Setup ?

[RACR_73s]

I am having trouble getting correct %'s on 05 grt
Left 53.5...should be 52.5
Rear 56.4...should be 55
Bite is 149#
Battery is on left side next to cell and can be moved to the right side but my ? is what does having too much left do to the car? What about too much rear?
Weight is on right side in middle under deck 100#

[sj valley dave]

Rear % How big a fuel cell and how much fuel?..

[TALON75]

Make sure jbar is the correct length and position and the wheel offsets are correct, the position of the rearend left to right can have a big effect on left side weight, might want to also check wheel base, if your a bit short you will have more rear. Just a couple ideas?

[RACR_73s]

Rear % How big a fuel cell and how much fuel?..

30 gal with 20 in it like GRT says. Normal feature is 15 laps in my limited division and if I ran super it probably wouldnt be more that 30. ~Thanks~

[RACR_73s]

Make sure jbar is the correct length and position and the wheel offsets are correct, the position of the rearend left to right can have a big effect on left side weight, might want to also check wheel base, if your a bit short you will have more rear. Just a couple ideas?

Panhard is 19 1/4 like GRT states, not sure I have the angle correct as both my mounts are adjustable and dont have holes as they state for a starting points. Have not checked wheel base as of yet, but is set to GRT lengths as to being square in the car...have not dropped the RR back a 1/4-3/8 like GRT says as of yet...undecided if I was going to do it as I like a tighter car and do not like the tail end hanging out...also dont like alot of stagger for the same reason. ~Thanks~

[lovinlatemodels]

Too much LS% you will loose side bite on a car not knowing a GRT or weather your numbers is with or with out driver for me 53.5 with driver should be OK. And a heavy R% can be good on corner exit for drive but will hurt on corner entry making the car loose 56.4 is alittle much i think i would try moving your battery foward and right. We actually ran are's just behing the motor plate on the right side of the car and this was with a all cast iron motor and still had 54 LS and 54.5 R.

[sj valley dave]

When the track goes slick, move your ballast up higher on the frame and that will help the car roll over and will help with side bite...We have an old underslung GRT and went with a 16 gallon cell mounted high in the frame, close to the deck and moveable.

[drtrkr244]

Try scaling car with 15 gals of fuel. 20 gals is just a starting point. In a 15 lap feature, you will only use 2-3 gals.

If that makes car too light, add weight to fifth coil upper bar. That will change % very little.

[RACR_73s]

Thanks to everyone for the advice. Sorry I should have been more specific...the car must weight 2400#(@ 2440# right now) and numbers are with diver(240#). Going to move battery to the right and take 5 gal out of cell and see where I end up.

[drtrkr244]

Thanks to everyone for the advice. Sorry I should have been more specific...the car must weight 2400#(@ 2440# right now) and numbers are with diver(240#). Going to move battery to the right and take 5 gal out of cell and see where I end up.

You just need a smaller driver....LOL

At least, you dont have to add alot of lead like most of us!

[dualdj1]

With where you run I don't think you'll be out of line with that. too much left makes it "harder" for weight to transfer to the right going through the corner. the more rear you have, the more the car wants to go straight (or in whatever direction the rear axle is pointing). The more you push down on a solid axle, the more traction it gets, allowing the rear tires to slip less (until they break loose).

what's your cross at?

[MasterSbilt_Racer]

Thanks to everyone for the advice. Sorry I should have been more specific...the car must weight 2400#(@ 2440# right now) and numbers are with diver(240#). Going to move battery to the right and take 5 gal out of cell and see where I end up.

53.5 is on the low side for left percent with driver. GRT states 52.5 WITHOUT driver.

I think you should just lose some rear percent.

[joedoozer]

I have an older Warrior that had a huge 32 gallon cell in it, and it was mounted low in the car. I have down sized to a 16 gallon and have it mounted as high as possible. It made a big difference in the car. As far as making the cell movable, I can't move mine up or down, just not enough room. I didn't make mine movable left to right. I got it centered between the wheels so Bite doesn't change as fuel burns off.

It really depends on what you are trying to get the car to do. And if you are in a "Limited" class, I assume that means a motor with alot of restrictions; maybe even running against Crates? Lower HP motors tend to need less Rear% than a car with 600-700 hp. Something to think about.

[jason29a]

call Joe and tell him exactly what your running... your left is pretty close. Rear is heavy.... Especially if were not talking about an open car, and at 2400 pounds i doesnt sound like we are.

[RACR_73s]

53.5 is on the low side for left percent with driver. GRT states 52.5 WITHOUT driver.

I think you should just lose some rear percent.

Last time I talked to Joe @ GRT(couple months ago) he said that the %'s were with driver weight in the car. 2 yrs ago when I ran a GRT for someone else we did the setup without the weight in car. I am going to call in the next couple days for final setup help/questions and will ask again. ~Thanks~

[MasterSbilt_Racer]

Last time I talked to Joe @ GRT(couple months ago) he said that the %'s were with driver weight in the car. 2 yrs ago when I ran a GRT for someone else we did the setup without the weight in car. I am going to call in the next couple days for final setup help/questions and will ask again. ~Thanks~

http://www.teamgrt.com/2010_LATE_MODEL_STANDARD_CAR_SETUP_SHEET.pdf

He may have sheets both ways, but there is no sense to state what weight of driver these numbers are based on if the sheet is with driver.

A dirt car should have 53.5% to 55% left side weight.

[drtrkr244]

I used too be a crew member for the team car to Skip Arp, Joe told us the base setup included drivers weight.

Those cars are generally very tight in tacky conditions, so we would lengthen RR trailing arms .5 inch, just like the setup sheet says to.

Generally by the feature, we would take out the roll steer.

[MasterSbilt_Racer]

I used too be a crew member for the team car to Skip Arp, Joe told us the base setup included drivers weight.

Those cars are generally very tight in tacky conditions, so we would lengthen RR trailing arms .5 inch, just like the setup sheet says to.

Generally by the feature, we would take out the roll steer.

I don't see how they even turn with 52% left. LOL

[drtrkr244]

I don't see how they even turn with 52% left. LOL

If you've been around like I have, you've heard it said that GRT's run off of the RF. I did a roll center analysis on one years ago and believe me, they run off the RF.

They were really good on the oil based tracks back in the day.

Wherever you need a tight racecar, esp. the sandy tracks here in the south, they're hard to beat!

[sj valley dave]

I was told by Skip that the % were figured with out driver, but based upon a 200 lb driver, so adjust accordingly..I agree that if you only had 52% and that includes driver...good luck on getting it to turn...we are usually about 53.5-53.8% w/o driver start at about 53-54% rear on heavy track...go up to 56-57% if it slicks...820 HP

[RACR_73s]

Bolted some weight down today on the main right side frame rail up by the front of the X(30lb). Another chunk(45lb) above it on upper rail. I have another 25lb chunk that I am still trying to decide on where to put. Moved the battery to the right side behind the RR tire. Took 5 gal out of fuel cell.

25lb chunk up by fifth coil shock
L 52.4
R 54.7
C 53.3


25lb chunk over LR shock
L 52.9
R 55.5
C didnt check
LR 142#

All weights are with driver weight in car.
Moving battery to right side was worth about 1% loss of left side. Kept the left battery mount in the car so I could change back if I wanted.

Which would you start with and why?

Would you change anything and why?

I am leaning towards the one with lead over LR shock.

I called GRT and Joe was too busy to talk and didnt call me back so I will have to talk to him later.

~Thanks for all the help~

[sj valley dave]

We scale our w/o the driver...He is about 210 lbs...We are usually 52.8-52.9 LS w/o driver...start the night somewhere around 54% rear with 8 gallons of fuel and 75 lbs of bite

[drtrkr244]

I would be concerned with the battery mounted on the right side.Those cars are generally tight and that would make it more so.GRT, MB, Rocket all mount their batteries on the left with BWRC in the center.

With that said,if ur on a spec hard RR or the track tends to get sandy or slick by the feature, it might not be a bad idea.

Sometimes you just have to try things in dirt racing to see if it makes your car faster. Good luck

[RACR_73s]

Just got off the phone with GRT and asked again if # on web site were with driver and he said yes. When I sarted to explain what I did and what I was doing he said no those are without driver...with driver you need 54.5 left and 55 rear...These sound better to everyone?

Also he seemed preoccupied with work in the shop and I was not able to get good info on indexing the bird cages. He gave me a starting point of all the way to the back of the 3 slots and as high as possible...I take it that this provides the least amount of indexing? Do this on both sides? What does this mean/do compared to other options? When and why do you change this? What does moving up/down/forward/back do?

[WV_Race_Fan]

The closer to center of the axle the quicker the reaction and thrust.. I'm not sure about moving it foreward, The last set of cages we had that had that option were Berts and that was years ago.We have played with bar location on the birdcage in the past on both sides. If your car is hooked up, and your driver has a soft foot they may like dropping it on the LR 1/2" (at a time), as they don't have to work the pedal as hard to manipulate the car, but if the car isn't hooked up its a burden because it still reacts quicker and that can make it harder to keep the tires connected to the track (easier to break them loose).On the right side, dropping the top bar tends to loosen the car up on the throttle. Some drivers like this on a tacky track, especially if you frequently encounter tight on exit symptoms (GRT's typically do).I'd just worry about getting the car handling pretty good before I started making adjustments like that. Sometimes if the car isn't right, it can do more damage than good, but if the car is right, these changes can help you gain a little bit if used in the correct situation.Later,WV Race Fan

[RACR_73s]

Thanks WV, that helps. I am just trying to understand all the adjustments as best I can and probably won't get to this one for a while, but would like to understand what it does. ~Thanks again~