Need help deciding Spring-Rates

[Derek69SS]

'69 Chevelle (LT1/4L60) with approximately 2100 pounds on front and 1600 pounds on the rear with driver and full tank.

The car will see autocross/road-course action maybe 2-3 times/year, drag-strip 4-5 times/year, and I'll put about 4,000 miles on it each summer. I will drive it aggressively, but also do semi-frequent 100+ mile trips. I will be running QA1 adjustable shocks to adjust for different driving.

Front Suspension: stock spindles with tall upper & lower ball-joints, adjustable upper control arms with solid bushings, and stock lowers with delrin bushings. Adjustable shocks and 15/16" sway-bar (I have 15/16, 1-1/8, and 1-1/4... I'd prefer to run the small bar and have a little stiffer spring, but if I go too soft, I can fine-tune with the others)

Rear Suspension: Wolfe Racecraft spherical on all 8 ends, no sway-bar, adjustable shocks.
Lets hear it :) What do you suggest for my combo and how I'm going to use it :drive1:

[sinned]

700/175

[Derek69SS]

Thanks Dennis, will that still be tolerable on rough roads and long distances?

BTW, I changed the plan from Fatman spindles to the tall ball-joints because I got sick of hearing "next week" for when I'd be able to get the spindles :rolleyes: I'm thinking AFCO 9.5" springs with the height adjusters... is this also what you'd recommend?

[sinned]

Oh yeah, the ride isn't bad at all. The hidden adjusters are the only way to go.

[JodysTransmissions]

Oh yeah, the ride isn't bad at all. The hidden adjusters are the only way to go.

Dennis,

Do you have a pic of these hidden adjusters?

Thanks, Jody

[Norm Peterson]

700/175 should ride OK. I think your 'flat ride' speed works out to ~45 mph, which is slightly higher than OE but still within the range of speeds that you'll be driving.

I've got 640/165 in my slightly lighter '79 Malibu (weight distribution something like 1850/1600) and it still has a 'drive it just about anywhere' ride. Slight differences in motion ratio between your car's front suspension and mine shouldn't make for too much difference in this respect. FWIW, my car is still a bit too softly suspended for auto-x, but that's partly personal preference for a somewhat more serious auto-x campaign than you're considering, and partly from still running the OE balljoints.

Norm

[Derek69SS]

Do you have a pic of these hidden adjusters?
http://www.speedwaymotors.com/xq/aspx/paging.yes/dept_id.712/display_id.3389/qx/Product.htm

I do intend to run these, and AFCO springs :)

I'm looking for about 3" drop over stock... my lower ball joints give me 1/2" drop, so 2-1/2" spring drop is what I need. Do I go with the 9.5" springs and the short adjusters?

[sinned]

I'd go with the tall adjusters. A stock free length "A" body coil is typically 17" or so at around a 350lbs rate. The 9.5 coil with a 5.5 adjuster comes in at 15" max height and around 13" min height. AT min that that about 3" of drop (considering the increased rate won't compress as much). You can always trim a little of the tall adjusters if need be; in fact, there is enough material to trim about 2.5" of the tall adjusters.

Pic of the tall version adjusters..
https://static1.pt-content.com/images/noimg.gif

[Derek69SS]

I just ordered the 9.5" 700lb front springs and the tall spacers, as :) Thanks again :)

I may temporarily run my existing rear end configuration (which really sucks, but I'm blowing through my funds way too quickly)

[sinned]

I picked up a pair of Black Magic rear springs from Circle Track Supply I think, they were only about 90/pair with shipping.

[JodysTransmissions]

I'd go with the tall adjusters. A stock free length "A" body coil is typically 17" or so at around a 350lbs rate. The 9.5 coil with a 5.5 adjuster comes in at 15" max height and around 13" min height. AT min that that about 3" of drop (considering the increased rate won't compress as much). You can always trim a little of the tall adjusters if need be; in fact, there is enough material to trim about 2.5" of the tall adjusters.

Pic of the tall version adjusters..
https://static1.pt-content.com/images/noimg.gif

Dennis,

Where do you get these adjusters?

Thanks, Jody

[sinned]

Speedway Motors. http://www.speedwaymotors.com/xq/aspx/paging.yes/dept_id.712/display_id.3389/qx/Product.htm

[JodysTransmissions]

Speedway Motors. http://www.speedwaymotors.com/xq/aspx/paging.yes/dept_id.712/display_id.3389/qx/Product.htm


Thanks Dennis,

Regards, Jody

[Derek69SS]

Pic of the tall version adjusters..
https://static1.pt-content.com/images/noimg.gif
They look familiar :) The UPS man dropped mine off today :seizure: