opinions/ ideas about modifying stock struts to be stiffer

[aust92pearl]

my dad is experimenting with putting thicker oil in the spare set of struts i have

so far he has drilled a hole in the bottom of the shock and i think he plans to put one in the side too ,

he told me there was only about 300 ml of fluid in the one he drilled and that it was very thin fluid

so he is going to see how it reacts with some trans fluid and if that doesnt do much he will try a thicker fluid

his plan to re-seal them is to weld a nut over the hole so a bolt can be used to seal it back up

once he gets one done and it seams like it works well he will do the other 3 and we will install them and see how they feel

i will get a few pictures to show what it looks like/ how it was done

[icingdeath88]

Struts are not filled only with oil though. AFAIK, they are filled with a pressurized oil/air emulsion. So, I don't know how well that will work.

[Tapani]

The gas is nitrogen, I believe. Very low pressure on the SVX strut. The idea is to try to prevent cavitation at high speed displacement.

Be very careful you drill only thru the outer tube !

Mine had a little over 250ml of fluid - very thin indeed. If you experiment with several fluids you might want to try the ones intended for bike forks.

Make sure you bleed the strut like this (must be off the car):

http://www.subaru-svx.net/forum/showthread.php?t=60066

Tapani

[aust92pearl]

Originally Posted by icingdeath88

Struts are not filled only with oil though. AFAIK, they are filled with a pressurized oil/air emulsion. So, I don't know how well that will work.

Originally Posted by Tapani

The gas is nitrogen, I believe. Very low pressure on the SVX strut. The idea is to try to prevent cavitation at high speed displacement.

Be very careful you drill only thru the outer tube !

Mine had a little over 250ml of fluid - very thin indeed. If you experiment with several fluids you might want to try the ones intended for bike forks.

Make sure you bleed the strut like this (must be off the car):

http://www.subaru-svx.net/forum/showthread.php?t=60066

Tapani

thanks for your input guys

dad said he didnt notice any air being expelled from the strut when he drilled through the bottom of it
i mentioned bike fork fluid and he said trans and bike fork fluid have a very similar viscosity

i told him about the bleeding thing and he said yeah he knows haha

he just bought some stuff (nuts/bolts/nipples i dont actually know what hes doing with that part yet ) to bung it back up with

but he thinks that the idea should work well
if not really well

he told me what he is doing is basically what the rally guys used to do back in the older rally days (although they would have had servicable struts that didnt need to be drilled to replace with thicker fluid )

[oab_au]

Originally Posted by aust92pearl

thanks for your input guys

dad said he didnt notice any air being expelled from the strut when he drilled through the bottom of it
i mentioned bike fork fluid and he said trans and bike fork fluid have a very similar viscosity

i told him about the bleeding thing and he said yeah he knows haha

he just bought some stuff (nuts/bolts/nipples i dont actually know what hes doing with that part yet ) to bung it back up with

but he thinks that the idea should work well
if not really well

he told me what he is doing is basically what the rally guys used to do back in the older rally days (although they would have had servicable struts that didnt need to be drilled to replace with thicker fluid )

Your dad and I must be from the same old school.
The fluid to use is the bike fork oil as you can get a range of viscosities. To check what the original oil is, use a sheet of glass at an angle to run a drop of oil down, and compare with a known fork oil.

Harvey.

[aust92pearl]

Originally Posted by oab_au

Your dad and I must be from the same old school.
The fluid to use is the bike fork oil as you can get a range of viscosities. To check what the original oil is, use a sheet of glass at an angle to run a drop of oil down, and compare with a known fork oil.

Harvey.

hahah yeah , (he is 58 this year )

yeah , he is just seeing how it acts with the trans fluid ,

il have to tell him that trick (although he probably knows it )

[bwb3]

The August issue of Grassroots Motorsports has a related article which may be of interest. I also have a pdf file I can e-mail.
Gene

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[aust92pearl]

Originally Posted by bwb3

The August issue of Grassroots Motorsports has a related article which may be of interest. I also have a pdf file I can e-mail.
Gene

thanks for the input
its a lot easier to do this with struts that can actually pulled apart though

he has been a mechanic since the late 70's - early 80's
i think he did it to one of his old cars back before i was born (he had one particular ute (truck) for about 25 years )