So I recently took advantage of the Koni sale and got myself a set of sport yellows for my 944. These are single, rebound, adjustable on an otherwise stock 944 suspension. My problem is that I dont know where a good starting baseline is or a good methodology for adjusting. Digging through the usual 944 places has opinions on all spectrums of settings about where, when, and how to adjust these, which isn't helpful.
I'm hoping some more knowledgeable people here could help me with the signal/noise and enlighten me on a good place to start. Also what to look for that indicates a shock should be adjusted, bump or rebound, "stiffer" or "softer".
From the book "Autocross to Win"; the author basically says the adjusters on Koni's are almost useless for tuning on the fly and only really good for tuning the shock on the shock dyno and never touching it again. The adjusters don't match from shock to shock on identicals shocks.
Read here.
http://farnorthracing.com/autocross_secrets6.html
dps214
Reader
4/30/20 4:59 p.m.
In reply to Patientzero :
The first part of that isn't really true. The second part is kinda true sometimes. But even if they don't match perfectly side to side there's still a plenty noticeable difference between full stiff and full soft. Now, if you're trying to adjust in 1/8 turn increments...yeah that's pointless. I've had a couple of sets of 944 konis in the past but we were using them for rallycross and trying to control an autocross car with way too much power and tire for the suspension, so I imagine in both cases the setting was just full stiff across the board. Generally speaking I'd start them all in the middle and see how it feels. There's plenty of charts floating around that show what shock adjustments generally do in various cornering situations.
I had them adjusted to the middle of the range on my race car. I was at Nelson Ledges and was getting a big push coming on to the front straight. I softened them up eventually 3 or 4 clicks and the push went away and I was 10 mph faster through that turn. My suggestion would be trial and error with 1 click at a time until you hit the sweet spot, either stiffer or softer.
In reply to dps214 :
I'm not the shock expert, just passing along what I read and linked above.
It's not that the adjusters don't do anything, the problem is "full stiff" on one shock might be the same as "midway" on another shock along with the adjuster not having a linear effect on either. I have Koni's on my own car.
dps214 said:
In reply to Patientzero :
The first part of that isn't really true.
From the Author;
"Note that I consider knobs on shocks as ways to get the forces to match on the dyno, or to rough in forces while testing; I never, ever, ever muck with the shocks during competition. I've run hundreds of shocks on my shock dyno and the repeatability of shock adjusters is downright horrible on anything except the highest end shocks (and even these have their quirks). When you have the damping right, it's right"
dps214
Reader
4/30/20 5:18 p.m.
Patientzero said:
In reply to dps214 :
I'm not the shock expert, just passing along what I read and linked above.
It's not that the adjusters don't do anything, the problem is "full stiff" on one shock might be the same as "midway" on another shock along with the adjuster not having a linear effect on either. I have Koni's on my own car.
This is far from a full sample size, but I've had or seen probably 10 or more sets of konis on the dyno and while they're usually not matched amazingly well, I don't think I've ever seen a pair off by more than about a quarter turn (1/8 of the adjustment range) and that pair was race valved dampers, I've never seen a pair of sports mismatched by a noteworthy amount. Off by half the adjustment range isn't a mismatch, it's a broken damper...which i have seen several konis broken out of the box or after minimal use.
To the other point about not making adjustments on the fly, I agree. For most people and with the adjustment resolution of konis, it's usually better to get a decent tuneup and then just learn to drive the car as it is, rather than trying to chase fine tuning changes.
For the track I ran Koni's with Eibach springs and fully adjustable bars In my 944 and my 951. I would tune the balance of the car with the bars with the shocks and struts set to all the way stiff. You could tell the sex of earthworms when you ran them over in my car. I got the car dialed in with some extremely minor adjustments of the bars.
For the street I would start in the middle and you will probably back them off some from there . Potholes and bumps and what not get old after a while with the suspension fully cranked down in race mode.
You know who I'd ask? Ground Control. They sell Koni sets for the Spec944 racers and probably have forgotten more than many of us know.
That said, I'd start at full soft and adjust upward from there on a street car.
General shock setup: it's easier to feel an underdamped spring than an overdamped one. Start at full soft. The car will feel floaty with uncontrolled body motions. Start adding damping until it comes into focus - the float goes away and the car feels stable. Increasing from there will likely just add harshness.
At some point, crank them all the way stiff if only to know what overdamping feels like. If it feels like a lot of "performance" aftermarket suspensions, well, yes.
On a smaller car (ie, no real rear seats) I've found that the ride feeling seems to come more from the rear. The nose will "bob" until it's properly damped.
I'm also in the start soft and go up until the car stop feeling floaty crowd. Suspension compliance is everything.
The 944 was a heavy car for its time. I found that they needed more dampening on track than other cars of the same time period. I also found that the smoother the track the more dampening I wanted.
dean1484 said:
The 944 was a heavy car for its time. I found that they needed more dampening on track than other cars of the same time period. I also found that the smoother the track the more dampening I wanted.
The long trailing arms in the rear really cause all sorts of oddities when trying to tune damping and spring rates. Basically you can get it pretty close at steady state, but you'll never kill the squat it gets under accel unless you fix the roll centers. The turbo and V8 cars suffer the most from this since they tend to have a good amount of power to provide.
The front is just a standard MK1 VW front end that is as good as it can get, so the lack of camber curve and the need for more caster means you set it for as much static camber as you need and lock it down from moving too much and causing more trouble than its worth.
I was able to get the 944 so you could drive it with the throttle through sweepers. The basic handling was you just had to lift a little in to corners setting the nose and it would set the rotation of the car into and through the corner. You then maintained it with the throttle. The more perfect you got the set of the car at entry meant that you could put more throttle into it through the corner while maintaining rotation through the corner increasing your exit speeds. In tighter corners you just lifted a bit more to get the car rotating more and then just hammer the gas. The brakes were key in the setup as well. I would set the bias initially to stabilize/slow rotation the slowly adjust the bias so it would not change the rotation. In effect you were "drifting" (the old school 4 wheel drifting not the current drifting) the car. It makes the 944 very fast as you are on power much more and being it was kind of an underpowered car for its weight this made the car very fast when properly driven. The key to a 944 is to get the car neutral with the bars and the shocks at a shock setting you like and then tweak it to perform as I describe above. Again I found the smoother and or faster the track the more firm I liked the shock setting.
You also have to adjust to how the car wants to be driven. I found that Porsche in general as a brand are picky cars in that they have a very specific way that they want to be driven. If you master it you will be very fast. You can make fine adjustments to the suspension to tweak it but the biggest adjustment to any Porsche has to be to the driver. I almost think that Porsche intentionally made the 944 platform handle kind of like a 911 in that is responds really well to driving with the throttle (very 911 ish). I always wondered if this was on purpose as the 944 platform was thought to be the 911 replacement at one point. Were they making it more 911ish on purpose? My other thought is that the 944 platform was tested by the same drivers that tested the 911s so it would only make sense that they would want to make it have 911 handling tendency. If you drive a 944 at the limit that is really set up well you will feel a little bit of the 911 DNA in it. Mind you that this is in comparison to the 911's of the same time period. You can not make this comparison to later 911s.
Thanks for the tips everyone.
dean1484 said:
I was able to get the 944 so you could drive it with the throttle through sweepers. The basic handling was you just had to lift a little in to corners setting the nose and it would set the rotation of the car into and through the corner. You then maintained it with the throttle. The more perfect you got the set of the car at entry meant that you could put more throttle into it through the corner while maintaining rotation through the corner increasing your exit speeds. In tighter corners you just lifted a bit more to get the car rotating more and then just hammer the gas. The brakes were key in the setup as well. I would set the bias initially to stabilize/slow rotation the slowly adjust the bias so it would not change the rotation. In effect you were "drifting" (the old school 4 wheel drifting not the current drifting) the car. It makes the 944 very fast as you are on power much more and being it was kind of an underpowered car for its weight this made the car very fast when properly driven. The key to a 944 is to get the car neutral with the bars and the shocks at a shock setting you like and then tweak it to perform as I describe above. Again I found the smoother and or faster the track the more firm I liked the shock setting.
You also have to adjust to how the car wants to be driven. I found that Porsche in general as a brand are picky cars in that they have a very specific way that they want to be driven. If you master it you will be very fast. You can make fine adjustments to the suspension to tweak it but the biggest adjustment to any Porsche has to be to the driver. I almost think that Porsche intentionally made the 944 platform handle kind of like a 911 in that is responds really well to driving with the throttle (very 911 ish). I always wondered if this was on purpose as the 944 platform was thought to be the 911 replacement at one point. Were they making it more 911ish on purpose? My other thought is that the 944 platform was tested by the same drivers that tested the 911s so it would only make sense that they would want to make it have 911 handling tendency. If you drive a 944 at the limit that is really set up well you will feel a little bit of the 911 DNA in it. Mind you that this is in comparison to the 911's of the same time period. You can not make this comparison to later 911s.
I think that's why I wasn't able to be fast with the 944 I had. I later saw drivers with more stock 944s than mine (stock size tires, no Konis) go much faster than I did because they knew what they were doing with the throttle. I made a lot of assumptions about what was fast by using what I learned with other cars or by racing quads rather than figuring out what 944s like. There really weren't very many other IRS RWD cars for me to learn from when I was growing up.
From what I've seen, 944s are fastest as tripods.
Keith Tanner said:
From what I've seen, 944s are fastest as tripods.
After having a bunch of GTIs and a very tripod happy race car, it seems I just cant own anything that wants to keep all 4 wheels on the ground.
