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Really liking the ride height on both of your cars. I am looking for moderately priced suspension upgrade that gets me to ROW height. Looks like it would be a good idea to replace top-hats.
How much adjustment on these shocks?
Any suggested suppliers for shocks and springs?
Just in case I got a set of used H&R Green springs not planning to use. If interested send me a PM for pics.
My specialist told me PSS10 is too much for a street car, so assuming he has a point this looks like a good (and more affordable) alternative? Looks like something you should be able to do yourself? Did a lot of work on my C4 already, like calliper removal and after refurb mounting again, replaced disc brakes, total bleed of break fluid, blower motor replacement etc. So think I should be able to change shocks, or special tools / skills required?
My specialist told me PSS10 is too much for a street car, so assuming he has a point this looks like a good (and more affordable) alternative? Looks like something you should be able to do yourself? Did a lot of work on my C4 already, like calliper removal and after refurb mounting again, replaced disc brakes, total bleed of break fluid, blower motor replacement etc. So think I should be able to change shocks, or special tools / skills required?
Lots of DIY threads and user manual. It is not difficult, usual sticky bolts & nuts. You will need spring compressors if you want anything off your old setup eg top hats, bump stop, nylon washer etc. Torque wrench, breaker bar, 7mm hex key, open 22mm socket.
As others have noted, if you’re changing the springs and shocks you should consider the control arm bushings, top hat and also inspect the rest of the suspension for worn bushings. I was unfortunate as my car had a seeping steering rack and I decided to change it out which was much more invasive and resulted in changing a few other parts since it was all apart. The pics above are the current stance after the new suspension.
Check your front compression travel before committing to a ride height. From what I measured, the front b6 have very little compression travel below RoW height. Which means you’ll be hitting bumpstops often. The difference between a real matched strut/spring coilover and the HR+B6 combo is significant. Much more significant on the street than in competition; not vice-versa. My customized kwv3 are dramatically nicer on the street than the HR+B6 that they replaced.
Check your front compression travel before committing to a ride height. From what I measured, the front b6 have very little compression travel below RoW height. Which means you’ll be hitting bumpstops often. The difference between a real matched strut/spring coilover and the HR+B6 combo is significant. Much more significant on the street than in competition; not vice-versa. My customized kwv3 are dramatically nicer on the street than the HR+B6 that they replaced.
Where are you at for ride height? Same for both setups? I don't want to be super low, just less than stock suspension, ROW height. Looks like KW's would be a bit more than a HR/B6 even with the addition of top hats and bump stops.
I’m at RS height. But I’m using KW’s kit for the RS. The struts/shocks are different than the regular c2/c4 parts. I played with different spacers beneath the top mounts so that the travel is centered at my static height. Drives very nice even on our awful pothole ridden streets.
If you just want RoW height, then any of the aftermarket options will get you there or even a bit lower. True RS height is more involved.
I’m at RS height. But I’m using KW’s kit for the RS. The struts/shocks are different than the regular c2/c4 parts. I played with different spacers beneath the top mounts so that the travel is centered at my static height. Drives very nice even on our awful pothole ridden streets.
If you just want RoW height, then any of the aftermarket options will get you there or even a bit lower. True RS height is more involved.
Nick can you post a stance pic of your car to show what RS height looks like. Just curious how much lower it is than what I have my car set at. I personally haven’t noticed any issues with my setup other than on very large bumps I can feel the front bottom out but honestly here in Cali that’s a rare occasion where I use this car. Having lived in the South Shore in MA I know the kind of roads you’re contending with and I would agree that hitting bump stops may be a frequent event unfortunately.
Nick can you post a stance pic of your car to show what RS height looks like. Just curious how much lower it is than what I have my car set at. I personally haven’t noticed any issues with my setup other than on very large bumps I can feel the front bottom out but honestly here in Cali that’s a rare occasion where I use this car. Having lived in the South Shore in MA I know the kind of roads you’re contending with and I would agree that hitting bump stops may be a frequent event unfortunately.
Second that request, it will be a while before buy but your experience is another data point.
The B6 and H&R lowering springs at RS height had certainly improved the C4 handling and the stance athestics. However I was still unsatisfied with the understeer / push traits in deep corners.
So, after reading many threads, and “How to Make Your Car Handle” recommended by Steve.W I sourced a new Porsche rear C2/C4 21mm sway bar to replace the stock 18mm sway bar. I know a lot of people have done this upgrade, and it is also recommended by Adrian.S.
Today I got around to installing the new sway bar, followed by a test drive on my local road circuit. Wow, what a difference. The rear is now planted, and the steering is now point and shoot. I feel a lot more confident now pushing the deep corners. Hard to believe 3mm would make such difference, although there is math to support the difference. It is an easy DIY so I wont document.
I am curious about the sway bars as I find the car to still have some mushiness when pushing hard through corners. I initially attributed this to the 16” tires but I see you have the same. What’s interesting is that I’m not experiencing any understeer, it feels very balanced and predictable. Did you have the car corner balanced after installing the B6 and H&R’s?
Yes, if your 964 is 92+ B6 & H&R springs as advertised in your link, No, if your 964 is earlier.
“Shock absorber outer tube length increased by 38mm/(1.5in)
Rear coil spring length and length of dust cover increased.”
From Adrians book
And as I discovered, upgrading the struts & springs leads to new hats, bushes, bolts & nuts (recommended), bump stop, dust covers. And while you are there...
S
You will find that although a lot of Adrian's info is correct, there are many mistakes that need correcting. The shock towers were lowered as of build date November 1, 1990. AFAIK the shocks were shortened and not increased in length. This can be checked by a simple visual inspection of the rear shock towers. If it doesn't have the additional cap added to the tower it is the later version needed. You can use the later version shocks on the earlier cars but it requires an adapter to compensate for the shorter shock but cannot be used the other way around.
997Pilot, I would wait until you have the 964 and the VIN. A 91 car could be a 90 production. My K series was registered and recorded as a ‘90, but it was manufactured in ‘89.
This won't impact US spec cars unless they were 718 coded.
I have tried more suspensions than I care to admit and IMO any lower than RS+10mm is too low for most driving and anything below RS height will result in poor handling and excessive bump steer. Unless you are willing to make major modifications the slammed look is only for looks and only negatively impacts ride and handling. Especially when using Bilstein H&R combo. If you think you might consider lowering it to RS or lower consider spending up for a better setup early on or plan to spend a lot more later.
It appears the newer B6's offer less adjustability than the HD's and limit lowering the car as much. Probably a smart move on Bilstein's part as people tried to lower the cars past the point of the shocks useable dampening and ended up damaging their mounting points.
I am curious about the sway bars as I find the car to still have some mushiness when pushing hard through corners. I initially attributed this to the 16” tires but I see you have the same. What’s interesting is that I’m not experiencing any understeer, it feels very balanced and predictable. Did you have the car corner balanced after installing the B6 and H&R’s?
MB,
After I installed the B6 and H&R springs I did my first wheel alignment, I set the car to RS specs. As it was my first DIY wheel alignment I had our local race specialist check my work. So only small adjustments but still at RS alignment toe, cambers, & caster. I haven't done a weight balance yet. I am lining up to do a complete bushing replacement over winter (yes, "winter is coming" down under). So post the bushing install I will do another alignment, and then a balance.
Back to the mushiness you mention, I know what you mean, and there was some float on the front as well, however, the sway bar has eliminated both. It is well worth the investment to upgrade to a 21mm ARB. I am sure in the USA finding a 21mm bar is lot easier to source than from NZ. I ended up buying a new bar from FVD Europe. Don't ask me about the freight cost! I know some folk have gone to H&R and RUF bars, but I wasn't convinced about 24mm to 26mm bars. I think the bigger bars are more for full time race / track set up. And of course a thicker bars doesn't nessceraly mean stiffer: e.g material, solid or hollow etc.
02-15-2018, 03:26 PM
