renvagn

Those of you running 951's what type of spring rates on the rear are you using. I still have my torsion bar with turbo cup springs, but am thinking of raising the rates front and rear. The car is essentialy stock weight @ 3,000.
I am hearing rates in the range of 275-350. I have been told a tender spring is a nice additon compared to the helper springs.

Question, Is the overall spring rating a combination of the tender spring and the linear spring rate. I am guesing this is not an exact rate do to spring differences, but close. This may be why with the tender spring option it was suggested a 250 or 275 spring on the back. So a 250 with a 90 tender = @ 340 lb. ????????

993944S2

You need to spell out how you will use the car. Street, street/track, track, full race?

shiners780

Tenders don't quite work that way. As I understand it, using a tender yields somewhat of a progressive overall spring rate. As the suspension goes into bump, the tender spring compresses first (if it's already not fully compressed at static ride height) due to it's lower rate, then the main spring compresses.

renvagn

Don, Closer to full race.

Russ Murphy

Here you go: 944 Spring rates
Your current setup is 3rd from the top.

Thanks to DanD

Oddjob

You currently have the Turbo Cup springs, front and rear helpers, in conjuction with t-bars?

For a track/race car, stock weight, I think I would stay away from the tender/progressive setup. May cause more complications than you want. Just go with straight linear springs front and rear.

If you want something stiffer than Turbo Cup, dont go any softer than 600 lb/in in front. Any less and it wont be a significant upgrade (the cup springs are around 400 front). You will have to proportionally balance the rear spring rate with the front rate, depending on the existing t-bars, swaybars, tire sizes, alignment, driving style, etc.

And if you do go much stiffer, make sure your shocks are valved for the higher spring rates.

renvagn

Coil Spring Rates
Front Front Rear Rear Front/
Coil Wheel Wheel Coil Rear
Rate Rate Rate Rate Differential
Stock setups
924 120 108 54 19 50%
944 140 126 126 23.5 100%
951 160 144 126 23.5 88%
M030 175 158 175 25.5 111%
I am not sure i an interpreting the chart correctly. From this chart having the cup set up and the differental rate being 91% Do I want to maintain the percentage to maintatin the balance of the car?

Oddjob

Chart indicates 30mm rear t-bars for the "Cup" entry, which is incorrect. Spring rates for the 944, 951 and M030 are also not correct, so probably not the best to try to determine a balance comparison from that.