Roostie

My friend has an '86 944 that she autocrosses with the local PCA, which is quite active. Her street tire class for this car has a lot of competition and is fun. She is allowed to use non-adjustable aftermarket shocks, so I think she should use Bilstein HD's. The dilemma is that she has a choice of getting sway bars OR springs, but she cannot get both and stay in her class. Does anybody have an informed opinion about whether springs or bars would be better for *this car*?

If so, what brand of spring or bar do you recommend?

Thanks!


P.S. Also, just to mention, on her OEM 15x7 wheel, I am recommending that she use a BFG g-Force KD in size 225/50/15. Tires in her class must have a treadwear rating of 140 or above.

mroberts

A couple of options:

1) Replace the stock springs with higher rated ones from a different model - they will go in the stock location, and may be allowed by the updated / backdate rules. Even if they aren't, who's going to notice

2) What is she trying to change with the shocks or springs ? Dive / squat / roll / understeer / oversteer ?

Springs will reduce roll somewhat, but also reduce dive / squat and generally stiffen the car or let you vary stiffness between the ends.

Sway bars will reduce body roll more than springs, but have no effect on dive / squat.

Roostie

Well, she is trying to fix the fact that the car is floppy and doesn't go around an autocross course very fast. :-) The better tires and the Bilstein shocks will help that a lot. To answer your question, the real point of my inquiry is which parts will lower her autocross times more: bars or springs? And which brand to buy.

Update/backdate is a good idea, but this being a stock street tire class, the point of the class is to reduce what can be done to the car so that participants don't *have* to do a lot in order to field a competitive car. Thus, while I need to review the rules to confirm it, I suspect that update/backdate of springs is not allowed. As for people not noticing it even if it isn't legal, probably true, but my friend would know and it wouldn't sit well with her sense of sportsmanship.

tifosiman

That's the kind of talk I like to hear. I hate it when people try to get away with mods that they should not have in a certain class. Kudos to you and her.

This answer is simple. If you are only allowed springs or sways, go for sways. If you change springs, you can only do the front anyway (as the rears are torsion bars). Adding more spring rate to the front will only exxagerate the already built-in understeer that the car has. Go for a 28mm front sway, and a 968 M030 19mm adjustable rear sway. You can play with the settings of the rear to steer in a little or less oversteer.

What sanctioning body has such rules? It's not SCCA or PCA.

EDIT: I see you stated PCA. You and your friend need to read the latest Parade Rules for Autocross 2005 on the main PCA site. They have changed the classes for this year. She is allowed more modifications than you think, and will still be in stock class.

Roostie

The rules in this case are local... PCA San Diego (Zone 8). A local set of rules and a point system applies. In street stock, the cars are only allowed 2 points, so little can be done to the cars. Non-adjustable shock absorbers are allowed (0 points), and only tires w/ treadwear of 140 or above are allowed (but 140 to 200 is 1 point). Springs and sway bars are each two points so you have to pick one. "Springs" allows changing the front springs and the rear torsion bars.

tifosiman

Ah, I see. Local rules eh?

Well, then I would still do sways. And, if the rules allow, dial in a little more negative camber, say around -1.5 to -2 degrees in the front, around -1 or so in the rear. Play around with the three holes on the rear M030 sway to get it to where she likes it. Start in the middle hole and see if it needs to be stiffer or looser.

Good luck!

jim944s2

like tifosiman said; how's your alignment? A good auto-x alignment will do wonders for the 944.

Geo

I'm with Tifo. Swaybars. Autocross is all cut and thrust and swaybars will speed up the load transfer and really help transitions a lot. And since autocross is ALL about transitions it makes the choice simple.

You can certainly speed up the load transfer with springs as well, but to get the same effect would require much much stiffer springs and t-bars.

Dano_944

Rootsie:

For the PCA-San Diego Region, you can use any parts off a 944-series car and still be legal in SS class. Thus, springs/torsion bars off an '87, '88, '89 are okay on an '86 and may be slightly stiffer. Same is true for sway bars. If her stock OEM 16mm/24mm sway bars are replaced by a stock OEM 18mm/25.5mm swaybars, it's okay since it is a standard part in the car manufacture-series. You cannot use 944S, 944Turbo, or MO30 parts, as they are either a different 'series' make (944S, S2, Turbo) or they are not 40% or more available equipped vehicles off the showroom floor, as originally purchased (MO30 package).

I was last year's A-X Chair, and current VP for the region. Drop me an email for more info. I'll be happy to help. ;-)