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Author Topic:   Scaling ??????
sixwillwin
Member
posted May 07, 2000 10:48 PM
2900# metric stock car. IMCA tires. 3/8 mile dirt track. Car is good but needs to be better. Car tends to be tight on entry and therefore my corner speed thru the middle is slow, other racers tell me I am driving way to deep in the corners and causing the push myself. My question is.. what is the relationship between the actual weights on the LR and RR..........and the RF and LF........and crossweight? I have scales and would like to get the individual wheel weight where they need to be. Presently LF is 845 #...RF is 710 #..........LR is 700#.....RR is 636 #. Cross is 48.5. I usually run about 49.2 cross for the feature. I feel like I need to increase my croosweight %. But I need a better understanding of where the individaul wheel weights and what they should be. Thanks alot.



jammin
Administrator
posted May 07, 2000 11:08 PM
Unless your running a 40 degree banked track, your running entirely too much RR. If you increase your cross, you will loosen the car on entry and tighten on exit, will rocket out of turns. I would try about 51 percent cross in your car if your running a semi banked track..



sixwillwin
Member
posted May 08, 2000 09:11 AM
Jammin, you confused me. You said to increase my cross to help loosen the car on entry?? Is that right, I thought more cross=tighter car?? You said my RR was heavy, I was thinking about decreasing the rear weight split to around even up and decreasing the front split also, that way I could maintain around the same cross%, what do you guys think about that? Thanks


jammin
Administrator
posted May 08, 2000 09:45 AM
Six, right now you have so much RR bite that it is going to be tight going into the turns, if you increase the crossweight, you will take RR bite out of the car and put more left rear bite into the car. This will allow you to enter the turns easier because the RR tire is not already set when you enter the turn. Weight will have to transfer before the RR is set.


sixwillwin
Member
posted May 08, 2000 07:46 PM
Ok jammin, more info, I had a 200# LR spring and a 175# RR spring, on the 2nd nite out I switched them around and readjusted ride heights and cross to exactly the same as before the swap and the car felt alot better to me. When you say RR bite, are you talking about the actual weight on the RR scale pad? If so, would you decrease that number therefore increasing the LR weight and cross%? What about the front split? What springs should I put in the rears?? I have 175, 200 and 225's available?? What would you like to see my cross % at?? OK nevermind you already said 51% earlier, sorry, is that for heat race too? I will be increasing rear % to 49.5 for feature with ballast, I am getting lots of wheelspin with good 406. Thanks for your help, I appreciate it. sixwillwin


jammin
Administrator
posted May 08, 2000 08:39 PM
Your rear should also be around 51. When you put the harder spring on the outside, you reduced the roll in the car, which kept the left rear on the ground longer, if you increase the cross in the car, you do the same thing. When I say RR bite that means the amount of weight on the RR tire, if you increase the crossweight, it will reduce that RR bite and increase forward bite. It will loosen you up more going into the turns and tighten you up more coming out because the left rear tire stays down with more weight on it. You want it to stay down as much as possible and still be able to set the car, this will make you very fast.


sixwillwin
Member
posted May 09, 2000 03:32 PM
JAMMIN'........OK. I will increase my LR bite and decrease the RR bite. How much? Will 100 -120 LR heavy be in the ballpark?? What about my question to you on what rear springs to use with this setup?? Thanks


jammin
Administrator
posted May 09, 2000 03:50 PM
sounds close, on the springs, it really depends on how you want the car to react....If you want it to roll more decrease the RR spring rate, if you want more LR bite and even more roll, increase the left rear spring rate. It really depends on the reaction of the car to the track and how the driver feels about it... Hope this helps.


CHASSISCAT
Member
posted May 09, 2000 08:36 PM
Thanks jammin and Chassiscat!! Took some of both of your advice and on Friday won heat and 5th in A feature after having flat while up to second and going to rear after that. On Sat. (last nite)....dominated both heat and feature!!! (Won both). Car was alot better off the bottom , still a fine line between push and loose on entry, but not too tight like it was, I increased cross to around 50% and the rear split was 110#. Thanks again, you guys shave given quality advice!!! sixwillwin


jammin
Administrator
posted May 14, 2000 10:37 AM
Great, keep us posted on your upcoming races.


CHASSISCAT
Member
posted May 14, 2000 07:45 PM
WAY TO GO,KEEP UP THE GOOD WORK AND KICK SOME BUTT.


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