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Author Topic:   4- BAR HELP!!!!!
FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted July 12, 2004 10:46 PM  
Ok guys heres the problem, first off I have a GRT remake(jigged from a grt) Springs are LF 800 RF 850 LR 250 RR 200. 56% rear 53% cross. Running on a 1/4 mile track. During hot laps when the track still has bite in it, the car is a rocket ship! But as soon as the track starts to dry out this is what happens. The car is loose getting in, so I try to keep it as straight as I can. About midway through the turn (maybe not that far) before I even hit the throttle the front end pushes like heck. No front bite at all so I have to throttle steer it by braking loose the rear tires, then they never hook back up till half way down the straights. I've tried feathering the throttle once I get it turned but it doesn't help it just spins. I did have 51% cross but went to 53% to help the forward bite. Didn't help much!! I noticed the RF tire was wearing more on the outside, so of course it needs more camber but it seems like something else must be wrong too. It is a metric frame, are the front springs right?? I'm getting about 2-2.5" travel on the RF shock. I have a AFCO progressive spring pull bar, its getting 2.5'" travel I put 1/4" preload to try to help hook it up on dryslick but it seemed to make it worse. Guys I'm about sick of this car I've had it for 2 years, it was built for me, I'm the only owner. For 2 years it has made me look like a fool on the track. I have to be doing something wrong, please help if you can.

badfastjr
Dirt Maniac

Total posts: 193
posted July 12, 2004 10:50 PM  
i had the exact same problem and i put a 850 lf spring and a 750 rf spring in my car and it was perfect. the car went from impossible to drive to completely under control.

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to finish first, first you must finish

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted July 12, 2004 10:53 PM  
oh yeah it has 160 lbs. LR bite, everyone who runs this track that I've talked to says thats about right. It did have just over 100 lbs, I increased it but it didn't seem to help much. That much weight should make a helluva difference!!

2nd2none
Dirt Forum Champ
Total posts: 755
posted July 12, 2004 11:29 PM  
where are your bars at? You need to correct the loose in before you can even think about fixing the tight off.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted July 13, 2004 12:06 AM  
both bottom bars are in the lower holes, the top bars are in the 2nd hole from the top. the straight bar is in the 2nd hole from the bottom on the pinion.it has about 8" of rake in it. Also the pull bar has about 20 deg. angle in it.

[This message has been edited by FlyNLoIMCA17 (edited July 13, 2004).]

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted July 13, 2004 12:08 AM  
even though the car feels loose to me going into the turns I seem to drive the car 1/2 to 1 full car length deeper into the turns than anyone on the track but I lose them coming off unless I'm able to slide up in front of them.

Dman
Dirt Freak

Total posts: 270
posted July 13, 2004 07:54 AM  
We run a GRT modified swing arm Z link and the car wont hook up on a dry track with less than 58% rear.We go out for the main at 60% rear, 50% cross and about 130 LR. The car is at 58% rear at the end of the main.We run the recommended spring rates from GRT.We have tried softening the Front springs but the tracks we run are usually rough and the a-frame bottoms on the RF. The car turns hard right when that happens.Scary!! Good luck!

Dman
Dirt Freak

Total posts: 270
posted July 13, 2004 08:09 AM  
Also you make have a brake balance problem.If you can get more rear brake the car will rotate better on entry so you don't have to throttle it around.We run a 7/8 master to the rear and a 1" master on the front.The brake balance bar is adjusted almost all rear to start and we adjust brake forward as the track gets slicker to tighten entry.Make sure the balance bar on the pedals is free and not bent or binding. Have you checked it? Alot of people dont realise the importance of brake balance. It can make a MAJOR change in handling.

dogwalker
Dirt Full Roller

Total posts: 65
posted July 13, 2004 08:46 AM  
Badfast is on to something.....i would swap the front springs to get the car to turn through the middle. Would probably run more angle in both left bars than in the right to keep you from being loose off on dry. You may want to get it to turn good first, then work on bite.

STICK01
Dirt Maniac

Total posts: 164
posted July 15, 2004 08:41 AM  
I used to have that problem last year and then finally realized that my taking the car in 1/2 to 1 car length deeper than everyone else was actually a driving flaw / car way too tight on entry...then just like you say the car does the erratic movemnent and is a handfull to try to get ahold of. I did pretty much what everyone else has said and swapped front springs, and then tried to mimic the front runners, as to when they lifted, got back in the gas, etc...this year I am the one in the front...no wins to show for it yet but we have lead twice in the last 4 weeks and have won numerous heats, and even a fast 6 race. It is just a matter of getting a little luck, and the right starting spot, and closing the deal.

STICK



Kromulous
Dirt Forum Champ
Total posts: 796
posted July 15, 2004 09:47 AM  
I wouldnt say straight out that driving a car into the corner harder than others is a bad thing. Driving the car hard in to the cvorners can be the best place to gain time, and distance on the guy in front of you.

Over driving the car in and making it push in the middle is a bad thing. Sometimes its better to back off on the entry speed so the car can turn, thats just taking what the car is giving you and making the best out of it.



mod70
unregistered Total posts: 796
posted July 15, 2004 10:43 AM           send a private message to Kromulous   Edit/Delete Message   Reply w/QuoteBBBBBB
Something that I'm suprised nobody else has picked up on, (badfastjr indirectly adressed it) is that as you increase cross, the car will loosen up on entry and tighten on exit. You actually went the wrong direction. If you do the 850 LF 750RF change it will help to tighten in and loosen off by taking cross out durring weight transfer.

imca22mbp
Dirt Newbie

Total posts: 4
posted July 15, 2004 05:32 PM  
buy a pierce car and your worries will go away!!!!!!!!! if u have heard of him!!!!!

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted July 15, 2004 10:35 PM  
Yeah I've heard of pierce but if I had the money to buy another car I would but thats part of the problem no cash! And I would buy a Dirt Works FIRST!!!

NJantz
Dirt Forum Champ
Total posts: 755
posted July 16, 2004 05:58 AM  
I have always had a tough time hooking up my GRT zlink on slick tracks and could always drive it in deeper than anybody else as well.

If you have a brake floater on the RR, raise the bar up on the frame bracket. Also increase your left front spring rate by 50lbs.

I'd also recommend getting your rear weight up to 58pct at least.

imca22mbp
Dirt Newbie

Total posts: 4
posted July 16, 2004 07:26 PM  
hey njantz have u raced against pierce cars before? they are something else!!!!GRT is also a good one.

imca22mbp
Dirt Newbie

Total posts: 4
posted July 16, 2004 07:29 PM  
what kind of weight are u running across the rear?

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