SPB Suspension Hardware Recommendations
10-20-2017, 07:35 PM
#1
Rennlist Member
Thread Starter
SPB Suspension Hardware Recommendations
I wasn't able to find a good thread discussing which of the legal Spec Boxster suspension components are strongly recommended and which are mildly helpful and/or better left stock.
The current rule set states:
I'm trying to figure out what the community has decided works well and what doesn't. Here's what I've gathered so far from reading up on forums and such. I'd like to ask the community to help correct and improve on my understanding. We don't have much of a local SPB community unless you count the next state over.
It sounds like most everyone uses the springs (usually Swift), GT3 LCAs all around, the GT3 FSB, and front drop links (Tarett EXTFDLNK?).
It sounds like a lot of folks prefer the stock rear swaybar so I'd assume the rear drop links are left stock as well.
Looking at the Tarett site, I've heard very little about the toe links, the locking plate, and the front shim kit. Are they necessary, nice to have, or do most prefer to stay stock on those components?
And do most prefer to have the softer 450# springs on the rear? (or maybe the opposite due to the GT3 front and stock rear sway bar?) Obviously they can be swapped end to end but I'd rather ask in advance so I am less likely to want to take off and reinstall parts.
The current rule set states:
Suspension/Wheels/Tires
A. Shock tower modification and strut braces are not allowed.
B. Camber plates are not allowed.
C. Except as otherwise allowed, all bushings must remain stock (e.g., no replacing the rubber in a bush with urethane or a spherical bearing). Porsche GT3 (street) adjustable A-arms are allowed.
D. Springs must be stock or can be changed to 450 lb. front and 500 lb. rear, or 500 lb. front and 450 lb. rear, but must be one of these three allowed configurations (i.e., you cannot run a square spring setup).
E. Bilstein PSS9 shocks, part #F4-GM5-8847-H0 or #48-181440 with stock valving are required. Shocks cannot be cockpit adjustable.
F. Sway bars, drop links and toe links may be stock or changed to the following:
- Front sway bar: Porsche street GT3, H&R 70779, or Engineering Tarett #996FSBK.
- Rear sway bar: H&R 71779 or Tarett Engineering #986RSBA
- Front drop links: modified stock (shortened for use with GT3 sway bar), Tarett Engineering #996FDLNK, or Tarett Engineering GT3 “long” links #EXTFDLNK
- Rear drop links: stock or Tarett Engineering #996RDLNK
- Rear toe links: stock or Tarett Engineering #996TLNKR, or any similar rear toe link as long as it does not alter suspension geometry beyond being longer and does not function differently than either of the other allowed toe links
G. Ride height minimum 90 mm front and rear as measured at front cross of aluminum cross member and front to rear braces near rear sway bar.
H. Any factory cast aluminum rims intended for a Boxster and matching the original offset are allowed; front wheels must be at least 18.5 lbs. and rear wheels at least 20 lbs. Rear wheels must be 17 x 8.5 inch, 48-50 mm offset. Front wheels may be either 17 x 7 inch, 55 mm offset, or the same size and offset as the rear wheels (17 x 8.5 inch, 48-50 mm offset)
I. Wheel spacers are allowed only for 17 x 8.5 inch front wheels for fender and fenderwell clearance.
J. Tires: Toyo RR front 235/40-17 or 255/40-17; rear 255/40-17. Toyo RA-1s may be used as rain tires.
K. Aftermarket locking plates may be used on all suspension adjustment eccentrics.
A. Shock tower modification and strut braces are not allowed.
B. Camber plates are not allowed.
C. Except as otherwise allowed, all bushings must remain stock (e.g., no replacing the rubber in a bush with urethane or a spherical bearing). Porsche GT3 (street) adjustable A-arms are allowed.
D. Springs must be stock or can be changed to 450 lb. front and 500 lb. rear, or 500 lb. front and 450 lb. rear, but must be one of these three allowed configurations (i.e., you cannot run a square spring setup).
E. Bilstein PSS9 shocks, part #F4-GM5-8847-H0 or #48-181440 with stock valving are required. Shocks cannot be cockpit adjustable.
F. Sway bars, drop links and toe links may be stock or changed to the following:
- Front sway bar: Porsche street GT3, H&R 70779, or Engineering Tarett #996FSBK.
- Rear sway bar: H&R 71779 or Tarett Engineering #986RSBA
- Front drop links: modified stock (shortened for use with GT3 sway bar), Tarett Engineering #996FDLNK, or Tarett Engineering GT3 “long” links #EXTFDLNK
- Rear drop links: stock or Tarett Engineering #996RDLNK
- Rear toe links: stock or Tarett Engineering #996TLNKR, or any similar rear toe link as long as it does not alter suspension geometry beyond being longer and does not function differently than either of the other allowed toe links
G. Ride height minimum 90 mm front and rear as measured at front cross of aluminum cross member and front to rear braces near rear sway bar.
H. Any factory cast aluminum rims intended for a Boxster and matching the original offset are allowed; front wheels must be at least 18.5 lbs. and rear wheels at least 20 lbs. Rear wheels must be 17 x 8.5 inch, 48-50 mm offset. Front wheels may be either 17 x 7 inch, 55 mm offset, or the same size and offset as the rear wheels (17 x 8.5 inch, 48-50 mm offset)
I. Wheel spacers are allowed only for 17 x 8.5 inch front wheels for fender and fenderwell clearance.
J. Tires: Toyo RR front 235/40-17 or 255/40-17; rear 255/40-17. Toyo RA-1s may be used as rain tires.
K. Aftermarket locking plates may be used on all suspension adjustment eccentrics.
It sounds like most everyone uses the springs (usually Swift), GT3 LCAs all around, the GT3 FSB, and front drop links (Tarett EXTFDLNK?).
It sounds like a lot of folks prefer the stock rear swaybar so I'd assume the rear drop links are left stock as well.
Looking at the Tarett site, I've heard very little about the toe links, the locking plate, and the front shim kit. Are they necessary, nice to have, or do most prefer to stay stock on those components?
And do most prefer to have the softer 450# springs on the rear? (or maybe the opposite due to the GT3 front and stock rear sway bar?) Obviously they can be swapped end to end but I'd rather ask in advance so I am less likely to want to take off and reinstall parts.
10-20-2017, 09:37 PM
#2
Rennlist Member
bump adjustment not allowed so forget toe link shims
front tie rods must remain stock
some people run 500f and 450r, depends on your taste, testing, sway bar setup, corner entry speed, etc
yes to lockout plates - cheap insurance
front tie rods must remain stock
some people run 500f and 450r, depends on your taste, testing, sway bar setup, corner entry speed, etc
yes to lockout plates - cheap insurance
10-20-2017, 10:34 PM
#3
Rennlist Member
Build another SPB and come race SPB. You know you want to.
10-23-2017, 07:32 PM
#4
Rennlist Member
10-24-2017, 07:55 AM
#6
Nordschleife Master
Get the extended front links, I didn't and am regretting it (although I bought used for a good price). There is too much angle in the short front links, causing them to bind, in fact, I broke one of the 10.9 bolts in half at the NOLA race. I will be replacing these soon.
I am running the tarett rear bar on the softest setting, I may test the standard bar in the near future.
I have not purchased the rear LCA's at this point, just didn't want to put the cash out at first. Even without, I have plenty of camber.
I have the rear toe links but not the locking plates.
I am running the tarett rear bar on the softest setting, I may test the standard bar in the near future.
I have not purchased the rear LCA's at this point, just didn't want to put the cash out at first. Even without, I have plenty of camber.
I have the rear toe links but not the locking plates.