Shock Upgrade Options

[kjbrew01]

I have a 1989 supra that I run in time trials class TTC (now will be TT5).

 

I haven't raced in the last 1.5 years however I am going through the car now to get it ready for next year. The car currently has 8 year old OEM replacement bilstein yellow shocks with 2.5" ID springs via a coilover conversion kit. I am looking at some options to get the shocks better matched to my springs

 

Front springs are 1250 lb/in, front motion ratio is 0.5:1 (Shock:wheel) ie wheel moves twice as much as shock

Rear springs are 550 lb/in, rear motion ratio is 1:1

 

Here are the options I have identified so far

 

Send OEM replacement bilsteins or Konis out for revalving. Cost 6-800

Pros: Easy swap, low cost

Cons: no gain in bump travel for front suspension, steel bodies are heavy. Cobbled together 2.5" spring setup/perches

 

Custom valved circle track shocks from Afco Cost 900-1200

Pros: threaded body with spherical mounts built in, lots of valving available, shock adjustment, aluminum body

Cons: likely twin tube construction, I am responsible for determining valving selection

 

Custom built MCS TT1 single adjust shocks Cost $3000 with mounts

Pros: proven brand in race shocks, shop setup valving, custom mounts provided with shocks, ability to upgrade to double adjust/reservoir as needed

Cons: High cost

 

Does anyone have any anecdotal experience with these various levels of shocks and what I could expect performance, lap time wise? I don't know if a MCS shock is worth 1-2 seconds over a OEM replacement style shock etc. I am considering going spec miata in a year or two so I am not sure tying up a lot of money in the MCS setup is worth it if the circle track or OEM revalves can get me some improvement.

[TurboShortBus]

IMO if the driver has been parked for a year and a half, then I would not recommend spending any money on the car, other than regular maintenance items; investing in seat time and consumables would be a better idea. Besides, if you might to go another car and class in a year or two, you will get pennies on the dollar then for any speed parts you buy now.

 

Mark