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.
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.
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.
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.
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.
It would be interesting to see which would improve the lap times. Slightly lighter wheels vs a wider contact patch.
I have done quite a bit of testing on this on my CAM Cobra and there is a high margin of diminishing returns on wheel weight, and a bell curve on contact patch. Let me expand on that. If you run an exaggeratedly heavy wheel, say a 35 pound steel wheel, and then a regular alloy of say 25 pounds, you will not only see a difference in the lap times, but actually physically feel the momentum difference. Dropping again to say a 20 pound wheel will net more improvement, but maybe only 35-40% of the previous as opposed to the expected 50%. Every pound more you take off (at increasingly higher expense) takes off less and less repeatable time. When it comes to diameter, there isn't really a strong correlation in just 1-2" steps. In other words, if you go from a 17" wheel and 24" tire to a 19" wheel and a 24" tire (thus no overall size difference, but a 1" shorter sidewall) you will gain about as much from the sidewall height reduction as you lost from the increased weight, but it might not even make a measurable difference (in autocross!).
Way way back in the day we experimented with 13", 14", 15" and 17" rims all with nearly identical height tires on my FB RX7 autocross car and saw a bell curve of grip. The 13's were slowest, the 14's went faster, the 15's went fastest, and the 17's went about like the 14's. That's when I started figuring out that tire width to rim width was an issue. All of the tires were 205 mm but the 13's were 6" wide, the 14's 6.5", the 15's were 7", and the 17's were 6.5". You want the closest to square wheel width to tire width cross section that you can get, erring on the side of wider wheels/narrower tires, assuming good suspension travel/camber gain. (With camber issues like my 086 S has, it's better to run a much wider wheel and narrower tire to try and counteract that force trying to push the sidewall over on the outside edge).
All of that is completely useless unless you have the grippiest compound possible though. I did a lot of testing on tire compounds and sizes last season. A 305 Nitto NT05 is slower than a 275 Falken Rt615K+ is slower than a 255 Bridgestone RE71R, all on the same wheel on the rear (so no camber issues) and they are all 200TW. Compound is everything in autocross, that's why the schizoid guys are buying pallets of tires, shaving, heat-cycling, and keeping temperatures in check with warmers and/or sprayers. Getting the grippiest compound to it's absolute traction sweetspot is the majority of the game and you have to be willing to do that if you want to e on the trophies end of the stick (but at least it's not Hoosier's anymore!).
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.
1973 Trans Am Championship Edition with a 360/727TF combo. I did a Grand Cherokee quick-ratio box on it, the biggest front factory sway bar, all graphite bushings, modern raised ball joints, and swapped the rear differential for an Explorer 8.8 with a 3.73 Track-Loc. I ran 17x9/17x10.5 wheels with Dunlops and it did well for the big old beast it was (which is terrible by any other standard).
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.
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.
Winter storm Maya meant that annual tech got postponed, so we changed the first event the car will be at, it will now be the ORSCCA AX #1 and #2 March 2nd and 3rd at PIR in Portland. More updates in the new episode:
Today was Annual Tech day for both the Oregon Region SCCA and PCA clubs, so I took the Boxster to both and passed both. It now has Annual Tech stickers for both clubs for the season, saving us time at every event to better spend preparing the car and ourselves for the runs.
I also got a really close look at the only other 986 S in the Northwest to run CS at the National Tour since it was moved into that class. Chuck is a long time Nationals participant and is an inspiration to this build. It was pretty cool to get up close and personal with his car.
I finally got the tires put on. Bridgestone Potenza RE71R in 235/40/18 F and 275/35/18 R. My new numbers and class letters also came in. I'm pretty well set for the first two autocross events, which are this Saturday and Sunday March 2nd and 3rd at Portland International Raceway in Portland, OR with the Oregon Region SCCA.
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