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Author Topic:   fuel cell
gould
Dirt Maniac

Total posts: 125
posted January 28, 2003 09:37 PM
i got a 22gallon cell with a stainless steel can. hehe. anyways where do you all have yours mounted. i have no scales so im shooting in the dark. some say to the left and some say staight up in the middle.

racer17j
Dirt Forum Champ
Total posts: 1565
posted January 28, 2003 09:45 PM UIN: 54865418
depends on who you ask we have all our cars with it as far to the back and left as we can get it

chad01j
Dirt Full Roller

Total posts: 27
posted January 28, 2003 11:05 PM
ive been thinking about this question for a while...tell me if this makes sense...
as a race goes on you burn fuel thus making the left right or center of the car lighter, depending on where the fuel cell is located. Also as a race goes on the track gets dry. so if you mount the cell to the left you are taking weight off that tire as the race goes on. this will tend to make the car loose, which is not what you want as the track dries out. if you mount the cell to the right you will loose weight from the right rear as the race goes on, thus tightening the car up.
personally i have always put my cell in the center but,thought this idea made sense. does anybody else agree?????

racer17j
Dirt Forum Champ
Total posts: 1565
posted January 29, 2003 12:29 AM UIN: 54865418
we only burn about 5 gallons all nite and we also can't run weight jacks or offset wheels so in order to get my cross weight anywhere near right i have to have it to the left plus i'll add the mud i get from hotlaps and my heat and put it down in the trunk to help that also

outlawstock17
Dirt Forum Champ
Total posts: 620
posted January 29, 2003 07:24 AM
the current trend is like 17j said, left and back. i also like to mount mine up a little higher than some to raise the center of gravity and induce some body roll.

c21
Dirt Freak

Total posts: 346
posted January 29, 2003 11:08 AM
quote:
Originally posted by chad01j:
ive been thinking about this question for a while...tell me if this makes sense...
as a race goes on you burn fuel thus making the left right or center of the car lighter, depending on where the fuel cell is located. Also as a race goes on the track gets dry. so if you mount the cell to the left you are taking weight off that tire as the race goes on. this will tend to make the car loose, which is not what you want as the track dries out. if you mount the cell to the right you will loose weight from the right rear as the race goes on, thus tightening the car up.
personally i have always put my cell in the center but,thought this idea made sense. does anybody else agree?????

Chad,
add some weight to the left rear of your car while it is sitting on the scales .... you will probably be surprised. Most of the cars I have worked with will gain cross as weight is physically removed from the LR corner. Seems counter-intuitive, but like I said "check it out"


The benifit of removing LR weight as the race progresses is 2-fold. In many cars it INCREASES cross (2-3 tenths of a percent over the course of a Main in the case of my own car) and .....in all cars it reduces left side weight .... which can be benificial if the track is getting slick and you run a high static left percentage... because ... removing leftside weight has a very similar effect to sticking your LR tire out (or pulling your RR tire in) in that it moves your CG location to the right relative to your drive force (rear tires) ... which... all else being equal will tighten your car up.

c21

[This message has been edited by c21 (edited February 03, 2003).]

gould
Dirt Maniac

Total posts: 125
posted January 29, 2003 05:13 PM
well looks like its goin on the left side, seeings as i will be racing a track the does tend to get dry slick. thanks guys!!

chad01j
Dirt Full Roller

Total posts: 27
posted January 29, 2003 06:19 PM
well i guess i was wrong. like i said i have mine in the center. its raised about 4 inches also

bobaluuu
Dirt Full Roller

Total posts: 56
posted January 29, 2003 10:12 PM
C21/ my question on this is on a wet tacky track that never dries or slicks up wouldn't a center tank help a car that tightens up as race progresses

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Light it up, Baby!

c21
Dirt Freak

Total posts: 346
posted January 30, 2003 11:53 AM
If your car truly tightens up as the race progresses and ..... you were going to address the problem with fuel cell location alone (and could get your desired static corner weights back by shifting ballast)... then moving the fuel cell as far forward and as far to the right as possible should be the best location for you.

Mounting it to the right should have the opposite effect of mounting it to the left... and... mounting it forward reduces the rear percentage loss (thru fuel use) making the car tighten up less as the race progresses (by virtue of having a lower increase in front percentage as the race progresses).

However, I wouldn't bother redesigning your car to take advantage of this small amount of dynamic tuning.


I would look closely at how your tire pressures are changing as the race progresses (and if indicated... play around with different pressures, looking to lower the differnce in change between the 2 diagonals) and if nothing else, consider getting the water out of your tires.

Victory By Design 27K
Dirt Roller

Total posts: 11
posted January 30, 2003 05:00 PM
how high you mount it depends on how much body roll you want. As left and right goes, make a mount that you can move the tank either way at the track. Start in the center and play with it to see which way your car handles best.

gould
Dirt Maniac

Total posts: 125
posted January 30, 2003 07:11 PM
imca rules state "no adjustable fuel cell mounts. i'm gonna set it to the left side and to the rear

DL406
Dirt Roller

Total posts: 16
posted January 31, 2003 07:14 PM
c21 Your post stated that burning off fuel from a lr tank position decreases cross weight a small amount. I have always found that by removing fuel from my lr fuel cell I increase my cross weight a small amount,frame height is higher.

Flatlander
Dirt Freak

Total posts: 310
posted January 31, 2003 08:11 PM
I mount mine to left and back and I raise the right side about 3" higher than the left I don't over fill it but htis places mor weight where you wanted it to stay to help your setup

Big Dawg
Dirt Full Roller

Total posts: 36
posted February 01, 2003 03:51 PM
Depends on what you like,I have mine to the left as far as I can get it,also as high as you can get it,for more roll over.I have mine back pretty far in the car,but if it is to far back you might get a little of the swinging weight affect.

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Kent
Dirt Roller

Total posts: 24
posted February 01, 2003 04:32 PM
Check the rules at the track or tracks you will be running at. The track I am going to be running at requires the fuel cell be located in the center of the car with a minimum of 10" height from the ground in race configuration. It just might save you some hassel to check out the rules first!

c21
Dirt Freak

Total posts: 346
posted February 03, 2003 10:10 AM
quote:
Originally posted by DL406:
c21 Your post stated that burning off fuel from a lr tank position decreases cross weight a small amount. I have always found that by removing fuel from my lr fuel cell I increase my cross weight a small amount,frame height is higher.

DL406,
Thanks for reading my post more carefully than I did (boy am I embarrassed).

You may have noticed that I posted ....

" you will probably be surprised. Most of the cars I have worked with will gain cross as weight is physically removed from the LR corner. Seems counter-intuitive, but like I said "check it out"

The benifit of removing LR weight as the race progresses is 2-fold. In many cars it reduces cross"

..... I clearly typed "reduce" when I meant "increase" (although you should notice I disagreed with my own previous statement in the same post).

anyway, thanks for pointing out my mistake ... so I can correct it.

c21



DL406
Dirt Roller

Total posts: 16
posted February 03, 2003 09:07 PM
c21 I thought that is what you meant. Read all your posts and believe me I get crossed up on some of this all the time. Thanks for being a gentleman and not offended. Also thanks for all the knowledge and advice you share with us. DL

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