ITB Golf weight??

[Flyinglizard]

How much weight do you have to add to your car to make weight?.
My 88 Golf car needs to be @ 2280. I have about 100# in the car. Is this about the norm?
And.. how heavy is your spare tire???
TIA,MM

[racer_tim]

Eat more Pizza.

[wcmcarlos]

Hi Mike,
My steel rim spare was very very difficult to balance.
Good luck at the enduro.

[shwah]

I carry 100#, carpet, insulation and sound deadening in the floor, fire bottle sysetm and handheld, and need to finish with 3/8+ tank. Looking at a cool suit addition for this year.

[Knestis]

Hi Mike,
My steel rim spare was very very difficult to balance.
Good luck at the enduro.

Right.

Some of us really hate the "nudge, nudge, wink, wink" crap.

K

[lateapex911]

Kirk, reading that makes the fishing easier though!

[shwah]

Hi Mike,
My steel rim spare was very very difficult to balance.
Good luck at the enduro.

Meh. Why would you try to increase the moment of inertia to rotate the car? I don't need more weight way out back myself.

[quadzjr]

I think it is less to do with the rotational moment of inertia, and more to do with trying to balance the car.

[mossaidis]

oh, I thought spares tires must be removed... (I remember some old story of a volvo in the soutwest and something about concrete... you might know the rest)

[Knestis]

Spare tires MAY be removed. There's no provision that they may be modified.

K

[JamesB]

I carry 80# of weight and must top off the tank. I think ill have to add another 20# to the car with the new MARRS format with the longer Sunday races.

[shwah]

I think it is less to do with the rotational moment of inertia, and more to do with trying to balance the car.

Isn't that an oxymoron for these cars?

Seriously, I think we get too caught up in the 50/50 myth, especially with a low power fwd car. You can't get the balance 'right', so why not focus on making what you have change direction more easily?

[Flyinglizard]

Thanks for the help. I am not too far off.
Less front weight will usually go faster. Ice and dirt racing excepted. That is why the Jetta is a better race car. Much better balance . MM

[shwah]

Oh i do agree with that. I remove all of the front weight that I can within the rules. I just don't compensate and put it back at the opposite end. I don't want to race a dumb bell. I put the weight on the floor, at the lowest point I can, and take whatever I can off the front. The Jetta vs Golf piont may well be true, but is a different issue. I have pondered that one a lot, and think the Jetta would be a better enduro choice, but considering that shorter cars fit into smaller spaces, and can complete a pass in less space makes the Golf a better sprint race choice.

I still would like to build a Jetta just to test it though.

[quadzjr]

Isn't that an oxymoron for these cars?

Seriously, I think we get too caught up in the 50/50 myth, especially with a low power fwd car. You can't get the balance 'right', so why not focus on making what you have change direction more easily?

it may be kinda of an oxymoron but the 50/50 weight distribution is not a myth. You can increase the balance of the car by leaving weight on the rear of the car, this will make it more stable under braking and long sweeping corners.. If you want the car to change direction quickly you can always run the rear nearly rigid and just point the front where you want it to go.

there is some middle ground.. you just have to find where you are comfortable or faster with.

[shwah]

10 or 15 years ago one of the Honda BTTC teams acheived 50/50 on their car. They then put more weight on the front because it was slower. I agree that we all have too much weight on the front. I just don't think the solution is the put weight in the very back. We cannot achieve a very desireable distribution in our class, we can't really put much of a dent in it, so I focus on lower CG instead. There are very heavy things that we can put where we want - on the floor. Driver, ballast, fire system, cool suit system. That is what I place my focus on.

It probably matters how the rest of your car is set up. Take enough rear brake away and the car is plenty stable under braking. Run a locker diff and it will go where you point it with throttle. If you are not set up that way, or don't drive that way you might want different weight distribution.

I personally put a lot of value on being able to catch the car if needed, and extra weight behind the rear axle will have the wrong effect on that attribute.

[quadzjr]

I am glad we agree.. it all depends on driver style, and setup. adding more weight to the rear will keep the rear in check easier however when it does start to come around, it will be a little harder to stop.

Currently building a ITB MR2. and with weight distribution coming in prodominately towards the rear, and most the weight lost came from the front or middle of the car. am major difference is noticed when adding weight to the front of the car. In my street car MR2 just adding a heavy bag of tools to the frunk dramatically increases turn in and mid corner traction.. I haven't done a test day with racecar with tools up front yet however :D

[shwah]

I think you have made an excellent choice of a car for the class. I know there are power limitations, but that thing has serious potential in B. Glad to see more cars getting built.

[quadzjr]

we will see.. I am not putting much money in it just yet.. working on jsut gettin track time first. will be running on old sets of hand me down tiers and wheels a motor that is of unkown quality, and replacing parts as they break.

All money and time.. then more money and time :happy204:

[racer_tim]

That's what you want to achieve is 50/50 cross weights, but you will never get there because gas weighs how much a gallon? and how much fuel do you use in a 1/2 race?

[quadzjr]

gas doesn't affect my cross-weight as much as it does others.. seeing that the tank is between the driver and passenger, and in the exact middle of the car :D. I thought about adding a fuel cell in the frunk, but then my turn in characteristics would change farily dramatically during the race.

Cross weights is what we focus on first when setting the car up. It is usually the easiest to get close to 50/50 first with 100% legal adjustments. Then from there you can try to move the wieght front back without adjsuting the ride height out of wack.

[Bill Miller]

But that's one of the beauty things about an AW11 MR2 Tim, the gas tank is in the transmission tunnel, almost dead-center, front to back. So your X-weight percentage should be close to the same regardless of how much fuel is in the tank.

/edit/ Damn, should have clicked on the 2nd page before responding!

[racer_tim]

Sorry, I've not had an A2 to compare with my A1 Wabbit.