Can’t get up on the bars

[JetstreamBodies]

Hey guys,

I’m having problems with my ‘15 Barry wright getting on the bars. Car has a 604 crate motor and weighs about 2360lbs with me in it (54% left, 54.5% rear, 110lbs of bite). The car is really good when there is any kind of traction on the top or bottom, especially out of the corners, but seems like it doesn’t even try to hike up. When it slicks off, I’m always bad loose exiting corners. Any gas at all and the rear end tries to come around on me in a hurry. Still, not hiking up. I think it’s so lose because it is not getting up on the bars.

We’ve scaled it twice checking to make sure the percentages are where we left them. We have a ‘16 Barry wright too that hikes up and hugs the corners. We set them side by side to make sure everything mounted to the rear end is the same. With all of the four links and Jbar mounted the same on both cars we still have the same problem. We’ve tried changing the left rear spring from 225lbs to 200lbs to transfer more weight across the rear and we’ve raised the ibar on the frame probably 2” trying to tighten up. Still haven’t figured it out.

When we jack the frame up in the rear, the rear end hangs freely with no binds and there is plenty of room for it to hike up. Any advice is appreciated.

[JetstreamBodies]

Has anyone had an issue like this in the past that’s not obvious when the car is static, and how have you addressed it?

[MasterSbilt_Racer]

Battery location the same in both cars?

[billetbirdcage]

1. Does the LR hike in the traction?

2. Once slick does the LR hike more in the corner but comes down or looses hike once a little ways out of corner.

3. If it ever does at some point get way up, does it appear that would/could be all the way against the chain? (Get an idea by jacking up LR corner of car on ground and look at the gap on the body to the top of tire or bottom of door relationship to the center of LR tire for reference to judge once on the track)

If your not sure, get video or have a crew guy to stand in the middle of one of the corners and only watch the LR separation and get answers to those 2 questions.

[Punisher88]

Could also be the car isn't rolling in the rf in the slick without the added speed to transfer the weight and gives the appearance that the lr is down because the rf is up..

[Len72P]

sounds tight , heavy track its ok , then slick you are shearing the rear loose. Berry's std. setup is tight. I have heard of J-bar at pinion and 8" on frame,for crates. On slick , reduce left rear "rebound" way down, right rear "comp." way down (soft). Take comp. out of RF . Are you on a 2 stage RF spring? If so, open the gap up (3 turns on Ohlins.) If std. RF spring , rock the chassis over, turns out of RF( 2 turns)and RR.( 4 turns). If you drop the LT rear top bar at the frame you will lift more , but lose rear steer , so roll RR back a turn on the rods to compensate. I would run a 175 left rear. Also add compression to LR shocks to help hold the chassis up. Just suggestions!

[Jim11h]

If not using ballspline check to make sure driveshaft isn't bottoming out into trans

[CCHIEF]

If not using ballspline check to make sure driveshaft isn't bottoming out into trans

This^^.. jack up the LR with the car on the ground, MAx bar angle on both LR bars @ frame that are recommended you ever use by chassis builder. Panhard bar mounted too high on frame can and will cause a bind,and limit droop. stay within manufactures recommendations. Some front slip yokes aren't deep enough. Driveshaft too long.also check for lift bar crashing into frame at front. Are shocks long enough that they are not the travel limiter? What limits LR droop on a BW? Report back

[JetstreamBodies]

Mastersbuilt-in the ‘16 the battery is right behind the (not a nice word)(not a nice word)(not a nice word)(not a nice word)pit. In the ‘15 the battery is in the center of the car about where most guys mount a dry sump tank.

Billet birdcages-Car doesn’t hike in the traction or the slick but still handles well when there is any traction. The chain is the travel limiter but the car never uses it on the track.

Punisher-One of the first things I checked was making sure the RF shock wasn’t bent, and it’s ok. I was worried it wasn’t able to get down on the right front and that’s what was keeping the left rear down but everything on the right front seems to be ok. Even when it’s tacky, I’ll ride the chip with the hammer down into the corner and the car handles good but still won’t throw the left rear up on the bars.

[7uptruckracer]

Check YOKE while it might look from the outside its going all the way in and you can even disconnect it and not push it in anymore there are some output shafts that don't have the deeper splines so the yoke will stop on the splines giving you the false assumption its at its max I think it was Gen 1 Berts?

[JetstreamBodies]

Len-I have more compression to give on the RF, so I’ll try that when it slicks off. Adjustable oil shocks on the car with a single stage RF spring. I was mistaken on the left rear springs. We went from a 200 to a 175 so we are closer there. I’ll start adding in your other suggestions!

Jim- I called and talked to Barry and he said that that if the transmission tailshaft is slightly misaligned or worn enough to introduce side play that the yoke could be binding on it. Car has a falcon in it right now with aluminum driveshaft. When jacked all the way up the car still has atleast 3/4” of room before the driveshaft bottoms out. The transmission still shifts fine but hasn’t been freshened in a while. We are gonna swap in a fresh Brinn this week and try that.

Chief- we’ve had the rear end jacked up to max bar angle and when it’s hanging from the chain we still have atleast 3/4” on the yoke before the driveshaft bottoms out. Droop is limited by the chain. Without it, we could get a little bit more but would then be limited by one of the four links binding on a bolt in the birdcage. I would worry that this might be limiting us when the car is moving but with no hike, I don’t think the birdcage is rotating anywhere close enough to bind. I’ll check on the lift bar and get back to you. Hadn’t thought of that.

Like I said we are going to swap the transmissions this week. Barry also suggested we put more preload in the left rear to help get the left rear off the spring whenever weight is moving. I’m hoping this might be the key because the ‘16 rides higher in the left rear and has more turns into the spring to get the numbers right. We are going to put it on the scales with more preload and move some lead to get our numbers where we want them. Thanks for all of the input everyone!

[JetstreamBodies]

7up - I know what you mean but the transmission will take the yoke until the yoke runs into the seal in the back. Years ago (before last rebuild on transmission) I found that one out the hard way and had to replace the seal and fluid :/

[Kromulous]

Its interesting to hear that Barry say the side play load may be introducing a bind under load. I have wondered about this for some time now, it would make since at some point when the angle become extreme that there could be a side load, but i would think it would be a lot less at static ride height.

That or maybe its a rotational bind while on the throttle, rotational speaking in terms of the splines being loaded, via the engine torque etc.

[7uptruckracer]

Its interesting to hear that Barry said the side play load be introducing a bind under load. I have wondered about this for some time now, it would make since at some point when the angle become extreme that there could be a side load, but i would think it would be a lot less at static ride height.

That or maybe its a rotational bind while on the throttle, rotational speaking in terms of the splines being loaded, via the engine torque etc.

Wonder if this is why the New Rocket sits the way it does....