Spec Boxster build @ ATLspeedwerks - 986 Forum - The Community for Porsche Boxster & Cayman Owners

toddlamb · 11-17-2015, 06:03 AM

Just picked up a Boxster donor (no key) and looking forward to getting into some PCA racing. Spec classes are great - I spend a lot of time in the Spec Miata crowd. Hoping to see the class continue to grow. We'll do our part here in the SE.

Some pics from yesterday, pulling apart the interior but leaving everything else intact until this afternoon when I get the key from Porsche and get it programmed into the immobilizer:

toddlamb · 11-18-2015, 04:44 AM

Spec Boxster: More teardown and we got the key programmed at Porsche to finally be able to start the car. Engine fired immediately and runs well. Transmission seems good too. It appears we have a solid donor!

RedTele58 · 11-18-2015, 06:53 AM

Cool!

Keep the pictures and information coming!

thstone · 11-24-2015, 05:02 PM

Keep us updated!

spacearchitects · 11-25-2015, 04:55 AM

subscribed. looking forward to updates

toddlamb · 01-27-2016, 11:17 AM

UPDATE

We've been extremely busy with the Spec Miata side of the business. Just got back from Sebring where we did live streaming in-car. It wasn't ideal but it's a start. You can see the replay from both races here (sat race 3rd/65, sun race 2nd/65):
Toddspeed on USTREAM: .

For SPB, we actually have 3 donors in-house right now, and we decided to build up a black car instead of the white one we stripped, as we have a customer interested in a white car after ours is done. We obtained a factory hard top and a couple of fiberglass hard tops for fitment. Right now we're in the process of designing our own cage, as we have a lot of experience doing cages for other cars and feel like we can build a better mousetrap.

So having said that, sadly we've had to back out of Sebring and expect to get the SPB done for PCA at our home track of Road Atlanta.

Here's a few pics as the floor plates are installed and the cage is tacked into place.

thstone · 01-27-2016, 12:26 PM

I would suggest use of the aftermarket fiberglass top. The factory hard top weights a lot and puts the weight in the wrong place (up high).

What type/size tubing are being used for the roll cage?

toddlamb · 01-27-2016, 01:38 PM

Yes we plan to use the fiberglass top, but we are designing the cage to be used for either top. Although I've heard once the factory top is prepped it's actually the same or lighter than the fiberglass top when you include the window/hardware.

1-1/2" .095 for the majority of the cage. We're waffling on what exactly to do since SCCA would theoretically require 1-3/4" in T4 (we are working on getting the SPB classed in T4 for Majors). And also for PCA the car weight is right at the limit for bigger tubing, but we were unable to get any definitive answer from the PCA tech gurus.

Greg Holmberg · 01-27-2016, 05:38 PM

I personally chose 1.75 x 0.095 DOM MIG-welded for my Spec Boxster after consulting with Josh Lucas of Lucas Fab in Huntington Beach, who built my cage.

A spec Boxster with driver minimum weight is 2650 lbs. I weigh 180, so car minimum is 2470 lbs without driver.

PCA says for a car without driver, under 2500 lbs. requires 1.50 x 0.095 in mild steel. Given that the Boxster is only 30 lbs under that, I think it's prudent to step up to the next level. For over 2500 lbs, the PCA says 1.75 x 0.095 or 1.50 x 0.120 in mild steel.

NASA has exactly the same rules for mild steel. They're different from the PCA for 4130, but my builder does not recommend 4130 because it's more brittle (gives suddenly), even though it's stronger in the same sizes.

The SCCA says for a car of "GCR Vehicle Weight" (with driver, I think), under 2700 lbs, 1.5 x 0.095 or 1.625 x 0.080 mild steel is required. Again, since a Spec Boxster is only 50 lbs under this, I would go up to the next level, which for the SCCA is 1.50 x 0.120 or 1.75 x 0.095 or 2.0 x 0.080.

So, in summary, with all three organizations, you can technically get away with 1.5 x 0.095 mild steel, but I think 1.50 x 0.120 or 1.75 x 0.095 would be smart, since the Boxster is right on the edge of the limits.

Save weight somewhere else. You can still get to 2650 with driver.

I also had the FIA vertical bar added, after seeing how the front of a cage collapsed in a Spec Boxster roll-over accident at Willow Springs a few years ago.

In addition, I had a knee bar added and bars forward to the front shock towers.

Hope this helps,

Greg

toddlamb · 01-28-2016, 05:06 AM

Yep that's pretty much what we found too, except in SCCA T4 we expect to have weight added and a restrictor, so it would push it into the 1-3/4" category.

Having said that, for SPB 1-1/2" is more than plenty for the weight of the car, based on 15+ years of hundreds of Spec Miatas racing at 2350-2450# with 1-1/2" .095 resulting in zero tubing failures, and that's with only 8 allowed attachment points.

thstone · 01-28-2016, 08:08 PM

Quote:

Originally Posted by Greg Holmberg

I personally chose 1.75 x 0.095 DOM MIG-welded for my Spec Boxster after consulting with Josh Lucas of Lucas Fab in Huntington Beach, who built my cage.

Josh also built my cage from the same materials with the FIA bar for added windscreen frame support.

There is no way that I would get into a race car with any less protection. We've seen what can happen...

toddlamb · 03-04-2016, 10:23 AM

Working away getting this car done for Road Atlanta.

Wiring harness is out for redux.

Cage is done and headed to paint.

toddlamb · 03-06-2016, 06:34 PM

24 days until Road Atlanta.

Finished up the cage in our shop on Friday, then sent the car out for interior paint over the weekend.

Assembly begins tomorrow, with lots of goodies from AIM, TuneRS, Pelican, and Tarett.

toddlamb · 03-10-2016, 05:13 AM

21 days to Road Atlanta.

Engine ready to reinstall after bolt-on upgrades.

Front of car disassembled, radiators being cleaned.

Unboxed a bunch of parts, it's like Christmas (the most expensive Christmas)!