ESP Question....

[380SS]

I've asked this of Mike M., but I'll throw it out here for comments.



After pouring over the book, I think it would be easier to tell you what I have and let you tell me if it's legal or not.

I think I get bounced out of ESP for the following:

I have both upper and lower A-arms replaced. Although my upper A-arm is non-rod end, it's still different.

I also think if I add control arms (rodded) that would bounce me out of ESP.

Your thoughts?

[mannix]

Yup, illegal. SP does not allow control arm replacement, upper or lower. You can change bushings (non-metallic), add camber plates (not applicable on your car), make the bushings eccentric - but you can't change the arms, can't add spherical bearings in the front.

SP does allow some nifty stuff on live/solid rear axle cars, but the front arms are off limits.


Iain

[S Abshire]

Well actually there is a technicality in the SP rules that may allow control arm replacement. From section 15 of the rule book:


Cars listed as eligible in and prepared to the current national Street
Touring (ST) class rules are permitted to compete in their respective
Street Prepared classes, with the additional allowance that they
may use any tire which meets the requirements of 15.3 and fits on
the ST-legal wheels and within the ST-legal bodywork.


From the ST rules in section 14:


I. Camber kits, also known as camber compensators, may be
installed. These kits consist of either adjustable length arms or
arm mounts that provide a lateral adjustment to the effective
length of a control arm. Alignment outside the factory specifications
is allowed. The following restrictions apply:
1. On double/unequal arm (e.g. wishbone, multi-link) suspensions,
only the upper arms OR lower arms may be modified
or replaced, but not both. Non-integral longitudinal arms that
primarily control fore/aft wheel movement (e.g. trailing
arm(s) or link(s) of a multi-link suspension) may not be replaced,
changed, or modified.
2. On arm-and-strut (MacPherson/Chapman) suspensions, the
lower arms may be modified/replaced OR other methods of
camber adjustment as allowed by paragraphs 14.8.B, C, or G
may be used, but not both.
3. On swing or trailing arm suspensions, the main arms may not
be modified or replaced, but lateral locating links/arms may
be modified or replaced.
4. The replacement arms or mounts must attach to the original
standard mounting points. All bushings must meet the requirements
of 14.8.B. Intermediate mounting points (e.g.
shock/spring mounts) may not be moved or relocated on the
arm, except as incidental to the camber adjustment. The
knuckle/bearing housing/spindle assembly cannot be modified
or replaced.
Note: Many modern suspension designs known by other names,
actually function as double A-arm designs. These include the
rear suspensions on 88+ Honda Civic/Integra, Neon, E36
BMW, and most “multi-link” and are covered by 14.8.I.1.


If you try to take advantage of this rule, remember that you can only use one rule set, not mix and match. Example cats arent needed in SP but are mandatory in ST. So you could replace an upper OR lower arm (not both) and leave the cats on and run in ESP. You do need to make sure all your other modifications fit the ST class rules. I think your car would be STU so wheel width wouldnt be an issue (no limits).

[00 SS]

Exactly. The ST? allowance in SP will then allow EITHER the upper or lower fronts to be changed. You still have to comply with the bushing rules. There is no ST? or SP allowance for lower rear arms. Put your lower front arms back to stock and you should be legal.