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Author Topic:   rear %
dirtbuster
Dirt Maniac

Total posts: 106
posted June 25, 2002 01:17 PM
How much have you guys run. We are at 59.5% and seems like we need more. Thinking of going up but don't know how much. We ran 60% last year and over 60% once this year and the car seemed to stick good that is why I want to try more.

Just dont want to get so much on the rear that there is noit enough to steer it with the front end.

dirtracer14
Dirt Freak

Total posts: 333
posted June 25, 2002 07:46 PM UIN: 23443678
I have been playing around with my rear % this last weekend i went out with 59.3 and the car was scary loose getting in the turns, was good everywere else it would just act like the rear was coming out from under me getting in. The track i race at has long straights and tight turns and we run the hoosiers. My car has never been that loose getting in along with another small change that i made i think the rear % made it loose when the track got a bit slick we will find out Fri when we go to test.

CUSTOMPERFORMANCE
Dirt Freak

Total posts: 464
posted June 25, 2002 09:57 PM
i am running around 58-59% rear and am slowly taking bite out of the car so it will turn and it has all the forward bite i need even when track starts to get slick. I am running 3 link. car sticks real good anywhere i want it to.

joeltjen
Dirt Full Roller

Total posts: 36
posted June 25, 2002 11:27 PM
we weigh 2600 with out driver, we are up to 60.8 % rear right now , but our track gets ugly dryslick. we put more bite in the car last week and went from running in the back to getting 9th in the feature. we had around 120# bite and now have 320# and are going to try more. know of a couple cars here with almost 400#!!! now your car isn't my car so this might not work for you but..... also our cross is 57.2%. left side is 56%. our car was loose like you said , try dropping your rear roll center. you need more downforce on the right rear going in. we dropped ours about 1 inch with about 2 inches rake in it( long bar, behind the rear, frame on left side) also STIFFENED right rear by 20#, gained side bite, forward bite and had less body roll. body roll doesn't equate to downforce on the right side(some may argue but thats my opinion)

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WPP
Dirt Maniac

Total posts: 162
posted June 26, 2002 08:17 AM
That is why when you put a stiffer spring on the right rear it will tighten the car going in on my swingarm i run 350 lf and 325 right rear and i have thought about switching the springs to see what happens i run my pullbar 2 1/2 inches to the left anyway

dluna
Dirt Full Roller

Total posts: 42
posted June 26, 2002 11:58 AM
Ok, so our car has never been good on dry slick. We run about 56% rear, and we tear it up on tacky but could possibly use more forward bite. My question is really to the first 3 or so people that have posts on this topic. Are you all running that high of a % on tacky or JUST when it get slick? We are going to raise the rear % this weekend but do not know how much to go for the transition between tacky and dry...THANKS...

dirtbuster
Dirt Maniac

Total posts: 106
posted June 26, 2002 02:36 PM
dluna,

if it is tacky then i believe you dont need as much rear % because the tires will hook up on there own. When it gets dry you have to create traction by loading the tires more heavily. WE usually run 57% min no matter what and on dry up to 60% and may try more this week to get more power to the ground.

If you get too much rear% and it is tacky then you will not have enough weight on the front tires to steer the car under acceleration and it will push. Also can get so much traction when you first get back on the gas that it will actually start to lift the front end and create a push because there is nothing to steer the car.

That is just my opinion. I don't like to run any heavier than we have too but we have to do what makes the car work even if that means being heavy. One race this year we were 250# heavier than the other cars but the car was fast and stuck like nothing else.....

joeltjen
Dirt Full Roller

Total posts: 36
posted June 26, 2002 11:22 PM
just my opinion,as i dont know what suspension or anything else about your car, so this is what i would do to my car if it pushed on tacky: add a little stagger, maybe raise the bar a little to help it turn in the middle. take out some cross weight(adding stagger will do some of this) just my .02 john

CUSTOMPERFORMANCE
Dirt Freak

Total posts: 464
posted June 27, 2002 06:39 AM
I am running that rear % all the time at 58%. In the heat when the ttrack is heavy it does tend to push because of the ammount of rear but in the feature it is fine when it starts to slick off. For the heats i use a litle more rear brakes and change the rf wheel offset to get it through the corners better without such a push with that kinda of rear %.

alkyholic
Dirt Roller

Total posts: 19
posted July 14, 2002 03:58 AM
we run around 56.5% rear and car is great on tacky, on dry we had no forward bite. we just added 25lbs to lr and 50lbs to rr and now we have more than enough forward bite. wouldnt having a lower rear and just adding weight be better overall so your not sacrifising bite on tacky?

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