What Would Cause a Car to do This?

[RACR_73s]

I have a 2005 GRT and the last 2 weeks it has started to pick the LF way up of the ground when I pick up the throttle...especially on the high side. It was picking the LF up the first night out and I was told by another driver to set my LR chain to not exceed 45%...problem solved. Have not changed the setup...what could be some possibilities to look for? Could a shock or spring have gone bad?

Here is my setup

Info for 2007 and previous year models:
RIDE HEIGHTS��(CHASSIS #2938 and before, Standard Front End, Black Spindles)
LF: 3�� Top of Lower Control Arm & Bottom of Frame (2.5�� on cars with gray spindles)
RF: 3" Top of Lower Control Arm & Bottom of Frame (2.75�� on cars with gray spindles)
LR: Will be set with the amount of bite
RR: 4.25�� Top of lower under slung & Bottom of Axle Tubes

STANDARD SPRINGS
LF: 550 RF: 350
LR Behind: 250 RR: 225

SHOCKS (MY #'s) SLICK TRACKS
LF: 75 RF: 75 LF: 5-3 RF: 3-5
LR: 7-2 STD RR: 94 LR: 7-2 RR: 3-4
Oil double adjustable afcos

BITE
130 LBS LEFT SIDE 54.7% REAR 55.4% (MY %'s)

TORQUE ARM
73-6 Shock with 325 pound spring and 75# gas
Approximately 3�� travel on 36�� center to center(Don't know the travel and mine is 32 c/c)

REAR END LEAD
Right rear back 1/4�� to 3/8��(Mine is straight up)

FRONT END ALIGNMENT:
CASTER: CAMBER:
LF: 1.5+ LF: 2.5+
RF: 3+ RF: 3.5-
Toe: 1/4 to 1/2 out

NEW STYLE PANHARD BAR BRACKET
�� Bottom of Frame to Bottom of Bracket (8 3/8��)
�� 3rd Notch up on chassis, 2nd notch up on pinion
�� Panhard bar: 19 1/4�� center to center

4-BARS (STANDARD)
Left Lower: 3rd Hole up (6 to 7 Degrees)
Left Upper: 7th Hole up (23 to 25 Degrees)
Right Lower: 4th Hole up (Level)
Right Upper: 5th Hole up (18 to 20 Degrees)

LR chain set to max at 44 Degrees to keep lf down

This is as close to GRT setup as I can get with what I have to work with as far as shocks.
Car weights 2450# and must run on LM40 Hoosiers and has steel block 550-600hp

~Thanks~

[Matt49]

If nothing is bent or in a bind, I'm guessing your RR shock has gone soft.

[RACR_73s]

What could be bent or in a bind that would cause it? ~Thanks~

[Racer111]

Check lr birdcage for a bind..or coilover

[RACR_73s]

Checked the RR shock today and it seems good. Just ran out and checked both birdcages and they rotate nicely. Thanks for the suggestions and keep them coming.

[BTDT]

If you are 100% SURE there is no binds of any kind and the shock is good. Go up 25lbs on the RR spring but I am with Matt I think the shock is suspect.

[LMracr17x]

I'm with them. Either your RR shock is giving up as it heats up, or another alternative is that your LF shock is binding and not allowing the LF tire to keep in contact with the ground. I had this happen once. I thought I was carrying the LF more, but in reality the car was rolling over the same, but the LF shock had gotten dented and wouldn't extend to allow the tire to stay in contact with the ground. Just a couple of ideas. Good-luck.

[grt74]

2 things i can think of if everything is free of binds,1st check the angle of your fifth coil and the bottom left bar is up hill alot from your post,just read it again do you have a chain limiter on the lr,the post says rr??you really need a chain on both sides even if it is an under rail car,that is on your bars angle part of the post

[dirtdiggerracing]

could have losed rebound in LR shock or SHOCKS !! JMO

[RACR_73s]

2 things i can think of if everything is free of binds,1st check the angle of your fifth coil and the bottom left bar is up hill alot from your post,just read it again do you have a chain limiter on the lr,the post says rr??you really need a chain on both sides even if it is an under rail car,that is on your bars angle part of the post

Thanks for pointing that out, it was in the wrong place...I corrected it. My 5th coill is straight up and down like it has been from day one... will check tomorrow to see if it is loose. I do not have a chain on the RR and it is an underail floating X. 6 degrees is alot of angle for bottom left bar? I drop it one for the feature and it was still pulling LF...makes it hard to see car underneath while running the top. ~Thanks~

[merc123]

Lay your shock out in the sun for several hours. Then check it. Had a friend had a "good" shock when it was cold but had it laying in the sun and it was bad when it got heat in it.

[RACR_73s]

could have losed rebound in LR shock or SHOCKS !! JMO

Checked all shocks today and replaced the RR just because maybe it might be the problem even though it seems good. The right front seemed to have a soft spot on compression the first couple times I cycled it but I could not get it to repeat...so I changed it also...will try it again tomorrow and see if it does it again. LR shock seemed fine as well as the LF so I did not change them.

If I put more rebound in the LR and more compresion in RF and RR would that help? (I have an old set of the oil double adjustable AFCO's)

[RACR_73s]

What is the correct way to check the car for a bind? ~Thanks~

[jedclampit]

Did your chain stretch?
Is there more grip in the track?

[LITE-INN]

ask dirtmod17x he knows it all

[fletch lives]

check your LR bite. You might have to much. Check all your wheel weights. I had same problem and found my wheel weights were off. to much LR and lost LF weight.

[RACR_73s]

Did your chain stretch?
Is there more grip in the track?

I am unable to check the chain right now (car is on jackstands waiting for a lower contol arm) but I will check it. There was a little more grip this week but I was able to keep it down on tackier tracks before. Thanks for the chain idea I never thought of it stretching. Do you have to replace them often or just keep shortening it? ~Thanks~

[RACR_73s]

check your LR bite. You might have to much. Check all your wheel weights. I had same problem and found my wheel weights were off. to much LR and lost LF weight.

I did not realize that LR bite would cause this. I have been going up small amounts on LR to fix my handeling problems and this was the one that was supposed to fix all (losen entry/tighten middle-exit). It was not losening entry early in the night enough so I moved the RRU bar down 1 hole last week and went up alittle more on LR and it was much better in. From the begining of the year til now I have gone up 20# of LR and the LF-RF split has gone from around 85# to 60#. I think I can go back to about 125# LR now with the RRU bar move to fix entry, but what is the best way to fix what I will give up on middle and exit? The way I see it on the GRT adjustment guide would be to raise the LRU bar. Also would moving the 5th coil towards the front of the car help keep the LF down? Mine is at 32" and GRT recomends 36" (1/4 mile with what I would call a medium banking) Thanks for the input.

What does everybody think about this idea?

[fletch lives]

Everybody on here has good points. But it cant hurt to just throw it on scales and double check your weights. especially since you said you kept putting more LR in it to free up entry. Something might have loosened up and coilover might have backed off or something somewhere else. You can flatten J-bar a little to free entry or even soften up LF spring a little to free entry instead of keep jacking LR into it

[RACR_73s]

Everybody on here has good points. But it cant hurt to just throw it on scales and double check your weights. especially since you said you kept putting more LR in it to free up entry. Something might have loosened up and coilover might have backed off or something somewhere else. You can flatten J-bar a little to free entry or even soften up LF spring a little to free entry instead of keep jacking LR into it

Good point but I always scale the car every week just to make sure nothing like that has happenned. The numbers I stated came from my weekly setup sheets. ~Thanks~

[Matt49]

With regard to checking for binds, this is how I do it.

Rear:
Remove shocks and springs. Put jack under center section of rear-end. Move rear end through range of motion (should be like a seesaw on the jack) and check 4-bars on each side to make sure they rotate freely through all points of the range of motion of the rear-end. Do the same check for the j-bar through all points of the range of motion of the rear-end. Also through all points of the range of motion of the rear-end, make sure the drive shaft rotates freely and does not bind or bottom out in the transmission tail housing.
Put shocks back on car and check to make sure that the shocks all spin freely though the rear-end's range of motion
Front:
Remove shocks and springs. Move RF spindle up and down through full range of motion. Keep moving it up and down rapidly while someone else turns the steering wheel through its full range of motion. Repeat that process for the LF. Put shocks back on car and check to make sure that the shocs spin freely though each sides range of motion (steering won't affect this so no need to steer it on this part).

Hope that helps.
Remove

[m_stagev]

with the 5th spring at 32" i cant see how i wouldnt pop wheelies.that is the best way i know how to keep the lf off the ground.

[RACR_73s]

Did your chain stretch?
Is there more grip in the track?

You were right...chain stretched. Top bar angle was at 51 degrees...shortened it 1 link and and bar angle is back to 44 degrees. I left my %'s where they were and kept 140# LR just to see if it was the chain. ~Thanks~

[jedclampit]

Your welcome brother, wish they were all that easy a fix!

Bet you start measuring that every week now!

[Tuckerr]

i would just suggest you that better you take your car to garage andc have its check up with good mechanic as this would be better option for you

[sj valley dave]

i would just suggest you that better you take your car to garage andc have its check up with good mechanic as this would be better option for you

Are you serious?

[racer69]

OK Tuckerr, should he also stop at Autozone to get new shocks on the way? Or maybe stop at BigO for some fresh rubber? Dont forget A good brake and exhaust garage!

[RACR_73s]

Update and another question.

Car was still a little crazy acting and pulling the left front in the heat so I decided to move the fifth coil towards the front of the car. I wanted to move it 2" but that hole was messed up so I went 3" and the car seemed to calm down and I didn't notice it pulling the LF but it was a 4" cushion(curb) and it was a wild night running up there. The car was fast and I went from a 12th starting spot to 5th before jumping the cushion real bad and getting thrown off the track with a hard right turn...lol...but it was exciting. The car was still unpredictable. .. Which leads me to my new question...

Today it was time for a bolt check and I found the upper left rear bar had issues. The bolt was tight but it spun real easy like it was loose. I have 3 slots on the birdcage that I can use and each slot has 3 vertical location to mount the bar. What had happened is the bolt had chewed up the birdcage and had worn out the seperation for the vertical mounting and was allowing the bar to ride up and down on the birdcage.

1) What would this do to the handeling of the car?
2) Which slot should I move it to? (towards the front or back of the car)
3) Where in the slot (up/middle/bottom) of the slot should I put the bar?

I chose to use the back slot and used the high position(furthest from rearend). My thought for the hight was to help take bar angle out to help keep left front down(correct?) but I don't really know benefits of front to back slot choice.

~Thanks Again~

[charcoal01]

Listing approximate bar lengths for each location on the birdcage would be easier for people to provide help. You did change your bar length for your left upper rod, correct?

[RACR_73s]

Listing approximate bar lengths for each location on the birdcage would be easier for people to provide help. You did change your bar length for your left upper rod, correct?

No I did not for a couple of reasons...

1) I didn't know if I had to
2) The location I put it in now is the one Joe Garrison said to put it in when I talked to him over the winter. The reason I did not put it there is because it did not look like it had ever been used on this car so I used the one they had been using.
3) I was hoping I would get an answer on here before I did my final setup for this weekend.
4) The bar lengths I am using now are the ones that Joe gave me when I talked to him so I thought I might try it.

I will post bar lenghts later ~Thanks~

[charcoal01]

Just make sure your indexing is correct. Someone who is familiar with grt's can probably tell you where it's supposed to be set to.

[RACR_73s]

Bar lengths are 17" top and 15" bottom on both sides.

[grt74]

the different slots on the birdcages are for different length bars on the top,shorter for the front and longer for the back,the middle should be the 17" bar,i cant remember the lengths for the other two but take a measurement at ride height (from center of axle to a reference point)and when you change lengths make sure you get that measurement and that will be your bar length,hope that helps,up and down on the birdcage will change indexing,the closer to the axle the quicker it indexes(quickens instant traction) but this can also hurt traction at the middle to end of the straightaway