buy a 1st-gen RX7 shell for $500-$1500
either cage the shit out of it or build a custom chassis. custom chassis would be my personal choice, because then I can do a suspension swap easily.
Cobra independent rear suspension
-easy to fab into custom chassis
-can take retarded power without failing
-expensive at ~$1300-$1500 just for the unit
OR-A4/S4 rear suspension swap, using porsche locking diff
-A4/passats are in junkyards everywhere (or $300 on ebay)
-polyurethane bushings and coilovers are available and easy to install.
-porsche locking diff ~$300 on ebay
extremely "german" and complicated, fabrication could be tricky.
01E 6 speed manual transmission
-shown to be able to handle 1200 hp
-~$600 in wrecking yards, +$600 for performance rebuild kit
mods to 01E
-switch 6th gear to .48 OD out of a diesel-ratio transmission
-straight-cut 1st+2nd gear
-4:1 diff mod
-updated 2nd gear shift fork
-Royal Purple full synthetic gear oil
-remove factory open front diff, using modified V8 Quattro or 944 porshe rear diff, make the front a locker.
[between VAG trans and GM motor]powerplant-
I'm undecided. if money were no problem, LS7 with TT's or an LS9.
however the dry-sump LS3 with a single GT45 turbo would weigh less than the other options, and still make more than enough power.
more budget conscious, an LM7/L33 with 6.0 crank, MAHLE pistons, Oliver forged rods, COMP cam/springs/rockers and an ebay or used (with new CHRA cartridge) turbo
I would go for a truck or "RV" cam to give the motor low end big-inch motor style torque, and size the turbo so it spools when the motor is almost off or after the cam, so it has that turbo big-inch V8 feel...HUGE NA power, then HUGE turbo power.
plumbing-a 7 inch tall by 3 foot intercooler would fit right behind the lower valance, and because its an LS, the motor itself is fairly small. giving room for the turbo to go either in front of the motor, or on the passenger side of the engine near the firewall.
of course its GM, so with a modified harness and HP tuners, I can make a stock minivan computer run the whole set up.
single turbo LS1 in an RX7. 3rd gen, but still shows the set up will fit
front suspension-
I'm actually not sure. stock RX7 steering rack though.
I need something FWD or AWD based, with the steering rack in front of the spindles. VW/Audi both use rack-behind-motor designs.
the Audi spindles are made of aluminum/magnesium alloy, so modifying them is out...making new ones to bolt to the audi suspension wouldn't be as bad as it could be, but still not easy. due to the wheel bearing and floating caliper/rotor A4 design, it would be easier than taper style bearing such as GM uses.
either modify Audi parts, or find something easier to work with. I haven't looked at Mazda 323/626/929 spindles to see if they could me used.
anyways, if you've actually read this far, I'm sure you are thinking-won't the 01E sit so far back that the front half-shafts could never reach the front hubs? yes. thats valid...solid driveshafts wouldn't make it.
I've seen this done on a 1-off drag car that used a hydraulic system as a transfer case instead of a transmission...high RPM hydraulic pumps easily carry enough power.
mounting to the adapter plate between the engine and trans, and the heat-shield bolt holes around the output shafts (deep and strong) I would mount hydraulic pumps, one on each front-output shaft, with the inlet hoses running to the reservoir. The extra outlet would run to a reservoir by the fuel cell. the high-pressure lines (probably hard lines) would run up ~a foot to the wheel well, where a high RPM hydraulic motor would be mounted, powering the halfshaft, powering the front wheels.
an oil-to-water cooler would be mounted on the low pressure side where the factory battery used to be...not necessarily to cool the oil, but to warm it on cold days.
other logistics-
fuel cell in hatch or modified gas tank under car. duel fuel cells would allow for a race tune while keeping 91 octane as well
methanol injection tank in hatch
battery in hatch
PCM in glove box
stock stereo removed for gauges/switches
stock dash removed for tach/speedo
depending on suspension choices, given the small wheel wells in the Rx7 body, big brakes of the audi hardware, and width needed for rubber, custom steelies would be best.
exhaust would be done either with truck headers bolted on backwards to mount the turbo in the front, or with a ram horn header on the driver side, and a modified truck header on the passenger side to mount the turbo in the rear passenger corner of the bay.
the trans would likely sit too far back to use audi hardware for the shift linkage. a bracket, shift cables, and a Nissan Versa shifter could solve this.
all drive shafts would have to be custom. because the rear diff in both options is fixed, it wouldn't have to be perfect.
I would leave the car as ratty looking as I could on the outside. no paint, nothing to hint that its a monster.
I know this whole build seems extremely far fetched, but with an oxy torch, lift, tig, some raw metal and a couple laser levels, I think it could be done.
the PeterCatillacthis is another frame up build, but not as bad as the last one because everything already exists...it just needs to be fabbed together.
I'd take the front of a '66-'70 Sedan Deville, cut behind the rear doors (I like 4doors, so I would use one)
I would have to Z notch or use some kind of step-up on the frame to fit the back half of a peterbuilt. yes, the part with 4 wheels.
the peterbuilt part of the frame is already bagged, and thanks to the lowrider nature of the Cadillac, off-the-shelf bags are available for the front suspension. an air tank can be mounted in the peterbuilt segment of the frame, along with keg-tanks. I'd make the bed welder-truck style, with toolboxes facing outward, a MIG welder as far forward as possible on the bed, oxy-acyteline-air drop lines mounted on top of the tool box. I'd make the rest of the bed and the bumper out of the back end of a '59 El Camino. it might have to be widened to fit the peterbuild chassis.
for the engine I would use a CAT 3126. why not a cummins? everyone uses a cummins...and I'm in school to be a CAT mechanic.
I'd mount an air compressor from a semi on the engine, power steering pump and alternator from the caddy, and a modern GM AC compressor.
exhaust would dump right out of the front passenger quarterpanel.
MANual transmission of course, using the pedal assembly from chevy B platform cars. I'd make the shifter so tall it would almost touch the roof, with a ratfink shift knob.
as for the interior of the Cadillac, I would make it as clean-resto-mod as possible, using the stock dash with a GM 4-toggle window switch for the airbags (I've seen it done, looks clean) with a custom console, I'd leave the stock deck in the dash for FM, but use a modern screen deck in the console for bluetooth/navigation/music management/backup camera. I'd hide all the gauges in the console too, camaro style but with old school sweeper gauges. seats would be newer caddy buckets, for the back seat I'd probably get the stock ones recovered. I'd keep the '60s dash, head liner, door panels and switches.
naturally, leaving the caddy in whatever state of disrepair I found it in, no paint.
the price of this build could very greatly depending on donor cars and the condition of parts going back in.
