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914World.com _ 914World Garage _ REAR SWAYBAR size question

Posted by: Marek Dec 26 2018, 03:58 PM

Hi Guys

Hope you all had a nice christmas hollyday

I am in the Final stage of the Rear swaybar reproduction

which I will have ready in a good few weeks

I am making the set complete in 16mm and 18mm and to OEM specs

( rubbers and bushing will be OEM Porsche )

the kit will come complete , we are at 350-420 Euro range for a full kit
, parts will be sold seperate also, also I made a plate so you dont need to weld the brackets on , more info will follow

BUT My question is straight forward

what would you put on 16, 18 , or do I also make a 20 mm

Marek



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Posted by: dr914@autoatlanta.com Dec 26 2018, 04:08 PM

15 front 16 rear for the four cylinder, 16 front 15 rear for the six cylinder

Posted by: TravisNeff Dec 26 2018, 04:31 PM

I didn't think the sixes came with sway bars, just the fours starting in 73??

I would be interested in the larger bar for sure, the 20mm sounds interesting. From a swaybar calculator; I think the stock 16mm bar is only good for about 43lbs of spring force. I guessed on the bar length and arm length to plug in the calculator.

Can you share the dimensions of the bar? (width and lever arm length). we could figure out what the rate is pretty easily.

My guess was 36 inches wide, 14 inch lever arm length, take away 4 inches for the position of end links in relation to the centerline of the axle.

Posted by: 914forme Dec 26 2018, 04:55 PM

Nice looking parts drooley.gif

20mm or even larger, but you need to run a true limited slip differential if you want to keep forward momentum, as one of the rear will lift in hard cornering. If running open or torque biased I would leave it off.

A flat cornering car does not it is mean a fast cornering car.

Posted by: Rand Dec 26 2018, 05:05 PM

Is this an originality thing? Most don't run rear sways, not even the AXers. Always learning.

Posted by: TravisNeff Dec 26 2018, 05:12 PM

I am interested in not running a 250lb rear spring. I want to move to softer springs and big sway bars

Posted by: rgalla9146 Dec 26 2018, 05:30 PM

QUOTE(dr914@autoatlanta.com @ Dec 26 2018, 05:08 PM) *

15 front 16 rear for the four cylinder, 16 front 15 rear for the six cylinder


Never saw any OE rear bar other than a 16.... and never saw an OE bar on a 6
only added
please show an OE bar stamped 15
18 ? 20 ? don't know

Posted by: SirAndy Dec 26 2018, 07:53 PM

QUOTE(Rand @ Dec 26 2018, 03:05 PM) *

Is this an originality thing? Most don't run rear sways, not even the AXers. Always learning.

Guess i'm not most people then ...
confused24.gif


As for the OP, i'd like to see some adjustable drop-links for the stock rear bars!
And yes, a 20mm option would be nice too.
driving.gif

Posted by: gandalf_025 Dec 26 2018, 08:16 PM

I have aftermarket front and rear bars on my 6.
I bought them around 1974 from a local guy.
Think it was H+H Specialties
I’ll post the sizes when I get out to my freezing cold
Garage tomorrow morning...

Posted by: 914forme Dec 26 2018, 08:26 PM

That would have been H & H, and they made some nice stuff

And Andy I remember seeing someone made an adjustable rear drop link. It only had one threaded end so you had to pop them, adjust, re-install. But once done how often do you adjust them afterwards?

Posted by: gandalf_025 Dec 26 2018, 08:30 PM

H&H Specialties was based out of Chelmsford Massachusetts, a few towns away from where I grew up. I picked the front and rear bars up
from the guys house in Chelmsford..

Posted by: ConeDodger Dec 26 2018, 08:54 PM

I run a rear bar with 200# Springs. With a rear bar, you have to be aware of the that moment where you go into a spin and stay just this side of it. I like the car with a rear bar. I wouldn’t go larger than the stock rear bar I have though...

Posted by: 914 Ranch Dec 27 2018, 01:38 AM

180 springs and a rear bar planted Carerror's ass. The front is still has a little under steer. She is Quaffed. The bar is 16 mm.

Posted by: TravisNeff Dec 27 2018, 07:18 AM

QUOTE(914 Ranch @ Dec 27 2018, 12:38 AM) *

180 springs and a rear bar planted Carerror's ass. The front is still has a little under steer. She is Quaffed. The bar is 16 mm.


How misleading! Your car only weighs 180 lbs poke.gif

Posted by: ConeDodger Dec 27 2018, 07:31 AM

Marek, what happened to the GT kit for fuel fill?

Posted by: sixnotfour Dec 27 2018, 07:37 AM

QUOTE(ConeDodger @ Dec 27 2018, 06:31 AM) *

Marek, what happened to the GT kit for fuel fill?

http://www.914world.com/bbs2/index.php?showtopic=334114&hl=

Posted by: ConeDodger Dec 27 2018, 07:44 AM

QUOTE(sixnotfour @ Dec 27 2018, 10:37 AM) *

QUOTE(ConeDodger @ Dec 27 2018, 06:31 AM) *

Marek, what happened to the GT kit for fuel fill?

http://www.914world.com/bbs2/index.php?showtopic=334114&hl=


Thanks Jeff! biggrin.gif

Posted by: TravisNeff Dec 27 2018, 08:26 AM

Does someone have a rear bar laying around and be able to take two measurements for me? I need the length of the lever arm and the width of the bar


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Posted by: gandalf_025 Dec 27 2018, 11:04 AM

I just went out to my very cold garage and measured the
H+H rear bar in my car... If you are looking for a factory bar,
I can't help.
But the H+H is 16mm, 38" long and the arms stick out 12".

Posted by: gandalf_025 Dec 27 2018, 11:18 AM

Just dug through some paperwork and found this..Attached Image

Posted by: 914forme Dec 27 2018, 11:26 AM

Thanks for sharing, that is a great piece of information

Posted by: TravisNeff Dec 27 2018, 12:22 PM

Using the online calculators I get different results from what the H&H page states. Anyways I can adjust the numbers on the lever arm length to get to that 70lbs per inch for a stock bar

16mm rear bar 70 lbs/inch
18mm rear bar 112 lbs/inch
20mm rear bar 171 lbs/inch

Posted by: Rand Dec 27 2018, 01:05 PM

QUOTE(SirAndy @ Dec 26 2018, 05:53 PM) *

QUOTE(Rand @ Dec 26 2018, 03:05 PM) *

Is this an originality thing? Most don't run rear sways, not even the AXers. Always learning.

Guess i'm not most people then ...
confused24.gif


As for the OP, i'd like to see some adjustable drop-links for the stock rear bars!
And yes, a 20mm option would be nice too.
driving.gif.


I confess that foremost here in decades, I want to learn. I have been told around here that rear swaybars are not used often. I am not here to be right. I am here to learn. So rear sways are back in?

Posted by: dr914@autoatlanta.com Dec 27 2018, 01:39 PM

It is certainly understandable that you have never seen one, the sway bar package was only offered on 71 and 72 sixes NOT 70 models. Here is a pic from the factory catalog, showing the two sizes and the part numbers (don't waste your time trying to order both have been discontinued


QUOTE(rgalla9146 @ Dec 26 2018, 04:30 PM) *

QUOTE(dr914@autoatlanta.com @ Dec 26 2018, 05:08 PM) *

15 front 16 rear for the four cylinder, 16 front 15 rear for the six cylinder


Never saw any OE rear bar other than a 16.... and never saw an OE bar on a 6
only added
please show an OE bar stamped 15
18 ? 20 ? don't know
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Posted by: Bobby Smith Dec 27 2018, 01:39 PM

QUOTE(Rand @ Dec 26 2018, 03:05 PM) *

Is this an originality thing? Most don't run rear sways, not even the AXers. Always learning.


Rand, I think a rear bar is a personal preference thing. I've been autocrossing 914's for 35 years. 1,600 lb four bangers and currently a 914/6 conversion with 3.2ltr and I've always successfully run a rear bar in order to get the car balanced and get good turn with excellent corner exit. I'm sure lots of folks have gone without a rear bar but don't dismiss them.

Posted by: Mark Henry Dec 27 2018, 02:54 PM

IIRC there's a stock racing class that has a rear spring/lb limit, the sway bar is a free spring rate addition. Some guys run the rear on the street, the disconnect and tie up the bar at the track.
Performance tune you likely would play around with the bars.

My 3.0 /6 has both stock F/R sways and feels OK, but I picked up a tarett front bar that I'm going to experiment with.

Posted by: SirAndy Dec 27 2018, 03:02 PM

QUOTE(dr914@autoatlanta.com @ Dec 27 2018, 11:39 AM) *
It is certainly understandable that you have never seen one, the sway bar package was only offered on 71 and 72 sixes NOT 70 models. Here is a pic from the factory catalog, showing the two sizes and the part numbers (don't waste your time trying to order both have been discontinued

George, the picture you posted shows 15mm for the front and 16mm for the rear.

hinten = rear

shades.gif


Posted by: Rand Dec 27 2018, 03:42 PM

QUOTE(Bobby Smith @ Dec 27 2018, 11:39 AM) *

QUOTE(Rand @ Dec 26 2018, 03:05 PM) *

Is this an originality thing? Most don't run rear sways, not even the AXers. Always learning.


Rand, I think a rear bar is a personal preference thing. I've been autocrossing 914's for 35 years. 1,600 lb four bangers and currently a 914/6 conversion with 3.2ltr and I've always successfully run a rear bar in order to get the car balanced and get good turn with excellent corner exit. I'm sure lots of folks have gone without a rear bar but don't dismiss them.

Thanks Bobby, I appreciate the input.

Posted by: Rand Dec 27 2018, 03:47 PM

It's hard sometimes to come out with a solid answer. I know every car is different, so I get the variance. But I swear, there has been so much talk on here about running no rear sway bars, I know I'm not making it up.

Posted by: TravisNeff Dec 27 2018, 04:02 PM

You are not making it up. A few people started saying they didn't like the rear bar as it can lift the inside rear wheel in racing or autocross. Enough people parroted that statement it and now its some sort of gospel.

Posted by: dr914@autoatlanta.com Dec 27 2018, 04:06 PM

Actually Andy, no. Maybe not written right in the translation but they are both the two rear sway bar part numbers. Here are the choices for the front sway bar:




QUOTE(SirAndy @ Dec 27 2018, 02:02 PM) *

QUOTE(dr914@autoatlanta.com @ Dec 27 2018, 11:39 AM) *
It is certainly understandable that you have never seen one, the sway bar package was only offered on 71 and 72 sixes NOT 70 models. Here is a pic from the factory catalog, showing the two sizes and the part numbers (don't waste your time trying to order both have been discontinued

George, the picture you posted shows 15mm for the front and 16mm for the rear.

hinten = rear

shades.gif

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Posted by: SirAndy Dec 27 2018, 04:54 PM

QUOTE(dr914@autoatlanta.com @ Dec 27 2018, 02:06 PM) *
Actually Andy, no. Maybe not written right in the translation but they are both the two rear sway bar part numbers.

This seems odd since 914.333.701.06 explicitly states that it is for the rear while 05 does not.

To me, that implies 05 is the front stabilizer bar for the 914/6 ...
idea.gif


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Posted by: Rand Dec 27 2018, 04:59 PM

QUOTE(TravisNeff @ Dec 27 2018, 02:02 PM) *

You are not making it up. A few people started saying they didn't like the rear bar as it can lift the inside rear wheel in racing or autocross. Enough people parroted that statement it and now its some sort of gospel.

Thanks Travis. Sometimes the gospel needs questioning.

I (duh) know it it is different between racers and their cars. My point wasn't to argue, it was to learn.


Posted by: TravisNeff Dec 27 2018, 05:05 PM

I agree. That is why I am willing to try this out smile.gif

Posted by: 914_teener Dec 27 2018, 06:23 PM

QUOTE(Rand @ Dec 27 2018, 02:59 PM) *

QUOTE(TravisNeff @ Dec 27 2018, 02:02 PM) *

You are not making it up. A few people started saying they didn't like the rear bar as it can lift the inside rear wheel in racing or autocross. Enough people parroted that statement it and now its some sort of gospel.

Thanks Travis. Sometimes the gospel needs questioning.

I (duh) know it it is different between racers and their cars. My point wasn't to argue, it was to learn.



If you look at the spring rates it makes sense why you might not need it, especially on the street and then especially in the rear.

It lists a 20 mm bar spring rate in the front at what.....1800 lbs?

Posted by: 914forme Dec 27 2018, 06:40 PM

On the street I never noticed tire lift on my car with the rear swaybar.

On tight turns on concrete in the autocross, I did notice tire lift with tire spinning. Only solution to that would have been reduce rear spring rate. Car was very well balanced, or figure out a way to maintain forward momentum while in the corner. I chose the latter and installed a Factory ZF limited slip, which latter was replace with a Guard Limited slip due to the declaration ramps.

I like a rear swaybar always have always will.

People like JP Stein never liked them, but we ran in two different areas, and on different surfaces, with different car setups.

The 914-6 I only have the front H&H unit right now. I plan on running 150 lbs rear springs, but I have spring sets that go all the way to 300. I am going to see what I get, as the plan was not to get the welder out for that car. wacko.gif The EG conversion car has 22 mm from t bars, 225 rear springs and a huge front swaybar. I will start with no rear bar, both cars are setup with a torque biased limited slip.

I would love to find an H&H for the 914-6 as it would fit the restored theme for that car. Will not know if I need one for either car until they are on the road.

Posted by: TravisNeff Dec 27 2018, 07:02 PM

QUOTE(914_teener @ Dec 27 2018, 05:23 PM) *

QUOTE(Rand @ Dec 27 2018, 02:59 PM) *

QUOTE(TravisNeff @ Dec 27 2018, 02:02 PM) *

You are not making it up. A few people started saying they didn't like the rear bar as it can lift the inside rear wheel in racing or autocross. Enough people parroted that statement it and now its some sort of gospel.

Thanks Travis. Sometimes the gospel needs questioning.

I (duh) know it it is different between racers and their cars. My point wasn't to argue, it was to learn.



If you look at the spring rates it makes sense why you might not need it, especially on the street and then especially in the rear.

It lists a 20 mm bar spring rate in the front at what.....1800 lbs?


That is for a front bar (which is 36 inches long vs 42 inches for the rear). Also the front has shorter lever arms which increase the rate over the rear configuration. Check my post a few up and I have some figures for the rear 171lbs.

I was running 22mm torsion bars, 22mm sway bar and 250lb rear springs. I am going down to a smaller torsion bar up front, larger front sway bar and want to run a rear bar then switch to 150-175lb rear springs. I am after the same or a bit more roll stiffness and softer springs.

Posted by: 914Timo Dec 29 2018, 05:38 AM

QUOTE(914forme @ Dec 27 2018, 04:26 AM) *

That would have been H & H, and they made some nice stuff

And Andy I remember seeing someone made an adjustable rear drop link. It only had one threaded end so you had to pop them, adjust, re-install. But once done how often do you adjust them afterwards?



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Thats my setup. Pics are from 2004. Still have it.

Posted by: gandalf_025 Dec 29 2018, 07:32 AM

Think this was in late 1973


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Posted by: bdstone914 Dec 29 2018, 08:40 AM

QUOTE(dr914@autoatlanta.com @ Dec 26 2018, 04:08 PM) *

15 front 16 rear for the four cylinder, 16 front 15 rear for the six cylinder


@http://www.914world.com/bbs2/index.php?showuser=4947 @autoatlanta.com

I have never seen a 16mm front or a 15mm rear on any 914 or 914-6.

No references in PET to those sizes. What is you source for that information George ?

Posted by: dr914@autoatlanta.com Dec 29 2018, 09:39 AM

factory publications. They are real Brad. Part numbers still exist in the Porsche price guide but all have been discontinued. Please remember sway bars from the factory were not offered on the four until 1973 and on the six in 1971-1972

The reason for the different sized bars is because of the weight difference, the four understeered the six over steered. SO to change under steer, bigger rear bar smaller front bar. To change over steer, bigger front bar smaller rear bar. The four cylinder really lit up with the addition of the bars, 16 front 15 rear. Became quite crisp.
The six really benefited from the bars as it made the car more stable rather than worrying about the rear end coming around in a hard quick turn. Yes that extra six cylinder engine weight made a difference


QUOTE(bdstone914 @ Dec 29 2018, 07:40 AM) *

QUOTE(dr914@autoatlanta.com @ Dec 26 2018, 04:08 PM) *

15 front 16 rear for the four cylinder, 16 front 15 rear for the six cylinder


@http://www.914world.com/bbs2/index.php?showuser=4947 @autoatlanta.com

I have never seen a 16mm front or a 15mm rear on any 914 or 914-6.

No references in PET to those sizes. What is you source for that information George ?

Posted by: Tdskip Dec 29 2018, 10:35 AM

Great discussion

Posted by: dr914@autoatlanta.com Dec 29 2018, 11:07 AM

I could list all of the different 914 sizes and parts numbers if anyone is seriously interested. The fronts are just like the 911 ones of the period, the rears (two of them) were 914 unique

Posted by: rgalla9146 Dec 29 2018, 11:46 AM

QUOTE(dr914@autoatlanta.com @ Dec 29 2018, 12:07 PM) *

I could list all of the different 914 sizes and parts numbers if anyone is seriously interested. The fronts are just like the 911 ones of the period, the rears (two of them) were 914 unique


Does anyone have a picture of a 15mm rear bar ?
Someone here whose had many many cars must have a picture.


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Posted by: TravisNeff Dec 29 2018, 02:08 PM

QUOTE(dr914@autoatlanta.com @ Dec 29 2018, 10:07 AM) *

I could list all of the different 914 sizes and parts numbers if anyone is seriously interested. The fronts are just like the 911 ones of the period, the rears (two of them) were 914 unique


Yes please.

Posted by: dr914@autoatlanta.com Dec 29 2018, 02:59 PM

the 916 has one on it !


quote name='rgalla9146' date='Dec 29 2018, 10:46 AM' post='2677468']
[quote name='dr914@autoatlanta.com' post='2677457' date='Dec 29 2018, 12:07 PM']
I could list all of the different 914 sizes and parts numbers if anyone is seriously interested. The fronts are just like the 911 ones of the period, the rears (two of them) were 914 unique
[/quote]

Does anyone have a picture of a 15mm rear bar ?
Someone here whose had many many cars must have a picture.
[/quote]

Posted by: dr914@autoatlanta.com Dec 29 2018, 03:10 PM

front 12 90134370301
front 14 90134370302
front 15 90134370303
front 16 90134370304
front 11 90134370305


rear 15 91433370105
rear 16 91433370106
rear 16 (914-4) 91433305506

Posted by: rgalla9146 Dec 29 2018, 06:07 PM

[quote name='dr914@autoatlanta.com' date='Dec 29 2018, 03:59 PM' post='2677495']
the 916 has one on it !

Excellent ! and a picture ?


quote name='rgalla9146' date='Dec 29 2018, 10:46 AM' post='2677468']
[quote name='dr914@autoatlanta.com' post='2677457' date='Dec 29 2018, 12:07 PM']
I could list all of the different 914 sizes and parts numbers if anyone is seriously interested. The fronts are just like the 911 ones of the period, the rears (two of them) were 914 unique
[/quote]

Does anyone have a picture of a 15mm rear bar ?
Someone here whose had many many cars must have a picture.
[/quote]
[/quote]


Posted by: rgalla9146 Dec 29 2018, 06:59 PM

New twist.
check the factory recommendation lower right
no part numbers provided
still want to see a 15mm


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Posted by: bdstone914 Dec 31 2018, 07:34 AM

QUOTE(dr914@autoatlanta.com @ Dec 29 2018, 03:10 PM) *

front 12 90134370301
front 14 90134370302
front 15 90134370303
front 16 90134370304
front 11 90134370305


rear 15 91433370105
rear 16 91433370106
rear 16 (914-4) 91433305506


Thanks George,
I never knew about those other size bars. Looks like 901.343.703.01 is a 13mm front 911 and 912 SWB bar not 13mm as you listed. Those are the ones I have most often seen on SWB cars.
Do you know what size bars the GT 914-6 used ?
And the name is Bruce not Brad. poke.gif

@http://www.914world.com/bbs2/index.php?showuser=4947 @autoatlanta.com


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Posted by: dr914@autoatlanta.com Dec 31 2018, 08:24 AM

Sorry for the name error Bruce, I got this information from the Porsche factory 914-6 GT parts book. Who am I to question them?)LOL)

QUOTE(bdstone914 @ Dec 31 2018, 06:34 AM) *

QUOTE(dr914@autoatlanta.com @ Dec 29 2018, 03:10 PM) *

front 12 90134370301
front 14 90134370302
front 15 90134370303
front 16 90134370304
front 11 90134370305


rear 15 91433370105
rear 16 91433370106
rear 16 (914-4) 91433305506


Thanks George,
I never knew about those other size bars. Looks like 901.343.703.01 is a 13mm front 911 and 912 SWB bar not 13mm as you listed. Those are the ones I have most often seen on SWB cars.
Do you know what size bars the GT 914-6 used ?
And the name is Bruce not Brad. poke.gif

@http://www.914world.com/bbs2/index.php?showuser=4947 @autoatlanta.com


Posted by: sixnotfour Jan 1 2019, 02:35 PM

might as well add this one
Sway Bar Front 18mm 91134370500. 75-76 turbo

Posted by: Marek Mar 11 2019, 03:33 AM

Hi Guys

just wanted to give a heads up

We are in the final stage in produccing the 16 mm and 18 mm Rear sway bars

all hardware for it is also made

all made to factory specs

and they will be priced VERY good

you can buy them seperat or just the parts for it
if you got the swaybar or the other way around

thanks for all the Feedback , I came to the conclusion
that most are interested in 18 mm but we did the 16 mm also

in the future we will do a test run of 20 mm

Marek
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Posted by: johnhora Mar 11 2019, 10:28 AM

popcorn[1].gif

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