Bmod setup help

[dirtracer07x]

Guys I need some help after being out of racing for 18 years im starting over in a bmod. have only ran 3 times so far. first night car pushed bad entering which made me loose off. made some changes and cars was a little better. 3rd night made a lot of changes and car was super loose. but scales say its closer to what it should be. DW8, solid pull bar 16" rear springs, lr in frt, rr behind, both rear bars are at 16", lr bar 3hole up, rr bottom or level. here are weights. 1st night springs lf 625 rf 525 lr 200 rr 150 weights lf 443 rf 585 lr 700 rr 510 left side 51.2% rear 54% cross 57% total 2237 2nd race changed rr spring to 175,added 25 lbs to front left frame rail lf 524 rf 531 lr 647 rr 566 rear 53% cross 51.9% 3rd race same springs added 60pounds to rear over axle lf 531 rf 497 lr 699 rr 639 rear 56.6% cross 50.5 ideas? one more thing. first two race ran 1" front stagger and 2" rear. 3rd race only 1" rear.

[DaveBauerSS6]

How was the entry on the 3 rd nite? Any static rear steer?

[dirtracer07x]

No rear steer and it just didn't feel like it had any rear bite. I had read somewhere that dw8's liked a lot of lr bite. I might add more back.Also have 3 off wheels all around

[dirtracer07x]

This might be a crazy question but why does everyone run stiffer lf springs now when it used to be stiffer rf springs? And could wheel offsets help?

[Dirtmod13]

Trying to get car to lean right in corner, helps side bite and also helps LR get on the bars to plant it harder. I was in same boat as you. 15 yrs away and straight to Bmod. Lot of things are different now. Give us some info on how the car was the 3rd night. Like entry, on or of gas. Mid, rolling into throttle or stabbing it. Off, etc

[dirtracer07x]

Car seemed free in but way loose as soon as I got back on gas. Coming off corner was terrible loose, had to baby the gas to get it to straighten out.

[dirtracer07x]

I was told that the dw8 liked a lot of lr bite so I might add some back in or change back to a 150 RR spring

[andy29]

shocks are key on a b-mod, what type are you running? and whats the angle of your left trailing arm? also is the rear end in square?

[dirtracer07x]

Custom shocks from afco for my car. Rear end is square. Not sure on left bar angle. Right side is mostly flat. But I haven't messed with bars and its gone from tight to loose.

[dirtracer07x]

Found out I have 1/2 of lr lead?

[Duckhnter83]

Are the springs on top the housing?

[Duckhnter83]

Also up your rear percent around 58% for an open motor 56% for crate will help drive off get more bar angle in the lr will tighten exit rr should be atlest 5° and trail the rr 1/4 to 3/8" and start with around 100lbs lr bite. Springs should be lf 500-550 rf 550-600. The rears will depend on where they are mounted. Left side 51.5-52 if your a heavier guy but if your lighter I wouldn't get over 53 left and keep cross below 50. Shocks will be a big deal too. What shocks do you have now?

[slim10]

would 11 degrees be to steep for the rr.jet recomends 18 lr and 11 rr.my car is a frankenstien monster the right is 16 inches long and the left is 18, I'm going to try running the front springs at 700 no split any ideas how this will work for me? 55 rear 51 cross 54 left with driver.I haven't any experiance with 3 links.3/8 dirt semi banked

[powerslide]

Found out I have 1/2 of lr lead?

Are you measuring at the wheels or on the axles dropping a plumb bob down off the over slung? If its at the over slung that is a a lot. Even if you are measuring at the wheel try cutting it down to 1/4in. If you have the means I would put the RR spring on top, Everything seems so bound up when you get the springs on opposite sides. What tire are you on?

[dirtracer07x]

I'm on the at kk704 tires. As far as lr lead I measured it at ride height. Did find out my front caster on right side is way off. Only like 2 deg. Was told to run 4 1/2. And that the caster split will add lr bite coming off. Going to also move RR bar up 1 hole. Will see what all this does.

[dirtracer07x]

Car was better with changes but still tight on entry. Also can somebody explain the panhard bar to me? Right now I am level with pinion and 8in up on frame.

[oldtrackchamp4x]

Typically speaking, dropping bar on pinion side or raising on frame side tightens entry to the center. Doing the opposite will loosen entry to center. Measure your split from ground to center of bolt on both ends and see what your split is between the two. Anywhere between 4-6 inches is pretty standard. I kinda think you have too much split for your car. JMO

[dirtracer07x]

Well I redid the RR bracket and go 18° of bar angle and the car is finally good on the gas. Little loose getting in Noe but boy does it turn good lol

[dirtracer07x]

Sorry lr bracket. Car is free now and great mid to exit but loose in

[Dirtmod13]

Lighter RF spring will take some of the wedge off the LR when entering corner off the gas and should tighten entry. Saw a guy doing this Friday. Came into corner sliding all the way up the track then when/ if it caught he could get on the gas but he lost a lot of ground doing that

[dirtracer07x]

Already down to a 525 on rf. I'm thinking I need to run the rear end straight up. Not trail the RR.

[dirtracer07x]

Here's the plan for this week. Put a 550 in the rf, a 200 in the RR, run the rear end straight up, put a hold up shock on lr and lower jbar on frame 2in.

[oldtrackchamp4x]

You are planning on doing WAY to many changes on the car. You should only make one change at a time so you know if it works or not. If it doesn't work put it back where it was and try something else, if it works leave it where it's at and go from there. In reading your post that the car is good mid to exit, i would just try dropping jbar 1/2 inch on pinion or raising an inch on frame. JMO.

[dirtracer07x]

Should jbar be level or lower then pinion on 9in?

[oldtrackchamp4x]

As I said before, measure from center of bolt that attaches jbar to frame bracket and rearend side pinion plate bolt center wto the floor with all ride heights and tire pressures set. If rear end measures 6 in to floor and frame side measures 12 in to floor you have 6 inches of jbar split. Also as I said before, if car is good except for entry to middle, drop jbar 1/2 inch on pinion or raise frame side 1 inch. If the track is the same as the last time you raced it, you should feel the difference. JMO.

[dirtracer07x]

OK I backed off on all the changes I was going to make. Checked measurements and had 8 1/2 ins of rake. Lowered it to 6in and set rear end square. That's it for this week. Thanks for the help.

[oldtrackchamp4x]

Run the car as you now have it in hot laps, if you get hot laps, and see how it enters corner. If jbar is at center of pinion now and car is loose on entry lower it a 1/2 inch on pinion. If it is already 1/2 in below pinion go to an inch below pinion if car is really loose on entry, or raise a 1/2 in on frame if just slightly loose on entry. If you don't get hot laps and car is loose on entry in heat race the way you have it now and track will be the same in the feature or drier, raise 1/2 to 1 inch on frame or lower the 1/2 inch on pinion. JMO. Good Luck.

[dirtracer07x]

It was really good in hot laps on tacky track. In the heat it slicked off some so I lowered RR bar to level. Main was super dry and car wanted to spin as soon as I got back on gas at mid corner. Think I will lower jbar at pinion for next week.

[dirtracer07x]

Question. Is there an advantage to moving the RR spring on top of the rear end and if so what is it? Right now I have a 16" on slider behind but I see a lot of guys going to the 13" ontop

[oldtrackchamp4x]

Remember, jbar is for entry to center. Did you raise lr bar? Did you increase your lr bite? If not you should probably try one or the other. You can drop your tire air pressures to 12 on the right side and 10 lf and 8 lr. On dry slick you really need to be VERY gentle on the throttle, or you could try a vacuum secondary carb. Keep good written records on how the changes effected the car and how dry or tacky the track was so you will know what changes to make to your car when it is dry or tacky. Again, one change at a time. And finally be honest with yourself and think about how well YOU did driving the car. JMO.

[dirtracer07x]

What about putting a 2off wheel on RR? Now all are 3 offs.

[oldtrackchamp4x]

What are you wanting to accomplish? JMO.

[dirtracer07x]

Tighten car up mid corner on gas. I changed RR spring to a 200, raised RR bar 1 hole, lowered jbar 1 hole at pinion and the car was awesome.

[oldtrackchamp4x]

Remember to keep notes on what the track was like and the changes that worked on that type of track. Sounds like you are good to go now. Good Luck. JMO

[dirtracer07x]

What front spring rates are guys running with chevelle clips? I have 625Lf 525Rf was told that is to soft and should go 700/600. Thoughts?

[UltimateRaceCars]

I have customers on 500-550 and 600-600 and 600-650, it really depends on your driving style and the amount of grip/banking your track has. If you enter soft or have a flatter dry track you can go softer than someone who enters hard and or races at a tacky high banked track.