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Front Engine Dragsters / FED bounce problem.
« on: June 20, 2020, 07:15:28 AM »
I have a 225 inch FED runs 4.90-5.0X and I am having a problem with it. Data logger is showing some bounce / tire spin down rack. Last race I took the wheelie bar off and weight out of nose to be able to run index in high altitude bad air. I THINK I know what the problem is but want some input on how to resolve it. Mind you it is not bad but I want this car to get down any track under all conditions as close to perfect as possible.
Last week in final round saw a video that kind of affirms my thoughts. The car took off at the hit and pulled front wheels up about 8 inches and carried them out about 60 foot and then set them down nice and smooth. That is more than normal but no big deal. What I saw that was interesting is a lot of chassis flex in the middle and what I think is happening is with the long car it is flexing and causing bounce down track. I understand some of that flex helps it hook but I think it is too much here.
I THINK stiffening up the chassis will help it hook better and smoother in the shut down area to. Several tracks we run at is rough in the shut down and it will get my car bouncing. I have also done a lot with tires and tire pressure but this is more than tires now.
My question is how can I test and verify my thinking on stiffening the chassis? Was thinking about tying the chassis with cable under tension to see if it helps and verify it is right direction to go. Something where it attaches in the front and back and goes over middle bar on top to limit downward flex. Then if it works could go in and add more bars to stiffen chassis. I want to do it right but want to verify it is heading in right direction and not making it worse before I do a bunch of major chassis changes.
Last week in final round saw a video that kind of affirms my thoughts. The car took off at the hit and pulled front wheels up about 8 inches and carried them out about 60 foot and then set them down nice and smooth. That is more than normal but no big deal. What I saw that was interesting is a lot of chassis flex in the middle and what I think is happening is with the long car it is flexing and causing bounce down track. I understand some of that flex helps it hook but I think it is too much here.
I THINK stiffening up the chassis will help it hook better and smoother in the shut down area to. Several tracks we run at is rough in the shut down and it will get my car bouncing. I have also done a lot with tires and tire pressure but this is more than tires now.
My question is how can I test and verify my thinking on stiffening the chassis? Was thinking about tying the chassis with cable under tension to see if it helps and verify it is right direction to go. Something where it attaches in the front and back and goes over middle bar on top to limit downward flex. Then if it works could go in and add more bars to stiffen chassis. I want to do it right but want to verify it is heading in right direction and not making it worse before I do a bunch of major chassis changes.