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#37racer
06-01-2010, 04:55 PM
Need some help. 600rf, 700lf, 225rr, 200lr, spring behind on lr birdcage, spring in front on rr locked. rr bar level, lr lower bar level, upper bar 20 degrees. spring on rr is on a coliover. spring on lr is on a slider. 56 left 53.5 rear 46 cross. lr bite 80lbs. car was loose on entry and really loose on throttle. even if i drove the car in easy and tried to pick the throttle up in the middle of the corner, the rear was coming in a hurry. any suggestions? thanks

washeduptoo
06-01-2010, 08:02 PM
Are those percents with the driver in car?
How much rake in jbar and where is it on pinion?
Do you have any ballast on car and location?
Have you tried the rr spring on top of axle?
Any lead/trail in rr? Just looking at your numbers, try adding some rear percent. Be willing to offer suggestions if you need or want them.
Good luck.

#37racer
06-02-2010, 08:31 AM
Exact weight and percents. 2526 lb full of fuel with driver.
56.61 left, 54.55 rear, 46.55 cross, bite 80
J-bar is in the bottom hole on a 5 hole bracket on the pinion. which acually locates it below the pinoin. Its mounted 8" from the top of the frame rail on the left.
I can move a 40lbs led next to the fuel cell to give more rear %
do you think spring on top of rear or behind rear is better for right side? I haven't tried spring on top.
no lead or trail on rr. 108.5 both sides
toe 1/4 out, 78" front, 77" rear, left side of car square
Thanks for any suggestions

washeduptoo
06-02-2010, 11:49 AM
How much rake is in the jbar, 4-5 inches of rake should work. Can you move some of the left side wt, try to get that down some. Is this an underslung car or overrail? What front clip?
How far is the rf shock from bottoming out, needs to get about an 1inch from bottoming.
We always run rr spring on top and shock on the back, the way you have it should add drive and loosen up the car.

#37racer
06-02-2010, 12:52 PM
not sure how to measure RAKE in j-bar. I can move some left weight to the right but only as low as the bottom of the fuel cell. Its an over rail car with a metric clip. The rf shock is right there at an inch from bottoming out now.

#37racer
06-02-2010, 12:59 PM
So are my springs ok? or do I need to change any. If they are ok. The changes I see making are.
Move RR Spring to the rear
Add rear %
Add right %
Maybe move J-Bar up 1 hole on Pinion
Also I have been running 2" of stagger. Is that to much?

washeduptoo
06-02-2010, 01:26 PM
On the rake, measure up from the ground to middle of bolt on pinion and then measure up from the gound to center of bolt where it mounts on the frame and the difference is the rake.
How long are your swedge tubes on the lrt and lrb and the rr, ? In my experience the 4-2 is a tighter set up more than the 4-4.

Is your car nova lowers or metric lowers? How much lr drop does your car have and how are you limiting the drop?

Your springs are close to what we ran on a metric with metric lowers.

#37racer
06-02-2010, 02:10 PM
Rake on J-bar is 10.5" I will be definitley will be changing that.
It has metric lowers.
lrt 18", lrb 14", rr 15"
the left rear shock looks like it was bottoming out last race

washeduptoo
06-02-2010, 02:34 PM
Yes, I would lower that jbar 1st without changing anything else to see what that does, lower it on the frame to about 5inch of rake. That could be the problem, your roll center is too high, not allowing the rear work.
The lr shock will bottom out usually when the car drops. Take a measurement at ride ht vertically down to the b/c, then jack up the car until the lr is almost off the ground but is still touching ground, that difference between will be the amount of lr drop. Should be 4-5 inches of drop.
Are you running a plug on the rr or can you run a longer bar? Try the jbar rake 1st, I think you'll be suprised at the difference it makes. Good luck and please let me know how it works.

washeduptoo
06-02-2010, 05:23 PM
I agree with pieman, even with the pinion is a good place to start and be sure to reset the rear end side to side measurement after setting the rake. Good luck.

#37racer
06-03-2010, 07:36 AM
Thanks for the input. My next race isn't till the 19th of june. I will let you know how it goes.

powerslide
06-03-2010, 11:40 AM
also try to lower ls weight to about 54.5 with driver all that ls is making it loose in. keep the lead about the hieght of the centerline of the cam if possible. maybe higher in your case since you were loose.

and are you running a 9in or q/c they have pinion in different places...

CHRISTINE
06-03-2010, 12:31 PM
When Mesuring Lr Drop Do You Go Striaght Down To The Axel Tube Or Should It Be Mesured At The Birdcage? The Reason I Ask Is From My Upper Rail To My Axel I Got 5.25 Inches Of Drop But My Measuring Piont Is About 4 Inches From My Birdcage Which Puts It At Bout 6.5 At The Birdcage Anyone On This ?

#37racer
06-03-2010, 12:38 PM
I'm running a 9". So ya the hole on the bracket is an 1.5 inches below the pinion. I was thinking about trying to get my left side to around 53%. and rear up to 57%. What ya think

powerslide
06-03-2010, 01:40 PM
I'm running a 9". So ya the hole on the bracket is an 1.5 inches below the pinion. I was thinking about trying to get my left side to around 53%. and rear up to 57%. What ya think

i would just move the piece of lead you have back and as far right as possible. see where you end up with that. and give it a try.

on the jbar put it with the pinion like they said and about 5in higher on the frame

the jbar will make a huge change in the car

powerslide
06-03-2010, 01:42 PM
When Mesuring Lr Drop Do You Go Striaght Down To The Axel Tube Or Should It Be Mesured At The Birdcage? The Reason I Ask Is From My Upper Rail To My Axel I Got 5.25 Inches Of Drop But My Measuring Piont Is About 4 Inches From My Birdcage Which Puts It At Bout 6.5 At The Birdcage Anyone On This ?

i would measure just outside of the birdcage or maybe even from on top of it... place the tape on the tube and measure up to the decking. easiest way to measure that ive found

powerslide
06-03-2010, 02:18 PM
Rake on J-bar is 10.5" I will be definitley will be changing that.
It has metric lowers.
lrt 18", lrb 14", rr 15"
the left rear shock looks like it was bottoming out last race

thats alot of bar lenght difference in the lr....

and your front springs are too soft for a TRUE metric lower a-arm car. are you sure it doesnt have nova lowers? if you have novas you are fine

but with everything else you've changed im gonna say just try to run it with the jbar and the lead change. report back after you run it and let us know how it feels.

circle dirt
06-04-2010, 12:01 PM
i would just move the piece of lead you have back and as far right as possible. see where you end up with that. and give it a try.

on the jbar put it with the pinion like they said and about 5in higher on the frame

the jbar will make a huge change in the car

I always thought that on the 9" just below the pinion and on the QC at the pinion. I have 2 cars with a 9 and a QC . So if I raise both j's up a hole on the pinion it will help drive off?? just curious

powerslide
06-04-2010, 03:22 PM
I always thought that on the 9" just below the pinion and on the QC at the pinion. I have 2 cars with a 9 and a QC . So if I raise both j's up a hole on the pinion it will help drive off?? just curious

im not sure what the measurement difference is in a q/c and 9in. but i would start even with the pinion on the 9in and measure to the ground. Then use that measurement to get it in the same place on the q/c and note where its at so you have the same starting setups on both.

washeduptoo
06-04-2010, 04:53 PM
Center of Pinion is about 1.5 inches lower on the QC than the 9in.

gummy63
06-06-2010, 07:02 AM
what shocks do you have on the car (brand, valving, etc.) and have they been dyno'd lately. How old are your springs? I measure mine when new and check them regularly to make sure they have not collapsed.

#37racer
06-14-2010, 06:46 PM
OK so i raced this weekend. it rained and the track was sloppy for the heat and i was 7th in my heat. I started 13th in the feature and the track was good. i worked my way to 9th and the rain came. So bottom line is this. Car was so much better than before.
57 rear
54.5 left
48.5 cross
j-bar 6.5" of rake.

junebug
06-14-2010, 11:48 PM
the added rear percentage probably helped a ton, if the car is still too loose when it slicks off try takin some more of that left side weight out thats pretty high .....and also you might need to add a little pre index to the lr birdcage or extra upper bar angle to get the index speed quicker thats an awfully big split from a 18 " upper to a 14 " lower my car is actually shorter on top bar to speed up the indexing

washeduptoo
06-15-2010, 07:49 AM
Glad the car worked better for you and good luck.

Toywagon
06-17-2010, 11:34 AM
With all of the rain, and a tackier track, you may find that your still too loose when you get back on dry.

The RR spring clamped up in front on a coilover is an area I would take a look at. When you roll out of the throttle, both mounting points for that coil over are going in the same direction to a degree, and you may not be getting enough RR spring into the car, loosening the off throttle entry. Same with the shock.

Then when you pick up the gas, again with the RR being clamped up, your rotating the RR spring into the chassis, which could be your loose that your getting on throttle.

Just throwing some ideas at you.

Jim

#37racer
06-17-2010, 05:58 PM
So you think I should take the RR coilover and move it behind the axel. I mean its an easy fix. I have mounts in the front and rear of axel. I was spinning some coming out the corner but i guess everyone else was to cuz i wasn't falling behind as usual. I am also going to move the battery to the right side of the car to bring down the left weight a little.

washeduptoo
06-17-2010, 06:23 PM
I would try moving the spring to on top on rear axle tube with shock on back and see what that does for your car, spring behind rr might make it too tight but it might fit your needs. Good luck.

Toywagon
06-18-2010, 09:19 AM
I agree as well on moving it to the top of the housing. The RR clamped up on back will take you too far the other way and get you too tight.

Jim

LFMotorsports
06-18-2010, 03:59 PM
If at all possible, I would suggest making 1 change such as RR spring on top of axle or even behind and feel out what that does....

There is alot of advice running here and all have merrit but if you change a bunch of things at once, you will never know what adjustment gave you the results you are looking for. It may seem hard to fight off the urge to change a bunch but you will know your car better and your driving in the long run. And be able to be ahead of the track, not fighting it.

washeduptoo
06-18-2010, 04:07 PM
I agree with that, change one thing at a time. Good luck.

#37racer
06-20-2010, 07:25 AM
Race went well last night. Started 12th and finished 7th. Car was the best it has ever been. This is what I did.
Moved the J-Bar up on the pinion. 5" of rake
Moved coilover to behind axel on RR
54.1 left
57.1 rear
48.5 cross
12.5 psi on right 10psi on left. 2" of stagger
Motor was missing in heat race for the first 2 laps. finished 6th
Motor was good for the race. The car was great for the first half of the race and then started getting loose going in. Track was slicking as the race went. Getting off the corner was awesome all race. Top 7 were nose to tail at end of race. Tire pressure grew 3psi on RR and 1 PSI on LR. The extra stagger probably didn't help the entry at the end of the race. So I'm still looking for more. Thanks guys for all the suggestions. Keep em coming. I'm willing to try just about anything.

washeduptoo
06-20-2010, 01:23 PM
I would try reducing the stagger or moving the jbar down equally on both ends.