Penske DA conversion to coilovers - who can do, and $$?

[JakeL]

Hey all -

Have been thinking about increasing the stiffness of the car, since I'm still having a tiny bit of rubbing problems with the shorter Penskes, and stock Z06 suspension pieces.

I've got a set of Hotchkiss bars on the way (T1's were just too stiff!), which I suspect will solve the problem.

However, I've been pondering playing with the spring rates a bit too, but the immense cost of the VB&P springs seems prohibitive.

I am curious as to what vendors might be able to take my existing Penske doubles and turn them into a complete coilover set, so I can use the $50/per hypercoils to toy with spring rates. Is this something Ankeny or Mallett can do? What kind of cost is involved, since I already have the shocks? (a significant portion of that cost, no doubt?)

Second, do any of you have hard data on what the Z06 spring rates are? If you were seeking to first duplicate the Z06 rates on a coilover setup, would you have those same numbers on the coils, or half that? i.e, if the Z06 front spring is 600#/in, would you buy 600# coils, or 300# coils? (since there are two of them, versus the one leaf spring?)

Cheers,

-Jake

[DJWorm]

Mallett, & Guy Ankeny are your best bet for the coil-over conversion along with the Penske factory of course.

LG Motorsports may also be able to help you with those also.

The spring rates will be different in that the coil overs are at an angle.
And to complicate things the front and rear are at different angles.

There is a formula to convert the actual coil spring rate to the net rate concerning the angle it's used at.

BTW I just sold mine and shipped them directly to Guy for rebuild/revalve and conversion to coil over and possibly an upgrade to Triple Adjustable for the new owner.

www.mallettcars.com
www.penskeshocks.com

www.lgmotorsports.com

Sorry I do not have Guy's link at the moment.

[truckrookie]

threaded shock bodies are about $75 a piece. Don't let them nail you cause it's a corvette.....www.bsrproducts.com or www.stockcarproducts.com. you can change them yourself if you aren't doing anything crazy with bleedholes or shimstacks, you just need to find somebody in your area to recharge them with nitrogen, which they need checked periodically anyway.

[No Doubt]

There is a formula to convert the actual coil spring rate to the net rate concerning the angle it's used at.

Dave Farmer came up with the following:

Measuring at the spring to a-arm point of a fiberglass leaf spring the ratios are as follows:

Front leaf spring X 0.73 = coil spring rate
Rear leaf spring X 0.875 = coil spring rate

With stock Z06 springs this works out to about a 475 lb. front coil and a 550 lb. rear coil.

The rear shocks are at a much greater angle and therefore the effective (installed) spring rate is less than the measured spring rate. Hence the greater measured spring rate of 550 in/lbs.

[DJWorm]

Penske DA's come with threaded shock bodies.

[No Doubt]

http://www.ankenyracing.com/

[mgarfias]

Sorry guys, shock/spring angle doesn't have as much to do with the rate, as where the shocks/springs mount to the a-arm.

The shock angle makes the springs progressive (get stiffer as they compress).