I know, this has been covered ad nauseum, and that's kind of my issue. I'm not sure what to believe any more. I'm gearing up to refresh my suspension, 1985 Euro 308QV GTS in Southern California. Suspension has about 50K miles on it. Car sits a little high (photo below), but honestly I'm not going to track this car, nor really care about getting the right 'look'. I have steep driveways in my neighborhood/city, so any additional ground clearance is appreciated. Presuming that Ferrari knows more about suspension than I do, I'm tempted to just get new Konis but not sure which springs (or re-use what I have)? I've looked over countless previous posts on the QA-1s, NFF, Spax, Koni custom perches, etc etc but frankly I'm having trouble being motivated to do anything other than stock. (I am considering 16 inch wheels which may help close the fender gap?) Any thoughts/suggestions? Cheers, Mike Image Unavailable, Please Login
It been talked to death because there is no "right" answer. if you are not unhappy with anything then there is no reason in the world to change anything IMO. As far as the wheel change, I'm pretty sure the 16" wheel/tire is pretty close to the 14" wheel tire OD wise. They look a bit different, but the gap should be about the same.
Get the QA-1 setup w/300/250 lb springs. It won’t cost any more than a set of new Koni’s. You can dial in the exact ride height you want and adjust the damping to your liking. It’s a bolt in solution that’s as easy as taking the Konis out and putting these in. Save your Konis to give to the next owner if he/she wants them. Image Unavailable, Please Login
I've seen the 300/250 numbers, but they are kind of mismatched giving the front 1.5hz and rear (1.7hz) and not idea. 400/250 1/7hz is a good match or 300/200 (1.5hz) is not bad to give similar F/R stiffness. You can make lots of things work, but tuning is easier when you start with matching sets. The factory springs are around 1.2 hz, I run 800/500, 2.4hZ on the frankenferrari with modest damping its fine on the street. As a reference 0.5-1.0Hz Passenger cars, typical OEM 1.0-1.5Hz Typical lowering springs 1.5-2.0Hz Rally Cars 1.5-2.5Hz Non-Aero racecars, moderate downforce Formula cars 2.5-3.5Hz Moderate downforce racecars with up to 50% total weight in max downforce capability 3.5-5.0+Hz High downforce racecars with more than 50% of their weight in max downforce But again, if there is nothing you really want to change, then why change anything? Honestly at 50k miles the factory shocks are most likely still within factory spec and only in need of fresh paint and maybe new bushings.
Maybe a better reference 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 1.45 Hz - Subaru BRZ (front and rear)
I think new bushings and ball joints will be a huge and noticeable refresh. I'm about to do that on mine.
Of in socal come to our stoogefest end of month in 90274. Plenty of guys there to take suspension. If I'm not bringing too much stuff to the party in my truck I'll have a maranello with a custom suspension there and you can learn what it takes to go that route.
As you know, I struggled with this for months before deciding on this: I really like the way the Konis ride. I can’t imagine a gas shock gives the same liquidy smoothness, and the damping/spring rate feel fine even when pushing the car in the canyons. Also, I have a noodly GTS, it has enough chassis flex and a stiffer suspension isn’t going to help with that. I bought new Konis, and the perch sits on a C clip which sits in a machined groove on the shock body. If you get the shocks, mount up the perch on the stock and do a dry run mounting on the car. Mark the lowest point you’re comfortable with before the perch touches the arm at full droop. Get a lower groove machined on the shocks and don’t look back. Slightly lowered car, same great ride and handling, and looks OEM.
There’s a chart out there, I’ll see if I can repost. I think the later US GTS had pretty soft springs, like 160lbs or something
If you measure the spring length with the car sitting on the ground, then pop the shock off and measure free length * might be in the manual) and give me both numbers for front rear, I can plug it into my spread sheet and give you the rate. I measured years ago and am recalling around 180-200, but we can recalculate Edit- looks like I remembered right...and they are Cadillac soft not sports car firm
I love these threads. I’ve posted similar questions and have reviewed other threads from over the last 15-20 years. And by osmosis, I think I’m starting to get it. [emoji23] To the few of you that have had the patience to keep reposting the info over the years, (re)educating us and answering these questions, I’m so appreciative of your support. And I’m not even the OP on this . [emoji119] Sent from my iPhone using FerrariChat
I promise stiffer springs make a GTS a whole lot better. I measured the 1G chassis twist to be about 0.5" iirc Stock suspension is well onto the snubbers at 1G, about 3in of motion?... and frame flex adds another 1/2', so 0.5/3.5 x100=14% from frame flex? It's not too bad. On my car with 800/500 springs the suspension moves about 1.6in at 1G, so 0.5/ 2.1x100=24%, suboptimal but still tolerable. Then depending on the OD wheels there is additional motion from tire flex...the sidewall is a mostly unnamed pneumatic spring. Stock is 14, I run 18 with a nearly identical tire OD...so roughly 1/2 the sidewall but the same chassis flex, and I'm back to nearly stock undamped wheel motion. Everything matters if you want it to handle well......but as I said at that start, any setup that makes you happy is a fine setup. The only caution is that most people never push to the limits until there is a need...like coming around a corner to find a refrigerator or deer or whatever in the road, the factory setup will produce controllable understeer under basically any condition, a lot or setups won't, best to know what your setup does before you find out the hard way.
