New fuel cell and tire position

MTPyle

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So we are doing a new fuel cell and trying to figure out the best way to put the tires.

we can center stack but it makes the truck a little longer and lower in the rear.

currently are tires are flat next to each other.

my question is will having all the weight in the middle make it less stable? Do the tires going out wider give more stability?

with center mount the over all CG would be lower but more mass in the center. What’s the opinion on which is better for handling?

Mike
 

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michael.gonzalez

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If your behind the axle fuel cell has cutouts for the stacked spares, do that.

Think of your mass concentration goal like an arrow. They fly straight. Lower CoG is always a plus.

I've never been a fan of the lay-down side-by-side configuration.
 

E motorsports

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Like MG said the lay down stack config will also make for a longer second flat
tire change because the need to remove the carcass of the first flat to access the good spare and then rerack both
 

michael.gonzalez

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I think having the fuel-cell centered behind the rear axle, with vertical spares on either side is the ideal setup. No stacking. No high CoF.

Fuel is heavier than tires.
 

TMorford

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Didn't you shell out the coin to SDG to set up and tune your truck? If so you might want to ask them what they think is best before they have to rework everything.
 

MTPyle

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Brenthal puts tires on outside vertical.

The Fuel cell and tires are and have to be behind the rear axle. The axle travels up in front of cell.

TMorford, Good point I will reach out to them. But this is more of a builder question. I think they can re adjust for more weight back there from a balance standpoint. But I am more thinking about how the CG works. Center mass vs outside mass.

I read somewhere that driver and co driver out to the outside helped stability compared to driver in tight and or behind each other. Thinking the outside wight acts as a out rigger balance.

Mike
 

MTPyle

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that photo of our truck i posted above has all types in the image. but the double stack on the Armarda has a shelf, which we could do. The vertical on the brenthal you can see in the background as well.

Another benefit of the stacked or vertical compared to our set up is its easier to get in the trailer. LOL now we have to take the spares off.

I agree we do not want a single point of failure too lose both spares.

But if we are changing the second tire we are not in the race anymore and might as well do our 8 min tire change we did at the Legacy race. LOL

Mike
 

MTPyle

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We have an enclosed trailer and with the tires on and the bed sides its too wide. We have to take the spares off and we collapse the rear fender mounts to slide in the fenders. Its a tight fit. LOL

Mike
 

SMS81

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Stacked works good and you can use them individually. Straight up and down is easier to change and re-rack. A good shock tune will make both work. Lower equal CG is always better.
 

MTPyle

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Jerry,

Do you have that set up for 40" or just 37" tires?

Mike
 

CHASETHISTOO

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MTPyle

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I think we are going with the set up like the new Geiser trucks. Keeps our tires balanced and out but lower and we get more fuel. I also think it will be aerodynamically better.

when we looked at the other type the fuel was higher and we want to keep the center of mass lower but spread out. Should be the best combo.

I am sure there are some pros and cons of every set up but this fits what we want to do. Also moving the jack and getting a bottle jack also.


Mike
 

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