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Author Topic:   Left rear on dry slick track
jello
Dirt Roller

Total posts: 16
posted November 23, 2004 06:03 PM  
Do you guys put more left in or take left
out?

Also, what do you do with wheel offsets
on the really slick tracks?


thanks


dogwalker
Dirt Full Roller

Total posts: 65
posted November 24, 2004 09:21 AM  
Usually you want to tighten a car on dry slick. To tighten car you would want to add left rear and/or less right rear. For offsets, move the right rear in and/or the left rear out. You may want to consider lowering the p-hard bar.


bachshute
Dirt Maniac

Total posts: 118
posted November 24, 2004 04:47 PM  
it really depends , more LR will tighten the car on exit but will actually loosen the car on entry , tucking the RR under for a slick track helps with roll over .

jello
Dirt Roller

Total posts: 16
posted November 24, 2004 05:32 PM  
I've heard some take left rear out on a slick
track to tighten the car up on entry. I guess you could adjust something else to help
get you out the other side.

Do the front wheels work opposite of the rear
wheels on offsets? for example: would you
move the right front out and **** the left
front in when it slicks off?

I am about to go and run a race on a
really slick track. I am just looking for
all the help I can I get.

thanks for the replies

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted November 24, 2004 06:06 PM  
yes the front works just the opposite. I run on a slick tight turned 1/4 mile track. I never change from heat to feature because its always slick. I run a 4 bar and my car reacts well to about 70 lbs of LR bite.

Greggie
Dirt Freak

Total posts: 298
posted December 09, 2004 10:43 PM  
Ideally, you get more left from "dynamic wedge" and right rear from "static wedge". Dynamic wedge is what you get when you are on the gas... The car gets up on the bars and drives the LR into the ground... When you get off the gas is when your static wedge happens. That is why you raise left bar angles on slick. Wheel offsets work 2 ways... They change where the car thinks the weight is and they also determine where the acceleration and deceleration leverage advantage is. A wider front offset will have more leverage on the centerline under braking than a narrow offset and try to turn the car in that direction.

boas51
Dirt Maniac

Total posts: 190
posted December 20, 2004 07:14 PM  
check your left rear rebound travel. in many cases the bar/bars are lifting the chassis off the spring. if this is the case no amount of wedge/crossweight/bite will effect exit, so you can set your cross to help entry.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted December 21, 2004 12:30 AM  
I could be wrong but on every 4-bar car I've seen with the spring behind the housing on the cage, the spring completely unloads on acceleration. There is a very interesting video on this site that shows this. Also when your following close behind a 4-bar you can actually see this, hard to see but if you look for it you can watch the spring floating around under there. One more thing, how many of you have lost the LR spring and finished the race?? I have. The car is just loose going in. I know it sounds like that goes against everything you know about suspensions but that is how it works.

Kromulous
Dirt Forum Champ
Total posts: 796
posted December 21, 2004 07:31 AM  
Once the car hikes up on the LR 4-bar mechanical leverage takes over and the spring is useless.

Its still dynamic wedge, but its controled via weight transfer and the 4 bar rods being in such a steep angle that the become locked, mechanical leverage.

Most of the time you will see or hear these guys pop the gas pedal to get the LR suspension on locked on corner entry. Usually you can see the car drop about a foot when they do it.

[This message has been edited by Kromulous (edited December 21, 2004).]

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted December 21, 2004 07:57 AM  
adding LR bite or wedge will still tighten a car coming off even if it comes off the spring when it gets on the bars. The more LR bite you have the more preload you have on the RF and LR. When the car gets on the bars you are still wedging on the RF spring so more preload on the right front from more wedge will tighten the car even if the LR spring is missing.

wfoondirt
Dirt Forum Champ
Total posts: 505
posted December 22, 2004 09:41 AM  
Typically a car goes loose on slick so you want to add diagonal it tighten the car. As long as you drive in the corner straight and take alot of rear brake bias out (which you should on slick) it won't loosen entry, but will tighten the car in general.

As far as wheel offsets go, typically when the track is slick the car is not capable of producing the lateral g's neccessary to transer weight to the right side so you want to reduce you static left weight. You can accomplish this by moving the right side wheels in and the left side out. This will also reduce you diagonal so you have to compensate by jacking diagonal back into the car.

As stated diagonal still effects jacked up 4-bars that same due to the fact that diagonal percantage is (lr+rf)/total.

quote:
greggie
They also determine where the acceleration and deceleration leverage advantage is. A wider front offset will have more leverage on the centerline under braking than a narrow offset and try to turn the car in that direction.

Care to elaborate more?

I'm triing to understand what you are triing to say here. I assume your triing to explain the effect of moving the rf out to let the car turn in better. Essentially you are reducing the wheel rate on the right front thus producing less dynamic diagonal on entry netting a looser car on entry. (or tighter if you use alot of rear brake and yaw angle)

[This message has been edited by wfoondirt (edited December 22, 2004).]

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted December 23, 2004 01:10 PM  
I wouldn't mess with jacking weight into the car unless the handling problem is extremely bad. Use bar angles and wheel offsets to tune, along with air pressure. When the track goes dry, go from a 3" to a 4" off set on the left rear ,and from a 3" to a 2" or if you've got a 2" on it already go with a 2" and a wheel spacer, and it also wouldn't hurt to bring the rearend to the left a good inch more also when it gets dry by shortening your panhard bar. Also when it goes dry you can raise your panhard bar up on the chassis an inch at a time until it bites

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