chassis tuning help neeeeeded

[dmartin1962]

seems some of you guys have alot of experience with making a 10 in tire car
go fast so here is what ive got so far
1969 nova ss 385ci w/ nx plate system...only 100 shot so far,the n2o is wired into
the trans brake switch so it comes on off the line,here are 2 back to back passes
motor only 4200 launch rpm/ 5500 stall conv,shifted at 7200 1/8 mi pass
tires are 29.0 tall with stiff sidewall and 13.0 lbs
60ft ..... 1.4711
330ft......4.2399
594ft......6.1469
1/8 et...... 6.5769
1/8 mph ...... 104.69
came back around and turned on the juice....
60ft ..... 1.4742 spinning with a wheelstand
330 ft...... 4.0703
594 ft ...... 5.8572
1/8 et..... 6.2591
1/8 mph ..... 111.97

ladder bar car with single adjust rear shock.
should i scrap the 90/10 front shocks ???
install whellie bars ???
different slick or air pressure ???
car is a handfull to drive with spray and even on motor will stand 2 feet and
bounce around when it comes down,fast is fun but going straight would be nice
any suggestions would be helpfull....test and tune will be here soon
i want to get to a 250 shot
dan

[want-a-be]

Slowing down the front shock rate should help slow the upward movement. Limiting movement will also. What angle do you have the bottom bar of the ladder bars? How high is this car from the ground? Does it launch straight when the wheels are up? Does the car dart left or right when the wheels come back down?

I would delay the spray for around .2-.4 seconds. Get the car to moving first then spray it. Might help control the tire spin. Once the tires break loose it can be tough to get them to rehook. Your 60' slowed with it on initial hit of the tires. Try different times to maximize this.

How much does the car weigh? Front suspension type, is it stock? Tube chassis or pretty much stock? How much of the weight is on the rear tires? Does this car see any street use at all? Where is the fuel cell?

Do you have a sway bar " torsion bar " installed in the rear?

This ought to get us started at least.

Don

[dmartin1962]

thanks for the reply,
the car will launch straight and the front end is level through the wheel stand
the problem comes in when the car comes down,the car bounces and the front
tires shake,then it goes where it wants to,seems to go right more often than left.
rear suspension is mini-tubbed and front is stock with a glass front end
weight is 3150 with me in it,this car sees no street useage. not sure where you
want me to measure front and rear but the front end is lower than the rear by a few inches.rear suspension is a quarter-max ladder bar set up with strange coil
over shocks and a track locater. fuel cell and battery are in the rear,cant remember what the scale readings were but slightly more on the rear,the car
needed 11 wrench flats turned on the rt side to balance the weight at the rear
wheels.

[want-a-be]

What I think you are experiencing when the tires are comming down is bump steer. If you have any pictures from the front with the wheels up look at them. I'm betting that both front wheels will be pointing out. When this happens the car will dart in the direction of the first tire that touches the ground. Which totally upsets the car and gets very uncomfortable to drive while under power.

How high off the ground is the front ladder bar mount? Does it have any up and down adjustments? Which hole is it in?

How high is the front of the rocker panel and how high is the rear of the rocker panel.

What 90/10 shockes do you have up front? Koni? If so then they use to make them somewhat adjustable. Take them off and compress them all way. Trun the shaft and it should adjust the shock.

Don

[dmartin1962]

the shocks are old comp eng 3 setting shocks
ladder bar forward mount has 4 settings and currently its in the second from the
bottom
the pictures do look as if both front tires are towed out
i cant get you any acutare measurments as the car is on my trailer
dan

[Awesome Bill]

Tie your front end down so there is only 1" of travel before both tires come off the ground with a floor jack. Take your front shocks off and put the front setting to the stiffest setting when trying to pull the shock apart.

Put your car on a flat floor style lift, and take the right side ladder bar mount front bolt out, set your weight in the car. Get and inclimetor and make sure you have 3-4° of pinion angle. Do not change the front ladder bar mounting position. Once you have this in place, move the passenger side ladder bar hole to within of being 1" above the same hole as the other side. Mark it with red paint on the flat it ends up on. Then pull the bolt back out and bring the ladder bar down to ½ a hole or so. I use a ½ hole for N/A and a full hole for NOS. Mark this setting blue.

This is a basic ladder bar position. Never change the front mount until you have tried everything 1 change @ a time. I would also set the rear shocks as loose as possible. I don't think you have double adjustable rear shocks? If you do set the extension to the softest side and the compression or rebound to ½ or ¾ way of the tight side. Raise the air pressure in your rear tires a couple of pounds and see what happens.

When you install your anti roll bar, leave the ladder bar positioned to the ½ hole position and install your connectors and adjust to a neutral position with your weight. I install on the tight side of slack on all settings. With the anti roll bar, you can either run it with spray on without and it will not require any adjustments other than a few minor shock settings.

Your only getting 590 hp @ best and you are loosing all your top end. What is the rpm your crossing the finish line @. Other than that, this is my basic tune up for a chassis out of control. Have fun. Work with the air pressure until your tire looks nice and round on the hit. If the tires sidewall looks stupid out of shape, keep putting air in both of them until it only has 3-4 small wrinkles in the side wall. Get a video, it is the best way to see the hit.
Take your car to a good front end shop after you install an anti roll bar on the rear. Put as much - caster in the top ball joint as possible. Before you

[want-a-be]

Hey dmartin,

Haven't seen any feed back on what happened to your set-up. Did you get it lined out?

Don

[Awesome Bill]

I think he is waiting for the snow to clear. We just got hammered in the Northeast, Ocean City, we got a crazy wild 12-14", havent seen this much snow since 1995 when we had the black out. Glad I got a Bobcat ST150, the ¼ of black top lane will be easy this time.

[want-a-be]

dmartin posted this last spring, so I was hoping to hear some feedback from the summer.

I'd love to have a Bobcat. One with the backhoe attachment to go along with it.

Don

[Awesome Bill]

dmartin posted this last spring, so I was hoping to hear some feedback from the summer.

I'd love to have a Bobcat. One with the backhoe attachment to go along with it.

Don

I bought that because my landscaping quote was $30,000.00 for my ¼ mile black top driveway, yes I have one but no I don't race on it. Did the Bobcat purchase and only had $27,000.00 in everything and now I got a Bobcat. Boy does that thing really save time. Ofcourse you have to learn how to use it. I was always good with equipment. Give me 10 minutes and its like walking

[Awesome Bill]

Good thing I had the Bobcat, three of the largest snow storms to hit the north east and we got over 40" in our little Ocean City Md area where we usually get on 1-2". Shut us down for 2 weeks. Been digging out since!

[dmartin1962]

:Dsorry i set the record for longest time to reply.....racing has taken a back seat to other responsibilites(my 6 yr old grand son)
i have barely used the car the past 2 summers.i had it out once last year for a grudge race with another nova...he had alot more car but i got off the tree first so my 6.28 beat his 6.27 :D
as for the chassis i tried to delay the n2o hit by leaving at 1/2 throttle and flooring it to the wot switch
after the car rolled out and the car went straight,only has a 100hp shot.Please allow me to make the following statement:
BRACKET RACING SUCKS !!!!!!!! i can say that after 8 seasons of boredom.The above race was the most fun i have had with this car in years and its a shame there arent any heads up series i can get into,my fiberglass front end rules me out of most 10.5 tire classes.Anyway i listed the car for sale but the best offer i saw was 10,500 this past winter.cant sell for that so i will get it back out soon.IF i can figure it out i will post a picture of the car on this site but my computer skills are limited.
Dan

[dmartin1962]

what timing! my daughter just stopped by and put pictures of the car in my profile.

[want-a-be]

Hang the fiberglass on the wall and get some sheet metal. You can buy new now-a-days. Cheaper then buying a whole car.

Nice hearing from you again.

Don

[want-a-be]

Where is a good place to go read over the rules of 10.5 tire racing?

Good looking Nova btw, looks like it leaves good and straight.

Don

[dmartin1962]

Where is a good place to go read over the rules of 10.5 tire racing?

Good looking Nova btw, looks like it leaves good and straight.

Don

try this site
nmcadigital.com
click on racers.then click class rules