25 Hour race tire changes and fuel stops

[Tim Comeau]

I'm still looking at entering this race. In the non-ES and ESR classes you can only change one tire per stop in the pits, but you can change all 4 in the paddock.

Have you guys been going to the paddock to change tires? Or rotating once, then changing all 4?

Regarding fuel stops, we can only add 10 gallons at a time! How many stops is that?! Any known reason for limiting it to 10 gallons at a time?

[Allegro Racing]

we never equally wore out more than one tire at a time on the Civic so it wasn't a big deal to spread the changes out but if we needed to do two, we could either go back to the paddock or simply go, do a lap and stop (more time consuiming). IIRC, you can rotate tires in a pitstop so we could maximize tire wear since we always wore them out in the same order and predomenantly "outside" tires wore FAR faster than "inside" ones (particularly with FWD).

 

I THINK the reason for the 10 gallon thing is to keep things relatively simple and safe and not have everyone buying fuel cells with dry breaks and huge storage tanks but that's just a guess.

 

Too bad those things are so expensive though, our ATL can with closed-loop fill/vent system is 100X safer than dumping fuel from 5 gallon cans and trying like hell not to spill. Since "overflow" comes back up the vent into the fuel can, we can't "spill" unless for some reason the dry-break jammed open (VERY unlikely).

 

But you start to get into thousands of dollars for that stuff if the car wasnt designed with it.

[Tim Comeau]

Any other input? Experience?

[civicrr]

Tim,

It all depends on the team. Your car's tire wear will tell you what you if rotating is a viable option. How fast will your crew be? As far as what we did....it is the same as the Allegro team. 'Cuz, I learned most of my enduro stuff from them. I crewed for them for 2, or was it 3, years.

 

Rotating tires is legal. You can rotate all four if you want or change one tire. You can't rotate & change a tire in the same stop.

[Tim Comeau]

Thanks for the reply.

I know the rules well. They just don't seem very workable. I'm trying to find out how other teams deal with these restrictions.

We'll have greater wear on one side, right? We'll rotate sides and maybe one front to rear. THEN, we'll need to replace all 4 tires because they will have worn out completely at the same time. See my point? We can't change more than 1 tire unless we go to the paddock at 5 mph. How close will my paddock spot be to my pit space? See what I mean? Unacceptable time loss.

We can't change 1 tire, do a lap, then change another tire. Unacceptable time loss.

The time loss would be really horrible.

And only 10 gallons of fuel at a time? I've considered entering my E2 car in ES so that I could change tires as needed and take on a full tank when I stop for fuel! We'd just go for an overall finishing position.

[slammed_93_hatch]

my guess is that, its all part of an enduro. It forces cars to make pit stops, and throws pit stop and stratagy into the game.

[Allegro Racing]

Remember, too Tim...the enduros get more difficult sort of as the square of the time they run...not scientifically but you'll find that a 12 hour is several orders of magnitude harder than a 3 hour and the 25 hour...well you get the idea.

 

So you and your drivers will have to be running a pace that they and the car can handle for that period of time. Since time lost in the pits nearly always exceeds what you can make up on the track (if you are 1 second a lap faster than everyone in your class and take 40 seconds longer in a pitstop, how much advantage do you lose?)....so this means CONSERVATION of brakes and tires and gas and the car (clutch, gearbox, engine).

 

It's true if you have unlimited $$$ and a Porsche GT3, you can run pretty much flat-out the whole time but for the rest of the world ENDURANCE is the key and driving to a reasonable pace that's not going to have you sitting in the pits any longer than is absolutely necessary will win the day.

 

ALSO, SURVIVAL will be a huge factor...more time (by far) will be lost if your guys spin or contact other cars and do some damage or go off course...so it's the ability of the team to stay focused, run to a pace, not make mistakes and also to carefully monitor the health of the car that will ensure success.

 

That's the endurance part of endurance racing. The 3 hour races are extended sprint races and you'll find the longer races require far more planning, preparation and conservation.

 

Good luck! All this talk is making me almost want to do the 25 hour this year...where's my rain gear

[Tim Comeau]

Yeah, I'm hungry for it too.

Thanks for the words of wisdom.

I appreciate it.

[Allegro Racing]

I HIGHLY recommend changing your wheel bearings before the race.

 

We won the 12 hour 3 years ago in E1 with a car with a failing wheel bearing and it was only because the 2nd place car spent 35 minutes in the pits (having the world's fastest Porsche 944 clutch replacement done) that gave us enough margin to win the class.

 

The stuff that starts that race "weak" or "used" will likely wear out or fail in the course of the race and if you work backwards from "most difficult to fix at the track" you'll spend some money but further increase your chances of finishing without extended pitstops.

[Tim Comeau]

Fresh clutch, fresh bearings already done........thanks.

More good advice though.

[FCYTravis]

I crewed for the E0 class-winning Bullet Motorsports BMW 325i last year, and because that team isn't running this year, I'll let you in on a little secret...

 

We changed tires ONCE in the whole race. One four-tire visit behind the wall and that was it. Still won our class going away, and finished seventh overall.

 

You don't have to have a megabucks tire budget and change 'em every 2 hours to run well at the 25 - it's all about running the right tires. Remember, it's not so much about speed as it is about survival... for an E2 car I don't see the point in going to ES just to change tires all the time. You'll lose far more time in the pits than you'll gain by running gumball slicks.

 

Blatant plug: the tires were unshaved Michelin Pilot Sport Cups.

[Tim Comeau]

Well.........that's certainly a fresh perspective. Thanks.

I guess you just assume everyone will be running the fastest tire they can afford while they're trying to stay alive.

Interesting........

[racercosmo]

In 2002, we did the entire 12 hour on one set of Ra-1s. This was in an E-3 car

[NASA Jim]

Instead of rotating all the time, why not just replace that one worn out tire on the heavy side? That way when you come in for gas, you just change one tire and probably won't have to change all 4 at a time except maybe once... of course depending on your car... and don't forget how a good flatspotting can ruin your day.

[Marc Rovner]

In previous 12 our races we have changes one tire at a time. 3000lb camaro changes RF on 4th stop (aprox. 6hr) and RR on 5th stop (aprox 7.5hr). Left side made 12 hours. These were RA1's.

[racercosmo]

Tim, another thing to remember is that if you are running a similar car and have similar tires, your competitors will most likely be down for the same amount fo time for tire changes.

[Tim Comeau]

Just incredible!............I had no idea.