Building a 986 S for SCCA CS Autocross for National competition

[SCCA_AX]

Chiming in because I've wanted to do this for a while. Are you on the standard suspension or the M030? I have all the US M030 part numbers saved somewhere if you need them.

Can you get to the adjusters on all 4 Konis while installed?

How's the gearing? I think my biggest concern with the 986 (or Porsches in general) is 2nd gear digs.

I think things got a lot tougher with the 2019 ND2, but still a fun project. STR 986S or 987 base is also on my list of things I'd like to try.

I too think I would try 17" 245s square first, but that's pure speculation.

[phook]

Originally Posted by SCCA_AX

Chiming in because I've wanted to do this for a while. Are you on the standard suspension or the M030? I have all the US M030 part numbers saved somewhere if you need them.

Can you get to the adjusters on all 4 Konis while installed?

How's the gearing? I think my biggest concern with the 986 (or Porsches in general) is 2nd gear digs.

I think things got a lot tougher with the 2019 ND2, but still a fun project. STR 986S or 987 base is also on my list of things I'd like to try.

I too think I would try 17" 245s square first, but that's pure speculation.

Do you have the part number for the US m030 springs? Are those even still available for sale? I've only found ROW at suncoast.

[SCCA_AX]

Originally Posted by phook

Do you have the part number for the US m030 springs? Are those even still available for sale? I've only found ROW at suncoast.

Here's a dump of my notes, which appear to be incomplete unfortunately.

Rear bars:
18.7mm
19.2mm
19.8 - P101966 - 98633370120 - STABILISER 19.8 MM

M 030 US Springs:
REAR 98633353140504 Identification Orange Brown
98633353140504 (03+) / 98633353132504 (00-02)
FRONT 98634353116504 Identification Yellow White

For a MY00 Boxster S 6 speed:
Front US M030 springs - red/white
Rear US M030 springs - violet/yellow

For M030 03+,
ROW has red/yellow front and silver/red rear
USA has yellow/white front and orange/brown rear

All that data is copied / pasta'd from forum searches, so double check. I'd bet people on this forum actually could correct any errors on this.

I appear to be missing the p/n for the red/white springs, which is M030 front 00-03.
Of course you'd have to get all 4 correct springs and one of the swaybars to be legal.

Not sure if it's worth all the effort, but if you put some of those part numbers into Google you might hit a website that's selling the springs you'd need for $150/pair used. New is about double that.

[phook]

Originally Posted by SCCA_AX

Here's a dump of my notes, which appear to be incomplete unfortunately.



All that data is copied / pasta'd from forum searches, so double check. I'd bet people on this forum actually could correct any errors on this.

I appear to be missing the p/n for the red/white springs, which is M030 front 00-03.
Of course you'd have to get all 4 correct springs and one of the swaybars to be legal.

Not sure if it's worth all the effort, but if you put some of those part numbers into Google you might hit a website that's selling the springs you'd need for $150/pair used. New is about double that.

Do you think this would be that part number?

[phook]

Originally Posted by SCCA_AX

Here's a dump of my notes, which appear to be incomplete unfortunately.



All that data is copied / pasta'd from forum searches, so double check. I'd bet people on this forum actually could correct any errors on this.

I appear to be missing the p/n for the red/white springs, which is M030 front 00-03.
Of course you'd have to get all 4 correct springs and one of the swaybars to be legal.

Not sure if it's worth all the effort, but if you put some of those part numbers into Google you might hit a website that's selling the springs you'd need for $150/pair used. New is about double that.

Do you think this would be that part number?

https://www.****************************.com/products/porsche-coil-spring-front-boxster-por-98634353116504

[Javelin]

Originally Posted by SCCA_AX

Chiming in because I've wanted to do this for a while. Are you on the standard suspension or the M030? I have all the US M030 part numbers saved somewhere if you need them.

Can you get to the adjusters on all 4 Konis while installed?

How's the gearing? I think my biggest concern with the 986 (or Porsches in general) is 2nd gear digs.

I think things got a lot tougher with the 2019 ND2, but still a fun project. STR 986S or 987 base is also on my list of things I'd like to try.

I too think I would try 17" 245s square first, but that's pure speculation.

Standard. I can't get a complete breakdown on Porsche letterhead of the M030 package and my car doesn't have it equipped already, so it's not worth risking right now. I can change the struts and one sway bar anyway, so it's basically just the springs and other swaybar if I ever do get my hands on the info.

Gearing is super favorable for Nationals-levels courses. Second fuel cuts at a GPS and data-logged verified 73 MPH, which is higher than the 67ish of the ND, and the 986 S makes more torque and from a lower RPM than the ND so grunt out of the hole should not be an issue. I'm going to dyno the car after finalizing the new exhaust to get good torque vrs RPM graphs to estimate acceleration G's.

I am running the staggered 18's and tires, I am theorizing that absolute peak grip is going to be more important than the superior transitioning of the square setup. I ran square setups on the RX7, Miata, 944, and 914 and staggered on the P71, Javelin, and Cobra, so I have experience with both.

[SCCA_AX]

Originally Posted by Javelin

Standard. I can't get a complete breakdown on Porsche letterhead of the M030 package and my car doesn't have it equipped already, so it's not worth risking right now. I can change the struts and one sway bar anyway, so it's basically just the springs and other swaybar if I ever do get my hands on the info.

Gearing is super favorable for Nationals-levels courses. Second fuel cuts at a GPS and data-logged verified 73 MPH, which is higher than the 67ish of the ND, and the 986 S makes more torque and from a lower RPM than the ND so grunt out of the hole should not be an issue. I'm going to dyno the car after finalizing the new exhaust to get good torque vrs RPM graphs to estimate acceleration G's.

I am running the staggered 18's and tires, I am theorizing that absolute peak grip is going to be more important than the superior transitioning of the square setup. I ran square setups on the RX7, Miata, 944, and 914 and staggered on the P71, Javelin, and Cobra, so I have experience with both.

Cool stuff. I agree that the M030 likely isn't worth the cost and effort at this point since you've already swapped the shocks. If you end up consistently within a tenth or two of the top NDs, then maybe it's worth tearing back in there.

According to thrust charts, I have the ND1 out-accelerating the 986S in 2nd up until about 50mph. I haven't run a chart on an ND2, but I'd wager it pulls on the 986 in 2nd all the way to 60. The 986 does have a tall 1st though, so any time you can use 1st you'll have an advantage over them. I doubt either car runs into issues putting their power down very often.

I waded into that GRM thread a bit, and looks like you have all of the mis-information covered already, but just to note anyone else wandering into this thread that:

- ROW M030 is not CS legal
- 18x7.5/18x9 are the widest legal factory wheel, which means you can run 17s or 19s in those widths as well

I've never driven a 986S but from what I hear you'll want to do everything possible to get more front grip. On a top-tier build I would consider experimenting with front bumpstops. They're open in street as long as they don't engage any sooner than the factory ones. That means you can shorten the long OEM ones, which would have the effect of softening the front end in most situations.

Good luck and I'll enjoy following this thread. Hell maybe I'll see you in Lincoln in CS.

[Javelin]

Originally Posted by SCCA_AX

Cool stuff. I agree that the M030 likely isn't worth the cost and effort at this point since you've already swapped the shocks. If you end up consistently within a tenth or two of the top NDs, then maybe it's worth tearing back in there.

According to thrust charts, I have the ND1 out-accelerating the 986S in 2nd up until about 50mph. I haven't run a chart on an ND2, but I'd wager it pulls on the 986 in 2nd all the way to 60. The 986 does have a tall 1st though, so any time you can use 1st you'll have an advantage over them. I doubt either car runs into issues putting their power down very often.

I waded into that GRM thread a bit, and looks like you have all of the mis-information covered already, but just to note anyone else wandering into this thread that:

- ROW M030 is not CS legal
- 18x7.5/18x9 are the widest legal factory wheel, which means you can run 17s or 19s in those widths as well

I've never driven a 986S but from what I hear you'll want to do everything possible to get more front grip. On a top-tier build I would consider experimenting with front bumpstops. They're open in street as long as they don't engage any sooner than the factory ones. That means you can shorten the long OEM ones, which would have the effect of softening the front end in most situations.

Good luck and I'll enjoy following this thread. Hell maybe I'll see you in Lincoln in CS.

Yeah, if I actually start getting close to the top of the field, I'll look a lot closer at the US M030 setup, especially for the springs and other swaybar. Shortening the front bumpstops is also a more advanced tweak that is an option as we go on.

Next step is the tires, then the swaybar. We are still on basics now.

[SCCA_AX]

Good luck, have fun!