Hoosier R100 blow out. Is this common?
07-12-2012, 12:34 PM
#61
Three Wheelin'
Thread Starter
going up to 34'ish will create other problems with the tire though. I found really uneven wear when I did that (34-36 range). These tires really need to be in the 30-31 range hot imo
07-12-2012, 12:38 PM
#62
Rennlist Member
Join Date: Aug 2003
Location: Naperville, IL
Posts: 387
Likes: 0
Received 0 Likes
on
0 Posts
I actually set my best lap time at 34psi...
That said, I'm not discounting what you are saying, perhaps the solution is to run Nitrogen to be able to run higher starting pressures and reduce the hot pressure increase... I'm going to try the next set at 33-34 and see if this problem goes away...
That said, I'm not discounting what you are saying, perhaps the solution is to run Nitrogen to be able to run higher starting pressures and reduce the hot pressure increase... I'm going to try the next set at 33-34 and see if this problem goes away...
...Things are looking better than the last time we met....
07-12-2012, 03:12 PM
#65
Rennlist Member
Running at a higher pressure such as 34-36, makes for a smaller sweet spot window, although you (or a really good driver)(and no that is not meant as a dig to you or anyone here) will typically be able to pull off a faster lap at that pressure. The higher pressure will skate a little more and scare a lessor driver into going slower, especially initially.
The trick obviously is being able to not overheat the tires and keep it in the sweet spot, and if you do overheat them then knowing how to cool them. It's harder to keep them in the smaller window which is why most people prefer to just use the lower pressures. But it's also part of the reason why people then have issues with the tires.
It's really just a loading issue. Additional tire pressure helps carry the load. That's why Hoosier always blame these blow outs on low tire pressure.
As for Hoosier occasionally replacing some tires for it, I'm sure if they saw a fault in any tire they would replace it, or if it were a real good customer they would replace it just as a goodwill gesture much like Porsche or any other smart business. Good business on their part.
07-12-2012, 05:40 PM
#66
Rennlist Member
And the drain spins opposite in Australia. Everywhere I've driven that applies. It has nothing to do with the car, it has to do with the construction of the tires. There is a reason that Hoosier, Michelin, Yoko, and anyone else that makes radial track tires tells you to run 25+ pounds in them. If you look at Goodyear set up sheets for bias plys, you'll see 18+ pounds recommended. But as always, YMMV.
So would you suggest running at e.g. 25lbs cold and keep coming in to bleed to the desired hot pressure level?
07-12-2012, 09:33 PM
#67
Rennlist Hoonigan
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
Our experience with nitrogen (or good dry air) is that we only see around 2-3 pounds increase, so it's not as big of a deal.
07-13-2012, 12:26 AM
#68
Nordschleife Master
Join Date: Oct 2004
Location: Vacuuming Cal Speedway
Posts: 7,306
Likes: 0
Received 7 Likes
on
5 Posts
Correct. Start with 25 or more, then come in and bleed until you get to your hot pressures. When you start with less than that, it's really easy to damage the tire carcass.
Our experience with nitrogen (or good dry air) is that we only see around 2-3 pounds increase, so it's not as big of a deal.
Our experience with nitrogen (or good dry air) is that we only see around 2-3 pounds increase, so it's not as big of a deal.
As for the only 2-3 lb. gain with N are you talking about go-carts on ice? I've never in 10 years of 6-cup racing seen Michelin, Yokes, Pirellis, or Hoosiers not gain at least 8lb. in a 30 minute session, usually more.....
07-13-2012, 07:00 PM
#70
Whether it's nitrogen or air the pressure will increase as the temperature increases. Pure nitrogen is less sensitive because it has lower moisture content. The condensation/evaporation of moisture content alters the pressure more significantly than for nitrogen with lower water content.
07-13-2012, 10:09 PM
#71
Rennlist Member
Well that's pretty impossible if you're starting out a race with stickers.
As for the only 2-3 lb. gain with N are you talking about go-carts on ice? I've never in 10 years of 6-cup racing seen Michelin, Yokes, Pirellis, or Hoosiers not gain at least 8lb. in a 30 minute session, usually more.....
As for the only 2-3 lb. gain with N are you talking about go-carts on ice? I've never in 10 years of 6-cup racing seen Michelin, Yokes, Pirellis, or Hoosiers not gain at least 8lb. in a 30 minute session, usually more.....
