Rotus
05-06-09, 10:47 PM
#1
Rotus
Well after years of fun autocrossing my first gen my mind began to wonder a bit. What If I could build a car that weight less than half as much as a first gen, with a far stiffer suspension that is 3” off the ground and stuck like glue?
This is what I came up with. A rotary powered Lotus clone – Rotus. I have been working on this since last summer and I am really, really close, so I thought I would share it with you.
Complete it will weight 1185 lb and has a S4 13B in it now. I have a Renny, but that bumps me out of class in the SCCA. I also have a set of 10” wide racing slicks for it.
I was going to wait until I was done before I told you, but here it is.
JEB
PS - I also added a phot from the first BSCC event this year.
This is what I came up with. A rotary powered Lotus clone – Rotus. I have been working on this since last summer and I am really, really close, so I thought I would share it with you.
Complete it will weight 1185 lb and has a S4 13B in it now. I have a Renny, but that bumps me out of class in the SCCA. I also have a set of 10” wide racing slicks for it.
I was going to wait until I was done before I told you, but here it is.
JEB
PS - I also added a phot from the first BSCC event this year.
05-07-09, 09:05 AM
#4
Well, I am working to get it done this month.
I will see how long it takes to get some of the plumbing pieces.
I thought I would add my two favorite youtube videos of lotus clone family, so people can see them in action.
http://www.youtube.com/watch?v=3Rhz19ZrpZg
http://www.youtube.com/watch?v=SYkXJ...E25894&index=0
I will see how long it takes to get some of the plumbing pieces.
I thought I would add my two favorite youtube videos of lotus clone family, so people can see them in action.
http://www.youtube.com/watch?v=3Rhz19ZrpZg
http://www.youtube.com/watch?v=SYkXJ...E25894&index=0
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05-15-09, 10:25 PM
#17
Well, I just re-measured the suspension system and did some math to come up with the spring rates I will need in order to achieve a suspension frequency of about 120 cycles per second. I am so pleased to get to a point where I have ordered the springs. They should be in next week and I will be rolling. Yahoo!
06-04-09, 06:30 PM
#18
Rotus
Hello all,
Well I am really close with my car, I may even get to start it this weekend. I thought I would share a few more details prior to the big day.
ROTUS
(Rotary – Lotus)
Frame – The frame is one of the last Champion Motor Car frames made around the time Caterham sued them and closed their production. For this reason the car does not of a Manufacturer of Origin number; yet was purchased from Kinetic Vehicles (a west coast distributer). This is the same brand of frame that Grassroots Motor Sports used in their build.
Front Suspension
Lower control arms are modified CMC arms (modified to use a Miata ball joint and for a drop through shock mount).
Upper control arm is a kit from Kinetic Vehicles
Spindles and brakes from first gen Miata donor car
Lower ball joint is a Miata joint from the donor
Heim joints and upper ball joint are from Kinetic Vehicles
Shocks are NOS Koni from the rear of a lotus Super Seven, coil over set is aluminum pipe
Springs are 550 lb black magic from Southwest Speed
Brake lines from a 95 Mazda Protégé.
Front de-powered rack from the first gen. Miata (donor car) shortened 5.5” (rack re-heat treated).
Adapters for tie rod end to extend 2 ½”
Settings 1/8” toe out, 2 deg negative camber, 7 degree caster, with 100% Ackerman
Rear Suspension
Rear axle housing from a 1985 Mazda Rx7 (cleaned up and heat bent to have 1deg. negative camber).
Four link with Panhard made out of ¾” alloy seamless steel
Third member is a Torsion unit from 1999 Mazda Miata with 29k, with 3.90 Rx7 gears
Rear brakes from first gen. Miata (donor car) and brake lines from a 95 Mazda Miata.
Heim joints are from Kinetic Vehicles
Shock is a NOS Koni from the rear of a lotus Super Seven, coil over set is aluminum pipe
Springs are 150 lb black magic from Southwest Speed
Adapters on the rear axles to run 4 x 100 wheels
Engine
1988 Mazda Rx7 S413B NA (that was from my 1985 Rx7 Autocross car) 146 hp at the wheels
Two piece intake (upper from Racing Beat (RB), low is stock)
Carb is a 48mm Delortto, Carter 4070 Electric Fuel pump (4 to 7 psi)
MSD 6AL Ignition, dual fire lost spark system through an MSD GM DIS coil
RB under drive pulley on eccentric shaft and alternator.
Oil cooler (10AN) 30 coils 13” by 9”, with a 3 qt Accusump pressure retention system.
Custom oil pan from a 1985 Rx7 GSL-SE with a shorted sump and a baffle plate.
Transmission is from a 1989 Mazda Rx7 S5 5 speed, with custom shortened shifter.
Header – old RB header cut up and re-welded to fit with 2 ½” collector and a turbo muffler.
Motors mounts are cut out of hockey pucks.
Radiator is from 1972 Mazda 618, hose made from a number of old hose and 1 ½’ copper pipe.
Body work
Nose (TTL) and scuttle from Kinetic Vehicles
Clamshell fenders and rear steam rollers fenders from Curtis Unlimited.
Body sheet metal .04 aluminum found on Craigslist
Interior
Seats are from a 1990 Miata (donor car), narrowed to fit in the frame.
Steering wheel is a vintage wooden Nardi wheel that matches the handmade cedar shift ****.
Varnished birch plywood dash with basic Summit Racing gauges, with a tach and speedo from a 1972 Mazda Rx2.
Handmade pedals using a Miata Clutch and brake master cylinders (Rx7 clutch slave cly.).
Wheels
13 x 7 steel wheels with Khumo 710s (Track days)
13 x 8 Keizer spun aluminum wheels (8 lbs) w/ Hoosier 9.5 x 13 x 20 R25 race tires (autocross)
16 x 7 Miata wheels with 215/45/16 Hankooks (street use)
Safety
4 point roll made out of 1 ½” 1525 alloy.
5 point racing belts (expired)
BC5 Kidde fire extinguisher
Misc
All key bolts are grade 8 aviation bolts, others came from the donor.
Battery 8 lb sealed cell jet ski battery
Total weight 1085 lb
Well I am really close with my car, I may even get to start it this weekend. I thought I would share a few more details prior to the big day.
ROTUS
(Rotary – Lotus)
Frame – The frame is one of the last Champion Motor Car frames made around the time Caterham sued them and closed their production. For this reason the car does not of a Manufacturer of Origin number; yet was purchased from Kinetic Vehicles (a west coast distributer). This is the same brand of frame that Grassroots Motor Sports used in their build.
Front Suspension
Lower control arms are modified CMC arms (modified to use a Miata ball joint and for a drop through shock mount).
Upper control arm is a kit from Kinetic Vehicles
Spindles and brakes from first gen Miata donor car
Lower ball joint is a Miata joint from the donor
Heim joints and upper ball joint are from Kinetic Vehicles
Shocks are NOS Koni from the rear of a lotus Super Seven, coil over set is aluminum pipe
Springs are 550 lb black magic from Southwest Speed
Brake lines from a 95 Mazda Protégé.
Front de-powered rack from the first gen. Miata (donor car) shortened 5.5” (rack re-heat treated).
Adapters for tie rod end to extend 2 ½”
Settings 1/8” toe out, 2 deg negative camber, 7 degree caster, with 100% Ackerman
Rear Suspension
Rear axle housing from a 1985 Mazda Rx7 (cleaned up and heat bent to have 1deg. negative camber).
Four link with Panhard made out of ¾” alloy seamless steel
Third member is a Torsion unit from 1999 Mazda Miata with 29k, with 3.90 Rx7 gears
Rear brakes from first gen. Miata (donor car) and brake lines from a 95 Mazda Miata.
Heim joints are from Kinetic Vehicles
Shock is a NOS Koni from the rear of a lotus Super Seven, coil over set is aluminum pipe
Springs are 150 lb black magic from Southwest Speed
Adapters on the rear axles to run 4 x 100 wheels
Engine
1988 Mazda Rx7 S413B NA (that was from my 1985 Rx7 Autocross car) 146 hp at the wheels
Two piece intake (upper from Racing Beat (RB), low is stock)
Carb is a 48mm Delortto, Carter 4070 Electric Fuel pump (4 to 7 psi)
MSD 6AL Ignition, dual fire lost spark system through an MSD GM DIS coil
RB under drive pulley on eccentric shaft and alternator.
Oil cooler (10AN) 30 coils 13” by 9”, with a 3 qt Accusump pressure retention system.
Custom oil pan from a 1985 Rx7 GSL-SE with a shorted sump and a baffle plate.
Transmission is from a 1989 Mazda Rx7 S5 5 speed, with custom shortened shifter.
Header – old RB header cut up and re-welded to fit with 2 ½” collector and a turbo muffler.
Motors mounts are cut out of hockey pucks.
Radiator is from 1972 Mazda 618, hose made from a number of old hose and 1 ½’ copper pipe.
Body work
Nose (TTL) and scuttle from Kinetic Vehicles
Clamshell fenders and rear steam rollers fenders from Curtis Unlimited.
Body sheet metal .04 aluminum found on Craigslist
Interior
Seats are from a 1990 Miata (donor car), narrowed to fit in the frame.
Steering wheel is a vintage wooden Nardi wheel that matches the handmade cedar shift ****.
Varnished birch plywood dash with basic Summit Racing gauges, with a tach and speedo from a 1972 Mazda Rx2.
Handmade pedals using a Miata Clutch and brake master cylinders (Rx7 clutch slave cly.).
Wheels
13 x 7 steel wheels with Khumo 710s (Track days)
13 x 8 Keizer spun aluminum wheels (8 lbs) w/ Hoosier 9.5 x 13 x 20 R25 race tires (autocross)
16 x 7 Miata wheels with 215/45/16 Hankooks (street use)
Safety
4 point roll made out of 1 ½” 1525 alloy.
5 point racing belts (expired)
BC5 Kidde fire extinguisher
Misc
All key bolts are grade 8 aviation bolts, others came from the donor.
Battery 8 lb sealed cell jet ski battery
Total weight 1085 lb
06-07-09, 07:51 PM
#24
Thought I would have it running this weekend. Got the cooling system done, fuel system working, as well as ignition. Took 1 ¼” off the bottom of the oil pan so less hands below. Need to run the line and mechanical linkage for the oil accumulator and as well at the oil temp gauge. Once that is done I should be set. I am still trying to get it to the June 14 BSCC event. We will see.
