Where to go with Suspension tuning

[1982 SS]

First off, here's a like to a video of my car on launch from two weeks ago, the last race of the season here.

http://www.youtube.com/watch?v=OtJRdq_pzSk

It'll do consistent 1.83 60' times with a best of a 1.75 on a really good track and ran consistent 12.96's up here at 4200 feet in Utah the day the video was taken.

The car has a 9.8:1 383, AFR 195's, Lunati Voodoo cam (.489/.504 lift at I think 228 and 234 duration without lookin it up), Performer RPM manifold mechanical secondary 750 demon carb. Its a reverse manual valvebody TH350 with a 3800 stall B&M holeshot that flashes at 4400 on lauch. The suspension has lots of room to improve, its got heavy duty front springs and KYB gas adjust shocks, no front sway bar and global west del-a-lum bushings in the A-arms. The battery is in the stock location and i know I can benefit from drag shocks and softer springs as well as moving the battery to the back.

The rear suspension has DickMiller Racing anti hop bars which are similar to the Edelberocks but far less severe. The theoretical instant center is 52" inches in front of the rear axle and I can change its mounting location to put it 67" in front of the rear axle. Its got the original springs and air shocks that I run completely deflated to make them effectively a 50/50 shock. Again, i know i can benefit from more race oriented parts. The tires are 29x11.5 hoosier slicks run at 14 psi with a max notch. I Notched the frame and pu the big tires under it because i was having a hard time hooking with Mickey Thompson 275/50/15 drag radials after I refreshed the trans and converter, besides too much tire isn't a bad thing at my local track where prep is marginal 90% of the time. Its consistent and thats what counts in bracket racing. I've tried the SSM bars before I switched the the anti hop style bars. The SSM really didn't work for the car as it squated on launch and now I'm getting nice separation or lift on lauch pushing the rear tires into the ground.

What do you guys think? I know relocating the battery and race oriented front end parts will help immensly.

 

[UMI Sales]

Thanks for including the video. Looks like a fun ride.

Are you foot braking and at what rpm are you leaving?

If you leave super hard, does it spin the tires?

What is the ElCo doing or not doing that you'd like to improve?

 

[1982 SS]

I'm a foot braker, I stall it to 1200 on the line and the converter flashes to 4400 when i smack it to WOT and come off the brake just hair after the third yellow. If i stall it too much the suspensin starts to bind and the 60' suffers. On the drag radials, that would make them spin, the slicks can hook, but the 60' falls away. I'm looking to make the most out of what i've got.

 

[UMI Sales]

With the slicks, are you bogging the engine?

 

[1982 SS]

Not that i can tell. It flashes to 4400 and hangs there for about 10-20 feet out (I can't tell exactly, its hard to say exactly how long from the drivers seat) and continues to rev cleanly to 6000 where i shift.

 

[UMI Sales]

It doesn't look too bad after watching the video a few more times. What happens if you'd stall at 500 rpm higher?

 

[1982 SS]

The body starts to roll over and i get some separation or lift between the body and the tires while I'm staging it up and the 60' starts to fall off about .02. I think the suspension starts to bind against itself if its stalled too much on the line against the brakes of the car. It seems like it hits the tires harder and reacts better stalled from 1200 rpm than it does at 1700+ or even 1500 rpm.

I agree, I've had lots of people compliment how nice the car leaves the line. I'm looking to improve what i've got to make it as effective as possible. At the moment I'm thinking I'll stick some v-6 springs in the front and I'd like a good adjustable drag shock, at least in the front also.

 

[UMI Sales]

We have some nice Viking double adjustables that you can tailor to your launch preference. QA1 R series work nice for a single adjustable but aren't very streetable (too harsh in compression). If your car carries the nose like it looks like it does, a QA1 standard single is effective.

V-6 springs work with adjustables but you may have to take the front tires off to get to the knob. Then there's always the Summit 90/10's up front if you just want to try something basic.