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Author Topic:   Front Springs on a 2400 Lb car
2quickfu
Dirt Roller

Total posts: 12
posted August 13, 2004 10:46 AM  
Has anybody ever swap the front Springs by runnung the rf#700 lf#800 and what is the best way to run the back spring lr#200 and rr#150.Will this work has anybody ever tried it.Also this is mounting the shocks and springs in stock location.Track has very little banking and it's about a 3/8 mile track.

[This message has been edited by 2quickfu (edited August 13, 2004).]

[This message has been edited by 2quickfu (edited August 13, 2004).]

racer17j
Dirt Forum Champ
Total posts: 5390
posted August 13, 2004 04:06 PM  
What problem are you trying to fix?I run lftfr.650 rtfr.750 lr.225 rr.175.The car is tight on tacky,and real good on dry.We have to run 16 lbs.in the rr.This is on a stock metric chassis.


2quickfu
Dirt Roller

Total posts: 12
posted August 13, 2004 09:19 PM  
Tryed that 700 rf and 650 lf 225 lr and 175 rr was too loosein turns on a dry track but was real good on tacky track the more spring I put in the back the looser I get in the turns.What would swapping the front springs do.

[This message has been edited by 2quickfu (edited August 13, 2004).]

ctfarm
Dirt Freak

Total posts: 206
posted August 15, 2004 12:01 AM  
Swapping the springs will loosen entry and tighten exit.You may need to stiffen the fronts 750-850 and drop the rears to 200-150.What percentages are you running and what shocks?

InItToWinIt
Dirt Newbie

Total posts: 2
posted August 16, 2004 09:33 PM  
There are a couple of questions that need to be answered before swaping front springs,i.e.(running a stiffer LF vs. RF) The first is, what kind of tire temps are you coming in with after the feature? Generally, if you come in with a real hot RR (30 degrees plus hotter than any other tire, or the RF is considerably warmer vs. the LF) this is telling you that your car is not balanced properly, and these tires are doing the work and picking up the slack for the LF. The RR tire gets to hot, the car gets loose towards the end of a run, and you end up towards the back of the pack. By running a stiffer LF vs. RF, this allows the LF to do more work, and not stress the RR. This in turn will allow the RR to stay cooler, and balance out the car. I would also reccomend running up to a 75lb. split in rear springs (LR stiffer vs. RR). Again, not only will this increase forward bite off the turn (assuming the correct Cross,Left,& Rear Weight Percentages are used) it will also help keep the RR cooler and balance out the tire temps around the car. Also, if a spring change is made up front, always remeber to re-align the car and re-set the front end geometry(toe,caster, camber, ackerman, etc.)
I should point out that these are reccomendations for a IMCA/USRA type stock car.
I also would not reccomend this for a track larger than a 3/8 mile, or an extremely steep banked track.
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2quickfu
Dirt Roller

Total posts: 12
posted August 17, 2004 10:36 AM  
Thanks for all the help it seams to be a little better this past weekend I may just leave it for a while the track Is a 3/8 mile with very little banking and it was a heavy track this past weekend.But usally it's a dry track at feature time what will happen if the track dry's out is it still good to run with reverse springs in the front.Again thanks for all the replys.Srry can't give an answer on the % of the car at this time.

InItToWinIt
Dirt Newbie

Total posts: 2
posted August 17, 2004 12:56 PM  
Actually, this set-up is geared towards a dry slick track, and not so much towards wet/heavy/tacky track conditions. The reason for this is that on heavy/tacky tracks, the RR does not slip as much, which in turn doesn't allow it to get overheated, and cause the car to become loose at the end of a run. We run a USRA/IMCA type stock car, weighing 3000lbs with driver, this is our current set-up for tracks 3/8 mile and under with medium to low banking: Springs: lf-1300, rf-1200, lr-250, rr-175. This set-up has won us numerous features this year. I stated in my earlier post though, the correct weight percentages must accomodate this spring package to be 100% effective.


    

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