Explain the 300 dollar shock to me, Thread on BOGE replacements and later on 5 lug 911 strut options Options

[emerygt350]

Just took her through some twisty mountain roads, roads with potholes, washouts, ripples, and poorly filled cracks. Very nice, can't feel any difference besides no more scary loss of control over bumps, that right side strut wasn't happy. Nice ride on the highway, otherwise not much different from the konis. No clue how the konis were adjusted. Probably pretty soft.

Here is the tag on the old konis


Everything went together fine, that big hold down thing didn't screw all the way into the strut but neither did the konis.

[mepstein]

At least on Bilsteins’ there is supposed to be a 2-3mm gap under the gland nut. This insures you are tightening the nut against the insert before it bottoms out on the strut body.

[emerygt350]

Ahh, well, I guess this is more like 5mm. It was nearly the same on the Koni. Maybe that is the point then.

[chmillman]

I'm tired of my bone-shaking Bilsteins... Really, really tired...

Late last year, had to replace a broken front Koni (that came with the car), my guy here suggested replacing both sides with Bilsteins and I said OK... There were already Bilsteins in the rear when I got the car.

Me and everyone else who has ever ridden in this car agrees it's now way too stiff.

I was looking around for alternatives and found this:



https://www.rosepassion.com/en/diagrams-por...1-103278-z90088

Real Boge's?? Didn't know they were made anymore. Look reasonably inexpensive too... Unfortunately, the rears are listed as out of stock...



https://www.rosepassion.com/en/diagrams-por...absorber-103279

I know AA has remanufactured both front and rear (further up in this thread). Shipping of a couple of rears to this side of the pond would be pretty expensive, and there is always the question if they even accept things with pressurized gas... @dr914@autoatlanta.com : you said above that they were manufactured in England... Any way to get them directly here in the "old world"?

EDIT: just found there are also front and rear KYB units available here… worth a try?

Also, I have no idea which springs/torsion bars are actually on the car. How to tell?

TIA

[mepstein]

I'm tired of my bone-shaking Bilsteins... Really, really tired...

Late last year, had to replace a broken front Koni (that came with the car), my guy here suggested replacing both sides with Bilsteins and I said OK... There were already Bilsteins in the rear when I got the car.

Me and everyone else who has ever ridden in this car agrees it's now way too stiff.

I was looking around for alternatives and

Real Boge's?? Didn't know they were made anymore. Look reasonably inexpensive too... Unfortunately, the rears are listed as out of stock...



https://www.rosepassion.com/en/diagrams-por...absorber-103279

I know AA has remanufactured both front and rear (further up in this thread). Shipping of a couple of rears to this side of the pond would be pretty expensive, and there is always the question if they even accept things with pressurized gas... @dr914@autoatlanta.com : you said above that they were manufactured in England... Any way to get them directly here in the "old world"?

Also, I have no idea which springs/torsion bars are actually on the car. How to tell?

TIA

99.9% have 17.9mm torsion bars. Larger diameter is aftermarket and not very common unless the PO was auto-x. or changed to 911/912 a-arms to use 18.9mm or bigger. Rear could be anything and difficult to tell if the paint is worn.

[chmillman]

Well, the car has had a 5 bolt conversion. So those might be 911 A arms, don’t know how to tell the difference.

[mepstein]

Well, the car has had a 5 bolt conversion. So those might be 911 A arms, don’t know how to tell the difference.

How was the conversion done. With redrilled rotors or a switch to 911 struts? Does it have 914 brake calipers or 911.

[wonkipop]

explanation?

you get what you pay for. (most times (IMG:style_emoticons/default/smile.gif) )

i've got the softest bilsteins.
a bit harsher than the old stock boges.

but i am not complaining.
even about the price tag which was not $5.59.
it cost $$$$ to get stuff to the antarctic research base at the bottom of the world.
live here and i will take your complaint about expenditure seriously. (IMG:style_emoticons/default/mad.gif) (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/beerchug.gif)

lets get serious for a minute.
even with a 72 horsepower cal spec 73 1.7 these here cars handle and go around corners.

they deserve every $ spent on a good set of shocks. (IMG:style_emoticons/default/beerchug.gif)
and a thorough going through of suspension components. bushes etc. you know the drill.
otherwise what kind of fun are you having?

i have a 1.8. and i sure am not enjoying its ability to peel its tyres off at the lights. (IMG:style_emoticons/default/biggrin.gif)
so................... (IMG:style_emoticons/default/confused24.gif)

[chmillman]

How was the conversion done. With redrilled rotors or a switch to 911 struts? Does it have 914 brake calipers or 911.

No it’s full 911 brakes with vented rotors on the front, so I guess the struts are also 911. So maybe the stiffness of the ride is coming not just from the shocks, but also the spring rate… When I get the car back up on the lift, I will try to see what diameter they are. Does that mean I need to be looking for 911 inserts for those? Is there a difference?

Again, for the rear springs no idea what they are, they look newish, black paint perfect, no rust, but no markings I could find either.

@wonkipop - I tacked my request to the end of this thread instead of starting a new one because it mentioned the Boge replacements made by AA. So the title is a bit OT relative to my issue, personally money spent is not an issue, getting a better ride is.

[mepstein]

If the struts have been switched out, you need to figure out if they are Boge, Bilstein or Koni and if the caliper spacing is 3” or 3 1/2. Early 3” Boge 911 struts will take the same Boge inserts as a 914 but everything else is different.
The most practical way to tell if the torsion bars are bigger is to measure them. If they are 911/914-6 size, they are 1mm larger. That makes them stiffer but doesn’t automatically make them “harsh”.
So the first step is to figure out what you have so you can decide on the best solution.

[chmillman]

If the struts have been switched out, you need to figure out if they are Boge, Bilstein or Koni and if the caliper spacing is 3” or 3 1/2. Early 3” Boge 911 struts will take the same Boge inserts as a 914 but everything else is different.
The most practical way to tell if the torsion bars are bigger is to measure them. If they are 911/914-6 size, they are 1mm larger. That makes them stiffer but doesn’t automatically make them “harsh”.
So the first step is to figure out what you have so you can decide on the best solution.

So, the bolt center to center spacing on the calipers looks to be around 76mm or 3", so older non-S 911 parts I assume.



Viewed from the front they look like this:



The green dust cap up top looks newer than the strut itself...

And I did actually find a marking on the rear springs...





Did a search for the number but didn't find anything right away, but I assume SP100 indicates 100# springs? (more or less stock... hopefully not 100Kg...) 912 parts?
Edit: AI is telling me they are probably aftermarket from Weltmeister.

The sway bars are 15 front / 16 rear (stock option size)

[mepstein]

It looks like the strut uses an early pinch bolt (large nut securing the bolt, split between the ends that secure the ball joint). If that’s correct, they are probably early 911T struts and probably Boge. Boge struts will have an embossed area halfway up the body with Boge name and part number. So long story short, if they are Boge 3” struts, Boge replacement inserts will drop right in. Easy to do at home. Jack up the side of the car, remove top nut on strut, drop the strut under the fender lip, pipe wrench to remove gland nut. Install is reverse but use a jack under the ball joint to raise the strut back into the strut retaining area on the car. Takes 15-20 minutes per side. No need to remove the entire strut from the suspension. Just be carrot the paint on the fender.

Personally, I would do the fronts and take it for a drive. You might not need the rears done. The front controls 75% of the feel of the car.

I could be wrong but the 914-4 rear sway bars were 15mm and 914-6 were 16mm. Not a significant difference in feel but if it’s a bar for a six, it’s pretty valuable compared to one for a four. At least to an owner of a real six. You can also disengage the rear bar and see if you like the ride. Using a rear bar isn’t mandatory on a 914. Some guys control the roll with just springs. Maybe a bit more understeer but it’s a common setup to just use a front. Easy enough to try it and see if it works for you.

[wonkipop]

How was the conversion done. With redrilled rotors or a switch to 911 struts? Does it have 914 brake calipers or 911.

No it’s full 911 brakes with vented rotors on the front, so I guess the struts are also 911. So maybe the stiffness of the ride is coming not just from the shocks, but also the spring rate… When I get the car back up on the lift, I will try to see what diameter they are. Does that mean I need to be looking for 911 inserts for those? Is there a difference?

Again, for the rear springs no idea what they are, they look newish, black paint perfect, no rust, but no markings I could find either.

@wonkipop - I tacked my request to the end of this thread instead of starting a new one because it mentioned the Boge replacements made by AA. So the title is a bit OT relative to my issue, personally money spent is not an issue, getting a better ride is.

was addressing OP (emery350gt) not you chmillman (IMG:style_emoticons/default/biggrin.gif) sorry for confusion.

for emerygt350's interest i found my receipts for the billsteins back at end of 2019.
B6 bills.
front pair $847 AUD
rear pair $770 AUD
googling the AUD back then - 1.00AUD = 0.72 USD
cost for pair of fronts $609.00 USD. or 300 each.

same price as now by the looks of it. zero inflation?

@chmillman - back in 2019 you could not get boges or boge replicas from mr atlanta.
choice was between billsteines and konis. don't think even cheapos were an option for me in north antarctica. not even available.

truthfully i would not have minded boges again (if they existed) as the car has factory sway bars. allow for the softer shocks in a kind of comfort/performance compromise.
most of the time the B6 are not too bad comfort wise.
but definitely a bit stiffer.

re your springs. not sure 100 lb springs are original spec.
others here know more.
i have a vague recollection the originals were in the 50-60 ib range.
there is some figure in the factory manual which is in kp.
seem to remember something about three different strengths.
but can't remember how that worked. someone here would know.
i reused my original springs. seems to be working ok with the B6s i put in 5 years back.

[chmillman]

i have a vague recollection the originals were in the 50-60 ib range.
there is some figure in the factory manual which is in kp.
seem to remember something about three different strengths.
.

Yes, the manual has 3 different values from 220-240 Kp - those are minor differences, possibly to keep springs matched due to manufacturing differences at the time.

60 pounds/inch is about right... Here is the calculation I infer from the manual info

Spring free length=471mm
The 220-240 Kp value is measured at L1=239 - from that I infer that the spring is compressed to that length to measure. That means a compression of 471-239 = 232mm or 9.13"

240Kp*2.2=528 lbs force at a compression of 9.13"
528/9.13 = 57.8 pounds per inch.

Hope i got that calculation correct.

[wonkipop]

i have a vague recollection the originals were in the 50-60 ib range.
there is some figure in the factory manual which is in kp.
seem to remember something about three different strengths.
.

Yes, the manual has 3 different values from 220-240 Kp - those are minor differences, possibly to keep springs matched due to manufacturing differences at the time.

60 pounds/inch is about right... Here is the calculation I infer from the manual info

Spring free length=471mm
The 220-240 Kp value is measured at L1=239 - from that I infer that the spring is compressed to that length to measure. That means a compression of 471-239 = 232mm or 9.13"

240Kp*2.2=528 lbs force at a compression of 9.13"
528/9.13 = 57.8 pounds per inch.

Hope i got that calculation correct.

thanks for translating my rubbish memory re rear springs into something factual. (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)

out of interest i just did a calculation on the rear boge shocks screen grab you posted above.
1 swiss francs currently = $1.90 aud. so cost would be $176 aud for each shock.
+ GST 10% payable when its landed in aus. good as $200 aud. + freight. thats a stab in the dark. but given its heavy-ish. wild guess. $50.00 aud.
so i'd be looking at around $250 aud per rear boge shock.
not too much different to billstein. maybe $100 cheaper but that depends of freight. though i have not checked bill prices in aus currently.

[emerygt350]

If it makes any difference, I have been enjoying autoatlantas boge struts. I did quite well with them and my all season radials at my last autocross. They are not crazy different from the adjustable konis that where in there but my suspension response is probably a bit different than normal with my 14 inch wider track width than a stock 914.

[carr914]

@Paragon

Jason can answer all your question. He is The 914 Koni Guy

[chmillman]

If the struts have been switched out, you need to figure out if they are Boge, Bilstein or Koni ...
So the first step is to figure out what you have so you can decide on the best solution.

It looks like the strut uses an early pinch bolt (large nut securing the bolt, split between the ends that secure the ball joint). If that’s correct, they are probably early 911T struts and probably Boge. Boge struts will have an embossed area halfway up the body with Boge name and part number

OK, so the first thing I did was look for the part number on the struts - which was more or less where you said it should be, but of course facing outward. So I pulled the front wheels off and tried to read the numbers... A bit hard because I think the struts may have been painted over once. With the help of the phone camera - which sometimes sees more than the naked eye - and some oblique light and chalk, I got most of it...





So, from what I can read:

Left side -
1 0221 32 090 0
914 341 091 00

Right side -
1 0221 32 091 0
914 341 092 00

Those numbers do not correspond with the Porsche parts catalog numbers I have here, which show

914 341 081 02 (up to '72, right side is 082)
914 341 081 05 (after '72, right side is 082)

And then there are those triangles you see in the photos... The Koni logo is triangular. So, maybe Koni replacement struts? Or what?

Aslo, looking at the parts diagram, the A-arms are separate parts from the struts. So might it be possible that they are still the original 914 parts with the 17.9mm torsion bars, or would they necessarily have to have been changed to 911 parts to go with the struts?

Always an interesting "archeological dig" to try to figure out what is really on/in these cars...

https://www.youtube.com/shorts/zXos_BJBX-Q

[mepstein]

Are the arms on the strut that secure the ball joint curved or straight?

[wonkipop]

If the struts have been switched out, you need to figure out if they are Boge, Bilstein or Koni ...
So the first step is to figure out what you have so you can decide on the best solution.

It looks like the strut uses an early pinch bolt (large nut securing the bolt, split between the ends that secure the ball joint). If that’s correct, they are probably early 911T struts and probably Boge. Boge struts will have an embossed area halfway up the body with Boge name and part number

OK, so the first thing I did was look for the part number on the struts - which was more or less where you said it should be, but of course facing outward. So I pulled the front wheels off and tried to read the numbers... A bit hard because I think the struts may have been painted over once. With the help of the phone camera - which sometimes sees more than the naked eye - and some oblique light and chalk, I got most of it...





So, from what I can read:

Left side -
1 0221 32 090 0
914 341 091 00

Right side -
1 0221 32 091 0
914 341 092 00

Those numbers do not correspond with the Porsche parts catalog numbers I have here, which show

914 341 081 02 (up to '72, right side is 082)
914 341 081 05 (after '72, right side is 082)

And then there are those triangles you see in the photos... The Koni logo is triangular. So, maybe Koni replacement struts? Or what?

Aslo, looking at the parts diagram, the A-arms are separate parts from the struts. So might it be possible that they are still the original 914 parts with the 17.9mm torsion bars, or would they necessarily have to have been changed to 911 parts to go with the struts?

Always an interesting "archeological dig" to try to figure out what is really on/in these cars...

the triangle things are porsche logos.

triangle with a P inside it (a stylised P).

this is what i understand that to mean.
its a production line part.
the sigla windscreens when fitted on production line had the triangle and P.
the kinonglas windscreens had the VW logo (and later VW and audi rings).
along the way the cars had either sigla screens or kinonglas depending on the batch - months of year basically. but the big difference between production line installed parts and then later spare parts is the vehicle manufacturer logo.

after the production line fitment, replacement OEM parts just had the supplier logos or names. but no longer the vehicle manufacturer logos.

i still had orig boge shocks and struts on mine in 2019 when i recommissioned.
cleaned them up a bit and put the bil inserts in at the front.
all they had were the date stamps on the struts.
date stamp was 1 week before the VW production number stamped on the chassis and k plate. nothing else. struts 22 jan. car chassis stampe 28 jan.




EDIT.

so what i am saying is if its got the triangle with P that alone means its very likely unless the struts came from some other car that its the orig production line fitted front struts.
the other empty triangle might well be a koni symbol i don't know.
and its got a 914 first three digits part number. so its 914 specific.

and konis were not standard production fitment. you had to tick a box to get them.

you can see from my photo the bog standard boges.
not much on them. just the date stamp. i could look again closely at mine.
but i don't think there is anything else there. no boge logo. no vw logo as far as i have ever been able to detect. maybe there is and i can't remember but the date stamps caught my eye. i cleaned up of stray undercoating and kept clear of those date stamps and then reinstalled.

anyways. i think you might have original struts. koni option ticked. (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/beerchug.gif)