Under slung bar on a Rocket

[grasshopper]

Does anyone have a problume with the under slung bar picking the left rear up off the ground? Or would using a chain be better in stead of the under slung bar?

[jedclampit]

Both will do the same thing, as will the shock, if you dare use it as a limiter. You need to control weight transfer to stop lifting off track....springs, ballast , panhard bar.

[grasshopper]

I dont think it is coming completly of the ground. But I think it is unloading the birdcage and not keeping spring presssure on the spring mount.

[jedclampit]

Do you have a handling problem? Or is this something that you or someone else observes?

[Graff Spee]

Most of the time when on the bars. The spring is just dangling. The bars are driving the chassis at that point. Hook up a camera or a travel indicater that will show you extention travel. I never set up a car to pop[ up anyhow. I like them come up when you need them up and to be graceful about it. Smooth and consistant wins the race. Good luck.

[fox1162002]

I've not had a problem with mine. You must be sprung wrong. It should help keep wedge in the LR.

[grasshopper]

Jed it wants to spin from the center off. We burnt up a RR tire in 15 laps the other night it was a brand new tire. I took the traction shock off and just used the under slung bar. Its the first time I did that didnt know if anyone else had this problume. I run a 200 on LR and a 225 on RR. All bars are in the netural postion.

[MasterSbilt_Racer]

Jed it wants to spin from the center off. We burnt up a RR tire in 15 laps the other night it was a brand new tire. I took the traction shock off and just used the under slung bar. Its the first time I did that didnt know if anyone else had this problume. I run a 200 on LR and a 225 on RR. All bars are in the netural postion.

What Jed is saying is that anything that stops the travel will unload the tire if you are "hitting" it too hard. Your car needs to not have too much weight too high, the j bar in the correct place, the correct amount of damping from shocks, etc to not lift up too violently or fast.

If the underslung bar is now unloading your tire and the lr wasn't unloading before, it is because you removed the front shock and the resistance to rebound travel that it provided. A rear shock only is likely not providing enough rebound damping.

[grasshopper]

I didnt know if the traction would stop the bird cage from rotating more so I tried it with out it the first time I ever did that.

[jedclampit]

Without knowing more info, I and others, can't give you accurate/ really useful help.
Make and year of car, best detailed setup info you can provide.
(ie....Scale #'s,springs,shocks,bar locations,track description, engine hp #,gas or alky,tire compounds etc.your lap times compared to best cars)

PM me if you like. JED

[grasshopper]

2006 rocket black front end. 500 LF, 2 stage spring on RF from RE Supesion, 225 on RR 200 on LR 300 on the 5th preloded 1/4 inch, 6th is a 400 preloded 1/4 inch. the J Bar is 8 3/4 up the 4 bars are in neutral postion. Shocks are from RE and set by them they are Ohlins gas shocks. Steel Head late model 640 HP. ON Gas VP C12. American racer SD-12 (we have to run a spec tire). Lap times to the leader was 3 tents off. 120 pounds of wedge. The track is a 1/2 mile high banked in the cornes, mid banking in the straights (track is shaped like a egg kinda 3&4 is a longer turn than 1&2) The track is in NC.

[V1SLM]

Maybe try stiffining bottom spring on stack by 50 to 100lbs to keep LR loaded, or reduce gap between lock nuts and slider. Where is this track in NC, sounds more like CLR than any half mile in the state?

[grasshopper]

311 speedway. we got it at 1 !/2 on the lock nut of RF

[jedclampit]

What rear % are you able to get....and total weight?

[grasshopper]

55% 2440 or around there total weight with 20 gallons fuel. The driver weighs around 160#.

[talclipse]

How much travel does your underslung bar limit you to?

EC

[grasshopper]

13 1/2 inches

[talclipse]

How much wedge are you running? How is the car on entry?

[jedclampit]

All good questions so far.

What is the track conditions when you are having this problem.

I have some thoughts on this, as does Talclipse as I can see.

This sounds like a track that you are turning most of the time, correct?

What are good track lap times and slick track lap times?

If your only .3 off from the best cars, and spinning your wheels, it should be pretty easy to get you up to their speeds..........or better!