Tarmac Rally Suspension Setup ?

[gtr777]

Hi There,

Just wanting info on Tarmac Rally suspension setups ?

R32/33/34 Coilover types and spring rates, sway bars and wheel alignment spec's would be great !

Really interested in seeing what evetyone is running at Tarmac Rally events.

Thanks for your help.

Regards

[black_gtst]

im also interested to know info on 33's set up for tarmac........... especially spring rates

[Duncan]

I'm no help - I run some crappy $1k jap coilovers.

How much do you have to spend? if its 10k, go the proper ohlins

[gtr777]

Hi there,

I think it would be interesting to know the range of what everyone is running.

There are alway many different ways doing something (and $ amounts)

Ohlins are great and highly regarded, would an average driver be faster / safer with $2000 or $10,000 worth of suspension under them ?

I realise that there is competitive angle to this..... that is maybe some Tarmac guys may not want to share specific info on there setup ?

Thanks again.

[Sydneykid]

Not an easy question to answer, some tarmac events run to different regulations than others. For example some allow swaybar upgrades some don't and that alone makes a massive difference to the spring and damper rates. Not to mention wheel alignment adjustment methods, bush changes, aftermarket control arms etc etc. So you ned to be more specific in the events you are planning on running and the allowables under their regulations.

Cheers

Gary

[gtr777]

Under the National Tarmac Rally Regulations ?

[Sydneykid]

If only it were that easy;

3.1 Eligibility

Each automobile shall comply with the Tarmac Rally Technical Regulations (TRTR) and/or the Historic and Classic (Gravel) Rally Car regulations.

Subject to the approval of ARCom, Supplementary Regulations may allow automobiles not complying with these requirements.

ARCom may regulate automobile performance by nominating the classes/categories which are eligible for an event.

This means an event organiser can let cars run with any mods they choose.

3.6 S Summary of modification levels

M1

This allows a very limited freedom of modification to make automobiles more suited to rally competition. Automobiles having a 0-60mph acceleration time from a standing start of between 3.5-4.8 seconds in standard form are restricted to level M1 modifications.

M2

This allows a limited freedom of modification which allows increased performance and greater suitability for rally competition. Automobiles having a 0-60mph acceleration time from a standing start of 4.8- 6.8 seconds in standard form are permitted Level M1 or M2 modifications.

M3

This allows a considerable freedom of modification which allows significantly increased performance and greater suitability for rally competition. Automobiles having a 0-60mph acceleration time from a standing start of greater than 6.8 seconds in standard form are permitted Level M1, M2 or M3 modifications.

M4

FIA Group N and CAMS Group N(P). or CAMS PRC* automobiles eligible for and modified to the regulations outlined in the CAMS Manual of Motor Sport or the FIA web site as appropriate.

M5

This category is provided for automobiles that are powered by alternative energies such as electric or other hybrid automobiles as approved by ARCom and/or CAMS and subject to acceptance of entry by event organisers.

Your choices would seem to be M2 or M4 unless you are running it on ethanol etc then M5 might be attractive.

So I assume M2, let me know if otherwise

4. Suspension

4.1 Spring seats: The spring seats may be made adjustable.

For MacPherson strut suspensions, the shape and material of the spring seats is free. It is permitted to add or incorporate a threaded sleeve to the exterior of the strut for the purpose of allowing adjustment of the height of the spring seat.

4.2 Coil and leaf springs: Provided the type and number is the original, springs are free.

4.3 Torsion bars: The diameter and their mounting spline is free.

4.4 Dampers: Dampers are free, provided that their number, their type (eg, telescopic), their working principle (eg, hydraulic, mixed etc.), and their attachment points remain unchanged. The damper tanks may be separate and may be attached to the shell of the automobile, providing this does not entail modification, other than the drilling of the minimum number of holes for mounting. Notwithstanding, for MacPherson strut suspensions which are integral with the stub axle/steering arms, then the original outer housing must be retained. The damping mechanism is free.

An elastomeric bush mounting the damper may be replaced by a “uniball” joint, but only on the condition that the damper has no guiding function (for example as in a MacPherson strut).

4.5 The reinforcing of the suspension and its anchorage points by the addition of material is allowed, provided it follows the original shape and is in contact with it.

4.6 Anti-roll bars and attachments are free; save that they may not be adjustable from the crew compartment. Automobiles fitted with existing cockpit adjustable sway bars shall have either the adjustment system sealed or the actuating rods removed.

4.7 In the case of oil-pneumatic suspensions, the spheres may be changed in regard to their dimensions, shape and material, but not the number. A tap, adjustable from outside the automobile, may be fitted to the spheres.

6.2 F Fasteners

Throughout the automobile, any nut, bolt, screw may be replaced by any other nut, any other bolt, any other screw and have any kind of locking device (washer, lock nut etc.).

(ii) Suspension:

(a) Elastomeric bushes: alternate ‘option’ bushes, also elastomeric in nature but which may be of different hardness.

So that means to me;

1. Adjustable swaybars would be a must

2. Decent remote cannister shocks double adjustable, MSA (nee Proflex) would be the most economical at around $9K with Eibach springs. If the budget stretches, then Ohlins (from Sweden, not Yamahas from Japan) at around $11K, or Penskes at $12K. I would stay away from triple or more, adjustable shocks, they can be too consuming to set up if you have limited experience.

3. Adjustable polyurethane bushes for caster and camber, front and rear. You would want them to be externally adjustable in case you need to make some repairs to the geometry after an off.

Some things for you to think about.

Cheers

Gary

[t01-100]

pm me and i'll give you some detail on what i ran in my gtr and what set up i've put in r32 and r33 gtr for targa tasmania, rally tasmania and rallye burnie.

i'm also the technical manager for one of these events so can steer you right on regulations.