fuel burn off

[bottomfeeder]

you guys have helped us all year on this forum and car is starting to get top 5 finishes and have gotten a couple wins. question this week is concerning car starts to pick up a push about 10 to 12 laps into a 20 lap feature. im assuming because of fuel burn off transfering more weight to front end. we can pull away from guys and they gradually reel us back in towards the end of race cause car starts pushing on entry. looking for some changes to help entry and not take away from exit. i posted all our set up #"s a few posts ago. newer 4-bar/4-bar chassis, this weekend was our 18th night in 4-bar chassis.

[clm15]

You should stay the way you are, just use more comp in the RF shock. This will change only early in the race and stay the same later When you are good you are good.

[Dirtrunner35]

You should stay the way you are, just use more comp in the RF shock. This will change only early in the race and stay the same later When you are good you are good.

Wouldn't a stiffer compression on the Rf cause more of a push ?? Due to the shock wedge ?

IMHO, I would go to a softer RF compression, So the Lf works better on entry and when the fuel burns off the car will be tighter, and hopefully the car will not push.

[Egoracing]

http://www.integrashocksandsprings.com/general/assets/PDFs/4LinkDirtSuspensionShockTuningGd.pdf

[clm15]

sorry I should have said ext! Brain fart!

[bottomfeeder]

we have a 6-2 billstein and a 7-3 billstein for rf. which would work better at fixing this problem ?

[JustAddDirt]

shock

6-2 would be better
could also raise RR bottom 4 link bar 1 hole and that will loosen just a smidge on entry
also if you have an adjustable pinion mount, raise j-bar on pinion 1/4"

[Dirtrunner35]

What shock is on the RF now and what are your tire temps ??

[bottomfeeder]

we ran the 6-2 on rf all weekend. we havnt been putting 7-3 on unless track slicks off. we dont use temp gauge, i check air pressure gain.lr gains 2-3 lbs., rr gains 3-4 lbs.

[Dirtrunner35]

Are you aloud to run bleeders ? What is your lF shock? I wouldn't run that high of compression on the RF, it will tighten the car on entry, if that's what you need?? But if it's too tight on entry I would go down on compression.

[bottomfeeder]

no bleeders aloud. lf is a 5-4. from what i understand billsteins are rebound # first. so our compression numbers are 2 on the 6-2, and 3 on that 7-3 right?. so isnt that as soft as you can go besides 1? im still trying to figure these shocks out. when they say less compression do they want a smaller #?

[Dirtrunner35]

You are correct, my bad. If it's pushing with that low of compression, I would say it's not a shock issue. So the fuel burn off could be it, can you lower you fuel cell ? Maybe a bigger lb spring in the Lf, or start you tire pressures lower at the start of the race. I have started with 11 1/2 on the RR on a slick track.

[bottomfeeder]

i think were going to try trailing rr one turn and getting camber to -5 degrees in rf and see if that helps. our next step would be lf spring, but im getting 2 different opinions. we were told to try softening lf spring from 500 to 450. rf is a 550 now also.

[Dirtrunner35]

Moving the RR back will effect entry also, but it may work.Camber wedge( more negative camber ) will help on the RF if that's what the car needs. Check the outside tire temp on the RF to see if you need more negative camber.