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Old 04-06-2017, 09:19 PM   #6 (permalink)
EcoModding Lurker
Join Date: Jan 2017
Location: australia
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One I have been thinking about , but too time poor (And $$$ poor!!) to start on...

Budget Bracket $15001-->$30,000

Purpose of car : sports car

Proposed basis for car : Utilise a 1992-->2002 Mazda Rx7 - this is a lightweight platform, with superb aerodynamics, great handling, and importantly a good sized engine bay..Would require a transmission tunnel modification to fit gearbox of choice, and conversion of the popup lights to fixed units (Kits available on the market for HID)

Engine of choice : Chevrolet Duramax 6.6 from as late a model as budget allows..Turbo of course..boosted slightly to give around 500hp which would make for a fun ride (The FD rx7 has a factory installed 13Brew engine (13B Rotary with twin turbos, intercooler etc), Conversion to LS v8 is a relatively easy thing these days with kits designed to bolt in...modifying from one of these to suit the big diesel should be relatively straightforward...expected weight difference to factory should be less than 200KG extra (440lbs))

Transmission of choice : TR-6070 7 speed manual from a 2014 corvette (0.42 final overdrive) - This is a big box, and would require some tin work to fit into the transmission tunnel..but would have the big torquey diesel ticking over at idle at 60mph ...for highway driving this should deliver outstanding fuel economy.

Drivetrain of choice RWD - Samberg diff conversion kit..replacing rear end with a cobra IRS kit is also possibly worthwhile to handle the torque, and give a broader choice of final gear ratios ..

Modifications required to above : apart from the fitment kit, and small amount of bodywork, the basic car and drivetrain are more than adequate for the task. Multiple 1000hp Rotary and V8 examples exist worlwide showing the chassis is strong enough for a simple 500-600hp diesel conversion. The Big duramax can handle 500-600hp without too many mechanical mods (injectors / pump / ECU), and for normal day to day driving tune could be configured to deliver a lazy 300hp for enhanced fuel economy..then turned up for some playtime on the track..

Expected mileage : - Wild estimate..but based on the corvette getting close to 40mpg with a petrol engine, on a less aerodynamic and heavier would be estimated an easy 50mpg, and potentially with hypermiling driving upwards of 60mpg...from a 500hp sports car...

Expected cost to build: Base car $8000, Selling running gear $-3000, Used Duramax $4000, Transmission $3000, Conversion kit $5000, ECU / Ancilleries - $3000 - so around the $20,000 mark for a car that would return insane fuel economy better than some hybrids..and have 500hp, 10 second 1/4 mile times, and 300kph top speed...OBVIOUSLY if driven like a sports car, fuel economy would be poor however...Additionally, if some of the engine mods I am testing at the moment work as expected, applying them to this engine would result in a 40% further reduction in maybe close to 90mpg from a 500hp car for ~$25k....

Last edited by craysus; 04-06-2017 at 10:12 PM..
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