Gaz Shocks - Adjustable supension for 308's

no paper weights required.

 

Someday I would like to try a set on my ‘82 308GTSi……

 

Morning Andy,

Did they make a noticeable difference?

I'm working through the suspension on my car and choosing between a rebuild to the Koni's or replacement is one area I'm pondering. I was actually hoping to see Koni at the Goodwood FoS but my Saturday ticket was rained off.

For how I use my car, improving the handling and braking is the main area I want to focus on. Most of the effort will be getting the suspension back to factory fresh but I like the idea of adding adjustability here as its really the only area of the suspension you can't tune as standard.

 

No info on this specific setup but some general info.

Springs control the way the car sits, how much travel is used (which has a some impact on ride) and also how it rolls so what sway bars are needed. There are lot of theories on what is right but in general cars that expect only smooth road and gentle driving use soft springs with lots of preload and performance cars stiffer spring with little or no preload. My car has negative preload mean the springs sit loose when its jacket up...they make some very soft spacer springs to spot any rattle I may add but at the moment there is about a 1.5" gap so its designed for about 4" total travel not the factory 6(?) which gives firmer and more controlled feel with WAY less body roll. Springs are 800F/500R
Image Unavailable, Please Login


The shocks control ride. I have attached the damping curves for my shocks which also include the curves for the shock konis (Black on front graph, purple on rear). The things to look at are that in general the new compression damping is similar to original....this is what you feel when you hit a bump and adding compression damping makes the ride harsh and can cause the car to bounce up which besides knocking out your fillings will cause a lot of grip as the tire unloads over the bump. Looking closer at compression t(he graphs aren't perfectly done as the 0 force is shifted slightly koni to ohlins) you will see and slope on the koni curves is steeper at very low velocities, and the koni ride feels notably harsher.

Rebound is about controlling the springs, stiffer springs want more rebound. When I originally bought the shock I had softer springs...400/250? and stock is like 180/200? numbers close to that. Anyway I may be a little low on rebound with the current 800/500 springs but in the little I've drove it with these springs it still felt pretty good.

Overall this setup is pretty nice on the street and does very well at autocross events. I run it with with the adjusters about centered normally but for high speed (over 100-120) it wants mores.

Hope this helps.

Edit there are more opinions about correct suspension setup than there are setups so please understand results many vary

 

I think my last setup was 450/400 and I had to remove the rear sway bar because it over-steered terrible. 400/350 would be better but not by much, nothing you'll notice in calm driving but that makes the inherent rear roll stiffness higher than the front so it will oversteer if you don't corect the issue with sway bars.

Attached is a spreadsheet setup for a 308. You put in the springs on the left and the outputs on the right are the spring frequency and the droop.

frequency is about how the suspension moves with the general guidance being:
" 1.0 Hz - passenger cars. 1.25 to 1.75 Hz - sports cars. 2.0 to 2.5 Hz - autocross and racecars with low downforce. 2.5+ Hz - high downforce racecars."

Droop is how much the spring will compress to hold up the car. I didn't need preload so its not in the sheet, but you just subtract the preload from the output droop to get the droop with preload. This also tells you stuff. droop/travel tells you how stiff the suspension is, you never want actual droop (droop - preload) to be more that 1/2 the total travel and sport set ups want to be about 1/3.

You generally want the car to have inherent understeer as that is stable. ALL oem setups are this way and most street race class don't allow spring or rear sway bar changes to make sure the car stays setup with understeer. When picking springs you want less droop in front and more frequency in front. 400/350 reverses the numbers so you need to add additional roll stiffness with the front sway bar to get a stable setup. 400/250 and 500/300 are a balance setups but the sheet is attached for all to play with.

 

175 pounds, that is quite affordable especially if no paperweight needed. Anybody knows if this works on 1989 328?