Gallery: Chassis

cut-up 2 - Copy

 The NSX rear suspension is an engineering masterpiece. The aluminum “bridge” is visible thru the new cut-out @ center of rear bulkhead (but not for long!).

OEM rear xmember

 After a few minutes on the bandsaw—bridge no longer in the way of Porsche transaxle, but a new crossmember is necessary to tie the R & L suspension components together.


This is the beginning of “VERSION 1.0″Â rear suspension crossmember (would you believe VERSION 2.0 doesn’t evolve until 2 yrs later!)


 I’m the design engineer, pattern-maker, cutter, fitter, bolter-on’er, & “back-to-the-drawing-board” guy—but I’m no welder! I’ve used several talented TIG artists over the 3+ year build.


 All aluminum fab work through-out utilizes 6061-T6 material, & is TIG welded.


 Aluminum bushings are 3 different lengths to accommodate the fact that the milled bolt bosses (in the NSX suspension pieces), are not all in the same plane.


 With aluminum plate perfectly aligned, bushings are positioned for weld-up.


 One bolt on each side, just to secure during weld-up.


 More pattern testing for gussets.


 Final welded assy. before “clean-up”.


 Trial fit—view from engine bay looking towards rear.


 View from back of car—before lightening holes & dressing-down.

R xmem 22

 OEM suspension all bolted-up. Also visible is custom-fab “shock-bridge”, which ties the frame rails together in the same plane as OEM shock towers. Notice the special 3/8ths” plates that are welded to underside of frame rails—these allow entire OEM suspension to be placed 2″ aft of stock placement (details in next 3 pics). Also in photo; foam-core “mock-up” of new engine bay firewall—gotta love that duct tape!


 Driver’s-side rear frame rail with new holes cut-in exactly 2″ aft of stock holes (front of car towards right)


 Close-up from previous pic.


 3/8ths” frame plates with bosses (that are drilled & tapped for Keenserts)—note boss placement is 2″ aft of OEM frame holes—which will still have bolts securing assys, in addition to full-perimeter weld-up!


 Driver’s-side frame plate ready for welding (rear of car towards left).


 Ditto to above.


Axle centerline 2″Â aft of OEM—sort of funny-looking, for now.

Shock-bridge 1

 View from rear thru trunk shows “shock-bridge”, & newly fabbed chrome-moly engine-support crossmember laying on the floor of engine bay.

shock-bridge 2

 View from passenger side engine bay looking into trunk area shows how shock-bridge welds into the strongest portion of rear chassis, namely where the 2 shock towers intersect with the frame rails. Also visible is lower transaxle support crossmember & how it ties the R. & L. OEM suspension castings together. (I know there’s a lot of you NSX’rs out there who think these are forgings—but they’re not—the control arms ARE forged, however).

shock-bridge 3

 View from inside trunk looking forward into engine bay—engine-support crossmember is bolted in place, ready to cradle the LS7. Note how front of crossmember triangulates into the lower-main bar of roll cage (where it crosses thru tunnel)—this provides additional stiffening of the already incredibly stiffer-than-stock chassis—it also keeps the engine & transaxle from wanting to move forward in a critical event (front impact for those of you in Rio Linda).

shock-bridge 4

 Another perspective on the 2 aluminum crossmembers—one ties the top-half of chassis together, while the other ties the bottom.

shock-bridge 5

 Better view of how engine-support crossmember bolts into the lower-main bar of roll cage (@ top of pic).


 Engine support at top, & transaxle support at bottom.

engine bay crossmembers

 View from lower edge of “notched” rear bulkhead shows all 3 crossmembers in their relative positions.

drivers rear rocker 1

 Close-up of drivers-side rear frame re-inforcement & chrome-moly shock-rocker (ball bearings inside tubing portion of rocker)

drivers rear rocker 2

 Pin-hole just to left of top end of rocker is a pilot hole for the opening that will be cut that allows end of shock to “poke-thru” OEM shock tower, & connect to rocker.


 Frontal view at this stage shows passenger-side OEM NSX suspension still in place, while drivers-side is completely removed. This was done to gauge original axle centerline, while extending it forward by 2″ on drivers-side—it also allowed accurate calculations for increased track width (5.5″), as wheel-hub flange to frame rail dimensions are projected to yield a Zero scrub radius (easier to accomplish when you’re designing your own suspension!). The orange tie-down strap at top of pic is actually holding the OEM control arms (left side of pic) in their accurate static ride height position even though chassis is on “rollable” jig.


 Over-engineered battery tray is actually Version 1.0, & was designed around the optimum Odessy Battery configuration at the time. Of course Odessy came out with an even more ideal shape & size since this pic—SOOO, Version 2.0 looks totally different—will post when completed. Also visible in this pic is drivers-side front shock rocker (R. side of pic) already bolted to top of frame rail near firewall.

front rocker 1

 Close-up of passenger-side front shock rocker (front of car towards right). In this photo rocker actually extends thru “window” in inner wheel well. Turned out later on window wasn’t necessary, as decision was made to remove entire wheel-well assy’s. (see pics below).


 Preview of upcoming horror flick?—no, just cutting away unnecessary sheet metal & wheel wells. (fabricator’s note: cut-off wheel much easier to control, & cleaner resulting cut than Plasma torch!)


 The aluminum sheet metal is several layers (laminations) —have to make certain cuts are all the way thru, & then carefully “tweak” until loose.


 Taking “wiggling” to an un-desired art-form—but it works (shoulda had the MsBadwrench girls stage this shot!)


 Voila!—entire structure only weighs 6 lbs, but the placement is relatively high to desired center of gravity!


“Cleaned-up” front end much easier to work with for all sorts of systems that will be incorporated in “Top-Secret” front suspension design.


 Now to perform the same “clean-up” procedure on rear frame rails. Cutting passenger-side wheel-well from inside of trunk. Notice OSHA -approved “invisible” safety-guard on 4″ grinder! Nothing that is structurally important is cut/removed (i.e. shock towers, frame rails, etc.)


 Cut line leading towards bottom of pic is actually the outside edge of frame rail “stamping”—where the multi-layer frame is spot-welded together.


Cutting around back end of frame rails (easier from backside than laying under car, cutting overhead). Decision to remove box-like trunk structure was arrived at late in project—to facilitate a much more aggressive “slope” in rear body profile that blends with the rear hatch glass angle (between rear wheel tubs). Also, rear axle centerline is now plotted 3″ farther aft than stock—-which allows for state-of-the-art “aero” packaging. I have to build the rear body “clip” from scratch anyway…anyone want to buy a complete Cantrell GT wide body kit?


Removal is easy if you double check all of your cuts to make sure they are clean thru multi-layers of stamped aluminum—again, wiggling becomes an art form (shoulda let the MsBadwrench girls do this part for photo).

9 pounds

Entire shell weighs only 9 pounds, but placement is relatively high (to center of gravity)–which is undesireable.


“Cleaned-up” rear frame rails—different perspective. Note cardboard template for rear radius on left rear suspension sub-frame mock-up.


Good view of firewall / engine & transaxle / rear suspension sub-frame placement. (Note: this, & all subsequent pics are in a different garage resulting from time-honored Real Estate tradition of buying high & selling low while going thru a divorce–haha)


View from lower rear shows “shock-bridge” & rear sub-frame detail. Note the engine support crossmember (blue) & rear sub-frame (unpainted) are in the same plane as bottom of NSX tub—full CF belly pan will incorporate ground effects tunnels similar to LMP1 cars.


Left-rear frame rail—lower control arm billet “pick-ups” are visible already bolted to the sub frame. The aluminum dowel rod is simply used to ensure the pick-ups are in the same plane, as each is serrated, & can be adjusted up or down a total of 1.5″ (for roll-center tuning).


Top view of front frame rails shows one master cylinder mounted to firewall, as well as driver’s-side shock-rocker positioned on frame rail for final clearance check. The orange-handled clamp @ top-ctr of pic is holding the bracketry for the “mini-rack” & other steering-enhancing components for weld-up.


(see caption on pic above this one)


Bottom view of “mini-rack” bracketry—ready for weld-up. Note also red markings on crossmember—more stuff welds on that as well!

L.F. air-jack cut-out

Cut-out in L.F. frame rail for air-jack can—this is a very strong part of the frame—Note the inside structural “filler” & the OEM spot welds & susp. mounting holes.

L.F. air-jack can gusset

Trial-fitting a “doubler” for the air-jack can (spreads the load across a larger welded area).

L.F. air-jack can

Final-fitting the air-jack can—flush with frame, & plumb in all axis’.

L.R. air-jack can 4

Trial-fit air-jack can inside L.R. frame rail—note can is positioned to also attach (bolt) to CM sub-frame assy. (those hot glue guns sure come in handy when affixing things to irregular places)! Note the welded-in gusset in the frame “kick-up” for extra strength—roll cage “down-tubes” attach just behind this “kick-up”.

L.R. air-jack can

L.R. air-jack can viewed from bottom-rear of car. Note round aluminum spacer between can & CM sub-frame tubing—this is so rear CM sub-frame can be easily dropped without interference with the “can”.

L.R. air-jack can 2

L.R. air-jack can viewed from driver’s-side rear wheel well. Numerous aluminum gussets will weld between frame rail & can, to spread the load. One of those gussets has a “tab” which positions just above the CM tubing (closest to lens)—and will bolt to a CM tab that gets welded to the CM sub-frame tubing.

4 air jack cans all complete with stiffeners, top-gussets, & pich-bolt bosses. Note the “doubler” is also plug-welded to front cans @ right.

Holes in “top-gussets” (near-end) are where the air line / bulkhead fastener protrude. Rear cans are on the left, & Fronts are on the right.

Close-up of pinch-bolt boss, which is already threaded half-way thru for 5/16th’s – 18 SS button head. The boss & lower inch-and-a-half of can will be “slit” with a cutting wheel (on a mill), before cans are welded to frame rails.

This pic is in my friends garage (I’m renting his home)—it is the 4th garage my project has taken place in! (at the 4 yr mark, July ’10) Â The toy on top is a 69 GTO going thru total frame-off resto. It belongs to my friends Tom & Jerry (their real names).

Hot-gluing an aluminum crossmember for trial-fit.

These 2 “mirrored” brackets have the most complicated (frustrating) contours—to mate up to underside of tub / front. Even using a contour gage, they represent nearly 40 man-hours of work—CRAZY!

I’m sighting this piece because the front side is “taller” than the rear side, & it only fits correctly one way.

Trial-fitting center of crossmember. This pic is taken from driver’s front wheel well.

Close-up of fitting process (thanks, Caroline for the great shots!)

Marking where part needs to be “massaged” on sander.

Belt sander is a necessity if you’re going to be doing any serious fab-work.

I know—I look pretty happy with myself! (these are all late summer night shots—heat makes you punchy!) Arch is to allow for coolant hoses & oil lines that route thru tub tunnel (just behind my left hand).

The white foam-core boards are patterns for aluminum fuel cell partitions—which will weld into, & become part of engine bay. The final aluminum panels will be sprayed with Lizard-Skin to minimize heat transfer to fuel cells. (its a ceramic coating approx .060″ thick—way cool!)

A different view of passenger side partition.

Making patterns that have to fit multiple angles / planes is tedious, but the only way to insure the final panel will be perfect. This is an art form that accepts the reality of “do-overs”!

Bottom-Up shot of multi-piece pattern (passenger side).

Note “Gorilla Tape” is used extensively to hold boards in place while measurements taken, contours transferred etc.

Not so obvious is partitions need to be plumb if fuel cells are to slide up into the resulting “chamber” without interference. High density closed-cell foam is laminated inside the final “chamber” to prevent fuel cell from chafing. Chamber becomes completely sealed (from engine bay & driver’s compartment) after cell is installed from bottom, via bottom partition, which incorporates a sealing-lip, &Â is bolted-in.Â

Late-night plumbing! Everything gets re-checked after good night’s sleep, BEFORE patterns are transferred to .060″ 6061 T6 aluminum sheet!

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