Need some advise on Rocket adjustments

[PA Dirt Fan]

Were running a 2011 black front car aluminum 800 hp engine car has all good components on it and well maintained The problem that were having is it seems to lack the forward drive to launch off the corner driver says its good going in but gets free at the later part of the middle and comming out of corner (wants to pull the back around not walk to the wall). I'm not sure if this is a case of actually being to tight in and misreading or over adjusting the car too much to try to get the drive in it. Here's what we've been running
550. LF. 275 RF.

200 LR. 250 RR.

300 5th coil on a gas Integra Ida 1/4 in preload
15 gal fuel
584 475
700 547
Left 55.6%
Rear 54.0%
Cross 50.9
153 lb LR
13 1/4 drop
Jbar 9 in at frame bottom of pinion plate right side
bars set to netural to scale
Integra Ida shocks

LR top 3 rd hole (short rod ). RR upper 3rd hole
LR lower 4th hole. RR lower 3rd hole
I've been running the LR adjuster nut down to the spring when it drys out along with dropping the Right upper down a hole and J bar at 9 in also shortend the right side bars 3 turns
We're running Hoosiers 1300 to 1450 range
I also took the "dummy shock" off to try it out some advise I was given but the car seems kinda lazy lifting up the LR
We're on mostly dusty dry dirty type tracks not with that glassy slick.
Any help or ideas would be appreciated thanks

[jedclampit]

An aluminum engine car should have more rear % than 54.

Why is there a 275 in the rf?

[PA Dirt Fan]

The driver likes it pinned down and rolled over on the RF said it felt much better turning in with it in there

[jedclampit]

If you must run the soft rf spring I wouldn't run the short lr upper,run the long bar and incresae your drop to 13.75 to up to14 ".

Not sure of the bar angles on that car but making your rr lower level to 2* uphill to front may help also.(assume that would be down one from where you are) and drop both left bars one hole.

Your current bar setup, from what I think the bar angles are, makes for a ton of dynamic rear steer! Get your bar angles from when you scale and where you run them at.

Try swap of rear springs l-r to 250 200.
or
I would try a 350 RF or possibly dual stage(not a fan of them) .Light rf springs make for a lack of foreward drive, save that for smooth, big, momentum tracks with high corner speeds.

Why is your rear % so low? And your left so high? Where do you set your rear end l-r?How many turns is it to make the nut touch when you do that, and fine or coarse thred shocks?





I really don't like that shortner unless your on a really short track.

pm me with your feedback if you'd like more help.

[dirtdiggerracing]

i agree raise that rf spring rate up !! then if front dont want to pin down drop lf spring as well !! the more even the front springs the more drive you will have !!! you might even try a 400LF & 350RF and i would also get that rear % up to at least 56 with that much HP !! PM ME WITH FEED BACK I WILL TRY TO HELP !!

[let-r-eat]

I don't think the short LU is doing you any justice either. 14" on the drop will make it much better with the left bars down a hole as recommended.The car isn't hitting the left rear with that soft right front and the lack of drop. Your compensating for a car that's not getting in. Has a bunch of dynamic steer but during the set is pushing like a dump truck.

[huckleberry_hound]

What exactly are you guys meaning by 13.75-14 drop?

[MasterSbilt_Racer]

What exactly are you guys meaning by 13.75-14 drop?

Jack the car up under the driver's seat until your travel limiter is tight. Now measure ride height between the frame and axle as you would when setting ride height. This number is the "drop".

[dfhotlm33c]

Just to be clear..does this mean jack up until the LR tire is about to come off the ground, or do you continue until the limiter is tight? I am going to switch over to going on the chain instead of using the dummy to limit, and want to make sure I am accurately measuring drop. For instance, with my LRU bar in top hole, if I jack under driver's seat until just before the LR tire comes off, I am at 12.25" (If I have my Dad and son, about 350 lbs sit on right side to simulate weight transfer, this goes up to about 12.75"), the LRU bar is at 42.5 degrees, but there is definitely still room for the shocks to travel. I just want to make sure I accurately measure drop and what length cable I need...sorry if I am hijacking...

[Matt49]

You should NEVER use a shock as a travel limiter for two big reason:
1) you will destroy the shock
2) the amount of travel allowed will change with bar angle and length changes because the birdcage will index at a different rate

Use a chain mounted to the axle tube. As you jack the car up to check drop, the chain should go tight at the same time the LR starts to come off the ground.

[dfhotlm33c]

I am aware of this..this is why we are changing it..we are slowly making changes to the car as we learn..this is next on the list..

In fact, this all started as a result of a lesson learned..I could never seem to get the car to walk off the corners..entry and middle were awesome, but i could never get it to come off right, it always felt good to a point then felt like it was just going to snap loose..

looked at some pics, noticed I wasn't getting up on bars very much, even though I was carrying same speed into corners as others..

jacked up car from frame just under drivers seat..standard ride height is 8.25" on LR..car was only getting to 10" before the LRB shock was maxed out! So, we put extension on it (Dummy in front already had one), and now we have 12-12.5", depending on if I simulate transfer with people sitting on right side, and still room in shock..

So, we now want to put cable/chain on it, and want to know proper way to measure for this!

Thanks!

[PA Dirt Fan]

Thanks for the ideas guys! Jed I measure the rear at 16 3/4 it's a 1 3/4 frame from the Outside of the right lift bar plate at top to the inside of the RR frame rail, is that the correct way? The shocks are fine thread intrgra Ida's it's around 5-8 turns (ill have to check for sure)till it starts to touch the LR spring. I don't really have an answer for why the rear % is so low thats how it came out when we scaled it the battery is on the LR frame rail with about a 30lb lead piece on the bar in front of the fuel cell to the right around 200lb driver.
I have the LR under slung with the rocket adjuster on it set to the thinnest point so if I'd put the long 18 1/4 bar on the top LR should I take the adjuster out and let it rest on the under slung bar to get the 13 3/4, 14 in drop ?

Let-r-eat you said that it's not hitting the LR with the soft rf spring and lack of drop could it be that with the lack of drop and the under slung combined be the reason why it doesnt seem to want to "hike" the LR up because its hitting to early just never seemed to want to lift quick I've noticed some cars even under caution just touch the gas it starts to lift up the LR how are they doing that ?