Koni or Bilstein ? Options

[Fazasport]

I am looking to replace the rear shocks and front strut inserts on my 1970 914. I will be using the car for tours, rallies, spirited driving and maybe an occasional Autocross not for track work. I am interested in a firmer ride than stock but not a harsh ride. The car does not have front or rear anti-roll bars currently.
If choosing between Koni or Bilstein which would provide the LEAST harsher ride quality?
I will also replacing the rear springs. With that in mind, should I stay with the stock 90lb springs or substitute that 100lb springs from the 914-6?

[mlindner]

Six years ago at the end of my 914-6 GT Tribute build I went with adjustable Koni shocks and springs from Ground Control. Just the perfect fit for heigh adjustment, order any spring rate you want (I did 150). I pushing 80, still an auto-x, hill climb and just a lot of high speed driving. Best, Mark

[Steve]

I tried both.. Koni's on the softest setting is a slightly better ride than Bilsteins. Also put the front sway bar on the softest setting for the street. I did learn the hard way that pot holes cause a harsher ride with a stiff front sway bar. I am running a 22mm Tarret bar on the softest setting.

[tygaboy]

I don't mean to get deep into suspension geek mode but as a point of potential interest: The Koni Sports are one-way adjustable for rebound only. So unless you re-valve them, you get the valving they come with. Meaning your ride quality is down to factory valving plus your chosen spring rate. That also implies that if you opt for spring rates "outside the normal range", you're headed into under- or over-damped territory. Not to scare you away from Konis as that's true for any one-way adjustable damper.
Just something to be aware of as you're setting your expectations.

And yes, I have those same shocks on my LS car. They work fine but where I typically drive, the roads have lots of chop and sharp-edged bumps. So on the Ferrari swapped car, I'm going all in on 3-way adjustable: high- and low-speed compression and low speed rebound. I'll be working with a suspension tuner, providing unsprung weights, corner weight and suspension motion ratio information so they can work out specific valving and spring rates for the car. Yes, complicated and more costly but I want as sophisticated a ride quality as I can get. I'll document all this on the Ferrari build thread and report back on "is the juice worth the squeeze?"

[Superhawk996]

I don't mean to get deep into suspension geek mode but as a point of potential interest: The Koni Sports are one-way adjustable for rebound only. So unless you re-valve them, you get the valving they come with. Meaning your ride quality is down to factory valving plus your chosen spring rate. That also implies that if you opt for spring rates "outside the normal range", you're headed into under- or over-damped territory. Not to scare you away from Konis as that's true for any one-way adjustable damper.
Just something to be aware of as you're setting your expectations.

And yes, I have those same shocks on my LS car. They work fine but where I typically drive, the roads have lots of chop and sharp-edged bumps. So on the Ferrari swapped car, I'm going all in on 3-way adjustable: high- and low-speed compression and low speed rebound. I'll be working with a suspension tuner, providing unsprung weights, corner weight and suspension motion ratio information so they can work out specific valving and spring rates for the car. Yes, complicated and more costly but I want as sophisticated a ride quality as I can get. I'll document all this on the Ferrari build thread and report back on "is the juice worth the squeeze?"

(IMG:style_emoticons/default/agree.gif)
Geek it brother

Nice to see someone talking sensibly.

[Cairo94507]

I am running Bilsteins all around, 140 pound rear springs, stock 914 (later) F&R sways bars, Elephant Racing rubber bushings, raised spindles by 19mm with turbo tie-rods and stock torsion bars. My car is about 1" lower than stock and I run 15x6 Fuchs with 195x65x15 tires, set at 28 pounds front and 30 pounds rear. Everyone who rides in it says it rides nice. We drive it exclusively on the street and I am not racing anyone. Importantly, when my wife rides with me, or on occasion drives, she says it rides nice.

Now, given all that, I still wish I had a bit softer ride; probably the old man in me. On my list is a set of Ground Control coil-overs for the rear as I would like to corner balance the car. Maybe I will go to a slightly softer rear spring when I switch to coil-overs. I could probably go to a 120 with no issues. Yeah, probably splitting hairs here. (IMG:style_emoticons/default/beerchug.gif)

[Jack Standz]

We too are running Bilsteins all around, 100 pound rear springs, stock 911 front and stock 914 rear sways bars, raised spindles by 19mm with turbo tie-rods and stock 911 torsion bars. Our car is lower than stock and we run 16 x7 front and 16x8 964 wheels (D90) with 185/50 front and 245/35 rear tires.

When first driving this combination (with new control arm and trailing arm bushings), it was awful. Very harsh. Did not like it. Now after around 3k miles, it’s much better. Street only, so maybe next time less rear spring and softer torsion bars.

However, the current plan is to restore our ‘72 to very close to stock, but with the addition of front and rear 914 sway bars, leave spindle height alone, stock 4 lug Mahle wheels, etc. Already have stock rear springs and shocks/struts all around, wheels, sway bars, etc.

[infraredcalvin]

https://www.elephantracing.com/914-suspension-builder/

I’ve always liked ER suspension builder as a starting point. Be honest with it as it’ll go sideways really fast on you. I’d say you’re probably looking at sport resto 1 or 2, it’ll recommend a setup and price it all out. Click customize and you can see exactly what it selected (spring rates, shock types, etc) add or subtract as you see fit.