Question for you low 10 and sub 10 sec. stock suspended A-body rear suspension

Hey, that pretty clever! I am suprized I didn't think of that. :laugh:

 

this wont be much help....

I know this wont be any help at all to you guys but I had to run my mouth ou: . Anyways...this is what mine has: factory boxed rear control arms with solid bushings,right side airbag at 10 psi,no anti-roll bar,factory rear springs (who knows how worn out they are), summit 3 way shocks (I have no recollection what setting they are on o No: ). rearend is a spooled 4:10 12 bolt,tires are MT 28 x 10.5 on 10" weld draglites.

front consists of chain travel limiters (about 6 inches of travel till they stop), summit 3 way shocks (setting unknown),moroso trick springs,stock control arms with old bushings and weld skinnies.

car weighed 3510 last time out with iron heads,8.5:1 hypers TA 210s cam,T400 and 3500 convertor. 10 point cage.

nitrous system was nos double cross with 40 jets squared and hit from home.

best 60 ft is 1.41 with an average of mid 1.40s,6.70s in 1/8th mile.(6.72 best)

tire pressures were kept between 10 and 10.5 and didnt have a problem hooking at a halfway decent prepped track.

Maybe I'm just lucky ,but I really didn't put alot of work into the suspension. I got it to hook and left it alone...its likely I'll have to do some work after the TE's go on it...I hope so coz that would mean I have more power :laugh: ...thanks for reading this .....fish

 

This run is 4 hundreths slower than my best. 60' time is 1.71 (best was a 1.69)

If anybody has a suggestion on suspension tweaks that could improve my 60' time I'd love to hear it.

Thanks!

http://www.blackholehunter.com/Videos/dave12.18andslow.wmv

 

Wow it really unloads

In the video, your car really unloads the rear on launch. It is pulling the front dr side up it appears. Also , it really has a nose up attitude as it goes down the track. I think this causes a bunch of resistance areodynamically( though I'm not an engineer). I think if you could keep the car from unloading the rear suspension you'd see a bunch of improvment in the 60' and total time. Smokin Hot car though. I wish mine looked that good. Keep up the good work. My 2 cents.

 

Dave,

Watch the slow motion video closely. As you begin to move forward the front end rises and begins to transfer weight to the back tires. AS SOON AS the front end travel ends you begin to wheel hop. At this point you STOP the weight transfer to the back tires and wheel hop begins.

With the correct front springs you will be able to lower the front end a bit and the spring will actually have what is called "stored energy". With this spring you will litterally throw the front end up and transfer weight to the rear wheels and this spring will allow for a bit more front end travel. It will also settle back down better as you travel down the track to reduce the amount of air going underneath the car.

Later

 

what would happen if he had a little stiffer rebound setting on the fronnt shocks?

 

Along those same lines, maybe stiffening the rear would limit the rebound. It would also give you a more sudden plant in the rear.

I think a common misconception, is having a lot of compression in the rear gives you a better launch.

When the rear goes back up and the front is going down it will unload the tires.

I'm not saying this as a veteran, as I have no real racing experience (it's just the engineering side coming out).

 

Thanks for the input guys. I would definitely like to lower the car front and rear with some new springs. The front shocks are cheapo-gas models so I plan to get some adjustable QA1's to match the rear.

I don't have any travel limiters on the front A-Arms. I'm thinking of adding them to get some adjustment out of that too. I need to get a list together and see what all I can tackle over the long cold winter

 

I am currently looking into shocks and rear arms. The shock I'm considering is the QA-1 Stocker Star. It seems to be the shock we're all looking for. The other QA-1's aren't too descriptive as to their application. Also, I'm considering rear arms. I have factory original ralley arms (boxed) but I'm either going to get tubular arms and replace the bushings with aluminum or just replace the bushings in the factory lowers and get adjustable uppers. Any other thoughts on shocks and arms?


http://www.jegs.com/webapp/wcs/stor...goryId=12939&parentCategoryId=10075&langId=-1

 

Lots of Great thoughts here

Great advice. I agree with the "stored energy" theory. If you do go with some drag springs and are running the BBB get springs designed for the BBB(Don't ask how I know), not the small block ones. Also the drag shocks with more rebound sounds good, but will require so trial and error and a bunch of runs to get it dialed in(Part of the fun if you ask me). After you get it dialed in you may be able to go to less tire as the thing hooks much better, this gets you less rolling resistance(And cheaper cost of tires). I used to get my T into the high 1.6-low 1.7 on some g60-15 M&H DOT launch with 5 or so psi. That big meat your running should get you there and beyond. This is what Test-n-Tune is all about. Good Luck

 

I got the SBC springs(Moroso 47160) due to the BBB w/Aluminum heads being identical weight with SBC. I don't have a motor in the car yet to see how they sit.

http://www.v8buick.com/showthread.php?t=63667&highlight=moroso+springs

 

Mines a little heavier

I run stock stuff and a/c which adds to the weight. Dropped to the rubber limiters when I installed them. Went back to some stock Moog ones. With those mods you should be able to get by with SBC Chevelle ones.

Another thing I was just reading about is a pinion snubber. The word is that these are good for the leaf spring crowd as they keep the wrap up to a minimum. It was stated that the snubber could cause the rear end to unload. Might be your problem if you are running one.