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Author Topic:   Metric setup fading
Fomocosho
Dirt Maniac

Total posts: 135
posted July 10, 2005 08:45 PM  
I have a 84 cutless hobby stock. In the feature the first two or three laps the car is very fast and handles great but then it starts pushing more and more each lap. Laps 4-6 I can get the car to turn by throwing it into the corner as hard as I can and stand on the gas. But after that I cant get it to turn at all. This is when the track is dryslick. What could be causing this? I checked the tire pressures after the feature and they didnt build up very much pressure so I know that isnt the problem. Any ideas would be greatly appreciated.


Thanks

rfb320
Dirt Maniac

Total posts: 150
posted July 10, 2005 08:59 PM  
Do you have a good set of shocks? Maybe the shocks are fading.

Fomocosho
Dirt Maniac

Total posts: 135
posted July 10, 2005 09:03 PM  
I have pros on the rf and lr and bilsteins on the rest. Would having them dynod tell me if they are fading? I have heard of bilstein shocks fading. they are only about eight races old.


Thanks

racer17j
Dirt Forum Champ
Total posts: 5390
posted July 10, 2005 09:35 PM  
I had 11's in the car but I put longer ball joints in and the car sat way to low so I went to 12's. I can try switching the rears but I dont understand why the push would get worse the longer I race? Could a bad spring cause this? My rims are all the same offset. I have a couple 2" offsets but I can't use them. With the tires I have I can only get an 1 1/2" stagger and I use those in the front and I only have a 1/2" in the rear.


Thanks, If I could get it to handle the whole race like it does in the first couple laps Id have a top 3 car. Hope to get this figured out soon.

Eljojo
Dirt Forum Champ
Total posts: 968
posted July 11, 2005 04:44 AM  
I have a set of very soft tires that, on a dry track, will make you start looking for the trailer after about 6 laps. I'd say that your car is pushing on the first lap just a tick, and by the third or fourth has overheated the RF and it's gone away. Take a little wedge out of the chassis andtry a different RF tire.

racer17j
Dirt Forum Champ
Total posts: 5390
posted July 11, 2005 08:09 PM  
Yes I moved the battery to the trunk right above the left spring and no it didnt do this before I moved it. Eljojo's discription of how the car was sounds like he was in the car with me LOL. Yes the thought crossed my mind to pull off half way through the feature and load her up before I flew off the track in the corner LOL.

Thanks guys.

racer17j
Dirt Forum Champ
Total posts: 5390
posted July 11, 2005 08:33 PM  
Fomocosho where do you race?

Donnie Ross
Dirt Freak

Total posts: 264
posted July 12, 2005 07:37 PM  
check camber, had a car was good for 3 laps then gave up, owner set camber wrong and was using very little tire when that strip got hot push city.

YAZ
Dirt Maniac

Total posts: 147
posted July 12, 2005 08:21 PM  
glad to see this question, I have been fighting the same thing all season, I have
been changing spring rates in the front
every week to try and fix it. nothings seemed to work. tried a heavier rh rear spring and it helped, but still started pushing bad at the end of the feature. I
called jr motor sports today, and they said I have to much bite. I'm going to try and take some out and try it this weekend.
by the way what is everyone else running for bite?

doubletrouble racing
Dirt Forum Racer

Total posts: 88
posted July 12, 2005 10:08 PM  
We had this problem last year.....by they way are those Pro shocks the "adjustable" ones? If they are TRASH them they are JUNK we put bilsteins on this year with a taller RF tire and car hooks up......well have a little problem in the heavy sloopy mud of the heats but that due to lead foot.

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Visit www.doubletroubleracingteam.com

racin78p
Dirt Freak

Total posts: 333
posted July 13, 2005 07:59 AM  
Bite, bite, bite.

I have experienced the problem of way too much left rear bite and the result is a severe THROTTLE push. Just to be sure I am clear; when getting back into the throttle after entering a turn the car "pushes" up the track and nothing you can do will steer the car back DOWN except getting out of the throttle. That said,...

I finally listened to a set-up guru friend of mine who convinced me to loosen up my car. He had me switch front springs to:

1000 lb. right front
900 lb. left front

rear springs stayed the same:

250 lb. left rear
225 lb. right rear

Now here is the secret to my car, the track I run at, and the set up I run (I understand that I have more that I can adjust on my car because of the difference in rules than you can, but,...):

I start out with:

G60 American Racers;
16 lbs. right front (2" off)
14 lbs. right rear (4" off bead lock)
11 lbs. left front (3" off AND left rear 3" off).

This gives me between 108 and 110 rear bite.
I run this for the heat races usually and if necessary maybe a "B" feature. Then before the "A" feature I MAY drop 1 lb of tire pressure to the left front and/or add 1/2 lb to the left rear. This drops the rear bite to between 98 lbs. and 102 lbs. The problem I was having is the car was a rocket during heats, but near the end of the feature it would tighten up the last two or three laps and was getting too hard to turn. The right front was developing too much tire pressure and transfering the weight to the left rear causing the throttle push (too much bite to the left rear).

I run at a 4/10ths track, MOSTLY it is dry slick and the set up I run now is the best I have every had. The car is very controllable now (and VERY smooth).

Shocks? I have run Bilsteins for two years, and was convinced to try the Pro adjustables in the rear. I put them on this past weekend for the first time, and I was close to pulling the left front off the ground. The tire was "dancing" as my crew chief told me. All I know is the car drove even better that before.

It is very hard to tell somebody what to do to correct a problem with a push situation or anything for that matter, on a web site. What I have written here is just my experiences and how they were corrected.

Maybe this will help? Keep in mind that just a 1/2 pound of tire pressure change can drastically alter how a car gets around the track. Scaling the car, adjusting tire pressures when doing so to see what difference it makes, is the key to knowing what you need to do at the track come race time. Take GOOD notes when doing so. Memory fades in time.

Just my thoughts!

Race on.

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racin78p
if it ain't fun, then don't run

Fomocosho
Dirt Maniac

Total posts: 135
posted July 13, 2005 03:43 PM  
What kind of pressures do you guys use on 205 70 tires?

racer17j
Dirt Forum Champ
Total posts: 5390
posted July 13, 2005 06:45 PM  
between 20-25 on the right side and 18-22 on the left i used to run 25rf and 20 rr but with my car bent the way it is it's like 78 said twords the end of the year wouldn't turn for anything this year swapped the rear springs took all stagger out of the front and put 2 inches in the rear and 5# in the rr loosened me right up haven't had a chance to fine tune it but those changes madea heck of a difference

    

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