and I decided to brake harder and take the second turn-out. I was shocked - with justslightly more than average braking the anti-lock kicked in!The smaller footprint made a big difference.I'm re-thinking skinnies (call me chicken schist) due to a trackaccident a week ago Sunday.The son of one of our club guys was running a quick fox mustang (10-11 sec) and at about 1000' something in the rear susp. broke.He crossed the other lane, t-boned the guard rail, got airbournand a light pole t-boned him behind the driver door.The car had slicks and skinnies, which left skinny little skid marksfrom where he broke, all the way to the guard rail.The roll cage held, but the impact broke his back in 3 places.Spinal cord was not cut, but beat up bad enough that he is paralized.Makes me think that some decent tires might have slowed him downenough that he might have come out better, but we'll never know.From now on, for me, stock fronts at normal pressure.Mel C.93 garnet/greyGarage Queen
[/div]

Yeah, probably not worth that extra 0.05 (at most) in the 1/4...
 
RE: Dunlop Racing Tires

Yes, they do look hard and they are a hard rubber compound.

[div class="dcquote"][strong]Quote[/strong]
I'm re-thinking skinnies (call me chicken schist) due to a track accident a week ago Sunday.[/div]

I appreciate the concern and duly take note. I have thought about safety, and braking is a key component in the safety equation. I've never had any braking concerns at the track and I routinely air the stock tires to 40-45 psi. I've occasionally left the track forgetting to bleed the air pressure back down, but I don't get far until the increased rickshaw ride factor reminds me. But then again, I'm no 10-11 second ride either.

I figure the first run on these tires will be different experience and I plan to adjust accordingly. But IMHO, it certainly has to be more safe than running on the T-type front runners I know I've seen so many others do.

Anyways, I had a tire shop mount the new wheels. One temp tire had to be cut off the rim for fear of bending the rim attempting to remove it on the tire machine. The tubes added slightly more than I thought. The new wheel/tube/tire combo weighs in at 29 pounds. Still significantly lighter than the 50 pound stockers and lighter than the snowflake/Hoosier combo(35 pounds). I suspect the reduction in mass will yield more than 0.05 seconds off the ET. If they do not, they are not worth the time to change tires at the track.

Next test is mounting and checking suspension clearance.
 
RE: Dunlop Racing Tires

Its a 13 second car you should have plent of braking distance and if you loose itn I would think it would be due more towards blowing somthing up/off and oiling the track and your tires down in the process. Your tires arent gonna make a huge difference when theres water underneith them. :p
 
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