Re-designing & improving structural integrity of roll cage originally built in 2000. Cross-bracing is 1 & 5/8″ x .095 chrome moly. Notice “major” 1 & 3/4″ bar at lower tub, thru tunnel, & how it features a curved intersection at lower chrome-moly “foot-plate”, which is epoxied & Cherry-rivited to tub (lower-left of pic).

 Cross-bracing in top of cage–trial-fit before weld-up.

 ”Earnhardt bar”—at center of windshield. Notice duct tape represents plane of glass, to ensure adequate clearance.

 Main cross-bar features welded-in “spuds” for shoulder harness attachment. All cross-bracing welded-up. Notice how lower-main bar incorporate welded-on seat rail / seat belt attachment points (lower-center of pic), which index exactly over OEM anchor-holes in tub.

 This shot shows hole in firewall in “first-draft”—eventually would be cut much larger to facilitate custom firewall that also houses twin fuel cells.

Detail of how windshield center-bar attaches to OEM under dash support tubing, as well as front heater-defrost chamber (which is stamped aluminum, but fairly stout because of its triangular cross-section).

 Upper cross-bracing after weld-up.

 View from rear, looking down into engine bay. “Spuds” for sholder-belt attachment (in main cross-bar) are readily visible here, as are the R. & L. fuel cell filler tubes, which are the bright 3″ curved aluminum tubing at upper R. & L. sides of pic.

 Driver’s-side down-tube, & its “foot-plate” which is epoxied & Cherry-rivited to frame rail.

Rear downtubes of cage attachment to frame (note also OEM suspension casting moved aft 2 inches)

Entire cage is epoxied (with 4000 lb./ sq. in. epoxy) & Cherry riveted (using 2000 lb. tensile steel Cherry rivets) at 10 points! (3 of which are visible in this pic). Notice rectangular chrome-moly tubing (1″ x 2″ x .125″) spanning door sills, & front “down-tube” (center of pic). These provide additional protection from side-impact, & they serve as a plane that will be the “back-up” for carbon fiber & Kevlar “crush-boxes” to attach to. This is the newest science in driver protection, as the CFK crush-boxes are designed to absorb impact, whereas the “old-school” 3-bar, in-the-door Nascar bars were extremely rigid, & didnt absorb nada!

 Front “firewall” cage bar (1.25″ x .095″) basically strengthens tub where main front frame rails tie into it, & also improves torsional rigidity!

 Tilton “3-master cylinder” bracket is visible just above the universal joint (OEM rack & pinion still in car at this point) that is poking up thru driver’s footwell. You can also see how down-tube intersects & welds to OEM “dash-support” cross tube. (see also in next pic)

 Good shot of multi-faceted, welded-together footplate, formed over the “corner” of passenger-side front wheel well (one of the structurally stiffest points in tub). Also visible thru the “oval” hole in firewall are the fullcrum tabs for right-front shock-rocker.

 Moi, trial-fitting custom hand-formed tube, which will weld to firewall, & provide “tunnel” for front radiator hose to be routed to water pump on LS7. Also visible is “dimple-die’d” aluminum plate which bolts to top of main-hoop of cage, &  is welded to inside roof of driver’s compartment—extra stiffening results.

 This shot reveals section of NSX partition between the driver’s compartment & engine bay already removed to facilitate special firewall “roof”—which allows for CF plenum to nest between intake manifold (Harrop rear-inlet supercharger) & rear hatch “glass” (Lexan). Diagonal brace-tubes are already welded to rear down-tubes & top of “main” bar, as well.

 View from engine bay, looking into tunnel, shows lower-main roll bar where it passes thru tunnel. Note the .090″ moly “collars” have been “hammer-formed” to tub contour, in preparation for epoxy & rivets.

 Final fit—will also weld to 1 & 3/4″ x .095″ moly tubing.

 Trick cage-vertical is hand-formed .090″ moly plate with 90 degree breaks & dimple died holes, and is being trial-fit, for eventual weld-up (after cage & firewall are painted).

 Final clearancing by hand—for closest tolerance fit.

 Removing part of the “dimple” from backside, to clear special “radiator hose tunnel” that protrudes from front of fierwall just behind this moly cage-vertical.

 ”Horseshoe” is 3/8″ aluminum, & welds to tub, & bolts to moly cage-vertical—helps tie the aluminum tub to the steel cage at tunnel.

“Horseshoe” fits to thickest area of tub-tunnel—trial fit before welding.

 10-32 stainless buttonheads will secure the 2 parts after both are welded in car.

 With “horseshoe bolted to cage-vertical, assy is positioned so horseshoe can be tacked to tub from rear—all to make sure the 2 pieces are in perfect alignment with each other in final assembly.

Hand formed moly cage-vertical ties lower tub & main bar to cross brace (keeps engine out of drivers compartment too!) Wont get welded in until after firewall is painted, installed, & welded into car! (there’s a reason for this sequence!)

 Better perspective shows “horseshoe” during final weld-up. Note also cage is already primered at this stage.

Shaking the sweat outta my glasses while dressing the Moly for paint with a cup brush (Arizona, you know!).

Over 250 hrs in cage prep & paint! Note tabs welded to “Earnhardt bar” to facilitate aluminum windshield support at center. Also visible in this pic are the “dimple-die’d” aluminum plates that bolt to front downtubes of cage, & weld to inside edge of “A-pillars”–again, extra stiffening is the result.

 Just shot entire cage with House of Color Urethane “shimmerin-base” black primer. The gloss will be knocked off with Scotchbrite before color is applied.

Yes, I am a do-it-yourselfer (engine crossmember & cage piece are chromemoly). I didn’t know much about automotive paints, or even how to achieve professional results when I started, but thanks to the gurus at SpaceAge Auto Paint (Mesa, AZ) I got excellent technical support & advice—I must say, even I was amazed how nice things turned out!  (note CRG shifter kart in background–sorta my “cardio”–if I put it back together).

 ”Kandy” colors require a lot of focus–especially during hot weather! Color is House of Color “Kandy Oriental Blue”.

 Cage was painted before firewall was inserted into position—only way to get the backside of main & cross-brace bars painted! You can see a perimiter of un-painted firewall, literally everywhere the firewall will weld to tub. Also note firewall has no paint where 3″ aluminum fuel-filler tubes intersect it—again for clean weld-up. Long “paper clip-shaped” hole in center of firewall (& tub tunnel) is where hand-formed aluminum tube will be welded (about 18 pictures back) after it is painted. Also visible is latest high-tech racing indoor-outdoor carpet! (I already had the entire inside of tub clean & prepped for paint, & didn’t want to mess it up while painting cage).

The entire firewall was TIG welded into the car in a “slow-as-you-go” manner, with cooling periods in between “stitching”–to keep firewall from “walking” (expanding too much), or warping—even managed to not burn any of the paint off the “pretty side” (inside driver’s compartment)!!! Now that’s Art!

 Cool shot of welding firewall into car—all from engine bay side for appearance-sake!

Firewall is .060″ 6061 aluminum—which is slightly thicker than the OEM bulkhead it is being welded to, which is about .050″—but definitely NOT 6061!  I was surprised just how thin some of the NSX’s sheet metal is, —and how most of it doesn’t seem to have any heat treat at all! (rigidity for those of you in Rio Linda).