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tstomp
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11 Posts
Discussion Starter · #1 ·
Hello fellow LT members, allow me to introduce myself:
Thilo Stompler, living in the CA Bay Area, in San Rafael.
My 2005 Lotus Elise story:
I bought this car about 2 years ago, used it as a daily driver for about 6 months, and became very addicted to it and the driving precision at affords.
The car, as I purchased it, had a Greddy supercharger, no other modifications, ECU programming was unknown, so basically likely an incomplete Katana kit. Unbeknownst to me, the car had an intake air leak (that I did not notice, or perhaps was not present yet, when I bought it. We fixed this with a new intake from MWR, however the leak recurred due to my error in choosing intake manifold stud lenghts that were slightly too short, so fixed that, changed the SC pulley from 3.4" to 3.1", got the ECU reprogrammed with Katana tune, then immediately had a valve lift that destroyed the engine on the first day I drove it, likely because I was an idiot and stepped on the throttle to see "how fast it would go", thus not allowing the ECU to "learn", which apparently takes awhile.
At this point, I decided to "upgrade" the engine, instead of fixing it, and "do a few things while i'm in there", a story many of us know, I'm sure!

Upgrades evolved as the project is fast becoming a one year project:

Here goes the madness:
2ZZ-GE 2.0L MWR stroker motorwith 9:1 compression, ferrea valves, MWR Performance valve springs and retainers, MWR Stage 3 Performance camshafts, Carillo H-beam +CRB rods, Wiseco 82mm Pistons, Darton Sleeves, ported head work, Ferrea Solid Rocker VVL eliminator rocker arms, MWR 4340 93.5mm stroker crankshaft, Toyota Transmission 3.9:1 final drive, Toyota Quaife style LSD, MWR billet oil pump, MWR underdrive water pump pulley, MWR alternator underdrive pulley, SSC C6X Helical Gear upgrade for 3rd and 4th, resulting in:
1st: 3.166 - too short for this motor, but expensive to change, since 1st and 2nd are on the input shaft, taller final drive 3.9:1 vs 4.5:1 stock helps)
2nd: 1.904 - ok because of taller final drive
3rd: 1.310 - SSC 3rd is 1.44, this seems better spaced
4th: 0.969 - SSC 4th is 1.11, better spaced
5th: 0.815
6th: 0.725
Final Drive: 3.941 - seems like a very tall final drive, but likely ok with supercharged motors, good for freeway cruising
Assuming 8400 RPM max, 3.9 final drive, 255/40-17 rear tires, this results in max mph and shift points as follows:
1st: 50mph
2nd: 83mph @ 5047rpm
3rd: 110mph @ 6336rpm
4th: 143mph @ 6472rpm
5th: 194mph @ 6178rpm
6th: 219mph @ 7456rpm
Of course those last two numbers will be very much limited by air resistance and rolling resistance. Assuming an Elise S2 drag coefficient Cd=0.44, a frontal area A=1.7 square meters, and a rolling resistance Cr=0.015, the power required to move at 200mph (200mph = 89.4m/s) is 446whp! For those of us that want to do this calculation for fun, here is the formula:
Fd (force, in newtons) = Cr*m*g + 1/2*rho*Cd*A*V^2
where Cr = rolling resistance, m = mass of car in kg (assumed 907kg), g = 9.81m/s^2 earth gravity, rho= earth air density at desired altitude (assumed 1.2. Lastly, P (power in Nm/s or Watts, same) = Fd*v, (where v=velocity in m/s again) and 746 Watts = 1 whp.

470whp from a similar setup has been achieved by Fred (@BWR) and Phil (@BOE), but I do not aim for that top speed nor that amount of whp, since I wish to live, do not have their cojones, and do not have much exerience with whp/weight ratios of this magnitude, basically in McLaren territory.
Purely hypothetically, to achieve 210mph, 515whp would be required, all else being equal, and I highly recommend wings and a parachute, and a good life insurance policy!!
A standard BOE RevX SC pulley apparently produces approx 25psi of max boost, with a 3.5" pulley. I increased the pulley size to 4.5", which should result in 8 psi less, so about 17 psi max; still a lot; I hope for a power reduction (yes!) that results in around 350whp, but I do have that smaller pulley for later, and the Darwin awards are calling me!

Other parts:
Inokinetik Oil pan, TRD 170F thermostat, Greddy Oil filter block, Emtron KV8 ECU, BOE RevX supercharger kit(2.3 liter Whipple SC unit, same as on some Corvettes, don't know which one), BOE rear oil cooler, BWR 70mm large throttle body, stock is 65mm (76mm Toyota Tundra throttle body would be even better, but needs wire throttle, not cable), ITG RevX air intake, flex fuel sensor (E85 capable and ECU mapped for it for automatic adjustment of timing to octane), BWR Larini N muffler with activalve, BOE brake balance bar, Denso F1 26mm radiator, BOE Hex Intercooler cooler, Radium Surge tank, Radium Fuel Rail, 1100cc injectors, Radium Catch can, Inokinetik Rear Toe Link Brace, Tractive ACE+ semi-active suspension, 949 17x9 and 15x7.5 wheels, Hankook Ventus RS4 225/45-15 and 255/40-17 tires, MWR lift point kit, Truleo Letsla shifter and stiffener, Russel speed bleeders, Fidanza Aluminum 2 piece 7 lb flywheel, Action Clutch with organic pad and extra heavy pressure plates (similar to ACT XTSS clutch).

I must give a big thanks to my experienced buddy Josh K, also has a 2005 Lotus Elise, who puts up with my madness and has done the heavy lifting of installing the critical stuff with me, as well as to Miles and Andrew at Fineline tuning in Santa Rosa, CA, wo have taken on the dyno tuning and wiring of the engine, with a custom engine wire harness (for the Emtron KV8 standalone ECU) from Kris at DRS, due to arrive in the next few weeks.

The current plan is to reassemble the car beginning on June 4, 2021; I'll report on the results soon!

Cheers,

Thilo


Wishlist (isn't there always one?):
DRS/DMC 2zz header
3" i/o BWR spec ProFab Coast 2-stage custom exhaust, perhaps one stage and loud instead!
Swifter Dynamics Widebody clams, front and rear
 

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Administrator
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4,450 Posts
Welcome to LT Thilo! Sounds like quite an engine build! Looking forward to reading of your results.
 

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tstomp
Joined
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11 Posts
Discussion Starter · #4 ·
Perhaps surprisingly, we had to cut a hole into the firewall in order to prevent the supercharger from pressing against the firewall. This may not be an issue to others, but I'm certain that the engine vibration turns the firewall into a large noisy vibrating panel, if touching. Before we decided to do that, we modified the motor mounts slightly to move the entire engine back, but even that was not enough. I riv-nut mounted an Al plate on the passenger side of the firewall, to restore the function of the firewall.
1286505
 

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tstomp
Joined
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11 Posts
Discussion Starter · #5 ·
All the added electronics needed to be accommodated, and I really wanted it all on one plate, so I enlarged the OEM plate to the left, as follows:
1286506

It still ended up being jam-packed, with even the left back side occupied by fuse holders etc, more pics to share soon.
 

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tstomp
Joined
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11 Posts
Discussion Starter · #6 ·
I do have one question about the Tractive Active suspension I am still waiting for, the Tractive ACE+
Lotus Elise TracTive ACE+ Suspension
general info:
Does anyone have experience with Tractive Active suspensions?
Cheers,
Thilo
 
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