Love the simplicity of our cars...

[RSGulp]

Today's job was to fit the 993 steering rack brace upgrade for running 18" wheels on a 964rs.

I did a bit of research on PelicanParts and Rennlist and came across a few threads talking about the hassle of fitting the bracket in between all the tubes and pipes up there...

...well, not on the K.I.S.S. lhd RS there isn't... []

Also, while fitting the bracket my 12 yr old nephew who's staying with us for Easter popped his head under the car, had a look around and said, "It looks just like a toy car." I wondered what he meant. "You know, when you turn your toy cars over and they're just smooth and flat underneath." [] []

 

[chfs911]

Do you have a part no and price for the update? I run 18" on Cup and RS and may do this too.

Charles

 

[964rsdatabase]

Me too. Never heard about this one.

 

[RSGulp]

The part numbers and prices from OPC (inc PCGB discount) are:

993.347.131.02 (LHD) Steering Rack Support £32.84 + vat
999.218.103.09 Pan-head screw M8 x 80 £2.06 + vat each (2 needed)

Takes about 20 mins to fit and apparently helps support the additional loading on the steering rack - stops the relatively weak casing on the steering rack from bending/twisting. Some people say you need it, some don't - internet experts all of them. []

Standard issue from Porsche for cars with 18"s after '95 I believe. Really simple to fit and at £40 cheap peace of mind IMO.

See here: http://p-car.com/technical/wheel.htm

Technical bulletin available here: http://forums.rennlist.com/rennforums/attachments/964-forum/366054d1245503624-18-wheels-for-de-tech-bul-9604.pdf

 

[964rsdatabase]

Thanks Rich. Will sort one after Easter.

 

[RSGulp]

Just realised you need to be registered to Rennlist to view the tech bulletin. If anyone isn't PM me and I'll email the pdf.


Have you fitted 18s now Martin?

 

[h_____]

What does this mod achieve? Is it because 18" wheels are heavier? i am struggling to work this one out, and why it would be relevent to 18" wheels?

 

[RSGulp]

ORIGINAL: h_____

What does this mod achieve? Is it because 18" wheels are heavier? i am struggling to work this one out, and why it would be relevent to 18" wheels?

Looking at the pics above, the two 'lower bolts' attached the steering rack to the subframe via the two part clamps. The two upper bolts simply hold the clamps around the steering rack. I guess the bracket ensures the upper clamp bolts are held at a fixed distance so the steering racking can't be stressed either way.

Perhaps heavier wheels = more stresses; or larger wheels therefore more 'leverage' stress on the steering arms running back through the steering rack. Porsche made the upgrade on the 993 and there was a Tech Bulletin to upgrade any 993 using 18" wheels. I figured (along with many other 964 drivers on Pelican and Rennlist) it made sense that if Porsche recommended it for the 993 on 18s, then 964s on 18 ought to do it too as it's essentially the same set-up.

Discussed here: http://www.porscheclubgbforum.com/tm.asp?m=591036&mpage=1&key=steering򐒼

Anyone own the Adrian Streather book? Other than linking to Amazon [8|] what does is say on the subject?

 

[chfs911]

It says on no account fit 18" wheels unless the car was available from factory with them.

3.8RS
3.6Turbo

I know 3.6 RS had option as later Cups were raced with them. 8" and 9.5" Speedlines

 

[clubsport]

Good to see you chaps are gradually upgrading by fitting all the 993 parts to your cars. []

This has been a mod on early 993's for years as people have wanted to spoil the ride and handling of 16/17's and strive for more of a bling appearance for their cars.

It does make you wonder how neccessary it is on a 964RS though, especially when you consider cup cars raced on slicks and supercups had the 18" speedlines anyway with slicks......if it was that important wouldn't Porsche have fitted it as standard to the variants that were likely to go near a track?

 

[RSGulp]

Found this. The beefed up version for racing...

 

[Steve Brookes]

I think your findings could benefit most of us in the future because the way things are going with tyre manufacturers, we might all have to move to 18s in the future if we want to use track tyres e.g. the new Michelin super sport is only available in 18s and upwards [&o]

 

[964rsdatabase]

Rich, I fitted a set of 18" BBS split rims just before Oulton last year. Probably only done about 1k miles since though.

 

[RSGulp]

ORIGINAL: sapex666

Rich, I fitted a set of 18" BBS split rims just before Oulton last year. Probably only done about 1k miles since though.

We need pics!

 

[964rsdatabase]

Ha ha. Knew you were gonna say that!

 

[RSGulp]

Ah go on then...

 

[Tony]

Pretty sure - but don't quote me - this was used on at least some cup cars. It provides additional stiffening to the rack to counter the greater turning forces inposed by the greater weight and bigger footprint of 18" wheels/tyres.

When fitting this you need to put some heat into the bolts to break the loctite seal - new bolts should be pre-coated.

Tony

 

[RSGulp]

ORIGINAL: Tony

Pretty sure - but don't quote me - this was used on at least some cup cars. It provides additional stiffening to the rack to counter the greater turning forces inposed by the greater weight and bigger footprint of 18" wheels/tyres.

When fitting this you need to put some heat into the bolts to break the loctite seal - new bolts should be pre-coated.

Tony

As Tony says, new bolts from Porsche are pre-blue-coated. My old bolts came out just fine but others may have to crank up the blowtorch.