Shaw rear wheel hop

[DRTRCR22]

Hi guys, I am brand new to this forum, so please bear with me as I fish around here seeking help.I have an '05 Larry Shaw 4 bar Modified, with 9" floater, currently 6.00 gear, and all IMCA legal trim. I have a beast of a Dart Little M 406 with Dart Platinum steel heads, and a PRC #9 flat tappet cam for IMCA rules.I am only into my third full year bar as a four bar modified driver, and am desperately trying to learn how to properly feather the pedals, trail brake, and rotate the car in the corners properly. Aside from that, once I get coming out of the corners and start carefully pouring on the coals, the rear tires start hopping like a jackrabbit, and I have to back out of it to stay connected. I just cannot get any forward bite...! When it does start to dig it hops even worse... and different gears 6.20, 6.33, nor 6.50 offer no change in the problem... ?Like most all other advice around dirt tracks, I have received dozens of recommendations, including some directly from Shaw, but none of the changes seem to work. I have been working diligently on my lead foot but I don't think that is the biggest problem...? This happens on both dead heavy clay and on the black dry slick too...? I currently have this suggested setup which seems to work the best on the dry slick A-main races...springs - r/f 650, l/f 600, r/r 175, l/r 175shocks - r/f 3-5, l/f 5-3, r/r 3-5, l/r 8-2 (all Bilstein gas, so the numbers are actually reversed)I have Shaw's new orange three biscuit wishbone pull bar, with no top shock.I have the rest of the car set up exactly to the specs Kevin Shaw and Wayne Brooks tell me. I have been told by several others that there are several year models near mine that have this problem. Does anyone know if this is true, and does anyone have a clue how I can eliminate this horrible jack rabbit hopping...? I am desperately trying to save up for a brand new 35 series Shaw chassis, but other than the hopping and horrible lack of forward bite this has been a good starter car for me and I hate to park it until I get more seat time experience in...?Any expert suggestions at all will be much appreciated. thanks, Jim

[LateModel B23]

Pull bar angle? Bad shock or spring?

[juice87]

to much left rear bar angle take some out tires are acting like shocks.

[juice87]

u might want to check ur caster settings also I know this sounds stupid but if u don't have enough split on a rough track will cause car to be darty which will upset the chassis bad. and if you get the car rocking it will cause that

[oldtrackchamp4x]

To much left rear upper bar angle. JMO

[racin6mod]

Pull bar angle? Bad shock or spring?

I agree to much pull bar angle.

[DRTRCR22]

All new Hyperco springs and Bilstien gas shocks on it, but I may switch shock valving to a 'normal track' setup instead of a 'dry slick' setup...? There are only two front pull-bar bracket holes... and the short wishbone style bar is pointed down into the bottom hole and top hole on the housing bracket. I was told this is about the only setup that works for dry slick...?Left rear upper bar is where Shaw and Brooks recommended, and I haven't moved it since. Wow on the caster split, I never would have thought of that, but it makes sense because the car does 'bobble' coming out of the rutted corners...!Ok guys... THANKS, I am going to try all your suggestions...!Wayne Brooks worked on my car last, and after he took it to 9th spot of 66 entries at the Southern New Mexico Fall Nationals last October, he told me to not touch or move anything... just swap wheel spacers around and the car will be fine...? Well, for him maybe, but it is not working for me... so I have to do something to make this car drivable for me. I really appreciate ALL your suggestions, and thanks for all the help. I will try report back my progress as I figure this out... Jim B

[JR. MECHANIC]

You're wasting your time with the caster thing. Jmo. Have you checked your shocks to make sure something isn't wrong there. Bent shaft, dead spot, dent in the body, etc.

[DRTRCR22]

Like I say JR, all new springs and shocks, and I have tried several other combinations but some are worse than others. I really need to send all my TSMs that came on the car back to Steve to get them rebuilt and freshened, or maybe try Shaw's new custom Integra shock package, or the Bilstien DP1 package...? Yes, I will try new spring shock options, as well as double check the Shaw recommended caster split settings again. I have taken a couple good front wheel hits lately and have had to replace some uppers and tie rods, so I will have to confirm they are still correct anyways...? Thanks for your input. Jim

[powerslide]

how much out travel does the RR have? How much air are you running in the RR?

[roundboy]

And are you on a J-bar or strait bar?

[DRTRCR22]

WOW... thanks guys...! I made the adjustments you recommended and finally got to race again this past weekend, and the hopping has completely quit, both dead heavy tacky track and black ice dry slick conditions...!I raised the pull bar front to the top hole, and lowered both left side bars down one hole, and the car was awesome with not even a hint of hopping. It drove like a completely different car...? Forward bite was much better, but still not what I would like, so I will work on that next. I did not change caster camber settings, but did put the TSM shocks back on the rear.For the other unanswered questions... I run 14 lbs air on both right sides and 12 lbs both left sides. I also run J-Bar set to exactly where Shaw says is needs be.Thanks again everyone, you have been a BIG help... Jim