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View Full Version : New project - '81 Z28 - leaf spring recommedations



68Malibu383
12-04-2018, 03:43 PM
I recently bought an '81 Z28 and plan to use the car for autocross, occasional open track (3-4 events/year) and general crusing. I'm planning now and will run 18 x 9 or 9.5s up front and 18 x 18 x 10s in the rear (no tubs). Looking for rear recommedations and how much I should lower the car with an emphasis on maximum handling advantage. I've seen rear springs from performance suspension companies that drop from as little 1.25" to 3". Any recommendations are appreciated.

79T/Aman
12-05-2018, 11:42 AM
Pro-touringF-body.com Comp leaf springs and suspension kit will do what you want it to do.

TheJDMan
12-05-2018, 05:15 PM
Contact RideTech and discuss your plans with them. They offer several levels of suspension upgrades.

F-Body International
12-05-2018, 05:57 PM
You're on a good path for sticking with leaf springs and getting good tires/wheels.

As mentioned by 79T/Aman before, PTFB (Pro-Touring F-Body) is an option. You'll save yourself the most money here and can invest elsewhere in the to build a nice street/track car. PTFB also has varying levels of leaf springs, whereas other companies may only sell one specific spring.
http://pro-touringf-body.com/


The most comparable to PTFB in terms of leaf spring choices would probably be Global West but again, more money.
http://www.globalwest.net/

Detroit Speed is an option as well. They don't have spherical spring-eye options like Pro-Touring F-Body or Global West but many people like the brand on this forum
https://www.detroitspeed.com/1970-1981-camaro-firebird-rear-suspension/detroit-speed-inc-multi-leaf-drop-spring-set-040101p-group

I've never dealt with Ridetech myself but as JDman mentioned, they have some leaf spring and non-leaf spring options.

c4racer2
12-06-2018, 08:12 AM
Hotchkis is another good option. I have the front and rear springs in my 71 along with their swaybars and the car handles pretty good.

I am adding Bilstein shocks to the front to match what the rear already has and then DSE UCA to pick up a better camber curve.

One thing to keep in mind is make the chassis as stiff as you can - that will help the car ride better and the suspension to work better.
Use solid body mounts first, then by all means add weld-in SFC's and as a final step I would also look at the PTFB adjustable engine bay braces.
I have all those items on my car and it really works well - very close to the chassis stiffness of a late model Camaro.

F-Body International
12-06-2018, 08:43 AM
Hotchkis is another good option. I have the front and rear springs in my 71 along with their swaybars and the car handles pretty good.

I am adding Bilstein shocks to the front to match what the rear already has and then DSE UCA to pick up a better camber curve.

One thing to keep in mind is make the chassis as stiff as you can - that will help the car ride better and the suspension to work better.
Use solid body mounts first, then by all means add weld-in SFC's and as a final step I would also look at the PTFB adjustable engine bay braces.
I have all those items on my car and it really works well - very close to the chassis stiffness of a late model Camaro.

Nice,

I used to have the Hotchkis rear leaf springs. They do provide a nice stance that’s not too low or high. Your setup sounds pretty identical to what I have going on my ‘79...

PTFB GT-Pro Kit with their specifically tuned AFCO Non-Adjustable shocks
DSE upper/lower control arms
Stock GM front sway bar paired with a PTFB Adjustable rear sway bar
PTFB solid body mounts

c4racer2
12-06-2018, 09:50 AM
here is a picture of the stance. 17" wheels with 26" tires.

158951

ULTM8Z
12-06-2018, 11:54 AM
PM sent!

BMR Sales
12-07-2018, 06:32 AM
here is my '73 on our 2" Drops

https://i.hmjimg.com/images/2018/12/07/_MG_0769.jpg

https://i.hmjimg.com/images/2018/12/07/_MG_0770.jpg

https://i.hmjimg.com/images/2018/12/07/_MG_2353.jpg

https://i.hmjimg.com/images/2018/12/07/_MG_2354.jpg

c4racer2
12-07-2018, 08:31 AM
love those wheels - are those Vintage 18"?

68Malibu383
12-08-2018, 05:00 AM
here is a picture of the stance. 17" wheels with 26" tires.

158951

Thanks. Great looking car!

79T/Aman
12-10-2018, 07:02 AM
If you want to autocross a second gen F-body, you have two choices PTFB and Global West, I own PTFB and can tell you that those are your TWO choices, GW has a fine product as well, PTFB has 7 SCCA cam-T championships from 3 regions and 2 drivers both being full and true street cars.

79T/Aman
12-10-2018, 07:07 AM
PM sent!

WHAT A COWARD YOU ARE MIKE !! lol

Steve Chryssos
12-10-2018, 07:36 AM
An interesting nugget about leaf springs: We use bolt-on spring eyes. That way you lower your car without sacrificing spring arc. We vary the vertical offset of the billet spring attaching point relative to the center of the spring mounting point -- Top, Middle, Bottom -- wherever. Then, we spec bushings made of Delrin AF that never squeaks or requires lubrication. Springs are custom-matched with our adjustable monotube shocks. Valving is specific to your application and the shocks carry a 1,000,001 mile warranty -- for good reason. Links:

Springs
https://www.ridetech.com/products/streetgrip/1970-1981-camaro-streetgrip-composite-leaf-springs-set/
Bushings
https://www.ridetech.com/products/streetgrip/1970-1981-camaro-streetgrip-delrin-leaf-spring-bushings-set/
Shocks
https://www.ridetech.com/applications/musclecars/1970-81-camaro-rear-smooth-body-shock-hq-series/

79T/Aman
12-10-2018, 08:18 AM
PTFB uses a conventional upturned front leaf spring eye with an extended second leaf for wrap control, reversed eyes are not common for a reason, yes they allow for a lower stance for a given arch, looks good on magazine photos but does not do much for performance and it pulls at the front mounting bolt more causing a harsher ride on dual purpose cars.

The one thing that is always omitted from is the down sides of a different product, reversed eye springs can't fit with a relocated front mount to improve instant center because the spring will hit the bottom of the car.
Comparing Fiberglass leaf springs and steel requires diligence in making the comparison, a glass leaf is of parabolic mono design and has more torsional flexibility therefore a Delrin (solid) type front bushing is almost a must, not so with steel leafs where a solid type bushing will cause snap oversteer.
OP weigh out your cost VS return.

BMR Sales
12-11-2018, 07:34 AM
love those wheels - are those Vintage 18"?

Vintage 17's

c4racer2
12-11-2018, 09:25 AM
Vintage 17's

oh nice - same as my car then. I have 17x8 and 17x9.5

Looks like new tires - what did you go with? I need new tires soon - looking to get some 200TW before the spring.