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  #1  
Old 06-21-2001, 10:12 PM
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daren44 daren44 is offline
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Default Tight off

I need a little advice. I have a locker rear, which has made my car a little tight under throttle. I've gotten some of it out by adjusting wedge. But it seems that I'm going to have to use a lot to get it where I need it. I only have 1/2" stagger. I'll have to dig through a lot of tires to find the right combination, but how much should I have with a locked rear on asphalt? Or should I keep adjusting wedge?
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Old 06-22-2001, 01:13 AM
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DYNO360 DYNO360 is offline
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Thumbs up Less is more

Try reducing your stagger. That will loosen up your car.
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Old 06-22-2001, 08:11 PM
AVENGER29 AVENGER29 is offline
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Dont know much about asphalt,but for what its worth, i would try softer springs or adjust air pressure and re-access condition, something i've learned is to never stop changing or trying new things or combinations.
But you know us dirt racer think " that asphalt is for geeting yor there and yee aint racin unless yor geeting dirt in yor cerveca"
sorry just a little south tejas humor
good luck,race safe!!
avenger29
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  #4  
Old 06-24-2001, 02:07 AM
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Don't reduce stagger, put more stagger in it that will help tight off the corner. Make sure that is where your problem is, if it's in the middle let us know, that can be fixed different ways. I run a locked rear and a 1/2 of stagger isn't much. How big is the track? Give us some more details of what and where you race.

Michael
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  #5  
Old 06-24-2001, 09:03 AM
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First of all, we got halfway through qualifying and got rained out last night. I had my best qualifying time yet, and was 5th out of 6 cars that had qualified so far. And I came in second last race. Seems like if you ease up and think you've got it licked, everyone else keeps getting a little faster. No rest for the weary. I run on a 3/8 mile high banked track. I'm probably neutral in exiting 2, and pushing exiting 4. 4 being a much tighter corner than 2. Turn 4 is wider, however, and coming off 4 is where you either pass or get passed. If you can keep it low you can get under the other cars and them beat by the time you get to 1. We have to run track tires, which are 225/70's recapped with a slick tread. It's hard to find much stagger in production tires. In order to help stagger, I'm running only 15 lbs in the lr, and 35 in rr. Maybe that's not good, I don't know. I'm running a 74 Charger, which is nose heavy, and exagerates my problem. I've only got like 43% rear weight. No more weight left to move. Cross is about 52%. Total car weight 3000 lbs, with driver. My competitor chevies are probably 300 lbs lighter. But they don't have that 360 torquer under the hood. Thanks for the help.
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Old 06-24-2001, 01:46 PM
AVENGER29 AVENGER29 is offline
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Im totally out of my league on asphalt, however i think so much psi in right rear is not a good thing. Increase tire pressure also increases spring rate, which may be detrimental, may compound problem. Try finding the biggest tire you can, severely over inflate it and leave in the sun for a day or two, will help grow the tire. What torsion bars are you using,what spring rate in the rear, you may also experiment with smaller lowering block on left rear,versus right rear. That will help making the car looser coming out of the turn. Are you allowed pro shocks or other speciailized shocks or are you limited to stock pieces. If you are i would contact pro shock, their tech hotline is excellent. What is your left weight?? I would also go on a diet,would look for anything else that can be cut off or move. Remember safety is always first, not much fun watching racing from hospital bed.

Where all the big guys gone to??? 340king and others, you guys need to be answering this post...

Avenger29
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  #7  
Old 06-24-2001, 06:59 PM
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Thanks. I've got .960 bar on the right, .920 on the left. Rear springs are 122's. I am allowed racing shocks, I'll check into that. From the trouble shooting sheets I've read, the cure for pushing is stiffer rear springs, softer front. My car didn't handle too bad with an open rear, I just couldn't hold the power off the corners, so I went to a locker. That is what made me push so bad. So I'm going to "grow" a tire and hope that helps. I'm also going to check into shocks. I think I've got about 54% left side. I've got fuel cell in center, and battery as far left as possible. In static position the front sway bar is neutral, no preload. Thanks for all the suggestions. I'll get there.
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  #8  
Old 06-27-2001, 12:57 AM
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Thumbs up Sounds like my car

I have a '74 Charger small block that I am setting up for oval track racing, see www.southernracer.com. Anyway what tranny and rear axle ratio are you running? How long is your track and how steep is it banked? Highland Rim Speedway, where I will probably race, is a 1/4 mile D shaped oval with 14 degrees in the turns, 4 degrees in the front stretch and 6 degrees in the back stretch. Also how low is your car? I have heard that Mopars need to get down so low that they scrape the exhaust going into the turns. Also, I miss the experts that used to visit this forum. Where are you guys?
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  #9  
Old 06-27-2001, 02:58 PM
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The track I race at is banked 32 degrees, according to the track info. 3/8 of a mile. Turns 1 and 2 seem steeper to me than 3 and 4. I am using the 904 tranny with a 3.91 gear in a 8 3/4 rear with a powertrax locker. I have a 727 tranny, but the 904 is lighter, and so far it is holding up fine. I am hitting 6100 rpm's on the front stretch, maybe 5800 on the back, being shorter. I've got the left front at 6", rf 6 1/2", lr 6 1/2", rr 7". I am not supposed to go lower by track rules, but yes, I've also heard that on a mopar lower is better. Have you weighed yours? Mine weighs 3000 lbs with driver and full of gas. I don't know anywhere else I can slim up. Good luck and keep me in mind if you need handling help. Maybe we can trade ideas.
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  #10  
Old 06-27-2001, 07:35 PM
Mopar Trac Mopar Trac is offline
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Didn't know that there was so many old Chargers out there running any more! My son has a 74 that we built for street stock for dirt. Some of the places we found that you can lose a lot of weight is in the door posts 50+#'s and frames dash and front valance have removed all of those and car without ballast and with driver full of fuel only weights 2774# had to add a ton of weight to get up to class weight of 3400#
We run on a .4 mi track with 18 degree banking and a pretty good surface most times! We run a three speed in second gear ( b body trans with 1.70 gear) and an 8 3/4 with 3.55 and a locked rear.
The car handles like a dream have ride heights at 5" front and 5 1/2" rear.
Hope this helps if you have any question feel free to ask!
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  #11  
Old 06-29-2001, 12:26 AM
AVENGER29 AVENGER29 is offline
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For what it worth,we run final ratio of 7.02, hot 360 on methanol with a 727 tranny,(differential is a ford 9 inch with a spool,4.86 ratio),in a very competitive and slightly out of control hobby class. Pro shocks on all corners and we change them depending on conditions, we ususally run, 75 on left front,76 or 763 on right front, 94 on left rear and 95 on right. .93 bar left front with 1.09 on right, we run multi leaf chrysler spring,landrum, 175 left rear,150 right rear, we have to run spec tire,but we are allowed to run a fat right front, no bead locks, but we do some interesting things with tires and wheels, run 14/15 psi right side and 12 psi left side, we adjust set up using psi a great deal, we have also spent a lot of time on scales and recommend you do the same.
55 % rear weight, 54 left weight,53 to 54 cross depending on track condition, we run a dirt 1/4 mile oval,slight banking, 12/13 degrees, normally very dry slick, south texas, race time temps can be in high 90's and sometime triple digits.
we have 3 lead bars over the rear axle and rear ward, we usually run 175 to 225 lbs of bite.
normally we run an 86 left rear and a 87 1/2 to 88 1/2 right rear.
on any given nite we are fast enough to dominate, my problem is we cant seem unable to stay out of trouble, if there s$%^^^#(**^%
on the track, you can be assure i found it.
other wise we win the heat race and run top 5 in feature, all in a class where we are only slightly slower than the imca mods that run after us and most of the time we put on a better show.
good luck, race safe
avenger
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  #12  
Old 06-29-2001, 12:40 AM
AVENGER29 AVENGER29 is offline
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Ooops, our original frame,if we can call it that,came from a 66 valiant, we run underslung rear frame, with leaf spring sliders, stock front clip,except we have cut and shorten the right upper a-arm,the skin is a performance body, 2000 avenger body. However we have to run steel,a large number of our competitors also run late model bodies,monte carlo and so forth. have never concern ourselves with ride height that much, but front height at lower a arms, is 7 inch,rears 5 inch,we also run offset lowering blocks, 1 inch smaller on left side compare to right side. We also have to weight 3200 lbs, we have almost 250lbs of ballast in the car. hope it helps,let us know??
avenger
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  #13  
Old 06-29-2001, 10:09 AM
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MOPARVANN MOPARVANN is offline
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We run a Dart body with strong 360 on 3/8 mile high banked asphalt. Had severe push with locked rearend, changed to positrac unit and took push out completely. We had to go to light springs on rear and experimented with different size torsion bars and found after buying several sets that stock 318 bars handeled best. Everything we did to lower the car helped also. Good luck and keep the MOPARS out front.
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  #14  
Old 06-30-2001, 07:31 PM
340king 340king is offline
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Default Asphalt?

I have never had the joy of racing on asphalt, unless you count the time I took old Yeller out to the autocross. It really opened up some of the peoples eyes when the 340 4bbl kicked in. I was hell on the straights, but lost time in the corners, something about dragging the frame comes back to me now.

As for your handling ills. You stated that your rearend is a locking differential and not a spool. I also haven't played much with these. But handling is handling and the end results are usually the same. I look at racing on asphalt like I would a dry slick track. Now this is a perverse application of this, but hear me out. On dry slick it is always best to be able to roll through the center of the turns. The car that rolls the free-est through the center of the turns is usually the fastest in the corner. That means that you have to be neutral in the center of the corner and not have any push or loosness.

If you are good in the middle of the corner, then things like roll center to center of gravity height are correct. If the car is entering the corner well, then I wouldn't want to change the static weight distribution much.

I am tempted to pursue changing the forward bite under acceleration. To do this with leaf springs isn't hard, but there isn't much for adjustment at the track. Two areas to think about are changing the instant center of the rearend either by changing the front/rear mount height bias or by changing the size of the lowering blocks and possibly changing the makeup of the front half of the springs. You could look into playing with half leafs on the rear springs. Adding some to the left and removing some on the right. The half leafs only contribute slightly to the wheel rate.

Have you played with kicking the left rear wheel out with a different offset. This should lessen the bite on the left rear and free the car up also and if you get the car back to the same static weights, it should work nearly the same. These are just some things that I think might help. Sorry for the gap in replies this past couple of weeks guys, I was out working for Uncle Sam.
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