What would you do if you LST's rear end severely flew up over every bump and jump on the track causing a noise dive????


I know you can level the truck with gas and brake in the air, etc. etc. But this is to dramatic for that. What I am looking for is would you stiffen the rear suspension, lighten it, heavier oil, lighter oil, springs etc. The front absorbs the bumps well but the rear end even flips the truck even over little Moguls.

Tell me what you would change. I have the first race on Sunday and I want the LST to represent well!!! Tomorrow is my only day to work on the truck before then.

Thanks Much!

Thanks Much!

I am running 35WT, springs yellow 7.4pnds, threaded shocks turn down 6 threads showing. My suspension arms are just about level. Sticks like glue to track. This is for the back the front has 5 threads showing. I have not raced yet. This set up has been working for me.

With your radio and truck on but not running push the truck forward to see if the brakes or something else is dragging . This would be a good place to start to make sure it is not a mechanical problem.

Well first you should tell us your current rear shock setup. But it sounds as if you have too heavy of a spring with too light of an oil, or possibly too heavy of a spring and too heavy of an oil, or possibly too light of a spring with too light of an oil.

Did you ever watch the TV show, IN A FIX, they finish house projects that the owners started but then could not finish. I need that service for my LST.

OK- here are all my mods. Carbon Fiber chassis an upper plates, FOT tranny (works great), I put lite sway bars on front and rear, and threaded shock bodies. As for the shocks themselves, front has 30 weight oil with black springs, rear has 40 weight oil with silver (stock) springs. I do not believe I intended the spring set up that way it is just how it ended up. I also put in jet vent shock pistons for the hell of it. I adjusted the shock bodies through out the day but and found some difference but in the end my ass end was flying high in the sky. I need to be able to come of those bumps and jumps more level.

I also intended to experiment over the last few weeks with diff oil so I put 50 in front and rear. I noticed no turning improvements.
Thanks

I believe those jet vent pistons work faster in one direction than the other, because of the tapering in the holes only faces one side of the piston. Is that correct? I don't own them. Also since the oil moves through them faster than the stock pistons, you may need to use heavier oil. I've heard of people using up to 70 weight with the jet vent pistons. With the stock pistons and silver springs, 40 weight would be too heavy, but that's probably not the case with the jet vents.

When you drop the truck from waist level does the rear end bounce? And is the chassis slapping the ground?

When I drop the truck fram about 4-5 feet the rear end does not touch and the truck doesn't bounce. I actually thought the shocks handled it very smoothly but on the track that is not the case.

I have the jet vent pistons with tapered ends up meaning they would move faster on impact as opposed to rebound. I am going to put in some heavier oil. Would it make sense to stiffen the rear to prevent the rear flipping??

When you say "every bump and jump" do you mean every one that should involve air time? Meaning a significant jump instead of a bumpy track. If you mean a bump or jump where all tires are leaving the ground then I would think there is a problem with the breaks dragging. I'm currently battling this problem as well......sure makes flying my LST interesting!!


If the problem is just handling bumps I would suggest softening your suspension at the end that is bouncing the most first and work from there.

It is when air is involved. All the jumps and also some moguls as well. I checked the brakes for drag and they are free at idle. I prefer to have a little lift on the front of the truck when in the air as opposed to the rear. But this is insane the truck hits a foot high Mogul and flips rear end over front on my lid. No issues with turning or traction, just at lift off! What do you think??

If you are having problems with the brakes holding to much, you can try adjusting the brakes by tapping the button just to the left of the steering wheel (Left as you are looking at the radio controller) The way I got mine set correct, or at least close. I set the truck up off its wheels, while it idled with the controller in the neutral position, I tapped the button until the wheels stopped spinning freely. I then tapped the other way til the wheel just started to spin slightly. Before I did this, the truck would start going on its own at idle while in neutral. I may still need furture adjustments, but it seems to be close.

I would try flipping the jet vents the other direction.

From your description, it sounds as if the rear is bottoming out when hitting a bump. You have the stock (soft) springs on the rear, with 40 weight oil, and the pistons set up for fast upward travel. When accelerating, the rear shocks are probably already 3/4 of the way compressed, and just the smallest bump would cause them to bottom out, and the rear end bounces because of that. Since the rebound resistance is more than the impact resistance, hitting many bumps in succession is also probably causing the rear shocks to "pack up", which only adds to the poor performance.

I'd try flipping the jet vents, and putting heavier springs on the rear. Try it out, then you may even need heavier oil.

your brakes could be on slightly causing your truck to dive forwards when in the air, mine did that a few weeks back and i fixed it by adjusting the brakes on the truck, push it on the floor to test for resistance

watch my video on http://www.rcpics.net/view_single.php?medid=53596

Thanks for all the help so far. I have put the stiffer springs in the rear and 50wt oil. I will be able to test tomorrow and see what to do from there. I also will double check the brakes for drag but I believe they are good.

I thought about flipping the jet vent pistons and will try that if needed and I am also getting the yellow springs but hope to not need to go that stiff. Again thanks for the help and keep it coming. I will post my results tomorrow as well.