icsamerica

Seriously though...I have tried many setups. Here is what I know works very well for me. It's a simple formula and there is nothing better for the price...

New stock springs front and rear. Cut 1 coil off each of off the fronts, cut 2 coils off each of the rears.
Set up the 928 adjusters so she sits with in 13mm of stock ride height. Choose a shock that suites your needs but they will need adjusters. Since you have an early light weight, I'd choose the Koni's or Boge if ride quality is a concern. I have the Koni's... they are fine for the street, very confortable and they offer good over all motion control. That said... out on the track as a intermediate level driver, I think I've reached their limit so I may be upgrading to something much more serious soon. (springs and shocks)

This is a very affordable and DIY'able setup that delivers great performance on the street and for beginner level DE events. You COULD try this setup with your existing springs and get a taste how it goes before commiting on a set of new springs.

Have you done all the bushings yet? Every bushing is important but the Rocker bar bushings are are very important to how the rear of the car feels and responds. The other bushing that has an oversized influance are the front UCA bushings. These are super important for steering precision.

streetsnake

Not to open another can of worms but what are everyone’s thoughts on the Powerflex bushings?

icsamerica

I like them a lot ! They allow the front suspension (springs and shocks) to move and respond much quicker. I've said it before but the 928's front LCA bushings are compromised. This
bushing design mistake has NEVER been repeated by any other manufacturer for a very good reason. Porsche tried it and that's innovative and respectible but tire tech and shock valving has vastly improved since project 928 was conceived.

GregBBRD

Reasonable quality pieces, as long as you realize that they are cast and do not have the level of precision that is required on the very "high end" of suspension components.
We use them in different locations, depending on which suspension "level" we are using.
Their "grease" is amazing!

streetsnake

I sent you PM and email.

Petza914

We had this discussion a couple weeks ago. Consensus was that the OEM bushings and the stichtion (resistance to rotation of the control arm) they result in is part of the designed operation and a supplemental spring to the actual coilovers.

It still doesn't make good sense to me how an essentially binding control arm can positively contribute to handling so I'm going to experiment on my own car with a set of the front Powerflex front & rear
lower control arm bushings on the shot and am going to install them, as I'd like the spring and strut to control the suspension. The way the front of a 928 hangs up in the air until pulled down or driven 50 miles just doesn't seem like it lets the suspension work the way it should. I don't pretend to know more than the folks on here or Porsche, but I need to understand stuff and prove it to myself, so that's what I'm going to do. Maybe it sucks and I say, yep, that's worse and I order a rebuilt set of arms from Roger and replace them again, but I'm doing it anyway.

GregBBRD

The lower control arm bushings were absolutely genius level stuff, given the spring technology that was available in 1976. (Keep in mind that 911's had torsion bars until 1989.)
Porsche wanted to make sure that the 928 model had understeer, for various legal and practical reasons.
By putting in lower control arm bushings, in rubber, which twist and increase their "spring rate" (considerable) the further they twist, Porsche was able to dial in their desired understeer.
And the more/harder the 928 was driven, the more understeer it had.

Perfect engineering to get the desired goal!
Genius stuff, for the day....literally.

Today, we've got computer designed progressive springs, to do this job. Same exact thing, without the rubber "wear" issues. The more/harder a modern Porsche is driven into a corner, the higher the spring rate gets, ensuring the same understeer!

streetsnake

What are thoughts on the setup. Have never seen them mentioned. https://www.fvsuspension.com/product...CABEgJWwvD_BwE

icsamerica

I've seen a few variaitons of these all of a sudden. It may not be a co-incidence that the KW brand coil overs also just became available. The lack of an accurate picture and the timing suggests these might be knockoffs of the KW setup. In any case they are certainy Chinese made based on the price...so who knows, might be a faithful copy. You have to ask yourself.... are you feeling lucky... KW does 100% have manufacturing facilites in China and Taiwan and they've been known do do stuff like this.

Chinese products are not as bad as they were and their manufacturing has come a long way in the last few years. Many of the high quality items we all depend on are wholey made in China. That said. Not for me. I'd perfer something else at the moment. Although my Chinese made replacement blower motor is performaing flawlessly.

The knock off game is getting silly. At the entry level...AFR is selling a Chinese knockoff of a Brodicx head they call call the "Enforcer" And Brodix is selling a chinese Knockoff of an AFR head. Quite nutz... but by all accounts both heads perform great! Yes the made in USA fully CNC heads are better but not by much for 3x the price.

GregBBRD

Have not tried this....so no idea.
My initial reaction, in seeing this offering, was that because they completely eliminated the stock thick rubber upper spring and associated shock mount, this would be both severe and noisy.
Looks like the "poster child" for increased NVH, to me.

One of Porsche's other brilliant ideas was to isolate the shock rate from the spring rate, slightly. (On both the front and rear.)
This, for all intents and purposes, gave them digressive valving....long before Bilstein came up with that design.
Again, genius design stuff!

Hopefully, these people are using digressive valving on their shocks...otherwise this set-up would be very unforgiving at low shock speeds. (Less than 1.5" per second.)

icsamerica

Here's another. 1 sold. anyone here? Same drill, low price and lack of accurate picts.
Odd.... Koni, Boge and Bilstiens only for the last 35 years, 2 weeks after KW releases a set these show up. LOL

They say rubber bushed and pillow ball top mounts are available. Same as KW.

Darklands

The question you should ask yourself is has the manufacturer the know how to test and refine the suspension to a point the system works better than stock.
For KW I would say they can do it but for the 1300 $ variants? KW has for a lot of the classic cars a solution but they need a very long time till they do the 928 one.

Greg, over the tump, how much research cost did you have in your solutions ? 1xx.xxx $ are quick on the table if you count every hour.

For that you must sell a lot of shocks and I understand why Greg is careful about his intellectual property.

ROG100

Stock Boge and Bilstein are currently not available as a set.
Koni are available but in short supply. Externally adjustable Koni conversion can be a two month wait.
Boge red are available but the rears are in short supply with only 8 left here and Germany.

GregBBRD

I rarely sell stock Boge....for reasons listed above, (I've never seen a pair that dynoed the same.)
I've got Bilsteins. Both new and several super pairs of low mileage rear "takeoffs". (Changed out for a high end double adjustable shock.)
Koni are a bit of a joke, in the stock form. (Unless the car is riding on or very near the bump stops.) Not enough compression to be of much value and then silly rebound ranges.
Boge red are a bit too stiff for an early car.
And I've got custom shocks....double adjustable. Increased travel, less droop, 5 years of development...all the things required for a lowered 928, for the clients who wants a 928 to handle like a modern "high end" car.

Here's the basic point of the entire last few pages, of what I have written:
Until everyone figures out where the front bump stops are located and what they do, "ride height" becomes the primary controlling part of the entire equation!
Our best handling street "test car" (with mostly stock suspension pieces) sits above 150mm, with internal modifications to keep the bump stock inactive until 130mm!

Speedtoys

Just waiting for Kyle to tell me to come down...