911 Tarmac Rally Suspension

[Walko]

Okay i am in the process of building my 911ST which is to be used for three things
1) Tarmac Rallying (ie Targa Tasmania)
2) Historic Circuit Racing
3) Road Work

What I am trying to figure out is should I use needle bearing or nolathane type bushings.


Michael

[TRE Cup]

i would not use the needle bearings- they are not designed to take the pounding from rally use. Elephant Racing's polybronze bushings would work best. We have seen a number of cars with the plastic bushings breaking up too- so that is out for us as well.

[Walko]

Thanks for that info.
Is there any other modifictaions taht you would recommend whilst building the car taking into consideration that I can't run wider than 7" rims on all four corners.


Michael

[TRE Cup]

Since you asked.....
Make up weld in gussets for the following:
each corner of the engine compartment
the rear shock bridge
the rear sway bar mounts- make them so they act as skids to lift the car over obstacles rather than act as hooks
Jack mounting holes
Front upper strut mount areas
Front lower control arm areas (again the "skid" approach)
Make weld in plates to reinforce:
front sway bar mount area
rear torsion tube areas
Make protection plates for the gas tank area, oil tank, engine/trans- these can be aluminum and drilled here and there for mounting and lightness

Get a good cage installed that has at least 10 square inches of support on each plate (at least 1/8" thick)

Fabricate reinforcements from the rear shock mounts to hub carriers. Make cages for each lower shock mount so the shocks have support inner and outer. On the inner mounts of the control arms- weld in a reinforcement from the torsion tube to the chassis- you might think of double plating the vertical section behind the front seats to support this reinforcement

This will now give you a very strong base for your rally car- have fun!

[Walko]

Thanks for your input

I understand the gussets in the engine bay

But have some questions about the other areas
1 Jack mounting holes do you mean to weld them up or just brace them

2 Rear shock carriers I have no clue what you are getting at with this one.

Remember this is Tarmac rally not dirt.

Thanks

Michael

[spydr32000]

Michael, we have set up many cars for Targa, Classic Adelaide, East Coast Classic, Bulla Sprint etc. The best thing to do is call on 0395320246
Regards Mike

[Walko]

Thanks

I would like to undertake as much work on this particular project as possible myself. Just trying to get some ideas on what areas I should reinforce.

TRE suggestions seem to have hit the nail on the head. I just am unsure as to what they meant in some of the terms.


Michael

[spydr32000]

Michael, I am not looking for work out of this. We have plenty of that, but if you would like some advice or parts thats fine! Tre has some very sound advice. I would suggest reading the spots off the regulations before doing anything! I know the rules are not universal for many of these events so you need to find a compromise somewhere in the building of the car to best suit your events! Again if you need advice or parts please use the above number to contact us.

[TRE Cup]

spydr32000 brings up very good points regarding the rules. Check your sanctioning bodies to see how extensive you can go before getting the welder warm. The jack points are vulnerable areas in case of an "off". extra bracing can be welded to them so they are smooth and strong to potential obstacles. You will hopefully never need to jack up your car during an event, but you must be prepared to- so shutting them off is not what i meant.
The rear shock mounts- as originally installed, the bottom eye of the shock is held in place with a bolt and washer. As this is one of the lowest parts of the car, it would be best to have a encapsulating type of mount- so the lower shock eye slips in from the rear (the meat between two pieces of bread) , and then the bolt passes through the assembly. Now you would have the protection from hitting obstacles.
I understand that the Tasmania is a tarmac rally, but don't you travel through forests where mother nature can contribute to sometimes perilous roads?

[Walko]

Guys,

Thanks for your input it all becomes clear.

TRE I now undersatnd what you are saying about the jack mounts and lower shock bolts.

Spydr2003 thank you for your offer i will give you a call.

I have read the regulations for teh events I plan on doing and on my reading the main concern is the roll cage is not allowed to be welded through the front or rear fire wall. The rest of teh regulations seem to be pretty unspecific about strengthing areas that may get bottomed out going over dips etc.

I must also always take into consideration that this car will also be used for circuit racing so I want to be careful about adding to much weight back into the car.

Michael

[TRE Cup]

The total weight of the reinforcements and welding wire will come to no more than 15-20 pounds for the entire car- if that much. Time for the driver and navigator to go on a diet? (heh heh....)
have fun!

[Walko]

Thanks for that assitance.

I will take photos of the areas and the mocked up reinforcements and post them befor I weld to make sure that I dont get it wrong.

Michael

[TRE Cup]

happy to help out
db