Koni vs Bilstein - Ride Height

[Clark Griswald]

Both Konis and Bilstein raise ride height because of the gas charge. I have Konis regular now and am thinking of swapping in Bilstein sport.

Do the Bilsteins change ride height the same amount as the Konis?

Or am I will I need to reset ride height after the change?

Chuck

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'86 Cab, '77 Targa, Family Truckster

[Joeaksa]

Clark,

Just did the swap you are talking about and had the feeling afterwards that my ride height did increase. Measured it and found that its NOW exactly within the normal limits (25 +/- .5 front and 25.5 +/- .5 rear) after installing the new Bilstein shocks. I did not measure the height beforehand.

I can only assume that the ride height with the old Boge shocks was a bit less than normal with the old shocks. A friend of mine is doing the switch in the next week or so and will do a "before/after" measurement to see just what the change is with new shocks.

Believe that any "gas filled" shocks will push your height upwards a bit if your old shocks are not up to snuff. When I pulled my old fronts out, the gas pressure inside was about 20% of the new Bilsteins.

[Wayne 962]

Theoretically, the shock change shouldn't add ANYTHING to the ride height. The shocks are slightly sprung, but they shouldn't make a difference in the height.

What may make a difference is the spacer in the top (used on the USA cars) if you remove it during the install...

-Wayne

[twin plugged targa]

How much approx. does the gas shock raise the car? as I was under the impression that it was a simple swap out and no suspension alignment afterwards neccessary?
Any info appreciated
rgds Ben

[911pcars]

I would be surprised if the Koni and Bilstein shocks have the same internal pressure.

I would assume ride height will change with a change from Koni to Bilstein Sports.

I would expect to adjust the vehicle height accordingly.

If ride height is identical before and after the change, disregard the above.

Sherwood Lee
http://members.rennlist.org/911pcars

[Clark Griswald]

I spoke with a guy today at shox.com. He seemed to know what he was talking about.

He says that the Koni fronts are low pressure gas shocks, and the Koni rear are high pressure shocks. Bilstein are high pressure front and rear, and provide a lift comparable to Koni rear.

He explained the reason Koni uses low pressure in the front is that it is a simpler design. Bilstein had to go with an inverted shock to make it work reliably. I don't know why this is so, but it sounded good.

This is all good news, because the front height is easy to adjust. What I really wanted to avoid was adjusting the rear height.

He claims the high pressure shocks deliver about 40 lbs of lift per shock. He says the low pressure deliver about 10 lbs per shock.

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Chuck - '86 Cab, '77 Targa, Family Truckster

[cds72911]

I have a stupid question - are the Bilsteins a direct fit replacement for the Konis?

Everyhting I 've read makes it sound like you can put almost anything in a Boge original strut car, but if you have Bilsteins or Konis you have to replace them with the same.

My '72 T has Konis all around (red paint). It has S front struts with aluminum calipers and stock looking front and rear swaybars. I think a PO must have either purchased S upgrade parts or it came that way from the factory (I need to order a Kardex to find out for sure). I thought it was a great find, since the car is definitely a T based on the serial numbers and VIN.

I have had excellent luck with Bilsteins on a variety of cars and would be interested in using them on this one if I can use them with my existing suspension. I 've had other Koni's too, but never used the adjustability, so it seemed like an unnecessary feature. Basically I like the Bilsteins better...

Thanks,
Charlie

[david c.]

Have any of you guys installed the adjustable spring plates when doing the work on the rear? I am considering this for the sake of making future height adjustments simpler. I'd be interested in hearing your experiences and costs.

Thanks!

David

[Clark Griswald]

Dave,

I just did a height adjust / corner balance. I have the factory adjustabale spring plates. You didn't say what year your car was, the adjustable plates were introduced around '76?

If you have the old style fixed plates, this is a highly recommended update if you will be doing height/weight adjustments. This will save you from having to pull the plates and tbars repeatedly to get it right.

If you have the factory adjustable, I would only consider the aftermarket ones if you plan on doing frequent adjustments (eg. a race car that is constantly tweaked).

The aftermarket ones have a greater range of adjustment and are a little easier to adjust than the factory.

Factory offers about .75 inches of range, I found this to be plenty and the adjusting was easy. If you are going to do this once (or infrequently) I'd save the $300 and stay with the factory plates.

I have pictures of my project in a thread titled "memorial day project" if you want to see it.



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Chuck - '86 Cab, '77 Targa, Family Truckster

[Early_S_Man]

Charlie,

Hydraulic (pre-gas version) Konis were standard-equipment on all early 'S' cars thru '73, and optional on all of the other models. You are pretty much limited to Koni replacement inserts up front, because Bilstein avoided making the replacements for their chief rival ... though Koni did make inserts for OEM Bilstein struts in the late '80s! Garretson Enterprises sold them and Bruce Anderson reported that Turbo owners liked them in preliminary testing at the time.

Dave,

I installed the Sway-A-Way adjustable spring plates at the same time as their 26 mm rear torsion bars in 1982. Costs have gone up a bit since then! Got mine from Karousel Racing off a sale flyer.

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Warren Hall
1973 911S Targa

[david c.]

Guys:

My mechanic tells me that the OEM spring plates are very difficult/impossible to adjust once they are more than a few years old. He worked at the factory as an engineer and tells me that they were "adjustable" for purposes of assembly, and not really designed for long term adjustability.

What is a decent price on the following, as this is what's going into my car within the next week or so:

Turbo tie rods

22mm front and rear sway bars replacing the teeny front OEM one and the delete in the rear.

21mmfront, 27mm rear torsion bars

Adjustable spring plates

Bilstein HD shocks.

I'm getting the parts estimate today from the mechanic! The car is heading towards some autocross use that I've been planning for years to begin.

Thanks!

Dave

[david c.]

bump (steer-ha!)

Dave